From 695afd3d7d58ec3044d25c9d2fe384ab8627fd20 Mon Sep 17 00:00:00 2001
From: Sedat Dilek <sedat.dilek@gmail.com>
Date: Sun, 16 Aug 2020 14:32:44 +0200
Subject: kbuild: Simplify DEBUG_INFO Kconfig handling

While playing with [1] I saw that the handling
of CONFIG_DEBUG_INFO can be simplified.

[1] https://patchwork.kernel.org/patch/11716107/

Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 Makefile          |  6 +++++-
 lib/Kconfig.debug | 10 ++++------
 2 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/Makefile b/Makefile
index f21168154160..4ef6a73e48a7 100644
--- a/Makefile
+++ b/Makefile
@@ -816,13 +816,15 @@ endif
 DEBUG_CFLAGS	:= $(call cc-option, -fno-var-tracking-assignments)
 
 ifdef CONFIG_DEBUG_INFO
+
 ifdef CONFIG_DEBUG_INFO_SPLIT
 DEBUG_CFLAGS	+= -gsplit-dwarf
 else
 DEBUG_CFLAGS	+= -g
 endif
+
 KBUILD_AFLAGS	+= -Wa,-gdwarf-2
-endif
+
 ifdef CONFIG_DEBUG_INFO_DWARF4
 DEBUG_CFLAGS	+= -gdwarf-4
 endif
@@ -838,6 +840,8 @@ KBUILD_AFLAGS	+= -gz=zlib
 KBUILD_LDFLAGS	+= --compress-debug-sections=zlib
 endif
 
+endif # CONFIG_DEBUG_INFO
+
 KBUILD_CFLAGS += $(DEBUG_CFLAGS)
 export DEBUG_CFLAGS
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index e068c3c7189a..60f3837f608c 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -212,9 +212,10 @@ config DEBUG_INFO
 
 	  If unsure, say N.
 
+if DEBUG_INFO
+
 config DEBUG_INFO_REDUCED
 	bool "Reduce debugging information"
-	depends on DEBUG_INFO
 	help
 	  If you say Y here gcc is instructed to generate less debugging
 	  information for structure types. This means that tools that
@@ -227,7 +228,6 @@ config DEBUG_INFO_REDUCED
 
 config DEBUG_INFO_COMPRESSED
 	bool "Compressed debugging information"
-	depends on DEBUG_INFO
 	depends on $(cc-option,-gz=zlib)
 	depends on $(ld-option,--compress-debug-sections=zlib)
 	help
@@ -243,7 +243,6 @@ config DEBUG_INFO_COMPRESSED
 
 config DEBUG_INFO_SPLIT
 	bool "Produce split debuginfo in .dwo files"
-	depends on DEBUG_INFO
 	depends on $(cc-option,-gsplit-dwarf)
 	help
 	  Generate debug info into separate .dwo files. This significantly
@@ -259,7 +258,6 @@ config DEBUG_INFO_SPLIT
 
 config DEBUG_INFO_DWARF4
 	bool "Generate dwarf4 debuginfo"
-	depends on DEBUG_INFO
 	depends on $(cc-option,-gdwarf-4)
 	help
 	  Generate dwarf4 debug info. This requires recent versions
@@ -269,7 +267,6 @@ config DEBUG_INFO_DWARF4
 
 config DEBUG_INFO_BTF
 	bool "Generate BTF typeinfo"
-	depends on DEBUG_INFO
 	depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
 	depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
 	help
@@ -279,7 +276,6 @@ config DEBUG_INFO_BTF
 
 config GDB_SCRIPTS
 	bool "Provide GDB scripts for kernel debugging"
-	depends on DEBUG_INFO
 	help
 	  This creates the required links to GDB helper scripts in the
 	  build directory. If you load vmlinux into gdb, the helper
@@ -288,6 +284,8 @@ config GDB_SCRIPTS
 	  instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
 	  for further details.
 
+endif # DEBUG_INFO
+
 config ENABLE_MUST_CHECK
 	bool "Enable __must_check logic"
 	default y
-- 
cgit v1.2.3


From 23cd88c91343349a0d67a227f9effdde0cbe09af Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Fri, 21 Aug 2020 11:43:58 +0900
Subject: kbuild: hide commands to run Kconfig, and show short log for
 syncconfig

Some targets (localyesconfig, localmodconfig, defconfig) hide the
command running, but the others do not.

Users know which Kconfig flavor they are running, so it is OK to hide
the command. Add $(Q) to all commands consistently. If you want to see
the full command running, pass V=1 from the command line.

syncconfig is the exceptional case, which occurs without explicit
command invocation by the user. Display the Kbuild-style log for it.
The ugly bare log will go away.

[Before]

scripts/kconfig/conf  --syncconfig Kconfig

[After]

  SYNC    include/config/auto.conf

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 Makefile                 |  5 ++++-
 scripts/kconfig/Makefile | 16 ++++++++--------
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/Makefile b/Makefile
index 4ef6a73e48a7..d96f2feddbfb 100644
--- a/Makefile
+++ b/Makefile
@@ -707,8 +707,11 @@ $(KCONFIG_CONFIG):
 # This exploits the 'multi-target pattern rule' trick.
 # The syncconfig should be executed only once to make all the targets.
 # (Note: use the grouped target '&:' when we bump to GNU Make 4.3)
+quiet_cmd_syncconfig = SYNC    $@
+      cmd_syncconfig = $(MAKE) -f $(srctree)/Makefile syncconfig
+
 %/config/auto.conf %/config/auto.conf.cmd %/generated/autoconf.h: $(KCONFIG_CONFIG)
-	$(Q)$(MAKE) -f $(srctree)/Makefile syncconfig
+	+$(call cmd,syncconfig)
 else # !may-sync-config
 # External modules and some install targets need include/generated/autoconf.h
 # and include/config/auto.conf but do not care if they are up-to-date.
diff --git a/scripts/kconfig/Makefile b/scripts/kconfig/Makefile
index 52b59bf9efe4..e46df0a2d4f9 100644
--- a/scripts/kconfig/Makefile
+++ b/scripts/kconfig/Makefile
@@ -20,19 +20,19 @@ endif
 unexport CONFIG_
 
 xconfig: $(obj)/qconf
-	$< $(silent) $(Kconfig)
+	$(Q)$< $(silent) $(Kconfig)
 
 gconfig: $(obj)/gconf
-	$< $(silent) $(Kconfig)
+	$(Q)$< $(silent) $(Kconfig)
 
 menuconfig: $(obj)/mconf
-	$< $(silent) $(Kconfig)
+	$(Q)$< $(silent) $(Kconfig)
 
 config: $(obj)/conf
-	$< $(silent) --oldaskconfig $(Kconfig)
+	$(Q)$< $(silent) --oldaskconfig $(Kconfig)
 
 nconfig: $(obj)/nconf
-	$< $(silent) $(Kconfig)
+	$(Q)$< $(silent) $(Kconfig)
 
 build_menuconfig: $(obj)/mconf
 
@@ -68,12 +68,12 @@ simple-targets := oldconfig allnoconfig allyesconfig allmodconfig \
 PHONY += $(simple-targets)
 
 $(simple-targets): $(obj)/conf
-	$< $(silent) --$@ $(Kconfig)
+	$(Q)$< $(silent) --$@ $(Kconfig)
 
 PHONY += savedefconfig defconfig
 
 savedefconfig: $(obj)/conf
-	$< $(silent) --$@=defconfig $(Kconfig)
+	$(Q)$< $(silent) --$@=defconfig $(Kconfig)
 
 defconfig: $(obj)/conf
 ifneq ($(wildcard $(srctree)/arch/$(SRCARCH)/configs/$(KBUILD_DEFCONFIG)),)
@@ -111,7 +111,7 @@ tinyconfig:
 # CHECK: -o cache_dir=<path> working?
 PHONY += testconfig
 testconfig: $(obj)/conf
-	$(PYTHON3) -B -m pytest $(srctree)/$(src)/tests \
+	$(Q)$(PYTHON3) -B -m pytest $(srctree)/$(src)/tests \
 	-o cache_dir=$(abspath $(obj)/tests/.cache) \
 	$(if $(findstring 1,$(KBUILD_VERBOSE)),--capture=no)
 clean-files += tests/.cache
-- 
cgit v1.2.3


From 8a685db32f2b3495c91efab6e9462c2fd934778f Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 22 Aug 2020 23:56:09 +0900
Subject: gen_compile_commands: parse only the first line of .*.cmd files

After the allmodconfig build, this script takes about 5 sec on my
machine. Most of the run-time is consumed for needless regex matching.

We know the format of .*.cmd file; the first line is the build command.
There is no need to parse the rest.

With this optimization, now it runs 4 times faster.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
---
 scripts/gen_compile_commands.py | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index c458696ef3a7..1bcf33a93cb9 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -125,11 +125,8 @@ def main():
             filepath = os.path.join(dirpath, filename)
 
             with open(filepath, 'rt') as f:
-                for line in f:
-                    result = line_matcher.match(line)
-                    if not result:
-                        continue
-
+                result = line_matcher.match(f.readline())
+                if result:
                     try:
                         entry = process_line(directory, dirpath,
                                              result.group(1), result.group(2))
-- 
cgit v1.2.3


From ea6cedc5b8a4e666da41f1173ea19970fa60683f Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 22 Aug 2020 23:56:10 +0900
Subject: gen_compile_commands: use choices for --log_levels option

Use 'choices' to check if the given parameter is valid.

I also simplified the help message because, with 'choices', --help
shows the list of valid parameters:

  --log_level {DEBUG,INFO,WARNING,ERROR,CRITICAL}

I started the help message with a lower case, "the level of log ..."
in order to be consistent with the -h option:

  -h, --help            show this help message and exit

The message "show this help ..." comes from the ArgumentParser library
code, and I do not know how to change it. So, I changed our code.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---
 scripts/gen_compile_commands.py | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index 1bcf33a93cb9..535248cf2d7e 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -45,24 +45,18 @@ def parse_arguments():
                    'compile_commands.json in the search directory)')
     parser.add_argument('-o', '--output', type=str, help=output_help)
 
-    log_level_help = ('The level of log messages to produce (one of ' +
-                      ', '.join(_VALID_LOG_LEVELS) + '; defaults to ' +
+    log_level_help = ('the level of log messages to produce (defaults to ' +
                       _DEFAULT_LOG_LEVEL + ')')
-    parser.add_argument(
-        '--log_level', type=str, default=_DEFAULT_LOG_LEVEL,
-        help=log_level_help)
+    parser.add_argument('--log_level', choices=_VALID_LOG_LEVELS,
+                        default=_DEFAULT_LOG_LEVEL, help=log_level_help)
 
     args = parser.parse_args()
 
-    log_level = args.log_level
-    if log_level not in _VALID_LOG_LEVELS:
-        raise ValueError('%s is not a valid log level' % log_level)
-
     directory = args.directory or os.getcwd()
     output = args.output or os.path.join(directory, _DEFAULT_OUTPUT)
     directory = os.path.abspath(directory)
 
-    return log_level, directory, output
+    return args.log_level, directory, output
 
 
 def process_line(root_directory, file_directory, command_prefix, relative_path):
-- 
cgit v1.2.3


From 6ca4c6d25949117dc5b4845612e290b6d89e70a8 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 22 Aug 2020 23:56:11 +0900
Subject: gen_compile_commands: do not support .cmd files under tools/
 directory

The tools/ directory uses a different build system, and the format of
.cmd files is different because the tools builds run in a different
work directory.

Supporting two formats compilicates the script.

The only loss by this change is objtool.

Also, rename the confusing variable 'relative_path' because it is
not necessarily a relative path. When the output directory is not
the direct child of the source tree (e.g. O=foo/bar), it is an
absolute path. Rename it to 'file_path'.

os.path.join(root_directory, file_path) works whether the file_path
is relative or not. If file_path is already absolute, it returns it
as-is.

I used os.path.abspath() to normalize file paths. If you run this
script against the kernel built with O=foo option, the file_path
contains '../' patterns. os.path.abspath() fixes up 'foo/bar/../baz'
into 'foo/baz', and produces a cleaner commands_database.json.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---
 scripts/gen_compile_commands.py | 32 ++++++++++++--------------------
 1 file changed, 12 insertions(+), 20 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index 535248cf2d7e..49fff0b0b385 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -59,23 +59,21 @@ def parse_arguments():
     return args.log_level, directory, output
 
 
-def process_line(root_directory, file_directory, command_prefix, relative_path):
+def process_line(root_directory, command_prefix, file_path):
     """Extracts information from a .cmd line and creates an entry from it.
 
     Args:
         root_directory: The directory that was searched for .cmd files. Usually
             used directly in the "directory" entry in compile_commands.json.
-        file_directory: The path to the directory the .cmd file was found in.
         command_prefix: The extracted command line, up to the last element.
-        relative_path: The .c file from the end of the extracted command.
-            Usually relative to root_directory, but sometimes relative to
-            file_directory and sometimes neither.
+        file_path: The .c file from the end of the extracted command.
+            Usually relative to root_directory, but sometimes absolute.
 
     Returns:
         An entry to append to compile_commands.
 
     Raises:
-        ValueError: Could not find the extracted file based on relative_path and
+        ValueError: Could not find the extracted file based on file_path and
             root_directory or file_directory.
     """
     # The .cmd files are intended to be included directly by Make, so they
@@ -84,20 +82,14 @@ def process_line(root_directory, file_directory, command_prefix, relative_path):
     # by Make, so this code replaces the escaped version with '#'.
     prefix = command_prefix.replace('\#', '#').replace('$(pound)', '#')
 
-    cur_dir = root_directory
-    expected_path = os.path.join(cur_dir, relative_path)
-    if not os.path.exists(expected_path):
-        # Try using file_directory instead. Some of the tools have a different
-        # style of .cmd file than the kernel.
-        cur_dir = file_directory
-        expected_path = os.path.join(cur_dir, relative_path)
-        if not os.path.exists(expected_path):
-            raise ValueError('File %s not in %s or %s' %
-                             (relative_path, root_directory, file_directory))
+    # Use os.path.abspath() to normalize the path resolving '.' and '..' .
+    abs_path = os.path.abspath(os.path.join(root_directory, file_path))
+    if not os.path.exists(abs_path):
+        raise ValueError('File %s not found' % abs_path)
     return {
-        'directory': cur_dir,
-        'file': relative_path,
-        'command': prefix + relative_path,
+        'directory': root_directory,
+        'file': abs_path,
+        'command': prefix + file_path,
     }
 
 
@@ -122,7 +114,7 @@ def main():
                 result = line_matcher.match(f.readline())
                 if result:
                     try:
-                        entry = process_line(directory, dirpath,
+                        entry = process_line(directory,
                                              result.group(1), result.group(2))
                         compile_commands.append(entry)
                     except ValueError as err:
-- 
cgit v1.2.3


From 0a7d376d04a3c84b503f1efecde8f9d9a7430269 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 22 Aug 2020 23:56:12 +0900
Subject: gen_compile_commands: reword the help message of -d option

I think the help message of the -d option is somewhat misleading.

  Path to the kernel source directory to search (defaults to the working directory)

The part "kernel source directory" is the source of the confusion.
Some people misunderstand as if this script did not support separate
output directories.

Actually, this script also works for out-of-tree builds. You can
use the -d option to point to the object output directory, not to
the source directory. It should match to the O= option used in the
previous kernel build, and then appears in the "directory" field of
compile_commands.json.

Reword the help message.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---
 scripts/gen_compile_commands.py | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index 49fff0b0b385..f37c1dac8db4 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -31,13 +31,13 @@ def parse_arguments():
 
     Returns:
         log_level: A logging level to filter log output.
-        directory: The directory to search for .cmd files.
+        directory: The work directory where the objects were built.
         output: Where to write the compile-commands JSON file.
     """
     usage = 'Creates a compile_commands.json database from kernel .cmd files'
     parser = argparse.ArgumentParser(description=usage)
 
-    directory_help = ('Path to the kernel source directory to search '
+    directory_help = ('specify the output directory used for the kernel build '
                       '(defaults to the working directory)')
     parser.add_argument('-d', '--directory', type=str, help=directory_help)
 
-- 
cgit v1.2.3


From 6fca36f1d82ad5bc385187f0aed93bbaefaa2172 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 22 Aug 2020 23:56:13 +0900
Subject: gen_compile_commands: make -o option independent of -d option

Change the -o option independent of the -d option, which is I think
clearer behavior. Some people may like to use -d to specify a separate
output directory, but still output the compile_commands.py in the
source directory (unless the source tree is read-only) because it is
the default location Clang Tools search for the compilation database.

Also, move the default parameter to the default= argument of the
.add_argument().

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---
 scripts/gen_compile_commands.py | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index f37c1dac8db4..71a0630ae188 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -39,11 +39,13 @@ def parse_arguments():
 
     directory_help = ('specify the output directory used for the kernel build '
                       '(defaults to the working directory)')
-    parser.add_argument('-d', '--directory', type=str, help=directory_help)
+    parser.add_argument('-d', '--directory', type=str, default='.',
+                        help=directory_help)
 
-    output_help = ('The location to write compile_commands.json (defaults to '
-                   'compile_commands.json in the search directory)')
-    parser.add_argument('-o', '--output', type=str, help=output_help)
+    output_help = ('path to the output command database (defaults to ' +
+                   _DEFAULT_OUTPUT + ')')
+    parser.add_argument('-o', '--output', type=str, default=_DEFAULT_OUTPUT,
+                        help=output_help)
 
     log_level_help = ('the level of log messages to produce (defaults to ' +
                       _DEFAULT_LOG_LEVEL + ')')
@@ -52,11 +54,9 @@ def parse_arguments():
 
     args = parser.parse_args()
 
-    directory = args.directory or os.getcwd()
-    output = args.output or os.path.join(directory, _DEFAULT_OUTPUT)
-    directory = os.path.abspath(directory)
-
-    return args.log_level, directory, output
+    return (args.log_level,
+            os.path.abspath(args.directory),
+            args.output)
 
 
 def process_line(root_directory, command_prefix, file_path):
-- 
cgit v1.2.3


From fc2cb22ec61c1a537337cd0eba458863564a0e1f Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 22 Aug 2020 23:56:14 +0900
Subject: gen_compile_commands: move directory walk to a generator function

Currently, this script walks under the specified directory (default to
the current directory), then parses all .cmd files found.

Split it into a separate helper function because the next commit will
add more helpers to pick up .cmd files associated with given file(s).

There is no point to build and return a huge list at once. I used a
generator so it works in the for-loop with less memory.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---
 scripts/gen_compile_commands.py | 44 ++++++++++++++++++++++++++++++-----------
 1 file changed, 32 insertions(+), 12 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index 71a0630ae188..e45f17be8817 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -33,6 +33,7 @@ def parse_arguments():
         log_level: A logging level to filter log output.
         directory: The work directory where the objects were built.
         output: Where to write the compile-commands JSON file.
+        paths: The list of directories to handle to find .cmd files.
     """
     usage = 'Creates a compile_commands.json database from kernel .cmd files'
     parser = argparse.ArgumentParser(description=usage)
@@ -56,7 +57,28 @@ def parse_arguments():
 
     return (args.log_level,
             os.path.abspath(args.directory),
-            args.output)
+            args.output,
+            [args.directory])
+
+
+def cmdfiles_in_dir(directory):
+    """Generate the iterator of .cmd files found under the directory.
+
+    Walk under the given directory, and yield every .cmd file found.
+
+    Args:
+        directory: The directory to search for .cmd files.
+
+    Yields:
+        The path to a .cmd file.
+    """
+
+    filename_matcher = re.compile(_FILENAME_PATTERN)
+
+    for dirpath, _, filenames in os.walk(directory):
+        for filename in filenames:
+            if filename_matcher.match(filename):
+                yield os.path.join(dirpath, filename)
 
 
 def process_line(root_directory, command_prefix, file_path):
@@ -95,31 +117,29 @@ def process_line(root_directory, command_prefix, file_path):
 
 def main():
     """Walks through the directory and finds and parses .cmd files."""
-    log_level, directory, output = parse_arguments()
+    log_level, directory, output, paths = parse_arguments()
 
     level = getattr(logging, log_level)
     logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
 
-    filename_matcher = re.compile(_FILENAME_PATTERN)
     line_matcher = re.compile(_LINE_PATTERN)
 
     compile_commands = []
-    for dirpath, _, filenames in os.walk(directory):
-        for filename in filenames:
-            if not filename_matcher.match(filename):
-                continue
-            filepath = os.path.join(dirpath, filename)
 
-            with open(filepath, 'rt') as f:
+    for path in paths:
+        cmdfiles = cmdfiles_in_dir(path)
+
+        for cmdfile in cmdfiles:
+            with open(cmdfile, 'rt') as f:
                 result = line_matcher.match(f.readline())
                 if result:
                     try:
-                        entry = process_line(directory,
-                                             result.group(1), result.group(2))
+                        entry = process_line(directory, result.group(1),
+                                             result.group(2))
                         compile_commands.append(entry)
                     except ValueError as err:
                         logging.info('Could not add line from %s: %s',
-                                     filepath, err)
+                                     cmdfile, err)
 
     with open(output, 'wt') as f:
         json.dump(compile_commands, f, indent=2, sort_keys=True)
-- 
cgit v1.2.3


From ecca4fea1ede446e9ce3afa0b68b07fd1550f4f5 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 22 Aug 2020 23:56:15 +0900
Subject: gen_compile_commands: support *.o, *.a, modules.order in positional
 argument

This script currently searches the specified directory for .cmd files.
One drawback is it may contain stale .cmd files after you rebuild the
kernel several times without 'make clean'.

This commit supports *.o, *.a, and modules.order as positional
parameters. If such files are given, they are parsed to collect
associated .cmd files. I added a generator helper for each of them.

This feature is useful to get the list of active .cmd files from the
last build, and will be used by the next commit to wire up the
compile_commands.json rule to the Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---
 scripts/gen_compile_commands.py | 100 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 96 insertions(+), 4 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index e45f17be8817..92ea0a2ee59e 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -12,6 +12,7 @@ import json
 import logging
 import os
 import re
+import subprocess
 
 _DEFAULT_OUTPUT = 'compile_commands.json'
 _DEFAULT_LOG_LEVEL = 'WARNING'
@@ -32,8 +33,9 @@ def parse_arguments():
     Returns:
         log_level: A logging level to filter log output.
         directory: The work directory where the objects were built.
+        ar: Command used for parsing .a archives.
         output: Where to write the compile-commands JSON file.
-        paths: The list of directories to handle to find .cmd files.
+        paths: The list of files/directories to handle to find .cmd files.
     """
     usage = 'Creates a compile_commands.json database from kernel .cmd files'
     parser = argparse.ArgumentParser(description=usage)
@@ -53,12 +55,21 @@ def parse_arguments():
     parser.add_argument('--log_level', choices=_VALID_LOG_LEVELS,
                         default=_DEFAULT_LOG_LEVEL, help=log_level_help)
 
+    ar_help = 'command used for parsing .a archives'
+    parser.add_argument('-a', '--ar', type=str, default='llvm-ar', help=ar_help)
+
+    paths_help = ('directories to search or files to parse '
+                  '(files should be *.o, *.a, or modules.order). '
+                  'If nothing is specified, the current directory is searched')
+    parser.add_argument('paths', type=str, nargs='*', help=paths_help)
+
     args = parser.parse_args()
 
     return (args.log_level,
             os.path.abspath(args.directory),
             args.output,
-            [args.directory])
+            args.ar,
+            args.paths if len(args.paths) > 0 else [args.directory])
 
 
 def cmdfiles_in_dir(directory):
@@ -81,6 +92,73 @@ def cmdfiles_in_dir(directory):
                 yield os.path.join(dirpath, filename)
 
 
+def to_cmdfile(path):
+    """Return the path of .cmd file used for the given build artifact
+
+    Args:
+        Path: file path
+
+    Returns:
+        The path to .cmd file
+    """
+    dir, base = os.path.split(path)
+    return os.path.join(dir, '.' + base + '.cmd')
+
+
+def cmdfiles_for_o(obj):
+    """Generate the iterator of .cmd files associated with the object
+
+    Yield the .cmd file used to build the given object
+
+    Args:
+        obj: The object path
+
+    Yields:
+        The path to .cmd file
+    """
+    yield to_cmdfile(obj)
+
+
+def cmdfiles_for_a(archive, ar):
+    """Generate the iterator of .cmd files associated with the archive.
+
+    Parse the given archive, and yield every .cmd file used to build it.
+
+    Args:
+        archive: The archive to parse
+
+    Yields:
+        The path to every .cmd file found
+    """
+    for obj in subprocess.check_output([ar, '-t', archive]).decode().split():
+        yield to_cmdfile(obj)
+
+
+def cmdfiles_for_modorder(modorder):
+    """Generate the iterator of .cmd files associated with the modules.order.
+
+    Parse the given modules.order, and yield every .cmd file used to build the
+    contained modules.
+
+    Args:
+        modorder: The modules.order file to parse
+
+    Yields:
+        The path to every .cmd file found
+    """
+    with open(modorder) as f:
+        for line in f:
+            ko = line.rstrip()
+            base, ext = os.path.splitext(ko)
+            if ext != '.ko':
+                sys.exit('{}: module path must end with .ko'.format(ko))
+            mod = base + '.mod'
+	    # The first line of *.mod lists the objects that compose the module.
+            with open(mod) as m:
+                for obj in m.readline().split():
+                    yield to_cmdfile(obj)
+
+
 def process_line(root_directory, command_prefix, file_path):
     """Extracts information from a .cmd line and creates an entry from it.
 
@@ -117,7 +195,7 @@ def process_line(root_directory, command_prefix, file_path):
 
 def main():
     """Walks through the directory and finds and parses .cmd files."""
-    log_level, directory, output, paths = parse_arguments()
+    log_level, directory, output, ar, paths = parse_arguments()
 
     level = getattr(logging, log_level)
     logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
@@ -127,7 +205,21 @@ def main():
     compile_commands = []
 
     for path in paths:
-        cmdfiles = cmdfiles_in_dir(path)
+        # If 'path' is a directory, handle all .cmd files under it.
+        # Otherwise, handle .cmd files associated with the file.
+        # Most of built-in objects are linked via archives (built-in.a or lib.a)
+        # but some objects are linked to vmlinux directly.
+        # Modules are listed in modules.order.
+        if os.path.isdir(path):
+            cmdfiles = cmdfiles_in_dir(path)
+        elif path.endswith('.o'):
+            cmdfiles = cmdfiles_for_o(path)
+        elif path.endswith('.a'):
+            cmdfiles = cmdfiles_for_a(path, ar)
+        elif path.endswith('modules.order'):
+            cmdfiles = cmdfiles_for_modorder(path)
+        else:
+            sys.exit('{}: unknown file type'.format(path))
 
         for cmdfile in cmdfiles:
             with open(cmdfile, 'rt') as f:
-- 
cgit v1.2.3


From 3d32285fa99598f1885ac7022785b9c343407e62 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 22 Aug 2020 23:56:16 +0900
Subject: kbuild: wire up the build rule of compile_commands.json to Makefile

Currently, you need to manually run scripts/gen_compile_commands.py
to create compile_commands.json. It parses all the .*.cmd files found
under the specified directory.

If you rebuild the kernel over again without 'make clean',
.*.cmd files from older builds will create stale entries in
compile_commands.json.

This commit wires up the compile_commands.json rule to Makefile, and
makes it parse only the .*.cmd files involved in the current build.

Pass $(KBUILD_VMLINUX_OBJS), $(KBUILD_VMLINUX_LIBS), and modules.order
to the script. The objects or archives linked to vmlinux are listed in
$(KBUILD_VMLINUX_OBJS) or $(KBUILD_VMLINUX_LIBS). All the modules are
listed in modules.order.

You can create compile_commands.json from Make:

  $ make -j$(nproc) CC=clang compile_commands.json

You can also build vmlinux, modules, and compile_commands.json all
together in a single command:

  $ make -j$(nproc) CC=clang all compile_commands.json

It works for M= builds as well. In this case, compile_commands.json
is created in the top directory of the external module.

This is convenient, but it has a drawback; the coverage of the
compile_commands.json is reduced because only the objects linked to
vmlinux or modules are handled. For example, the following C files are
not included in the compile_commands.json:

 - Decompressor source files (arch/*/boot/)
 - VDSO source files
 - C files used to generate intermediates (e.g. kernel/bounds.c)
 - Standalone host programs

I think it is fine for most developers because our main interest is
the kernel-space code.

If you want to cover all the compiled C files, please build the kernel,
then run the script manually as you did before:

  $ make clean    # if you want to remove stale .cmd files [optional]
  $ make -j$(nproc) CC=clang
  $ scripts/gen_compile_commands.py

Here is a note for out-of-tree builds. 'make compile_commands.json'
works with O= option, but please notice compile_commands.json is
created in the object tree instead of the source tree.

Some people may want to have compile_commands.json in the source tree
because Clang Tools searches for it through all parent paths of the
first input source file.

However, you cannot do this for O= builds. Kbuild should never generate
any build artifact in the source tree when O= is given because the
source tree might be read-only. Any write attempt to the source tree
is monitored and the violation may be reported. See the commit log of
8ef14c2c41d9.

So, the only possible way is to create compile_commands.json in the
object tree, then specify '-p <build-path>' when you use clang-check,
clang-tidy, etc.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
---
 Makefile | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/Makefile b/Makefile
index d96f2feddbfb..07fd96a25a20 100644
--- a/Makefile
+++ b/Makefile
@@ -634,7 +634,7 @@ endif
 # in addition to whatever we do anyway.
 # Just "make" or "make all" shall build modules as well
 
-ifneq ($(filter all modules nsdeps,$(MAKECMDGOALS)),)
+ifneq ($(filter all modules nsdeps %compile_commands.json,$(MAKECMDGOALS)),)
   KBUILD_MODULES := 1
 endif
 
@@ -1470,7 +1470,8 @@ endif # CONFIG_MODULES
 
 # Directories & files removed with 'make clean'
 CLEAN_FILES += include/ksym vmlinux.symvers \
-	       modules.builtin modules.builtin.modinfo modules.nsdeps
+	       modules.builtin modules.builtin.modinfo modules.nsdeps \
+	       compile_commands.json
 
 # Directories & files removed with 'make mrproper'
 MRPROPER_FILES += include/config include/generated          \
@@ -1704,9 +1705,12 @@ KBUILD_MODULES := 1
 
 build-dirs := $(KBUILD_EXTMOD)
 PHONY += modules
-modules: descend
+modules: $(MODORDER)
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
+$(MODORDER): descend
+	@:
+
 PHONY += modules_install
 modules_install: _emodinst_ _emodinst_post
 
@@ -1720,8 +1724,12 @@ PHONY += _emodinst_post
 _emodinst_post: _emodinst_
 	$(call cmd,depmod)
 
+compile_commands.json: $(extmod-prefix)compile_commands.json
+PHONY += compile_commands.json
+
 clean-dirs := $(KBUILD_EXTMOD)
-clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps
+clean: rm-files := $(KBUILD_EXTMOD)/Module.symvers $(KBUILD_EXTMOD)/modules.nsdeps \
+	$(KBUILD_EXTMOD)/compile_commands.json
 
 PHONY += help
 help:
@@ -1834,6 +1842,19 @@ nsdeps: export KBUILD_NSDEPS=1
 nsdeps: modules
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/nsdeps
 
+# Clang Tooling
+# ---------------------------------------------------------------------------
+
+quiet_cmd_gen_compile_commands = GEN     $@
+      cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
+
+$(extmod-prefix)compile_commands.json: scripts/gen_compile_commands.py \
+	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
+	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
+	$(call if_changed,gen_compile_commands)
+
+targets += $(extmod-prefix)compile_commands.json
+
 # Scripts to check various things for consistency
 # ---------------------------------------------------------------------------
 
-- 
cgit v1.2.3


From 8b61f748e2a022f9028c612e44b68ad61caec474 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Sat, 22 Aug 2020 23:56:17 +0900
Subject: gen_compile_commands: remove the warning about too few .cmd files

This warning was useful when users previously needed to manually
build the kernel and run this script.

Now you can simply do 'make compile_commands.json', which updates
all the necessary build artifacts and automatically creates the
compilation database. There is no more worry for a mistake like
"Oh, I forgot to build the kernel".

Now, this warning is rather annoying.

You can create compile_commands.json for an external module:

  $ make M=/path/to/your/external/module compile_commands.json

Then, this warning is displayed since there are usually less than
300 files in a single module.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
---
 scripts/gen_compile_commands.py | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
index 92ea0a2ee59e..19963708bcf8 100755
--- a/scripts/gen_compile_commands.py
+++ b/scripts/gen_compile_commands.py
@@ -21,11 +21,6 @@ _FILENAME_PATTERN = r'^\..*\.cmd$'
 _LINE_PATTERN = r'^cmd_[^ ]*\.o := (.* )([^ ]*\.c)$'
 _VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
 
-# A kernel build generally has over 2000 entries in its compile_commands.json
-# database. If this code finds 300 or fewer, then warn the user that they might
-# not have all the .cmd files, and they might need to compile the kernel.
-_LOW_COUNT_THRESHOLD = 300
-
 
 def parse_arguments():
     """Sets up and parses command-line arguments.
@@ -236,11 +231,6 @@ def main():
     with open(output, 'wt') as f:
         json.dump(compile_commands, f, indent=2, sort_keys=True)
 
-    count = len(compile_commands)
-    if count < _LOW_COUNT_THRESHOLD:
-        logging.warning(
-            'Found %s entries. Have you compiled the kernel?', count)
-
 
 if __name__ == '__main__':
     main()
-- 
cgit v1.2.3


From 6ad7cbc01527223f3f92baac9b122f15651cf76b Mon Sep 17 00:00:00 2001
From: Nathan Huckleberry <nhuck@google.com>
Date: Sat, 22 Aug 2020 23:56:18 +0900
Subject: Makefile: Add clang-tidy and static analyzer support to makefile

This patch adds clang-tidy and the clang static-analyzer as make
targets. The goal of this patch is to make static analysis tools
usable and extendable by any developer or researcher who is familiar
with basic c++.

The current static analysis tools require intimate knowledge of the
internal workings of the static analysis. Clang-tidy and the clang
static analyzers expose an easy to use api and allow users unfamiliar
with clang to write new checks with relative ease.

===Clang-tidy===

Clang-tidy is an easily extendable 'linter' that runs on the AST.
Clang-tidy checks are easy to write and understand. A check consists of
two parts, a matcher and a checker. The matcher is created using a
domain specific language that acts on the AST
(https://clang.llvm.org/docs/LibASTMatchersReference.html).  When AST
nodes are found by the matcher a callback is made to the checker. The
checker can then execute additional checks and issue warnings.

Here is an example clang-tidy check to report functions that have calls
to local_irq_disable without calls to local_irq_enable and vice-versa.
Functions flagged with __attribute((annotation("ignore_irq_balancing")))
are ignored for analysis. (https://reviews.llvm.org/D65828)

===Clang static analyzer===

The clang static analyzer is a more powerful static analysis tool that
uses symbolic execution to find bugs. Currently there is a check that
looks for potential security bugs from invalid uses of kmalloc and
kfree. There are several more general purpose checks that are useful for
the kernel.

The clang static analyzer is well documented and designed to be
extensible.
(https://clang-analyzer.llvm.org/checker_dev_manual.html)
(https://github.com/haoNoQ/clang-analyzer-guide/releases/download/v0.1/clang-analyzer-guide-v0.1.pdf)

The main draw of the clang tools is how accessible they are. The clang
documentation is very nice and these tools are built specifically to be
easily extendable by any developer. They provide an accessible method of
bug-finding and research to people who are not overly familiar with the
kernel codebase.

Signed-off-by: Nathan Huckleberry <nhuck@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 MAINTAINERS                                 |   1 +
 Makefile                                    |  20 ++-
 scripts/clang-tools/gen_compile_commands.py | 236 ++++++++++++++++++++++++++++
 scripts/clang-tools/run-clang-tools.py      |  74 +++++++++
 scripts/gen_compile_commands.py             | 236 ----------------------------
 5 files changed, 329 insertions(+), 238 deletions(-)
 create mode 100755 scripts/clang-tools/gen_compile_commands.py
 create mode 100755 scripts/clang-tools/run-clang-tools.py
 delete mode 100755 scripts/gen_compile_commands.py

diff --git a/MAINTAINERS b/MAINTAINERS
index f0068bceeb61..05bebba204cf 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4247,6 +4247,7 @@ W:	https://clangbuiltlinux.github.io/
 B:	https://github.com/ClangBuiltLinux/linux/issues
 C:	irc://chat.freenode.net/clangbuiltlinux
 F:	Documentation/kbuild/llvm.rst
+F:	scripts/clang-tools/
 K:	\b(?i:clang|llvm)\b
 
 CLEANCACHE API
diff --git a/Makefile b/Makefile
index 07fd96a25a20..37739ee53f27 100644
--- a/Makefile
+++ b/Makefile
@@ -634,7 +634,7 @@ endif
 # in addition to whatever we do anyway.
 # Just "make" or "make all" shall build modules as well
 
-ifneq ($(filter all modules nsdeps %compile_commands.json,$(MAKECMDGOALS)),)
+ifneq ($(filter all modules nsdeps %compile_commands.json clang-%,$(MAKECMDGOALS)),)
   KBUILD_MODULES := 1
 endif
 
@@ -1583,6 +1583,8 @@ help:
 	@echo  '  export_report   - List the usages of all exported symbols'
 	@echo  '  headerdep       - Detect inclusion cycles in headers'
 	@echo  '  coccicheck      - Check with Coccinelle'
+	@echo  '  clang-analyzer  - Check with clang static analyzer'
+	@echo  '  clang-tidy      - Check with clang-tidy'
 	@echo  ''
 	@echo  'Tools:'
 	@echo  '  nsdeps          - Generate missing symbol namespace dependencies'
@@ -1848,13 +1850,27 @@ nsdeps: modules
 quiet_cmd_gen_compile_commands = GEN     $@
       cmd_gen_compile_commands = $(PYTHON3) $< -a $(AR) -o $@ $(filter-out $<, $(real-prereqs))
 
-$(extmod-prefix)compile_commands.json: scripts/gen_compile_commands.py \
+$(extmod-prefix)compile_commands.json: scripts/clang-tools/gen_compile_commands.py \
 	$(if $(KBUILD_EXTMOD),,$(KBUILD_VMLINUX_OBJS) $(KBUILD_VMLINUX_LIBS)) \
 	$(if $(CONFIG_MODULES), $(MODORDER)) FORCE
 	$(call if_changed,gen_compile_commands)
 
 targets += $(extmod-prefix)compile_commands.json
 
+PHONY += clang-tidy clang-analyzer
+
+ifdef CONFIG_CC_IS_CLANG
+quiet_cmd_clang_tools = CHECK   $<
+      cmd_clang_tools = $(PYTHON3) $(srctree)/scripts/clang-tools/run-clang-tools.py $@ $<
+
+clang-tidy clang-analyzer: $(extmod-prefix)compile_commands.json
+	$(call cmd,clang_tools)
+else
+clang-tidy clang-analyzer:
+	@echo "$@ requires CC=clang" >&2
+	@false
+endif
+
 # Scripts to check various things for consistency
 # ---------------------------------------------------------------------------
 
diff --git a/scripts/clang-tools/gen_compile_commands.py b/scripts/clang-tools/gen_compile_commands.py
new file mode 100755
index 000000000000..19963708bcf8
--- /dev/null
+++ b/scripts/clang-tools/gen_compile_commands.py
@@ -0,0 +1,236 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) Google LLC, 2018
+#
+# Author: Tom Roeder <tmroeder@google.com>
+#
+"""A tool for generating compile_commands.json in the Linux kernel."""
+
+import argparse
+import json
+import logging
+import os
+import re
+import subprocess
+
+_DEFAULT_OUTPUT = 'compile_commands.json'
+_DEFAULT_LOG_LEVEL = 'WARNING'
+
+_FILENAME_PATTERN = r'^\..*\.cmd$'
+_LINE_PATTERN = r'^cmd_[^ ]*\.o := (.* )([^ ]*\.c)$'
+_VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
+
+
+def parse_arguments():
+    """Sets up and parses command-line arguments.
+
+    Returns:
+        log_level: A logging level to filter log output.
+        directory: The work directory where the objects were built.
+        ar: Command used for parsing .a archives.
+        output: Where to write the compile-commands JSON file.
+        paths: The list of files/directories to handle to find .cmd files.
+    """
+    usage = 'Creates a compile_commands.json database from kernel .cmd files'
+    parser = argparse.ArgumentParser(description=usage)
+
+    directory_help = ('specify the output directory used for the kernel build '
+                      '(defaults to the working directory)')
+    parser.add_argument('-d', '--directory', type=str, default='.',
+                        help=directory_help)
+
+    output_help = ('path to the output command database (defaults to ' +
+                   _DEFAULT_OUTPUT + ')')
+    parser.add_argument('-o', '--output', type=str, default=_DEFAULT_OUTPUT,
+                        help=output_help)
+
+    log_level_help = ('the level of log messages to produce (defaults to ' +
+                      _DEFAULT_LOG_LEVEL + ')')
+    parser.add_argument('--log_level', choices=_VALID_LOG_LEVELS,
+                        default=_DEFAULT_LOG_LEVEL, help=log_level_help)
+
+    ar_help = 'command used for parsing .a archives'
+    parser.add_argument('-a', '--ar', type=str, default='llvm-ar', help=ar_help)
+
+    paths_help = ('directories to search or files to parse '
+                  '(files should be *.o, *.a, or modules.order). '
+                  'If nothing is specified, the current directory is searched')
+    parser.add_argument('paths', type=str, nargs='*', help=paths_help)
+
+    args = parser.parse_args()
+
+    return (args.log_level,
+            os.path.abspath(args.directory),
+            args.output,
+            args.ar,
+            args.paths if len(args.paths) > 0 else [args.directory])
+
+
+def cmdfiles_in_dir(directory):
+    """Generate the iterator of .cmd files found under the directory.
+
+    Walk under the given directory, and yield every .cmd file found.
+
+    Args:
+        directory: The directory to search for .cmd files.
+
+    Yields:
+        The path to a .cmd file.
+    """
+
+    filename_matcher = re.compile(_FILENAME_PATTERN)
+
+    for dirpath, _, filenames in os.walk(directory):
+        for filename in filenames:
+            if filename_matcher.match(filename):
+                yield os.path.join(dirpath, filename)
+
+
+def to_cmdfile(path):
+    """Return the path of .cmd file used for the given build artifact
+
+    Args:
+        Path: file path
+
+    Returns:
+        The path to .cmd file
+    """
+    dir, base = os.path.split(path)
+    return os.path.join(dir, '.' + base + '.cmd')
+
+
+def cmdfiles_for_o(obj):
+    """Generate the iterator of .cmd files associated with the object
+
+    Yield the .cmd file used to build the given object
+
+    Args:
+        obj: The object path
+
+    Yields:
+        The path to .cmd file
+    """
+    yield to_cmdfile(obj)
+
+
+def cmdfiles_for_a(archive, ar):
+    """Generate the iterator of .cmd files associated with the archive.
+
+    Parse the given archive, and yield every .cmd file used to build it.
+
+    Args:
+        archive: The archive to parse
+
+    Yields:
+        The path to every .cmd file found
+    """
+    for obj in subprocess.check_output([ar, '-t', archive]).decode().split():
+        yield to_cmdfile(obj)
+
+
+def cmdfiles_for_modorder(modorder):
+    """Generate the iterator of .cmd files associated with the modules.order.
+
+    Parse the given modules.order, and yield every .cmd file used to build the
+    contained modules.
+
+    Args:
+        modorder: The modules.order file to parse
+
+    Yields:
+        The path to every .cmd file found
+    """
+    with open(modorder) as f:
+        for line in f:
+            ko = line.rstrip()
+            base, ext = os.path.splitext(ko)
+            if ext != '.ko':
+                sys.exit('{}: module path must end with .ko'.format(ko))
+            mod = base + '.mod'
+	    # The first line of *.mod lists the objects that compose the module.
+            with open(mod) as m:
+                for obj in m.readline().split():
+                    yield to_cmdfile(obj)
+
+
+def process_line(root_directory, command_prefix, file_path):
+    """Extracts information from a .cmd line and creates an entry from it.
+
+    Args:
+        root_directory: The directory that was searched for .cmd files. Usually
+            used directly in the "directory" entry in compile_commands.json.
+        command_prefix: The extracted command line, up to the last element.
+        file_path: The .c file from the end of the extracted command.
+            Usually relative to root_directory, but sometimes absolute.
+
+    Returns:
+        An entry to append to compile_commands.
+
+    Raises:
+        ValueError: Could not find the extracted file based on file_path and
+            root_directory or file_directory.
+    """
+    # The .cmd files are intended to be included directly by Make, so they
+    # escape the pound sign '#', either as '\#' or '$(pound)' (depending on the
+    # kernel version). The compile_commands.json file is not interepreted
+    # by Make, so this code replaces the escaped version with '#'.
+    prefix = command_prefix.replace('\#', '#').replace('$(pound)', '#')
+
+    # Use os.path.abspath() to normalize the path resolving '.' and '..' .
+    abs_path = os.path.abspath(os.path.join(root_directory, file_path))
+    if not os.path.exists(abs_path):
+        raise ValueError('File %s not found' % abs_path)
+    return {
+        'directory': root_directory,
+        'file': abs_path,
+        'command': prefix + file_path,
+    }
+
+
+def main():
+    """Walks through the directory and finds and parses .cmd files."""
+    log_level, directory, output, ar, paths = parse_arguments()
+
+    level = getattr(logging, log_level)
+    logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
+
+    line_matcher = re.compile(_LINE_PATTERN)
+
+    compile_commands = []
+
+    for path in paths:
+        # If 'path' is a directory, handle all .cmd files under it.
+        # Otherwise, handle .cmd files associated with the file.
+        # Most of built-in objects are linked via archives (built-in.a or lib.a)
+        # but some objects are linked to vmlinux directly.
+        # Modules are listed in modules.order.
+        if os.path.isdir(path):
+            cmdfiles = cmdfiles_in_dir(path)
+        elif path.endswith('.o'):
+            cmdfiles = cmdfiles_for_o(path)
+        elif path.endswith('.a'):
+            cmdfiles = cmdfiles_for_a(path, ar)
+        elif path.endswith('modules.order'):
+            cmdfiles = cmdfiles_for_modorder(path)
+        else:
+            sys.exit('{}: unknown file type'.format(path))
+
+        for cmdfile in cmdfiles:
+            with open(cmdfile, 'rt') as f:
+                result = line_matcher.match(f.readline())
+                if result:
+                    try:
+                        entry = process_line(directory, result.group(1),
+                                             result.group(2))
+                        compile_commands.append(entry)
+                    except ValueError as err:
+                        logging.info('Could not add line from %s: %s',
+                                     cmdfile, err)
+
+    with open(output, 'wt') as f:
+        json.dump(compile_commands, f, indent=2, sort_keys=True)
+
+
+if __name__ == '__main__':
+    main()
diff --git a/scripts/clang-tools/run-clang-tools.py b/scripts/clang-tools/run-clang-tools.py
new file mode 100755
index 000000000000..fa7655c7cec0
--- /dev/null
+++ b/scripts/clang-tools/run-clang-tools.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright (C) Google LLC, 2020
+#
+# Author: Nathan Huckleberry <nhuck@google.com>
+#
+"""A helper routine run clang-tidy and the clang static-analyzer on
+compile_commands.json.
+"""
+
+import argparse
+import json
+import multiprocessing
+import os
+import subprocess
+import sys
+
+
+def parse_arguments():
+    """Set up and parses command-line arguments.
+    Returns:
+        args: Dict of parsed args
+        Has keys: [path, type]
+    """
+    usage = """Run clang-tidy or the clang static-analyzer on a
+        compilation database."""
+    parser = argparse.ArgumentParser(description=usage)
+
+    type_help = "Type of analysis to be performed"
+    parser.add_argument("type",
+                        choices=["clang-tidy", "clang-analyzer"],
+                        help=type_help)
+    path_help = "Path to the compilation database to parse"
+    parser.add_argument("path", type=str, help=path_help)
+
+    return parser.parse_args()
+
+
+def init(l, a):
+    global lock
+    global args
+    lock = l
+    args = a
+
+
+def run_analysis(entry):
+    # Disable all checks, then re-enable the ones we want
+    checks = "-checks=-*,"
+    if args.type == "clang-tidy":
+        checks += "linuxkernel-*"
+    else:
+        checks += "clang-analyzer-*"
+    p = subprocess.run(["clang-tidy", "-p", args.path, checks, entry["file"]],
+                       stdout=subprocess.PIPE,
+                       stderr=subprocess.STDOUT,
+                       cwd=entry["directory"])
+    with lock:
+        sys.stderr.buffer.write(p.stdout)
+
+
+def main():
+    args = parse_arguments()
+
+    lock = multiprocessing.Lock()
+    pool = multiprocessing.Pool(initializer=init, initargs=(lock, args))
+    # Read JSON data into the datastore variable
+    with open(args.path, "r") as f:
+        datastore = json.load(f)
+        pool.map(run_analysis, datastore)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/scripts/gen_compile_commands.py b/scripts/gen_compile_commands.py
deleted file mode 100755
index 19963708bcf8..000000000000
--- a/scripts/gen_compile_commands.py
+++ /dev/null
@@ -1,236 +0,0 @@
-#!/usr/bin/env python
-# SPDX-License-Identifier: GPL-2.0
-#
-# Copyright (C) Google LLC, 2018
-#
-# Author: Tom Roeder <tmroeder@google.com>
-#
-"""A tool for generating compile_commands.json in the Linux kernel."""
-
-import argparse
-import json
-import logging
-import os
-import re
-import subprocess
-
-_DEFAULT_OUTPUT = 'compile_commands.json'
-_DEFAULT_LOG_LEVEL = 'WARNING'
-
-_FILENAME_PATTERN = r'^\..*\.cmd$'
-_LINE_PATTERN = r'^cmd_[^ ]*\.o := (.* )([^ ]*\.c)$'
-_VALID_LOG_LEVELS = ['DEBUG', 'INFO', 'WARNING', 'ERROR', 'CRITICAL']
-
-
-def parse_arguments():
-    """Sets up and parses command-line arguments.
-
-    Returns:
-        log_level: A logging level to filter log output.
-        directory: The work directory where the objects were built.
-        ar: Command used for parsing .a archives.
-        output: Where to write the compile-commands JSON file.
-        paths: The list of files/directories to handle to find .cmd files.
-    """
-    usage = 'Creates a compile_commands.json database from kernel .cmd files'
-    parser = argparse.ArgumentParser(description=usage)
-
-    directory_help = ('specify the output directory used for the kernel build '
-                      '(defaults to the working directory)')
-    parser.add_argument('-d', '--directory', type=str, default='.',
-                        help=directory_help)
-
-    output_help = ('path to the output command database (defaults to ' +
-                   _DEFAULT_OUTPUT + ')')
-    parser.add_argument('-o', '--output', type=str, default=_DEFAULT_OUTPUT,
-                        help=output_help)
-
-    log_level_help = ('the level of log messages to produce (defaults to ' +
-                      _DEFAULT_LOG_LEVEL + ')')
-    parser.add_argument('--log_level', choices=_VALID_LOG_LEVELS,
-                        default=_DEFAULT_LOG_LEVEL, help=log_level_help)
-
-    ar_help = 'command used for parsing .a archives'
-    parser.add_argument('-a', '--ar', type=str, default='llvm-ar', help=ar_help)
-
-    paths_help = ('directories to search or files to parse '
-                  '(files should be *.o, *.a, or modules.order). '
-                  'If nothing is specified, the current directory is searched')
-    parser.add_argument('paths', type=str, nargs='*', help=paths_help)
-
-    args = parser.parse_args()
-
-    return (args.log_level,
-            os.path.abspath(args.directory),
-            args.output,
-            args.ar,
-            args.paths if len(args.paths) > 0 else [args.directory])
-
-
-def cmdfiles_in_dir(directory):
-    """Generate the iterator of .cmd files found under the directory.
-
-    Walk under the given directory, and yield every .cmd file found.
-
-    Args:
-        directory: The directory to search for .cmd files.
-
-    Yields:
-        The path to a .cmd file.
-    """
-
-    filename_matcher = re.compile(_FILENAME_PATTERN)
-
-    for dirpath, _, filenames in os.walk(directory):
-        for filename in filenames:
-            if filename_matcher.match(filename):
-                yield os.path.join(dirpath, filename)
-
-
-def to_cmdfile(path):
-    """Return the path of .cmd file used for the given build artifact
-
-    Args:
-        Path: file path
-
-    Returns:
-        The path to .cmd file
-    """
-    dir, base = os.path.split(path)
-    return os.path.join(dir, '.' + base + '.cmd')
-
-
-def cmdfiles_for_o(obj):
-    """Generate the iterator of .cmd files associated with the object
-
-    Yield the .cmd file used to build the given object
-
-    Args:
-        obj: The object path
-
-    Yields:
-        The path to .cmd file
-    """
-    yield to_cmdfile(obj)
-
-
-def cmdfiles_for_a(archive, ar):
-    """Generate the iterator of .cmd files associated with the archive.
-
-    Parse the given archive, and yield every .cmd file used to build it.
-
-    Args:
-        archive: The archive to parse
-
-    Yields:
-        The path to every .cmd file found
-    """
-    for obj in subprocess.check_output([ar, '-t', archive]).decode().split():
-        yield to_cmdfile(obj)
-
-
-def cmdfiles_for_modorder(modorder):
-    """Generate the iterator of .cmd files associated with the modules.order.
-
-    Parse the given modules.order, and yield every .cmd file used to build the
-    contained modules.
-
-    Args:
-        modorder: The modules.order file to parse
-
-    Yields:
-        The path to every .cmd file found
-    """
-    with open(modorder) as f:
-        for line in f:
-            ko = line.rstrip()
-            base, ext = os.path.splitext(ko)
-            if ext != '.ko':
-                sys.exit('{}: module path must end with .ko'.format(ko))
-            mod = base + '.mod'
-	    # The first line of *.mod lists the objects that compose the module.
-            with open(mod) as m:
-                for obj in m.readline().split():
-                    yield to_cmdfile(obj)
-
-
-def process_line(root_directory, command_prefix, file_path):
-    """Extracts information from a .cmd line and creates an entry from it.
-
-    Args:
-        root_directory: The directory that was searched for .cmd files. Usually
-            used directly in the "directory" entry in compile_commands.json.
-        command_prefix: The extracted command line, up to the last element.
-        file_path: The .c file from the end of the extracted command.
-            Usually relative to root_directory, but sometimes absolute.
-
-    Returns:
-        An entry to append to compile_commands.
-
-    Raises:
-        ValueError: Could not find the extracted file based on file_path and
-            root_directory or file_directory.
-    """
-    # The .cmd files are intended to be included directly by Make, so they
-    # escape the pound sign '#', either as '\#' or '$(pound)' (depending on the
-    # kernel version). The compile_commands.json file is not interepreted
-    # by Make, so this code replaces the escaped version with '#'.
-    prefix = command_prefix.replace('\#', '#').replace('$(pound)', '#')
-
-    # Use os.path.abspath() to normalize the path resolving '.' and '..' .
-    abs_path = os.path.abspath(os.path.join(root_directory, file_path))
-    if not os.path.exists(abs_path):
-        raise ValueError('File %s not found' % abs_path)
-    return {
-        'directory': root_directory,
-        'file': abs_path,
-        'command': prefix + file_path,
-    }
-
-
-def main():
-    """Walks through the directory and finds and parses .cmd files."""
-    log_level, directory, output, ar, paths = parse_arguments()
-
-    level = getattr(logging, log_level)
-    logging.basicConfig(format='%(levelname)s: %(message)s', level=level)
-
-    line_matcher = re.compile(_LINE_PATTERN)
-
-    compile_commands = []
-
-    for path in paths:
-        # If 'path' is a directory, handle all .cmd files under it.
-        # Otherwise, handle .cmd files associated with the file.
-        # Most of built-in objects are linked via archives (built-in.a or lib.a)
-        # but some objects are linked to vmlinux directly.
-        # Modules are listed in modules.order.
-        if os.path.isdir(path):
-            cmdfiles = cmdfiles_in_dir(path)
-        elif path.endswith('.o'):
-            cmdfiles = cmdfiles_for_o(path)
-        elif path.endswith('.a'):
-            cmdfiles = cmdfiles_for_a(path, ar)
-        elif path.endswith('modules.order'):
-            cmdfiles = cmdfiles_for_modorder(path)
-        else:
-            sys.exit('{}: unknown file type'.format(path))
-
-        for cmdfile in cmdfiles:
-            with open(cmdfile, 'rt') as f:
-                result = line_matcher.match(f.readline())
-                if result:
-                    try:
-                        entry = process_line(directory, result.group(1),
-                                             result.group(2))
-                        compile_commands.append(entry)
-                    except ValueError as err:
-                        logging.info('Could not add line from %s: %s',
-                                     cmdfile, err)
-
-    with open(output, 'wt') as f:
-        json.dump(compile_commands, f, indent=2, sort_keys=True)
-
-
-if __name__ == '__main__':
-    main()
-- 
cgit v1.2.3


From 887af6d7c99e963c6f92af8e985f9aa6f4f9eac2 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Tue, 1 Sep 2020 03:22:39 +0900
Subject: arch: vdso: add vdso linker script to 'targets' instead of extra-y

The vdso linker script is preprocessed on demand.
Adding it to 'targets' is enough to include the .cmd file.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Greentime Hu <green.hu@gmail.com>
---
 arch/arm64/kernel/vdso/Makefile     | 2 +-
 arch/arm64/kernel/vdso32/Makefile   | 2 +-
 arch/nds32/kernel/vdso/Makefile     | 2 +-
 arch/powerpc/kernel/vdso32/Makefile | 2 +-
 arch/powerpc/kernel/vdso64/Makefile | 2 +-
 arch/s390/kernel/vdso64/Makefile    | 2 +-
 6 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index 45d5cfe46429..7cd8aafbe96e 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -54,7 +54,7 @@ endif
 GCOV_PROFILE := n
 
 obj-y += vdso.o
-extra-y += vdso.lds
+targets += vdso.lds
 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 
 # Force dependency (incbin is bad)
diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
index d6adb4677c25..572475b7b7ed 100644
--- a/arch/arm64/kernel/vdso32/Makefile
+++ b/arch/arm64/kernel/vdso32/Makefile
@@ -155,7 +155,7 @@ asm-obj-vdso := $(addprefix $(obj)/, $(asm-obj-vdso))
 obj-vdso := $(c-obj-vdso) $(c-obj-vdso-gettimeofday) $(asm-obj-vdso)
 
 obj-y += vdso.o
-extra-y += vdso.lds
+targets += vdso.lds
 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 
 # Force dependency (vdso.s includes vdso.so through incbin)
diff --git a/arch/nds32/kernel/vdso/Makefile b/arch/nds32/kernel/vdso/Makefile
index 7c3c1ccb196e..55df25ef0057 100644
--- a/arch/nds32/kernel/vdso/Makefile
+++ b/arch/nds32/kernel/vdso/Makefile
@@ -20,7 +20,7 @@ GCOV_PROFILE := n
 
 
 obj-y += vdso.o
-extra-y += vdso.lds
+targets += vdso.lds
 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
 
 # Force dependency
diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile
index 87ab1152d5ce..fd5072a4c73c 100644
--- a/arch/powerpc/kernel/vdso32/Makefile
+++ b/arch/powerpc/kernel/vdso32/Makefile
@@ -29,7 +29,7 @@ ccflags-y := -shared -fno-common -fno-builtin -nostdlib \
 asflags-y := -D__VDSO32__ -s
 
 obj-y += vdso32_wrapper.o
-extra-y += vdso32.lds
+targets += vdso32.lds
 CPPFLAGS_vdso32.lds += -P -C -Upowerpc
 
 # Force dependency (incbin is bad)
diff --git a/arch/powerpc/kernel/vdso64/Makefile b/arch/powerpc/kernel/vdso64/Makefile
index 38c317f25141..c737b3ea3207 100644
--- a/arch/powerpc/kernel/vdso64/Makefile
+++ b/arch/powerpc/kernel/vdso64/Makefile
@@ -17,7 +17,7 @@ ccflags-y := -shared -fno-common -fno-builtin -nostdlib \
 asflags-y := -D__VDSO64__ -s
 
 obj-y += vdso64_wrapper.o
-extra-y += vdso64.lds
+targets += vdso64.lds
 CPPFLAGS_vdso64.lds += -P -C -U$(ARCH)
 
 # Force dependency (incbin is bad)
diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile
index 4a66a1cb919b..d0d406cfffa9 100644
--- a/arch/s390/kernel/vdso64/Makefile
+++ b/arch/s390/kernel/vdso64/Makefile
@@ -25,7 +25,7 @@ $(targets:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_64)
 $(targets:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_64)
 
 obj-y += vdso64_wrapper.o
-extra-y += vdso64.lds
+targets += vdso64.lds
 CPPFLAGS_vdso64.lds += -P -C -U$(ARCH)
 
 # Disable gcov profiling, ubsan and kasan for VDSO code
-- 
cgit v1.2.3


From 596b0474d3d9b1242eab713f84d8873f9887d980 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Tue, 8 Sep 2020 13:27:08 +0900
Subject: kbuild: preprocess module linker script

There was a request to preprocess the module linker script like we
do for the vmlinux one. (https://lkml.org/lkml/2020/8/21/512)

The difference between vmlinux.lds and module.lds is that the latter
is needed for external module builds, thus must be cleaned up by
'make mrproper' instead of 'make clean'. Also, it must be created
by 'make modules_prepare'.

You cannot put it in arch/$(SRCARCH)/kernel/, which is cleaned up by
'make clean'. I moved arch/$(SRCARCH)/kernel/module.lds to
arch/$(SRCARCH)/include/asm/module.lds.h, which is included from
scripts/module.lds.S.

scripts/module.lds is fine because 'make clean' keeps all the
build artifacts under scripts/.

You can add arch-specific sections in <asm/module.lds.h>.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
---
 Makefile                              | 10 ++++++----
 arch/arm/Makefile                     |  4 ----
 arch/arm/include/asm/module.lds.h     |  7 +++++++
 arch/arm/kernel/module.lds            |  5 -----
 arch/arm64/Makefile                   |  4 ----
 arch/arm64/include/asm/module.lds.h   |  7 +++++++
 arch/arm64/kernel/module.lds          |  5 -----
 arch/ia64/Makefile                    |  1 -
 arch/ia64/include/asm/module.lds.h    | 14 ++++++++++++++
 arch/ia64/module.lds                  | 14 --------------
 arch/m68k/Makefile                    |  1 -
 arch/m68k/include/asm/module.lds.h    |  7 +++++++
 arch/m68k/kernel/module.lds           |  7 -------
 arch/powerpc/Makefile                 |  1 -
 arch/powerpc/include/asm/module.lds.h |  8 ++++++++
 arch/powerpc/kernel/module.lds        |  8 --------
 arch/riscv/Makefile                   |  3 ---
 arch/riscv/include/asm/module.lds.h   |  9 +++++++++
 arch/riscv/kernel/module.lds          |  8 --------
 arch/um/include/asm/Kbuild            |  1 +
 include/asm-generic/Kbuild            |  1 +
 include/asm-generic/module.lds.h      | 10 ++++++++++
 scripts/.gitignore                    |  1 +
 scripts/Makefile                      |  3 +++
 scripts/Makefile.modfinal             |  5 ++---
 scripts/module-common.lds             | 26 --------------------------
 scripts/module.lds.S                  | 29 +++++++++++++++++++++++++++++
 scripts/package/builddeb              |  2 +-
 28 files changed, 106 insertions(+), 95 deletions(-)
 create mode 100644 arch/arm/include/asm/module.lds.h
 delete mode 100644 arch/arm/kernel/module.lds
 create mode 100644 arch/arm64/include/asm/module.lds.h
 delete mode 100644 arch/arm64/kernel/module.lds
 create mode 100644 arch/ia64/include/asm/module.lds.h
 delete mode 100644 arch/ia64/module.lds
 create mode 100644 arch/m68k/include/asm/module.lds.h
 delete mode 100644 arch/m68k/kernel/module.lds
 create mode 100644 arch/powerpc/include/asm/module.lds.h
 delete mode 100644 arch/powerpc/kernel/module.lds
 create mode 100644 arch/riscv/include/asm/module.lds.h
 delete mode 100644 arch/riscv/kernel/module.lds
 create mode 100644 include/asm-generic/module.lds.h
 delete mode 100644 scripts/module-common.lds
 create mode 100644 scripts/module.lds.S

diff --git a/Makefile b/Makefile
index 37739ee53f27..97b1dae1783b 100644
--- a/Makefile
+++ b/Makefile
@@ -505,7 +505,6 @@ KBUILD_CFLAGS_KERNEL :=
 KBUILD_AFLAGS_MODULE  := -DMODULE
 KBUILD_CFLAGS_MODULE  := -DMODULE
 KBUILD_LDFLAGS_MODULE :=
-export KBUILD_LDS_MODULE := $(srctree)/scripts/module-common.lds
 KBUILD_LDFLAGS :=
 CLANG_FLAGS :=
 
@@ -1395,7 +1394,7 @@ endif
 # using awk while concatenating to the final file.
 
 PHONY += modules
-modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check
+modules: $(if $(KBUILD_BUILTIN),vmlinux) modules_check modules_prepare
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
 PHONY += modules_check
@@ -1412,6 +1411,7 @@ targets += modules.order
 # Target to prepare building external modules
 PHONY += modules_prepare
 modules_prepare: prepare
+	$(Q)$(MAKE) $(build)=scripts scripts/module.lds
 
 # Target to install modules
 PHONY += modules_install
@@ -1743,7 +1743,9 @@ help:
 	@echo  '  clean           - remove generated files in module directory only'
 	@echo  ''
 
-PHONY += prepare
+# no-op for external module builds
+PHONY += prepare modules_prepare
+
 endif # KBUILD_EXTMOD
 
 # Single targets
@@ -1776,7 +1778,7 @@ MODORDER := .modules.tmp
 endif
 
 PHONY += single_modpost
-single_modpost: $(single-no-ko)
+single_modpost: $(single-no-ko) modules_prepare
 	$(Q){ $(foreach m, $(single-ko), echo $(extmod-prefix)$m;) } > $(MODORDER)
 	$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.modpost
 
diff --git a/arch/arm/Makefile b/arch/arm/Makefile
index 4e877354515f..a0cb15de9677 100644
--- a/arch/arm/Makefile
+++ b/arch/arm/Makefile
@@ -16,10 +16,6 @@ LDFLAGS_vmlinux	+= --be8
 KBUILD_LDFLAGS_MODULE	+= --be8
 endif
 
-ifeq ($(CONFIG_ARM_MODULE_PLTS),y)
-KBUILD_LDS_MODULE	+= $(srctree)/arch/arm/kernel/module.lds
-endif
-
 GZFLAGS		:=-9
 #KBUILD_CFLAGS	+=-pipe
 
diff --git a/arch/arm/include/asm/module.lds.h b/arch/arm/include/asm/module.lds.h
new file mode 100644
index 000000000000..0e7cb4e314b4
--- /dev/null
+++ b/arch/arm/include/asm/module.lds.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifdef CONFIG_ARM_MODULE_PLTS
+SECTIONS {
+	.plt : { BYTE(0) }
+	.init.plt : { BYTE(0) }
+}
+#endif
diff --git a/arch/arm/kernel/module.lds b/arch/arm/kernel/module.lds
deleted file mode 100644
index 79cb6af565e5..000000000000
--- a/arch/arm/kernel/module.lds
+++ /dev/null
@@ -1,5 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-SECTIONS {
-	.plt : { BYTE(0) }
-	.init.plt : { BYTE(0) }
-}
diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index b45f0124cc16..76667ad47980 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -115,10 +115,6 @@ endif
 
 CHECKFLAGS	+= -D__aarch64__
 
-ifeq ($(CONFIG_ARM64_MODULE_PLTS),y)
-KBUILD_LDS_MODULE	+= $(srctree)/arch/arm64/kernel/module.lds
-endif
-
 ifeq ($(CONFIG_DYNAMIC_FTRACE_WITH_REGS),y)
   KBUILD_CPPFLAGS += -DCC_USING_PATCHABLE_FUNCTION_ENTRY
   CC_FLAGS_FTRACE := -fpatchable-function-entry=2
diff --git a/arch/arm64/include/asm/module.lds.h b/arch/arm64/include/asm/module.lds.h
new file mode 100644
index 000000000000..691f15af788e
--- /dev/null
+++ b/arch/arm64/include/asm/module.lds.h
@@ -0,0 +1,7 @@
+#ifdef CONFIG_ARM64_MODULE_PLTS
+SECTIONS {
+	.plt (NOLOAD) : { BYTE(0) }
+	.init.plt (NOLOAD) : { BYTE(0) }
+	.text.ftrace_trampoline (NOLOAD) : { BYTE(0) }
+}
+#endif
diff --git a/arch/arm64/kernel/module.lds b/arch/arm64/kernel/module.lds
deleted file mode 100644
index 22e36a21c113..000000000000
--- a/arch/arm64/kernel/module.lds
+++ /dev/null
@@ -1,5 +0,0 @@
-SECTIONS {
-	.plt (NOLOAD) : { BYTE(0) }
-	.init.plt (NOLOAD) : { BYTE(0) }
-	.text.ftrace_trampoline (NOLOAD) : { BYTE(0) }
-}
diff --git a/arch/ia64/Makefile b/arch/ia64/Makefile
index 2876a7df1b0a..703b1c4f6d12 100644
--- a/arch/ia64/Makefile
+++ b/arch/ia64/Makefile
@@ -20,7 +20,6 @@ CHECKFLAGS	+= -D__ia64=1 -D__ia64__=1 -D_LP64 -D__LP64__
 
 OBJCOPYFLAGS	:= --strip-all
 LDFLAGS_vmlinux	:= -static
-KBUILD_LDS_MODULE += $(srctree)/arch/ia64/module.lds
 KBUILD_AFLAGS_KERNEL := -mconstant-gp
 EXTRA		:=
 
diff --git a/arch/ia64/include/asm/module.lds.h b/arch/ia64/include/asm/module.lds.h
new file mode 100644
index 000000000000..eff68f362793
--- /dev/null
+++ b/arch/ia64/include/asm/module.lds.h
@@ -0,0 +1,14 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+SECTIONS {
+	/* Group unwind sections into a single section: */
+	.IA_64.unwind_info : { *(.IA_64.unwind_info*) }
+	.IA_64.unwind : { *(.IA_64.unwind*) }
+	/*
+	 * Create place-holder sections to hold the PLTs, GOT, and
+	 * official procedure-descriptors (.opd).
+	 */
+	.core.plt : { BYTE(0) }
+	.init.plt : { BYTE(0) }
+	.got : { BYTE(0) }
+	.opd : { BYTE(0) }
+}
diff --git a/arch/ia64/module.lds b/arch/ia64/module.lds
deleted file mode 100644
index eff68f362793..000000000000
--- a/arch/ia64/module.lds
+++ /dev/null
@@ -1,14 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-SECTIONS {
-	/* Group unwind sections into a single section: */
-	.IA_64.unwind_info : { *(.IA_64.unwind_info*) }
-	.IA_64.unwind : { *(.IA_64.unwind*) }
-	/*
-	 * Create place-holder sections to hold the PLTs, GOT, and
-	 * official procedure-descriptors (.opd).
-	 */
-	.core.plt : { BYTE(0) }
-	.init.plt : { BYTE(0) }
-	.got : { BYTE(0) }
-	.opd : { BYTE(0) }
-}
diff --git a/arch/m68k/Makefile b/arch/m68k/Makefile
index 4438ffb4bbe1..ea14f2046fb4 100644
--- a/arch/m68k/Makefile
+++ b/arch/m68k/Makefile
@@ -75,7 +75,6 @@ KBUILD_CPPFLAGS += -D__uClinux__
 endif
 
 KBUILD_LDFLAGS := -m m68kelf
-KBUILD_LDS_MODULE += $(srctree)/arch/m68k/kernel/module.lds
 
 ifdef CONFIG_SUN3
 LDFLAGS_vmlinux = -N
diff --git a/arch/m68k/include/asm/module.lds.h b/arch/m68k/include/asm/module.lds.h
new file mode 100644
index 000000000000..fda94fa38243
--- /dev/null
+++ b/arch/m68k/include/asm/module.lds.h
@@ -0,0 +1,7 @@
+SECTIONS {
+	.m68k_fixup : {
+		__start_fixup = .;
+		*(.m68k_fixup)
+		__stop_fixup = .;
+	}
+}
diff --git a/arch/m68k/kernel/module.lds b/arch/m68k/kernel/module.lds
deleted file mode 100644
index fda94fa38243..000000000000
--- a/arch/m68k/kernel/module.lds
+++ /dev/null
@@ -1,7 +0,0 @@
-SECTIONS {
-	.m68k_fixup : {
-		__start_fixup = .;
-		*(.m68k_fixup)
-		__stop_fixup = .;
-	}
-}
diff --git a/arch/powerpc/Makefile b/arch/powerpc/Makefile
index 3e8da9cf2eb9..8935658fcd06 100644
--- a/arch/powerpc/Makefile
+++ b/arch/powerpc/Makefile
@@ -65,7 +65,6 @@ UTS_MACHINE := $(subst $(space),,$(machine-y))
 ifdef CONFIG_PPC32
 KBUILD_LDFLAGS_MODULE += arch/powerpc/lib/crtsavres.o
 else
-KBUILD_LDS_MODULE += $(srctree)/arch/powerpc/kernel/module.lds
 ifeq ($(call ld-ifversion, -ge, 225000000, y),y)
 # Have the linker provide sfpr if possible.
 # There is a corresponding test in arch/powerpc/lib/Makefile
diff --git a/arch/powerpc/include/asm/module.lds.h b/arch/powerpc/include/asm/module.lds.h
new file mode 100644
index 000000000000..cea5dc124be4
--- /dev/null
+++ b/arch/powerpc/include/asm/module.lds.h
@@ -0,0 +1,8 @@
+/* Force alignment of .toc section.  */
+SECTIONS
+{
+	.toc 0 : ALIGN(256)
+	{
+		*(.got .toc)
+	}
+}
diff --git a/arch/powerpc/kernel/module.lds b/arch/powerpc/kernel/module.lds
deleted file mode 100644
index cea5dc124be4..000000000000
--- a/arch/powerpc/kernel/module.lds
+++ /dev/null
@@ -1,8 +0,0 @@
-/* Force alignment of .toc section.  */
-SECTIONS
-{
-	.toc 0 : ALIGN(256)
-	{
-		*(.got .toc)
-	}
-}
diff --git a/arch/riscv/Makefile b/arch/riscv/Makefile
index fb6e37db836d..8edaa8bd86d6 100644
--- a/arch/riscv/Makefile
+++ b/arch/riscv/Makefile
@@ -53,9 +53,6 @@ endif
 ifeq ($(CONFIG_CMODEL_MEDANY),y)
 	KBUILD_CFLAGS += -mcmodel=medany
 endif
-ifeq ($(CONFIG_MODULE_SECTIONS),y)
-	KBUILD_LDS_MODULE += $(srctree)/arch/riscv/kernel/module.lds
-endif
 ifeq ($(CONFIG_PERF_EVENTS),y)
         KBUILD_CFLAGS += -fno-omit-frame-pointer
 endif
diff --git a/arch/riscv/include/asm/module.lds.h b/arch/riscv/include/asm/module.lds.h
new file mode 100644
index 000000000000..4254ff2ff049
--- /dev/null
+++ b/arch/riscv/include/asm/module.lds.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2017 Andes Technology Corporation */
+#ifdef CONFIG_MODULE_SECTIONS
+SECTIONS {
+	.plt (NOLOAD) : { BYTE(0) }
+	.got (NOLOAD) : { BYTE(0) }
+	.got.plt (NOLOAD) : { BYTE(0) }
+}
+#endif
diff --git a/arch/riscv/kernel/module.lds b/arch/riscv/kernel/module.lds
deleted file mode 100644
index 295ecfb341a2..000000000000
--- a/arch/riscv/kernel/module.lds
+++ /dev/null
@@ -1,8 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-/* Copyright (C) 2017 Andes Technology Corporation */
-
-SECTIONS {
-	.plt (NOLOAD) : { BYTE(0) }
-	.got (NOLOAD) : { BYTE(0) }
-	.got.plt (NOLOAD) : { BYTE(0) }
-}
diff --git a/arch/um/include/asm/Kbuild b/arch/um/include/asm/Kbuild
index 8d435f8a6dec..1c63b260ecc4 100644
--- a/arch/um/include/asm/Kbuild
+++ b/arch/um/include/asm/Kbuild
@@ -16,6 +16,7 @@ generic-y += kdebug.h
 generic-y += mcs_spinlock.h
 generic-y += mm-arch-hooks.h
 generic-y += mmiowb.h
+generic-y += module.lds.h
 generic-y += param.h
 generic-y += pci.h
 generic-y += percpu.h
diff --git a/include/asm-generic/Kbuild b/include/asm-generic/Kbuild
index 74b0612601dd..7cd4e627e00e 100644
--- a/include/asm-generic/Kbuild
+++ b/include/asm-generic/Kbuild
@@ -40,6 +40,7 @@ mandatory-y += mmiowb.h
 mandatory-y += mmu.h
 mandatory-y += mmu_context.h
 mandatory-y += module.h
+mandatory-y += module.lds.h
 mandatory-y += msi.h
 mandatory-y += pci.h
 mandatory-y += percpu.h
diff --git a/include/asm-generic/module.lds.h b/include/asm-generic/module.lds.h
new file mode 100644
index 000000000000..f210d5c1b78b
--- /dev/null
+++ b/include/asm-generic/module.lds.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __ASM_GENERIC_MODULE_LDS_H
+#define __ASM_GENERIC_MODULE_LDS_H
+
+/*
+ * <asm/module.lds.h> can specify arch-specific sections for linking modules.
+ * Empty for the asm-generic header.
+ */
+
+#endif /* __ASM_GENERIC_MODULE_LDS_H */
diff --git a/scripts/.gitignore b/scripts/.gitignore
index 0d1c8e217cd7..a6c11316c969 100644
--- a/scripts/.gitignore
+++ b/scripts/.gitignore
@@ -8,3 +8,4 @@ asn1_compiler
 extract-cert
 sign-file
 insert-sys-cert
+/module.lds
diff --git a/scripts/Makefile b/scripts/Makefile
index bc018e4b733e..b5418ec587fb 100644
--- a/scripts/Makefile
+++ b/scripts/Makefile
@@ -29,6 +29,9 @@ endif
 # The following programs are only built on demand
 hostprogs += unifdef
 
+# The module linker script is preprocessed on demand
+targets += module.lds
+
 subdir-$(CONFIG_GCC_PLUGINS) += gcc-plugins
 subdir-$(CONFIG_MODVERSIONS) += genksyms
 subdir-$(CONFIG_SECURITY_SELINUX) += selinux
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 411c1e600e7d..ae01baf96f4e 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -33,11 +33,10 @@ quiet_cmd_ld_ko_o = LD [M]  $@
       cmd_ld_ko_o =                                                     \
 	$(LD) -r $(KBUILD_LDFLAGS)					\
 		$(KBUILD_LDFLAGS_MODULE) $(LDFLAGS_MODULE)		\
-		$(addprefix -T , $(KBUILD_LDS_MODULE))			\
-		-o $@ $(filter %.o, $^);				\
+		-T scripts/module.lds -o $@ $(filter %.o, $^);		\
 	$(if $(ARCH_POSTLINK), $(MAKE) -f $(ARCH_POSTLINK) $@, true)
 
-$(modules): %.ko: %.o %.mod.o $(KBUILD_LDS_MODULE) FORCE
+$(modules): %.ko: %.o %.mod.o scripts/module.lds FORCE
 	+$(call if_changed,ld_ko_o)
 
 targets += $(modules) $(modules:.ko=.mod.o)
diff --git a/scripts/module-common.lds b/scripts/module-common.lds
deleted file mode 100644
index d61b9e8678e8..000000000000
--- a/scripts/module-common.lds
+++ /dev/null
@@ -1,26 +0,0 @@
-/*
- * Common module linker script, always used when linking a module.
- * Archs are free to supply their own linker scripts.  ld will
- * combine them automatically.
- */
-SECTIONS {
-	/DISCARD/ : {
-		*(.discard)
-		*(.discard.*)
-	}
-
-	__ksymtab		0 : { *(SORT(___ksymtab+*)) }
-	__ksymtab_gpl		0 : { *(SORT(___ksymtab_gpl+*)) }
-	__ksymtab_unused	0 : { *(SORT(___ksymtab_unused+*)) }
-	__ksymtab_unused_gpl	0 : { *(SORT(___ksymtab_unused_gpl+*)) }
-	__ksymtab_gpl_future	0 : { *(SORT(___ksymtab_gpl_future+*)) }
-	__kcrctab		0 : { *(SORT(___kcrctab+*)) }
-	__kcrctab_gpl		0 : { *(SORT(___kcrctab_gpl+*)) }
-	__kcrctab_unused	0 : { *(SORT(___kcrctab_unused+*)) }
-	__kcrctab_unused_gpl	0 : { *(SORT(___kcrctab_unused_gpl+*)) }
-	__kcrctab_gpl_future	0 : { *(SORT(___kcrctab_gpl_future+*)) }
-
-	.init_array		0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
-
-	__jump_table		0 : ALIGN(8) { KEEP(*(__jump_table)) }
-}
diff --git a/scripts/module.lds.S b/scripts/module.lds.S
new file mode 100644
index 000000000000..69b9b71a6a47
--- /dev/null
+++ b/scripts/module.lds.S
@@ -0,0 +1,29 @@
+/*
+ * Common module linker script, always used when linking a module.
+ * Archs are free to supply their own linker scripts.  ld will
+ * combine them automatically.
+ */
+SECTIONS {
+	/DISCARD/ : {
+		*(.discard)
+		*(.discard.*)
+	}
+
+	__ksymtab		0 : { *(SORT(___ksymtab+*)) }
+	__ksymtab_gpl		0 : { *(SORT(___ksymtab_gpl+*)) }
+	__ksymtab_unused	0 : { *(SORT(___ksymtab_unused+*)) }
+	__ksymtab_unused_gpl	0 : { *(SORT(___ksymtab_unused_gpl+*)) }
+	__ksymtab_gpl_future	0 : { *(SORT(___ksymtab_gpl_future+*)) }
+	__kcrctab		0 : { *(SORT(___kcrctab+*)) }
+	__kcrctab_gpl		0 : { *(SORT(___kcrctab_gpl+*)) }
+	__kcrctab_unused	0 : { *(SORT(___kcrctab_unused+*)) }
+	__kcrctab_unused_gpl	0 : { *(SORT(___kcrctab_unused_gpl+*)) }
+	__kcrctab_gpl_future	0 : { *(SORT(___kcrctab_gpl_future+*)) }
+
+	.init_array		0 : ALIGN(8) { *(SORT(.init_array.*)) *(.init_array) }
+
+	__jump_table		0 : ALIGN(8) { KEEP(*(__jump_table)) }
+}
+
+/* bring in arch-specific sections */
+#include <asm/module.lds.h>
diff --git a/scripts/package/builddeb b/scripts/package/builddeb
index 6df3c9f8b2da..44f212e37935 100755
--- a/scripts/package/builddeb
+++ b/scripts/package/builddeb
@@ -55,7 +55,7 @@ deploy_kernel_headers () {
 		cd $srctree
 		find . arch/$SRCARCH -maxdepth 1 -name Makefile\*
 		find include scripts -type f -o -type l
-		find arch/$SRCARCH -name module.lds -o -name Kbuild.platforms -o -name Platform
+		find arch/$SRCARCH -name Kbuild.platforms -o -name Platform
 		find $(find arch/$SRCARCH -name include -o -name scripts -type d) -type f
 	) > debian/hdrsrcfiles
 
-- 
cgit v1.2.3


From 6212804f2d78e86f15dba5b46a4065cbf1403cde Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Wed, 9 Sep 2020 05:55:57 +0900
Subject: kbuild: do not create built-in objects for external module builds

'make M=/path/to/your/external/module' creates a pointless built-in.a
in the top of the external module directory because KBUILD_BUILTIN is
set to 1.

Clear KBUILD_BUILTIN when we are building external modules so that
'make M=...' and 'make M=... modules' work equivalently.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 Makefile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 97b1dae1783b..744b6c664404 100644
--- a/Makefile
+++ b/Makefile
@@ -1702,7 +1702,8 @@ else # KBUILD_EXTMOD
 #                      Install the modules built in the module directory
 #                      Assumes install directory is already created
 
-# We are always building modules
+# We are always building only modules.
+KBUILD_BUILTIN :=
 KBUILD_MODULES := 1
 
 build-dirs := $(KBUILD_EXTMOD)
-- 
cgit v1.2.3


From 9909b7681222299dcb6f3b0613c30a65498b6c72 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 10 Sep 2020 22:44:28 +0900
Subject: kbuild: remove redundant CONFIG_KASAN check from
 scripts/Makefile.kasan

Since commit e0fe0bbe57b8 ("kbuild: include scripts/Makefile.* only
when relevant CONFIG is enabled"), this file is included only when
CONFIG_KASAN=y.

This ifdef is redundant.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Marco Elver <elver@google.com>
---
 scripts/Makefile.kasan | 2 --
 1 file changed, 2 deletions(-)

diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index f4beee1b0013..1532f1a41a8f 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -1,8 +1,6 @@
 # SPDX-License-Identifier: GPL-2.0
-ifdef CONFIG_KASAN
 CFLAGS_KASAN_NOSANITIZE := -fno-builtin
 KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)
-endif
 
 ifdef CONFIG_KASAN_GENERIC
 
-- 
cgit v1.2.3


From bb2732112bc52bed7b20b9fc59d7246e4e7ce5ed Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 10 Sep 2020 22:44:29 +0900
Subject: kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles

Move CFLAGS_KASAN*, CFLAGS_UBSAN, CFLAGS_KCSAN to Makefile.kasan,
Makefile.ubsan, Makefile.kcsan, respectively.

This commit also avoids the same -fsanitize=* flags being added to
CFLAGS_UBSAN multiple times.

Prior to this commit, the ubsan flags were appended by the '+='
operator, without any initialization. Some build targets such as
'make bindeb-pkg' recurses to the top Makefile, and ended up with
adding the same flags to CFLAGS_UBSAN twice.

Clear CFLAGS_UBSAN with ':=' to make it a simply expanded variable.
This is better than a recursively expanded variable, which evaluates
$(call cc-option, ...) multiple times before Kbuild starts descending
to subdirectories.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Acked-by: Marco Elver <elver@google.com>
---
 Makefile               | 1 -
 scripts/Makefile.kasan | 2 ++
 scripts/Makefile.kcsan | 2 +-
 scripts/Makefile.ubsan | 3 +++
 4 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 744b6c664404..06890bb0e011 100644
--- a/Makefile
+++ b/Makefile
@@ -516,7 +516,6 @@ export KBUILD_HOSTCXXFLAGS KBUILD_HOSTLDFLAGS KBUILD_HOSTLDLIBS LDFLAGS_MODULE
 
 export KBUILD_CPPFLAGS NOSTDINC_FLAGS LINUXINCLUDE OBJCOPYFLAGS KBUILD_LDFLAGS
 export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
-export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE CFLAGS_UBSAN CFLAGS_KCSAN
 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
diff --git a/scripts/Makefile.kasan b/scripts/Makefile.kasan
index 1532f1a41a8f..1e000cc2e7b4 100644
--- a/scripts/Makefile.kasan
+++ b/scripts/Makefile.kasan
@@ -47,3 +47,5 @@ CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
 		$(instrumentation_flags)
 
 endif # CONFIG_KASAN_SW_TAGS
+
+export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE
diff --git a/scripts/Makefile.kcsan b/scripts/Makefile.kcsan
index c50f27b3ac56..cec50d74e0d0 100644
--- a/scripts/Makefile.kcsan
+++ b/scripts/Makefile.kcsan
@@ -9,7 +9,7 @@ endif
 
 # Keep most options here optional, to allow enabling more compilers if absence
 # of some options does not break KCSAN nor causes false positive reports.
-CFLAGS_KCSAN := -fsanitize=thread \
+export CFLAGS_KCSAN := -fsanitize=thread \
 	$(call cc-option,$(call cc-param,tsan-instrument-func-entry-exit=0) -fno-optimize-sibling-calls) \
 	$(call cc-option,$(call cc-param,tsan-instrument-read-before-write=1)) \
 	$(call cc-param,tsan-distinguish-volatile=1)
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
index 27348029b2b8..c661484ee01f 100644
--- a/scripts/Makefile.ubsan
+++ b/scripts/Makefile.ubsan
@@ -1,4 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
+
+export CFLAGS_UBSAN :=
+
 ifdef CONFIG_UBSAN_ALIGNMENT
       CFLAGS_UBSAN += $(call cc-option, -fsanitize=alignment)
 endif
-- 
cgit v1.2.3


From 8b42cf2fde0ee8b63d71d4bc442a03b6ea55b00b Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 10 Sep 2020 22:51:17 +0900
Subject: kbuild: remove cc-option test of -fno-strict-overflow

The minimal compiler versions, GCC 4.9 and Clang 10 support this flag.

Here is the godbolt:
https://godbolt.org/z/odq8h9

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Will Deacon <will@kernel.org>
---
 Makefile                          | 2 +-
 arch/arm64/kernel/vdso32/Makefile | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 06890bb0e011..7036dcb99cdf 100644
--- a/Makefile
+++ b/Makefile
@@ -928,7 +928,7 @@ KBUILD_CFLAGS += $(call cc-disable-warning, restrict)
 KBUILD_CFLAGS += $(call cc-disable-warning, maybe-uninitialized)
 
 # disable invalid "can't wrap" optimizations for signed / pointers
-KBUILD_CFLAGS	+= $(call cc-option,-fno-strict-overflow)
+KBUILD_CFLAGS	+= -fno-strict-overflow
 
 # clang sets -fmerge-all-constants by default as optimization, but this
 # is non-conforming behavior for C and in fact breaks the kernel, so we
diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
index 572475b7b7ed..3d99a9a249e3 100644
--- a/arch/arm64/kernel/vdso32/Makefile
+++ b/arch/arm64/kernel/vdso32/Makefile
@@ -90,7 +90,7 @@ VDSO_CFLAGS  += -O2
 # Some useful compiler-dependent flags from top-level Makefile
 VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,)
 VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign)
-VDSO_CFLAGS += $(call cc32-option,-fno-strict-overflow)
+VDSO_CFLAGS += -fno-strict-overflow
 VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes)
 VDSO_CFLAGS += $(call cc32-option,-Werror=date-time)
 VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types)
-- 
cgit v1.2.3


From 7d4eb0d8e229fa51e14f0f85de03c02880e7d742 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 10 Sep 2020 22:51:19 +0900
Subject: kbuild: remove cc-option test of -fno-stack-check

The minimal compiler version, GCC 4.9 supports this flag.

Nathan Chancellor pointed out:
 "This flag is technically ignored by clang (see commit
 05b0798916f01690b5903302e51f3136274e291f) but that obviously
 does not matter for the sake of this."

Here is the godbolt:
https://godbolt.org/z/59cK6o

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index 7036dcb99cdf..3722b42fd01e 100644
--- a/Makefile
+++ b/Makefile
@@ -940,7 +940,7 @@ KBUILD_CFLAGS	+= $(call cc-option,-fno-merge-all-constants)
 KBUILD_CFLAGS	+= $(call cc-option,-fmerge-constants)
 
 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
-KBUILD_CFLAGS  += $(call cc-option,-fno-stack-check,)
+KBUILD_CFLAGS  += -fno-stack-check
 
 # conserve stack if available
 KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
-- 
cgit v1.2.3


From 87de84c9140e1ccb221c68bb7e4939e880b3f2bb Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Thu, 10 Sep 2020 22:51:20 +0900
Subject: kbuild: remove cc-option test of -Werror=date-time

The minimal compiler versions, GCC 4.9 and Clang 10 support this flag.

Here is the godbolt:
https://godbolt.org/z/xvjcMa

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Will Deacon <will@kernel.org>
---
 Makefile                          | 2 +-
 arch/arm64/kernel/vdso32/Makefile | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 3722b42fd01e..e39ed7967cd6 100644
--- a/Makefile
+++ b/Makefile
@@ -946,7 +946,7 @@ KBUILD_CFLAGS  += -fno-stack-check
 KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
 
 # Prohibit date/time macros, which would make the build non-deterministic
-KBUILD_CFLAGS   += $(call cc-option,-Werror=date-time)
+KBUILD_CFLAGS   += -Werror=date-time
 
 # enforce correct pointer usage
 KBUILD_CFLAGS   += $(call cc-option,-Werror=incompatible-pointer-types)
diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
index 3d99a9a249e3..1259e5bd0fab 100644
--- a/arch/arm64/kernel/vdso32/Makefile
+++ b/arch/arm64/kernel/vdso32/Makefile
@@ -92,7 +92,7 @@ VDSO_CFLAGS += $(call cc32-option,-Wdeclaration-after-statement,)
 VDSO_CFLAGS += $(call cc32-option,-Wno-pointer-sign)
 VDSO_CFLAGS += -fno-strict-overflow
 VDSO_CFLAGS += $(call cc32-option,-Werror=strict-prototypes)
-VDSO_CFLAGS += $(call cc32-option,-Werror=date-time)
+VDSO_CFLAGS += -Werror=date-time
 VDSO_CFLAGS += $(call cc32-option,-Werror=incompatible-pointer-types)
 
 # The 32-bit compiler does not provide 128-bit integers, which are used in
-- 
cgit v1.2.3


From 548b8b5168c90c42e88f70fcf041b4ce0b8e7aa8 Mon Sep 17 00:00:00 2001
From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Date: Thu, 17 Sep 2020 08:56:11 +0200
Subject: scripts/setlocalversion: make git describe output more reliable

When building for an embedded target using Yocto, we're sometimes
observing that the version string that gets built into vmlinux (and
thus what uname -a reports) differs from the path under /lib/modules/
where modules get installed in the rootfs, but only in the length of
the -gabc123def suffix. Hence modprobe always fails.

The problem is that Yocto has the concept of "sstate" (shared state),
which allows different developers/buildbots/etc. to share build
artifacts, based on a hash of all the metadata that went into building
that artifact - and that metadata includes all dependencies (e.g. the
compiler used etc.). That normally works quite well; usually a clean
build (without using any sstate cache) done by one developer ends up
being binary identical to a build done on another host. However, one
thing that can cause two developers to end up with different builds
[and thus make one's vmlinux package incompatible with the other's
kernel-dev package], which is not captured by the metadata hashing, is
this `git describe`: The output of that can be affected by

(1) git version: before 2.11 git defaulted to a minimum of 7, since
2.11 (git.git commit e6c587) the default is dynamic based on the
number of objects in the repo
(2) hence even if both run the same git version, the output can differ
based on how many remotes are being tracked (or just lots of local
development branches or plain old garbage)
(3) and of course somebody could have a core.abbrev config setting in
~/.gitconfig

So in order to avoid `uname -a` output relying on such random details
of the build environment which are rather hard to ensure are
consistent between developers and buildbots, make sure the abbreviated
sha1 always consists of exactly 12 hex characters. That is consistent
with the current rule for -stable patches, and is almost always enough
to identify the head commit unambigously - in the few cases where it
does not, the v5.4.3-00021- prefix would certainly nail it down.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/setlocalversion | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/scripts/setlocalversion b/scripts/setlocalversion
index 20f2efd57b11..bb709eda96cd 100755
--- a/scripts/setlocalversion
+++ b/scripts/setlocalversion
@@ -45,7 +45,7 @@ scm_version()
 
 	# Check for git and a git repo.
 	if test -z "$(git rev-parse --show-cdup 2>/dev/null)" &&
-	   head=$(git rev-parse --verify --short HEAD 2>/dev/null); then
+	   head=$(git rev-parse --verify HEAD 2>/dev/null); then
 
 		# If we are at a tagged commit (like "v2.6.30-rc6"), we ignore
 		# it, because this version is defined in the top level Makefile.
@@ -59,11 +59,22 @@ scm_version()
 			fi
 			# If we are past a tagged commit (like
 			# "v2.6.30-rc5-302-g72357d5"), we pretty print it.
-			if atag="$(git describe 2>/dev/null)"; then
-				echo "$atag" | awk -F- '{printf("-%05d-%s", $(NF-1),$(NF))}'
-
-			# If we don't have a tag at all we print -g{commitish}.
+			#
+			# Ensure the abbreviated sha1 has exactly 12
+			# hex characters, to make the output
+			# independent of git version, local
+			# core.abbrev settings and/or total number of
+			# objects in the current repository - passing
+			# --abbrev=12 ensures a minimum of 12, and the
+			# awk substr() then picks the 'g' and first 12
+			# hex chars.
+			if atag="$(git describe --abbrev=12 2>/dev/null)"; then
+				echo "$atag" | awk -F- '{printf("-%05d-%s", $(NF-1),substr($(NF),0,13))}'
+
+			# If we don't have a tag at all we print -g{commitish},
+			# again using exactly 12 hex chars.
 			else
+				head="$(echo $head | cut -c1-12)"
 				printf '%s%s' -g $head
 			fi
 		fi
-- 
cgit v1.2.3


From a968433723310f35898b4a2f635a7991aeef66b1 Mon Sep 17 00:00:00 2001
From: Bill Wendling <morbo@google.com>
Date: Tue, 22 Sep 2020 16:21:40 -0700
Subject: kbuild: explicitly specify the build id style

ld's --build-id defaults to "sha1" style, while lld defaults to "fast".
The build IDs are very different between the two, which may confuse
programs that reference them.

Signed-off-by: Bill Wendling <morbo@google.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 Makefile                             | 4 ++--
 arch/arm/vdso/Makefile               | 2 +-
 arch/arm64/kernel/vdso/Makefile      | 2 +-
 arch/arm64/kernel/vdso32/Makefile    | 2 +-
 arch/mips/vdso/Makefile              | 2 +-
 arch/riscv/kernel/vdso/Makefile      | 2 +-
 arch/s390/kernel/vdso64/Makefile     | 2 +-
 arch/sparc/vdso/Makefile             | 2 +-
 arch/x86/entry/vdso/Makefile         | 2 +-
 tools/testing/selftests/bpf/Makefile | 2 +-
 10 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/Makefile b/Makefile
index e39ed7967cd6..088fb7d49dd7 100644
--- a/Makefile
+++ b/Makefile
@@ -982,8 +982,8 @@ KBUILD_CPPFLAGS += $(KCPPFLAGS)
 KBUILD_AFLAGS   += $(KAFLAGS)
 KBUILD_CFLAGS   += $(KCFLAGS)
 
-KBUILD_LDFLAGS_MODULE += --build-id
-LDFLAGS_vmlinux += --build-id
+KBUILD_LDFLAGS_MODULE += --build-id=sha1
+LDFLAGS_vmlinux += --build-id=sha1
 
 ifeq ($(CONFIG_STRIP_ASM_SYMS),y)
 LDFLAGS_vmlinux	+= $(call ld-option, -X,)
diff --git a/arch/arm/vdso/Makefile b/arch/arm/vdso/Makefile
index a54f70731d9f..150ce6e6a5d3 100644
--- a/arch/arm/vdso/Makefile
+++ b/arch/arm/vdso/Makefile
@@ -19,7 +19,7 @@ ccflags-y += -DDISABLE_BRANCH_PROFILING -DBUILD_VDSO32
 ldflags-$(CONFIG_CPU_ENDIAN_BE8) := --be8
 ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
 	    -z max-page-size=4096 -nostdlib -shared $(ldflags-y) \
-	    --hash-style=sysv --build-id \
+	    --hash-style=sysv --build-id=sha1 \
 	    -T
 
 obj-$(CONFIG_VDSO) += vdso.o
diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index 7cd8aafbe96e..3dc4b65da99d 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -24,7 +24,7 @@ btildflags-$(CONFIG_ARM64_BTI_KERNEL) += -z force-bti
 # routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so
 # preparation in build-time C")).
 ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv	\
-	     -Bsymbolic $(call ld-option, --no-eh-frame-hdr) --build-id -n	\
+	     -Bsymbolic $(call ld-option, --no-eh-frame-hdr) --build-id=sha1 -n	\
 	     $(btildflags-y) -T
 
 ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18
diff --git a/arch/arm64/kernel/vdso32/Makefile b/arch/arm64/kernel/vdso32/Makefile
index 1259e5bd0fab..7f96a1a9f68c 100644
--- a/arch/arm64/kernel/vdso32/Makefile
+++ b/arch/arm64/kernel/vdso32/Makefile
@@ -128,7 +128,7 @@ VDSO_LDFLAGS += -Wl,-Bsymbolic -Wl,--no-undefined -Wl,-soname=linux-vdso.so.1
 VDSO_LDFLAGS += -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
 VDSO_LDFLAGS += -nostdlib -shared -mfloat-abi=soft
 VDSO_LDFLAGS += -Wl,--hash-style=sysv
-VDSO_LDFLAGS += -Wl,--build-id
+VDSO_LDFLAGS += -Wl,--build-id=sha1
 VDSO_LDFLAGS += $(call cc32-ldoption,-fuse-ld=bfd)
 
 
diff --git a/arch/mips/vdso/Makefile b/arch/mips/vdso/Makefile
index 57fe83235281..5810cc12bc1d 100644
--- a/arch/mips/vdso/Makefile
+++ b/arch/mips/vdso/Makefile
@@ -61,7 +61,7 @@ endif
 # VDSO linker flags.
 ldflags-y := -Bsymbolic --no-undefined -soname=linux-vdso.so.1 \
 	$(filter -E%,$(KBUILD_CFLAGS)) -nostdlib -shared \
-	-G 0 --eh-frame-hdr --hash-style=sysv --build-id -T
+	-G 0 --eh-frame-hdr --hash-style=sysv --build-id=sha1 -T
 
 CFLAGS_REMOVE_vdso.o = -pg
 
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
index 478e7338ddc1..7d6a94d45ec9 100644
--- a/arch/riscv/kernel/vdso/Makefile
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -49,7 +49,7 @@ $(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
 # refer to these symbols in the kernel code rather than hand-coded addresses.
 
 SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
-	-Wl,--build-id -Wl,--hash-style=both
+	-Wl,--build-id=sha1 -Wl,--hash-style=both
 $(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
 	$(call if_changed,vdsold)
 
diff --git a/arch/s390/kernel/vdso64/Makefile b/arch/s390/kernel/vdso64/Makefile
index d0d406cfffa9..9acad762456d 100644
--- a/arch/s390/kernel/vdso64/Makefile
+++ b/arch/s390/kernel/vdso64/Makefile
@@ -19,7 +19,7 @@ KBUILD_AFLAGS_64 += -m64 -s
 KBUILD_CFLAGS_64 := $(filter-out -m64,$(KBUILD_CFLAGS))
 KBUILD_CFLAGS_64 += -m64 -fPIC -shared -fno-common -fno-builtin
 ldflags-y := -fPIC -shared -nostdlib -soname=linux-vdso64.so.1 \
-	     --hash-style=both --build-id -T
+	     --hash-style=both --build-id=sha1 -T
 
 $(targets:%=$(obj)/%.dbg): KBUILD_CFLAGS = $(KBUILD_CFLAGS_64)
 $(targets:%=$(obj)/%.dbg): KBUILD_AFLAGS = $(KBUILD_AFLAGS_64)
diff --git a/arch/sparc/vdso/Makefile b/arch/sparc/vdso/Makefile
index f44355e46f31..469dd23887ab 100644
--- a/arch/sparc/vdso/Makefile
+++ b/arch/sparc/vdso/Makefile
@@ -115,7 +115,7 @@ quiet_cmd_vdso = VDSO    $@
 		       -T $(filter %.lds,$^) $(filter %.o,$^) && \
 		sh $(srctree)/$(src)/checkundef.sh '$(OBJDUMP)' '$@'
 
-VDSO_LDFLAGS = -shared --hash-style=both --build-id -Bsymbolic
+VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 -Bsymbolic
 GCOV_PROFILE := n
 
 #
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index 215376d975a2..ebba25ed9a38 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -176,7 +176,7 @@ quiet_cmd_vdso = VDSO    $@
 		       -T $(filter %.lds,$^) $(filter %.o,$^) && \
 		 sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
 
-VDSO_LDFLAGS = -shared --hash-style=both --build-id \
+VDSO_LDFLAGS = -shared --hash-style=both --build-id=sha1 \
 	$(call ld-option, --eh-frame-hdr) -Bsymbolic
 GCOV_PROFILE := n
 
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile
index fc946b7ac288..daf186f88a63 100644
--- a/tools/testing/selftests/bpf/Makefile
+++ b/tools/testing/selftests/bpf/Makefile
@@ -133,7 +133,7 @@ $(OUTPUT)/%:%.c
 
 $(OUTPUT)/urandom_read: urandom_read.c
 	$(call msg,BINARY,,$@)
-	$(Q)$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS) -Wl,--build-id
+	$(Q)$(CC) $(LDFLAGS) -o $@ $< $(LDLIBS) -Wl,--build-id=sha1
 
 $(OUTPUT)/test_stub.o: test_stub.c $(BPFOBJ)
 	$(call msg,CC,,$@)
-- 
cgit v1.2.3


From 08beb669cb3f11ff5e05055bcab5e29385e69f98 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Fri, 25 Sep 2020 00:45:46 +0900
Subject: kbuild: split the build log of kallsyms

Currently, the build log shows KSYM + object name.

Precisely speaking, kallsyms generates a .S file and then the compiler
compiles it into a .o file. Split the build log into two.

[Before]

  GEN     modules.builtin
  LD      .tmp_vmlinux.kallsyms1
  KSYM    .tmp_vmlinux.kallsyms1.o
  LD      .tmp_vmlinux.kallsyms2
  KSYM    .tmp_vmlinux.kallsyms2.o
  LD      vmlinux

[After]

  GEN     modules.builtin
  LD      .tmp_vmlinux.kallsyms1
  KSYMS   .tmp_vmlinux.kallsyms1.S
  AS      .tmp_vmlinux.kallsyms1.o
  LD      .tmp_vmlinux.kallsyms2
  KSYMS   .tmp_vmlinux.kallsyms2.S
  AS      .tmp_vmlinux.kallsyms2.o
  LD      vmlinux

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/link-vmlinux.sh | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index e6e2d9e5ff48..d9bcf36a1583 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -169,10 +169,9 @@ gen_btf()
 	printf '\1' | dd of=${2} conv=notrunc bs=1 seek=16 status=none
 }
 
-# Create ${2} .o file with all symbols from the ${1} object file
+# Create ${2} .S file with all symbols from the ${1} object file
 kallsyms()
 {
-	info KSYM ${2}
 	local kallsymopt;
 
 	if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
@@ -187,13 +186,8 @@ kallsyms()
 		kallsymopt="${kallsymopt} --base-relative"
 	fi
 
-	local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL}               \
-		      ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
-
-	local afile="`basename ${2} .o`.S"
-
-	${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
-	${CC} ${aflags} -c -o ${2} ${afile}
+	info KSYMS ${2}
+	${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${2}
 }
 
 # Perform one step in kallsyms generation, including temporary linking of
@@ -203,9 +197,15 @@ kallsyms_step()
 	kallsymso_prev=${kallsymso}
 	kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1}
 	kallsymso=${kallsyms_vmlinux}.o
+	kallsyms_S=${kallsyms_vmlinux}.S
 
 	vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o}
-	kallsyms ${kallsyms_vmlinux} ${kallsymso}
+	kallsyms ${kallsyms_vmlinux} ${kallsyms_S}
+
+	info AS ${kallsyms_S}
+	${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} \
+	      ${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
+	      -c -o ${kallsymso} ${kallsyms_S}
 }
 
 # Create map file with all symbols from ${1}
-- 
cgit v1.2.3


From 51ccdbfbed79bae4b9c2529ec980de4508455a47 Mon Sep 17 00:00:00 2001
From: Guillem Jover <guillem@hadrons.org>
Date: Mon, 21 Sep 2020 00:25:50 +0200
Subject: builddeb: Pass -n to gzip for reproducible packages

We should not be encoding the timestamp, otherwise we end up generating
unreproducible files that cascade into unreproducible packages.

Signed-off-by: Guillem Jover <guillem@hadrons.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/package/builddeb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/package/builddeb b/scripts/package/builddeb
index 44f212e37935..30e8c6a20171 100755
--- a/scripts/package/builddeb
+++ b/scripts/package/builddeb
@@ -31,7 +31,7 @@ create_package() {
 	mkdir -p "$pdir/usr/share/doc/$pname"
 	cp debian/copyright "$pdir/usr/share/doc/$pname/"
 	cp debian/changelog "$pdir/usr/share/doc/$pname/changelog.Debian"
-	gzip -9 "$pdir/usr/share/doc/$pname/changelog.Debian"
+	gzip -n -9 "$pdir/usr/share/doc/$pname/changelog.Debian"
 	sh -c "cd '$pdir'; find . -type f ! -path './DEBIAN/*' -printf '%P\0' \
 		| xargs -r0 md5sum > DEBIAN/md5sums"
 
-- 
cgit v1.2.3


From 3e8541803624678925a477a03e19e3c155b5fc12 Mon Sep 17 00:00:00 2001
From: Guillem Jover <guillem@hadrons.org>
Date: Mon, 21 Sep 2020 00:25:54 +0200
Subject: builddeb: Enable rootless builds

This makes it possible to build the Debian packages without requiring
(pseudo-)root privileges, when the build drivers support this mode
of operation.

See-Also: /usr/share/doc/dpkg/rootless-builds.txt.gz
Signed-off-by: Guillem Jover <guillem@hadrons.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/package/builddeb | 9 +++++++--
 scripts/package/mkdebian | 1 +
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/scripts/package/builddeb b/scripts/package/builddeb
index 30e8c6a20171..6474084c32a4 100755
--- a/scripts/package/builddeb
+++ b/scripts/package/builddeb
@@ -26,6 +26,7 @@ if_enabled_echo() {
 
 create_package() {
 	local pname="$1" pdir="$2"
+	local dpkg_deb_opts
 
 	mkdir -m 755 -p "$pdir/DEBIAN"
 	mkdir -p "$pdir/usr/share/doc/$pname"
@@ -36,14 +37,18 @@ create_package() {
 		| xargs -r0 md5sum > DEBIAN/md5sums"
 
 	# Fix ownership and permissions
-	chown -R root:root "$pdir"
+	if [ "$DEB_RULES_REQUIRES_ROOT" = "no" ]; then
+		dpkg_deb_opts="--root-owner-group"
+	else
+		chown -R root:root "$pdir"
+	fi
 	chmod -R go-w "$pdir"
 	# in case we are in a restrictive umask environment like 0077
 	chmod -R a+rX "$pdir"
 
 	# Create the package
 	dpkg-gencontrol -p$pname -P"$pdir"
-	dpkg-deb ${KDEB_COMPRESS:+-Z$KDEB_COMPRESS} --build "$pdir" ..
+	dpkg-deb $dpkg_deb_opts ${KDEB_COMPRESS:+-Z$KDEB_COMPRESS} --build "$pdir" ..
 }
 
 deploy_kernel_headers () {
diff --git a/scripts/package/mkdebian b/scripts/package/mkdebian
index 48fbd3d0284a..dbe42500084c 100755
--- a/scripts/package/mkdebian
+++ b/scripts/package/mkdebian
@@ -174,6 +174,7 @@ Source: $sourcename
 Section: kernel
 Priority: optional
 Maintainer: $maintainer
+Rules-Requires-Root: no
 Build-Depends: bc, rsync, kmod, cpio, bison, flex | flex:native $extra_build_depends
 Homepage: https://www.kernel.org/
 
-- 
cgit v1.2.3


From 76c37668768464a6c2d5c49abd36ba0b48a0b131 Mon Sep 17 00:00:00 2001
From: Guillem Jover <guillem@hadrons.org>
Date: Mon, 21 Sep 2020 00:25:53 +0200
Subject: builddeb: Add support for all required debian/rules targets

These have been required by the Debian policy for a while, even though
the tooling can detect and workaround their omission, but are a hard
requirement when using rootless builds.

[masahiro:
The following Debian policy is particularly important for rootless builds:
"Both binary-* targets should depend on the build target, or on the
 appropriate build-arch or build-indep target, so that the package is
 built if it has not been already."
]

Signed-off-by: Guillem Jover <guillem@hadrons.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/package/mkdebian | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/scripts/package/mkdebian b/scripts/package/mkdebian
index dbe42500084c..3a13b834f281 100755
--- a/scripts/package/mkdebian
+++ b/scripts/package/mkdebian
@@ -218,11 +218,15 @@ cat <<EOF > debian/rules
 
 srctree ?= .
 
-build:
+build-indep:
+build-arch:
 	\$(MAKE) KERNELRELEASE=${version} ARCH=${ARCH} \
 	KBUILD_BUILD_VERSION=${revision} -f \$(srctree)/Makefile
 
-binary-arch:
+build: build-arch
+
+binary-indep:
+binary-arch: build-arch
 	\$(MAKE) KERNELRELEASE=${version} ARCH=${ARCH} \
 	KBUILD_BUILD_VERSION=${revision} -f \$(srctree)/Makefile intdeb-pkg
 
-- 
cgit v1.2.3


From 7dfbea4c468cfbc7e1ceb619fe337e7582eb1d2d Mon Sep 17 00:00:00 2001
From: Jacob Keller <jacob.e.keller@intel.com>
Date: Fri, 9 Oct 2020 17:18:44 -0700
Subject: scripts: remove namespace.pl

namespace.pl is intended to help locate symbols which are defined but
are not used externally. The goal is to avoid bloat of the namespace in
the resulting kernel image.

The script relies on object data, and only finds unused symbols for the
configuration used to generate that object data. This results in a lot
of false positive warnings such as symbols only used by a single
architecture, or symbols which are used externally only under certain
configurations.

Running namespace.pl using allyesconfig, allmodconfig, and
x86_64_defconfig yields the following results:

* allmodconfig
  * 11122 unique symbol names with no external reference
  * 1194 symbols listed as multiply defined
  * 214 symbols it can't resolve
* allyesconfig
  * 10997 unique symbol names with no external reference
  * 1194 symbols listed as multiply defined
  * 214 symbols it can't resolve
* x86_64_defconfig
  * 5757 unique symbol names with no external reference
  * 528 symbols listed as multiply defined
  * 154 symbols it can't resolve

The script also has no way to easily limit the scope of the checks to
a given subset of the kernel, such as only checking for symbols defined
within a module or subsystem.

Discussion on public mailing lists seems to indicate that many view the
tool output as suspect or not very useful (see discussions at [1] and
[2] for further context).

As described by Masahiro Yamada at [2], namespace.pl provides 3 types of
checks: listing multiply defined symbols, resolving external symbols,
and warnings about symbols with no reference.

The first category of issues is easily caught by the linker as any set
of multiply defined symbols should fail to link. The second category of
issues is also caught by linking, as undefined symbols would cause
issues. Even with modules, these types of issues where a module relies
on an external symbol are caught by modpost.

The remaining category of issues reported is the list of symbols with no
external reference, and is the primary motivation of this script.
However, it ought to be clear from the above examples that the output is
difficult to sort through. Even allyesconfig has ~10000 entries.

The current submit-checklist indicates that patches ought to go through
namespacecheck and fix any new issues arising. But that itself presents
problems. As described at [1], many cases of reports are due to
configuration where a function is used externally by some configuration
settings. Prominent maintainers appear to dislike changes modify code
such that symbols become static based on CONFIG_* flags ([3], and [4])

One possible solution is to adjust the advice and indicate that we only
care about the output of namespacecheck on allyesconfig or allmodconfig
builds...

However, given the discussion at [2], I suspect that few people are
actively using this tool. It doesn't have a maintainer in the
MAINTAINERS flie, and it produces so many warnings for unused symbols
that it is difficult to use effectively. Thus, I propose we simply
remove it.

[1] https://lore.kernel.org/netdev/20200708164812.384ae8ea@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com/
[2] https://lore.kernel.org/lkml/20190129204319.15238-1-jacob.e.keller@intel.com/
[3] https://lore.kernel.org/netdev/20190828.154744.2058157956381129672.davem@davemloft.net/
[4] https://lore.kernel.org/netdev/20190827210928.576c5fef@cakuba.netronome.com/

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 Documentation/process/submit-checklist.rst |   3 +-
 Makefile                                   |   6 +-
 scripts/namespace.pl                       | 473 -----------------------------
 3 files changed, 2 insertions(+), 480 deletions(-)
 delete mode 100755 scripts/namespace.pl

diff --git a/Documentation/process/submit-checklist.rst b/Documentation/process/submit-checklist.rst
index 3f8e9d5d95c2..e201a6033469 100644
--- a/Documentation/process/submit-checklist.rst
+++ b/Documentation/process/submit-checklist.rst
@@ -49,8 +49,7 @@ and elsewhere regarding submitting Linux kernel patches.
 
 9) Check cleanly with sparse.
 
-10) Use ``make checkstack`` and ``make namespacecheck`` and fix any problems
-    that they find.
+10) Use ``make checkstack`` and fix any problems that it finds.
 
     .. note::
 
diff --git a/Makefile b/Makefile
index 088fb7d49dd7..ddadab2f2e8b 100644
--- a/Makefile
+++ b/Makefile
@@ -1576,7 +1576,6 @@ help:
 	 echo  ''
 	@echo  'Static analysers:'
 	@echo  '  checkstack      - Generate a list of stack hogs'
-	@echo  '  namespacecheck  - Name space analysis on compiled kernel'
 	@echo  '  versioncheck    - Sanity check on version.h usage'
 	@echo  '  includecheck    - Check for duplicate included header files'
 	@echo  '  export_report   - List the usages of all exported symbols'
@@ -1876,7 +1875,7 @@ endif
 # Scripts to check various things for consistency
 # ---------------------------------------------------------------------------
 
-PHONY += includecheck versioncheck coccicheck namespacecheck export_report
+PHONY += includecheck versioncheck coccicheck export_report
 
 includecheck:
 	find $(srctree)/* $(RCS_FIND_IGNORE) \
@@ -1891,9 +1890,6 @@ versioncheck:
 coccicheck:
 	$(Q)$(BASH) $(srctree)/scripts/$@
 
-namespacecheck:
-	$(PERL) $(srctree)/scripts/namespace.pl
-
 export_report:
 	$(PERL) $(srctree)/scripts/export_report.pl
 
diff --git a/scripts/namespace.pl b/scripts/namespace.pl
deleted file mode 100755
index 1da7bca201a4..000000000000
--- a/scripts/namespace.pl
+++ /dev/null
@@ -1,473 +0,0 @@
-#!/usr/bin/env perl
-#
-#	namespace.pl.  Mon Aug 30 2004
-#
-#	Perform a name space analysis on the linux kernel.
-#
-#	Copyright Keith Owens <kaos@ocs.com.au>.  GPL.
-#
-#	Invoke by changing directory to the top of the kernel object
-#	tree then namespace.pl, no parameters.
-#
-#	Tuned for 2.1.x kernels with the new module handling, it will
-#	work with 2.0 kernels as well.
-#
-#	Last change 2.6.9-rc1, adding support for separate source and object
-#	trees.
-#
-#	The source must be compiled/assembled first, the object files
-#	are the primary input to this script.  Incomplete or missing
-#	objects will result in a flawed analysis.  Compile both vmlinux
-#	and modules.
-#
-#	Even with complete objects, treat the result of the analysis
-#	with caution.  Some external references are only used by
-#	certain architectures, others with certain combinations of
-#	configuration parameters.  Ideally the source should include
-#	something like
-#
-#	#ifndef CONFIG_...
-#	static
-#	#endif
-#	symbol_definition;
-#
-#	so the symbols are defined as static unless a particular
-#	CONFIG_... requires it to be external.
-#
-#	A symbol that is suffixed with '(export only)' has these properties
-#
-#	* It is global.
-#	* It is marked EXPORT_SYMBOL or EXPORT_SYMBOL_GPL, either in the same
-#	  source file or a different source file.
-#	* Given the current .config, nothing uses the symbol.
-#
-#	The symbol is a candidate for conversion to static, plus removal of the
-#	export.  But be careful that a different .config might use the symbol.
-#
-#
-#	Name space analysis and cleanup is an iterative process.  You cannot
-#	expect to find all the problems in a single pass.
-#
-#	* Identify possibly unnecessary global declarations, verify that they
-#	  really are unnecessary and change them to static.
-#	* Compile and fix up gcc warnings about static, removing dead symbols
-#	  as necessary.
-#	* make clean and rebuild with different configs (especially
-#	  CONFIG_MODULES=n) to see which symbols are being defined when the
-#	  config does not require them.  These symbols bloat the kernel object
-#	  for no good reason, which is frustrating for embedded systems.
-#	* Wrap config sensitive symbols in #ifdef CONFIG_foo, as long as the
-#	  code does not get too ugly.
-#	* Repeat the name space analysis until you can live with with the
-#	  result.
-#
-
-use warnings;
-use strict;
-use File::Find;
-use File::Spec;
-
-my $nm = ($ENV{'NM'} || "nm") . " -p";
-my $objdump = ($ENV{'OBJDUMP'} || "objdump") . " -s -j .comment";
-my $srctree = File::Spec->curdir();
-my $objtree = File::Spec->curdir();
-$srctree = File::Spec->rel2abs($ENV{'srctree'}) if (exists($ENV{'srctree'}));
-$objtree = File::Spec->rel2abs($ENV{'objtree'}) if (exists($ENV{'objtree'}));
-
-if ($#ARGV != -1) {
-	print STDERR "usage: $0 takes no parameters\n";
-	die("giving up\n");
-}
-
-my %nmdata = ();	# nm data for each object
-my %def = ();		# all definitions for each name
-my %ksymtab = ();	# names that appear in __ksymtab_
-my %ref = ();		# $ref{$name} exists if there is a true external reference to $name
-my %export = ();	# $export{$name} exists if there is an EXPORT_... of $name
-
-my %nmexception = (
-    'fs/ext3/bitmap'			=> 1,
-    'fs/ext4/bitmap'			=> 1,
-    'arch/x86/lib/thunk_32'		=> 1,
-    'arch/x86/lib/cmpxchg'		=> 1,
-    'arch/x86/vdso/vdso32/note'		=> 1,
-    'lib/irq_regs'			=> 1,
-    'usr/initramfs_data'		=> 1,
-    'drivers/scsi/aic94xx/aic94xx_dump'	=> 1,
-    'drivers/scsi/libsas/sas_dump'	=> 1,
-    'lib/dec_and_lock'			=> 1,
-    'drivers/ide/ide-probe-mini'	=> 1,
-    'usr/initramfs_data'		=> 1,
-    'drivers/acpi/acpia/exdump'		=> 1,
-    'drivers/acpi/acpia/rsdump'		=> 1,
-    'drivers/acpi/acpia/nsdumpdv'	=> 1,
-    'drivers/acpi/acpia/nsdump'		=> 1,
-    'arch/ia64/sn/kernel/sn2/io'	=> 1,
-    'arch/ia64/kernel/gate-data'	=> 1,
-    'security/capability'		=> 1,
-    'fs/ntfs/sysctl'			=> 1,
-    'fs/jfs/jfs_debug'			=> 1,
-);
-
-my %nameexception = (
-    'mod_use_count_'	 => 1,
-    '__initramfs_end'	=> 1,
-    '__initramfs_start'	=> 1,
-    '_einittext'	=> 1,
-    '_sinittext'	=> 1,
-    'kallsyms_names'	=> 1,
-    'kallsyms_num_syms'	=> 1,
-    'kallsyms_addresses'=> 1,
-    'kallsyms_offsets'	=> 1,
-    'kallsyms_relative_base'=> 1,
-    '__this_module'	=> 1,
-    '_etext'		=> 1,
-    '_edata'		=> 1,
-    '_end'		=> 1,
-    '__bss_start'	=> 1,
-    '_text'		=> 1,
-    '_stext'		=> 1,
-    '__gp'		=> 1,
-    'ia64_unw_start'	=> 1,
-    'ia64_unw_end'	=> 1,
-    '__init_begin'	=> 1,
-    '__init_end'	=> 1,
-    '__bss_stop'	=> 1,
-    '__nosave_begin'	=> 1,
-    '__nosave_end'	=> 1,
-    'pg0'		=> 1,
-    'vdso_enabled'	=> 1,
-    '__stack_chk_fail'  => 1,
-    'VDSO32_PRELINK'	=> 1,
-    'VDSO32_vsyscall'	=> 1,
-    'VDSO32_rt_sigreturn'=>1,
-    'VDSO32_sigreturn'	=> 1,
-);
-
-
-&find(\&linux_objects, '.');	# find the objects and do_nm on them
-&list_multiply_defined();
-&resolve_external_references();
-&list_extra_externals();
-
-exit(0);
-
-sub linux_objects
-{
-	# Select objects, ignoring objects which are only created by
-	# merging other objects.  Also ignore all of modules, scripts
-	# and compressed.  Most conglomerate objects are handled by do_nm,
-	# this list only contains the special cases.  These include objects
-	# that are linked from just one other object and objects for which
-	# there is really no permanent source file.
-	my $basename = $_;
-	$_ = $File::Find::name;
-	s:^\./::;
-	if (/.*\.o$/ &&
-		! (
-		m:/built-in.a$:
-		|| m:arch/x86/vdso/:
-		|| m:arch/x86/boot/:
-		|| m:arch/ia64/ia32/ia32.o$:
-		|| m:arch/ia64/kernel/gate-syms.o$:
-		|| m:arch/ia64/lib/__divdi3.o$:
-		|| m:arch/ia64/lib/__divsi3.o$:
-		|| m:arch/ia64/lib/__moddi3.o$:
-		|| m:arch/ia64/lib/__modsi3.o$:
-		|| m:arch/ia64/lib/__udivdi3.o$:
-		|| m:arch/ia64/lib/__udivsi3.o$:
-		|| m:arch/ia64/lib/__umoddi3.o$:
-		|| m:arch/ia64/lib/__umodsi3.o$:
-		|| m:arch/ia64/scripts/check_gas_for_hint.o$:
-		|| m:arch/ia64/sn/kernel/xp.o$:
-		|| m:boot/bbootsect.o$:
-		|| m:boot/bsetup.o$:
-		|| m:/bootsect.o$:
-		|| m:/boot/setup.o$:
-		|| m:/compressed/:
-		|| m:drivers/cdrom/driver.o$:
-		|| m:drivers/char/drm/tdfx_drv.o$:
-		|| m:drivers/ide/ide-detect.o$:
-		|| m:drivers/ide/pci/idedriver-pci.o$:
-		|| m:drivers/media/media.o$:
-		|| m:drivers/scsi/sd_mod.o$:
-		|| m:drivers/video/video.o$:
-		|| m:fs/devpts/devpts.o$:
-		|| m:fs/exportfs/exportfs.o$:
-		|| m:fs/hugetlbfs/hugetlbfs.o$:
-		|| m:fs/msdos/msdos.o$:
-		|| m:fs/nls/nls.o$:
-		|| m:fs/ramfs/ramfs.o$:
-		|| m:fs/romfs/romfs.o$:
-		|| m:fs/vfat/vfat.o$:
-		|| m:init/mounts.o$:
-		|| m:^modules/:
-		|| m:net/netlink/netlink.o$:
-		|| m:net/sched/sched.o$:
-		|| m:/piggy.o$:
-		|| m:^scripts/:
-		|| m:sound/.*/snd-:
-		|| m:^.*/\.tmp_:
-		|| m:^\.tmp_:
-		|| m:/vmlinux-obj.o$:
-		|| m:^tools/:
-		)
-	) {
-		do_nm($basename, $_);
-	}
-	$_ = $basename;		# File::Find expects $_ untouched (undocumented)
-}
-
-sub do_nm
-{
-	my ($basename, $fullname) = @_;
-	my ($source, $type, $name);
-	if (! -e $basename) {
-		printf STDERR "$basename does not exist\n";
-		return;
-	}
-	if ($fullname !~ /\.o$/) {
-		printf STDERR "$fullname is not an object file\n";
-		return;
-	}
-	($source = $basename) =~ s/\.o$//;
-	if (-e "$source.c" || -e "$source.S") {
-		$source = File::Spec->catfile($objtree, $File::Find::dir, $source)
-	} else {
-		$source = File::Spec->catfile($srctree, $File::Find::dir, $source)
-	}
-	if (! -e "$source.c" && ! -e "$source.S") {
-		# No obvious source, exclude the object if it is conglomerate
-	        open(my $objdumpdata, "$objdump $basename|")
-		    or die "$objdump $fullname failed $!\n";
-
-		my $comment;
-		while (<$objdumpdata>) {
-			chomp();
-			if (/^In archive/) {
-				# Archives are always conglomerate
-				$comment = "GCC:GCC:";
-				last;
-			}
-			next if (! /^[ 0-9a-f]{5,} /);
-			$comment .= substr($_, 43);
-		}
-		close($objdumpdata);
-
-		if (!defined($comment) || $comment !~ /GCC\:.*GCC\:/m) {
-			printf STDERR "No source file found for $fullname\n";
-		}
-		return;
-	}
-	open (my $nmdata, "$nm $basename|")
-	    or die "$nm $fullname failed $!\n";
-
-	my @nmdata;
-	while (<$nmdata>) {
-		chop;
-		($type, $name) = (split(/ +/, $_, 3))[1..2];
-		# Expected types
-		# A absolute symbol
-		# B weak external reference to data that has been resolved
-		# C global variable, uninitialised
-		# D global variable, initialised
-		# G global variable, initialised, small data section
-		# R global array, initialised
-		# S global variable, uninitialised, small bss
-		# T global label/procedure
-		# U external reference
-		# W weak external reference to text that has been resolved
-		# V similar to W, but the value of the weak symbol becomes zero with no error.
-		# a assembler equate
-		# b static variable, uninitialised
-		# d static variable, initialised
-		# g static variable, initialised, small data section
-		# r static array, initialised
-		# s static variable, uninitialised, small bss
-		# t static label/procedures
-		# w weak external reference to text that has not been resolved
-		# v similar to w
-		# ? undefined type, used a lot by modules
-		if ($type !~ /^[ABCDGRSTUWVabdgrstwv?]$/) {
-			printf STDERR "nm output for $fullname contains unknown type '$_'\n";
-		}
-		elsif ($name =~ /\./) {
-			# name with '.' is local static
-		}
-		else {
-			$type = 'R' if ($type eq '?');	# binutils replaced ? with R at one point
-			# binutils keeps changing the type for exported symbols, force it to R
-			$type = 'R' if ($name =~ /^__ksymtab/ || $name =~ /^__kstrtab/);
-			$name =~ s/_R[a-f0-9]{8}$//;	# module versions adds this
-			if ($type =~ /[ABCDGRSTWV]/ &&
-				$name ne 'init_module' &&
-				$name ne 'cleanup_module' &&
-				$name ne 'Using_Versions' &&
-				$name !~ /^Version_[0-9]+$/ &&
-				$name !~ /^__parm_/ &&
-				$name !~ /^__kstrtab/ &&
-				$name !~ /^__ksymtab/ &&
-				$name !~ /^__kcrctab_/ &&
-				$name !~ /^__exitcall_/ &&
-				$name !~ /^__initcall_/ &&
-				$name !~ /^__kdb_initcall_/ &&
-				$name !~ /^__kdb_exitcall_/ &&
-				$name !~ /^__module_/ &&
-				$name !~ /^__mod_/ &&
-				$name !~ /^__crc_/ &&
-				$name ne '__this_module' &&
-				$name ne 'kernel_version') {
-				if (!exists($def{$name})) {
-					$def{$name} = [];
-				}
-				push(@{$def{$name}}, $fullname);
-			}
-			push(@nmdata, "$type $name");
-			if ($name =~ /^__ksymtab_/) {
-				$name = substr($name, 10);
-				if (!exists($ksymtab{$name})) {
-					$ksymtab{$name} = [];
-				}
-				push(@{$ksymtab{$name}}, $fullname);
-			}
-		}
-	}
-	close($nmdata);
-
-	if ($#nmdata < 0) {
-	    printf "No nm data for $fullname\n"
-		unless $nmexception{$fullname};
-	    return;
-	}
-	$nmdata{$fullname} = \@nmdata;
-}
-
-sub drop_def
-{
-	my ($object, $name) = @_;
-	my $nmdata = $nmdata{$object};
-	my ($i, $j);
-	for ($i = 0; $i <= $#{$nmdata}; ++$i) {
-		if ($name eq (split(' ', $nmdata->[$i], 2))[1]) {
-			splice(@{$nmdata{$object}}, $i, 1);
-			my $def = $def{$name};
-			for ($j = 0; $j < $#{$def{$name}}; ++$j) {
-				if ($def{$name}[$j] eq $object) {
-					splice(@{$def{$name}}, $j, 1);
-				}
-			}
-			last;
-		}
-	}
-}
-
-sub list_multiply_defined
-{
-	foreach my $name (keys(%def)) {
-		if ($#{$def{$name}} > 0) {
-			# Special case for cond_syscall
-			if ($#{$def{$name}} == 1 &&
-			   ($name =~ /^sys_/ || $name =~ /^compat_sys_/ ||
-			    $name =~ /^sys32_/)) {
-				if($def{$name}[0] eq "kernel/sys_ni.o" ||
-				   $def{$name}[1] eq "kernel/sys_ni.o") {
-					&drop_def("kernel/sys_ni.o", $name);
-					next;
-				}
-			}
-
-			printf "$name is multiply defined in :-\n";
-			foreach my $module (@{$def{$name}}) {
-				printf "\t$module\n";
-			}
-		}
-	}
-}
-
-sub resolve_external_references
-{
-	my ($kstrtab, $ksymtab, $export);
-
-	printf "\n";
-	foreach my $object (keys(%nmdata)) {
-		my $nmdata = $nmdata{$object};
-		for (my $i = 0; $i <= $#{$nmdata}; ++$i) {
-			my ($type, $name) = split(' ', $nmdata->[$i], 2);
-			if ($type eq "U" || $type eq "w") {
-				if (exists($def{$name}) || exists($ksymtab{$name})) {
-					# add the owning object to the nmdata
-					$nmdata->[$i] = "$type $name $object";
-					# only count as a reference if it is not EXPORT_...
-					$kstrtab = "R __kstrtab_$name";
-					$ksymtab = "R __ksymtab_$name";
-					$export = 0;
-					for (my $j = 0; $j <= $#{$nmdata}; ++$j) {
-						if ($nmdata->[$j] eq $kstrtab ||
-						    $nmdata->[$j] eq $ksymtab) {
-							$export = 1;
-							last;
-						}
-					}
-					if ($export) {
-						$export{$name} = "";
-					}
-					else {
-						$ref{$name} = ""
-					}
-				}
-				elsif ( ! $nameexception{$name}
-					&& $name !~ /^__sched_text_/
-					&& $name !~ /^__start_/
-					&& $name !~ /^__end_/
-					&& $name !~ /^__stop_/
-					&& $name !~ /^__scheduling_functions_.*_here/
-					&& $name !~ /^__.*initcall_/
-					&& $name !~ /^__.*per_cpu_start/
-					&& $name !~ /^__.*per_cpu_end/
-					&& $name !~ /^__alt_instructions/
-					&& $name !~ /^__setup_/
-					&& $name !~ /^__mod_timer/
-					&& $name !~ /^__mod_page_state/
-					&& $name !~ /^init_module/
-					&& $name !~ /^cleanup_module/
-				) {
-					printf "Cannot resolve ";
-					printf "weak " if ($type eq "w");
-					printf "reference to $name from $object\n";
-				}
-			}
-		}
-	}
-}
-
-sub list_extra_externals
-{
-	my %noref = ();
-
-	foreach my $name (keys(%def)) {
-		if (! exists($ref{$name})) {
-			my @module = @{$def{$name}};
-			foreach my $module (@module) {
-				if (! exists($noref{$module})) {
-					$noref{$module} = [];
-				}
-				push(@{$noref{$module}}, $name);
-			}
-		}
-	}
-	if (%noref) {
-		printf "\nExternally defined symbols with no external references\n";
-		foreach my $module (sort(keys(%noref))) {
-			printf "  $module\n";
-			foreach (sort(@{$noref{$module}})) {
-			    my $export;
-			    if (exists($export{$_})) {
-				$export = " (export only)";
-			    } else {
-				$export = "";
-			    }
-			    printf "    $_$export\n";
-			}
-		}
-	}
-}
-- 
cgit v1.2.3


From 172aad81a882443eefe1bd860c4eddc81b14dd5b Mon Sep 17 00:00:00 2001
From: Olaf Hering <olaf@aepfle.de>
Date: Sun, 11 Oct 2020 20:54:31 +0200
Subject: kbuild: enforce -Werror=return-type

Catch errors which at least gcc tolerates by default:
 warning: 'return' with no value, in function returning non-void [-Wreturn-type]

Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index ddadab2f2e8b..b76c4122c967 100644
--- a/Makefile
+++ b/Makefile
@@ -497,7 +497,7 @@ KBUILD_AFLAGS   := -D__ASSEMBLY__ -fno-PIE
 KBUILD_CFLAGS   := -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs \
 		   -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE \
 		   -Werror=implicit-function-declaration -Werror=implicit-int \
-		   -Wno-format-security \
+		   -Werror=return-type -Wno-format-security \
 		   -std=gnu89
 KBUILD_CPPFLAGS := -D__KERNEL__
 KBUILD_AFLAGS_KERNEL :=
-- 
cgit v1.2.3


From bac977cbc0d6731fb8e67c2be0e4acbd959e10b3 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Wed, 14 Oct 2020 03:38:19 +0900
Subject: kbuild: deb-pkg: do not build linux-headers package if
 CONFIG_MODULES=n
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Since commit 269a535ca931 ("modpost: generate vmlinux.symvers and
reuse it for the second modpost"), with CONFIG_MODULES disabled,
"make deb-pkg" (or "make bindeb-pkg") fails with:

  find: ‘Module.symvers’: No such file or directory

If CONFIG_MODULES is disabled, it doesn't really make sense to build
the linux-headers package.

Fixes: 269a535ca931 ("modpost: generate vmlinux.symvers and reuse it for the second modpost")
Reported-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/package/builddeb |  6 ++++--
 scripts/package/mkdebian | 19 ++++++++++++-------
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/scripts/package/builddeb b/scripts/package/builddeb
index 6474084c32a4..1b11f8993629 100755
--- a/scripts/package/builddeb
+++ b/scripts/package/builddeb
@@ -207,8 +207,10 @@ EOF
 done
 
 if [ "$ARCH" != "um" ]; then
-	deploy_kernel_headers debian/linux-headers
-	create_package linux-headers-$version debian/linux-headers
+	if is_enabled CONFIG_MODULES; then
+		deploy_kernel_headers debian/linux-headers
+		create_package linux-headers-$version debian/linux-headers
+	fi
 
 	deploy_libc_headers debian/linux-libc-dev
 	create_package linux-libc-dev debian/linux-libc-dev
diff --git a/scripts/package/mkdebian b/scripts/package/mkdebian
index 3a13b834f281..273fd6ed790e 100755
--- a/scripts/package/mkdebian
+++ b/scripts/package/mkdebian
@@ -184,13 +184,6 @@ Description: Linux kernel, version $version
  This package contains the Linux kernel, modules and corresponding other
  files, version: $version.
 
-Package: $kernel_headers_packagename
-Architecture: $debarch
-Description: Linux kernel headers for $version on $debarch
- This package provides kernel header files for $version on $debarch
- .
- This is useful for people who need to build external modules
-
 Package: linux-libc-dev
 Section: devel
 Provides: linux-kernel-headers
@@ -201,6 +194,18 @@ Description: Linux support headers for userspace development
 Multi-Arch: same
 EOF
 
+if is_enabled CONFIG_MODULES; then
+cat <<EOF >> debian/control
+
+Package: $kernel_headers_packagename
+Architecture: $debarch
+Description: Linux kernel headers for $version on $debarch
+ This package provides kernel header files for $version on $debarch
+ .
+ This is useful for people who need to build external modules
+EOF
+fi
+
 if is_enabled CONFIG_DEBUG_INFO; then
 cat <<EOF >> debian/control
 
-- 
cgit v1.2.3


From 0fa21cf4489fe11737d56f8056dda1ba0257bd8d Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <masahiroy@kernel.org>
Date: Wed, 14 Oct 2020 03:38:20 +0900
Subject: kbuild: deb-pkg: clean up package name variables

Hard-code the names of linux-headers and debug packages in the
control file.

The kernel package is different for ARCH=um. Change the code
for better readability.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/package/mkdebian | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/scripts/package/mkdebian b/scripts/package/mkdebian
index 273fd6ed790e..60a2a63a5e90 100755
--- a/scripts/package/mkdebian
+++ b/scripts/package/mkdebian
@@ -94,16 +94,16 @@ else
 	packageversion=$version-$revision
 fi
 sourcename=$KDEB_SOURCENAME
-packagename=linux-image-$version
-kernel_headers_packagename=linux-headers-$version
-dbg_packagename=$packagename-dbg
-debarch=
-set_debarch
 
 if [ "$ARCH" = "um" ] ; then
-	packagename=user-mode-linux-$version
+	packagename=user-mode-linux
+else
+	packagename=linux-image
 fi
 
+debarch=
+set_debarch
+
 email=${DEBEMAIL-$EMAIL}
 
 # use email string directly if it contains <email>
@@ -178,7 +178,7 @@ Rules-Requires-Root: no
 Build-Depends: bc, rsync, kmod, cpio, bison, flex | flex:native $extra_build_depends
 Homepage: https://www.kernel.org/
 
-Package: $packagename
+Package: $packagename-$version
 Architecture: $debarch
 Description: Linux kernel, version $version
  This package contains the Linux kernel, modules and corresponding other
@@ -197,7 +197,7 @@ EOF
 if is_enabled CONFIG_MODULES; then
 cat <<EOF >> debian/control
 
-Package: $kernel_headers_packagename
+Package: linux-headers-$version
 Architecture: $debarch
 Description: Linux kernel headers for $version on $debarch
  This package provides kernel header files for $version on $debarch
@@ -209,7 +209,7 @@ fi
 if is_enabled CONFIG_DEBUG_INFO; then
 cat <<EOF >> debian/control
 
-Package: $dbg_packagename
+Package: linux-image-$version-dbg
 Section: debug
 Architecture: $debarch
 Description: Linux kernel debugging symbols for $version
-- 
cgit v1.2.3


From 0f6372e522237f39aff63f2e158d629038f26238 Mon Sep 17 00:00:00 2001
From: Sami Tolvanen <samitolvanen@google.com>
Date: Mon, 12 Oct 2020 17:31:45 -0700
Subject: treewide: remove DISABLE_LTO

This change removes all instances of DISABLE_LTO from
Makefiles, as they are currently unused, and the preferred
method of disabling LTO is to filter out the flags instead.

Note added by Masahiro Yamada:
DISABLE_LTO was added as preparation for GCC LTO, but GCC LTO was
not pulled into the mainline. (https://lkml.org/lkml/2014/4/8/272)

Suggested-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 arch/arm64/kernel/vdso/Makefile | 1 -
 arch/sparc/vdso/Makefile        | 2 --
 arch/x86/entry/vdso/Makefile    | 2 --
 kernel/Makefile                 | 3 ---
 scripts/Makefile.build          | 2 +-
 5 files changed, 1 insertion(+), 9 deletions(-)

diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index 3dc4b65da99d..ce2bb6270a4e 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -31,7 +31,6 @@ ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18
 ccflags-y += -DDISABLE_BRANCH_PROFILING
 
 CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS) $(GCC_PLUGINS_CFLAGS)
-KBUILD_CFLAGS			+= $(DISABLE_LTO)
 KASAN_SANITIZE			:= n
 UBSAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
diff --git a/arch/sparc/vdso/Makefile b/arch/sparc/vdso/Makefile
index 469dd23887ab..c5e1545bc5cf 100644
--- a/arch/sparc/vdso/Makefile
+++ b/arch/sparc/vdso/Makefile
@@ -3,8 +3,6 @@
 # Building vDSO images for sparc.
 #
 
-KBUILD_CFLAGS += $(DISABLE_LTO)
-
 VDSO64-$(CONFIG_SPARC64)	:= y
 VDSOCOMPAT-$(CONFIG_COMPAT)	:= y
 
diff --git a/arch/x86/entry/vdso/Makefile b/arch/x86/entry/vdso/Makefile
index ebba25ed9a38..21243747965d 100644
--- a/arch/x86/entry/vdso/Makefile
+++ b/arch/x86/entry/vdso/Makefile
@@ -9,8 +9,6 @@ ARCH_REL_TYPE_ABS := R_X86_64_JUMP_SLOT|R_X86_64_GLOB_DAT|R_X86_64_RELATIVE|
 ARCH_REL_TYPE_ABS += R_386_GLOB_DAT|R_386_JMP_SLOT|R_386_RELATIVE
 include $(srctree)/lib/vdso/Makefile
 
-KBUILD_CFLAGS += $(DISABLE_LTO)
-
 # Sanitizer runtimes are unavailable and cannot be linked here.
 KASAN_SANITIZE			:= n
 UBSAN_SANITIZE			:= n
diff --git a/kernel/Makefile b/kernel/Makefile
index 9a20016d4900..347254f07dab 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -38,9 +38,6 @@ KASAN_SANITIZE_kcov.o := n
 KCSAN_SANITIZE_kcov.o := n
 CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack) -fno-stack-protector
 
-# cond_syscall is currently not LTO compatible
-CFLAGS_sys_ni.o = $(DISABLE_LTO)
-
 obj-y += sched/
 obj-y += locking/
 obj-y += power/
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index a467b9323442..ae647379b579 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -111,7 +111,7 @@ endif
 # ---------------------------------------------------------------------------
 
 quiet_cmd_cc_s_c = CC $(quiet_modtag)  $@
-      cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) $(DISABLE_LTO) -fverbose-asm -S -o $@ $<
+      cmd_cc_s_c = $(CC) $(filter-out $(DEBUG_CFLAGS), $(c_flags)) -fverbose-asm -S -o $@ $<
 
 $(obj)/%.s: $(src)/%.c FORCE
 	$(call if_changed_dep,cc_s_c)
-- 
cgit v1.2.3


From 8402ee182c417a32d5e5a702f2fa2b01e76dc220 Mon Sep 17 00:00:00 2001
From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Date: Fri, 16 Oct 2020 14:58:46 +0200
Subject: kbuild: remove leftover comment for filechk utility

After commit 43fee2b23895 ("kbuild: do not redirect the first
prerequisite for filechk"), the rule is no longer automatically passed
$< as stdin, so remove the stale comment.

Fixes: 43fee2b23895 ("kbuild: do not redirect the first prerequisite for filechk")
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/Kbuild.include | 2 --
 1 file changed, 2 deletions(-)

diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include
index 83a1637417e5..08e011175b4c 100644
--- a/scripts/Kbuild.include
+++ b/scripts/Kbuild.include
@@ -56,8 +56,6 @@ kecho := $($(quiet)kecho)
 # - If no file exist it is created
 # - If the content differ the new file is used
 # - If they are equal no change, and no timestamp update
-# - stdin is piped in from the first prerequisite ($<) so one has
-#   to specify a valid file as first prerequisite (often the kbuild file)
 define filechk
 	$(Q)set -e;						\
 	mkdir -p $(dir $@);					\
-- 
cgit v1.2.3


From 121c5d08d53cb1f95d9881838523b0305c3f3bef Mon Sep 17 00:00:00 2001
From: Mark Wielaard <mark@klomp.org>
Date: Sat, 17 Oct 2020 14:01:35 +0200
Subject: kbuild: Only add -fno-var-tracking-assignments for old GCC versions

Some old GCC versions between 4.5.0 and 4.9.1 might miscompile code
with -fvar-tracking-assingments (which is enabled by default with -g -O2).
Commit 2062afb4f804 ("Fix gcc-4.9.0 miscompilation of load_balance()
in scheduler") added -fno-var-tracking-assignments unconditionally to
work around this. But newer versions of GCC no longer have this bug, so
only add it for versions of GCC before 5.0. This allows various tools
such as a perf probe or gdb debuggers or systemtap to resolve variable
locations using dwarf locations in more code.

Signed-off-by: Mark Wielaard <mark@klomp.org>
Acked-by: Ian Rogers <irogers@google.com>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 Makefile | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Makefile b/Makefile
index b76c4122c967..17a62e365a38 100644
--- a/Makefile
+++ b/Makefile
@@ -814,7 +814,11 @@ KBUILD_CFLAGS	+= -ftrivial-auto-var-init=zero
 KBUILD_CFLAGS	+= -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
 endif
 
-DEBUG_CFLAGS	:= $(call cc-option, -fno-var-tracking-assignments)
+# Workaround for GCC versions < 5.0
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61801
+ifdef CONFIG_CC_IS_GCC
+DEBUG_CFLAGS	:= $(call cc-ifversion, -lt, 0500, $(call cc-option, -fno-var-tracking-assignments))
+endif
 
 ifdef CONFIG_DEBUG_INFO
 
-- 
cgit v1.2.3


From 1e66d50ad3a1dbf0169b14d502be59a4b1213149 Mon Sep 17 00:00:00 2001
From: Chris Down <chris@chrisdown.name>
Date: Tue, 20 Oct 2020 10:34:59 +0100
Subject: kbuild: Use uname for LINUX_COMPILE_HOST detection

`hostname` may not be present on some systems as it's not mandated by
POSIX/SUSv4. This isn't just a theoretical problem: on Arch Linux,
`hostname` is provided by `inetutils`, which isn't part of the base
distribution.

    ./scripts/mkcompile_h: line 38: hostname: command not found

Use `uname -n` instead, which is more likely to be available (and
mandated by standards).

Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
---
 scripts/mkcompile_h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/mkcompile_h b/scripts/mkcompile_h
index baf3ab8d9d49..4ae735039daf 100755
--- a/scripts/mkcompile_h
+++ b/scripts/mkcompile_h
@@ -35,7 +35,7 @@ else
 	LINUX_COMPILE_BY=$KBUILD_BUILD_USER
 fi
 if test -z "$KBUILD_BUILD_HOST"; then
-	LINUX_COMPILE_HOST=`hostname`
+	LINUX_COMPILE_HOST=`uname -n`
 else
 	LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
 fi
-- 
cgit v1.2.3