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2020-06-06modpost: avoid false-positive file open errorMasahiro Yamada1-4/+3
One problem of grab_file() is that it cannot distinguish the following two cases: - It cannot read the file (the file does not exist, or read permission is not set) - It can read the file, but the file size is zero This is because grab_file() calls mmap(), which requires the mapped length is greater than 0. Hence, grab_file() fails for both cases. If an empty header file were included for checksum calculation, the following warning would be printed: WARNING: modpost: could not open ...: Invalid argument An empty file is a valid source file, so it should not fail. Use read_text_file() instead. It can read a zero-length file. Then, parse_file() will succeed with doing nothing. Going forward, the first case (it cannot read the file) is a fatal error. If the source file from which an object was compiled is missing, something went wrong. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: fix potential mmap'ed file overrun in get_src_version()Masahiro Yamada1-17/+11
I do not know how reliably this function works, but it looks dangerous to me. strchr(sources, '\n'); ... continues searching until it finds '\n' or it reaches the '\0' terminator. In other words, 'sources' should be a null-terminated string. However, grab_file() just mmaps a file, so 'sources' is not terminated with null byte. If the file does not contain '\n' at all, strchr() will go beyond the mmap'ed memory. Use read_text_file(), which loads the file content into a malloc'ed buffer, appending null byte. Here we are interested only in the first line of *.mod files. Use get_line() helper to get the first line. This also makes missing *.mod file a fatal error. Commit 4be40e22233c ("kbuild: do not emit src version warning for non-modules") ignored missing *.mod files. I do not fully understand what that commit addressed, but commit 91341d4b2c19 ("kbuild: introduce new option to enhance section mismatch analysis") introduced partial section checks by using modpost. built-in.o was parsed by modpost. Even modules had a problem because *.mod files were created after the modpost check. Commit b7dca6dd1e59 ("kbuild: create *.mod with full directory path and remove MODVERDIR") stopped doing that. Now that modpost is only invoked after the directory descend, *.mod files should always exist at the modpost stage. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: add read_text_file() and get_line() helpersMasahiro Yamada2-0/+51
modpost uses grab_file() to open a file, but it is not suitable for a text file because the mmap'ed file is not terminated by null byte. Actually, I see some issues for the use of grab_file(). The new helper, read_text_file() loads the whole file content into a malloc'ed buffer, and appends a null byte. Then, get_line() reads each line. To handle text files, I intend to replace as follows: grab_file() -> read_text_file() get_new_line() -> get_line() Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: do not call get_modinfo() for vmlinux(.o)Masahiro Yamada1-21/+24
The three calls of get_modinfo() ("license", "import_ns", "version") always return NULL for vmlinux(.o) because the built-in module info is prefixed with __MODULE_INFO_PREFIX. It is harmless to call get_modinfo(), but there is no point to search for what apparently does not exist. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: drop RCS/CVS $Revision handling in MODULE_VERSION()Masahiro Yamada3-73/+0
As far as I understood, this code gets rid of '$Revision$' or '$Revision:' of CVS, RCS or whatever in MODULE_VERSION() tags. Remove the primeval code. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: show warning if any of symbol dump files is missingMasahiro Yamada2-10/+5
If modpost fails to load a symbol dump file, it cannot check unresolved symbols, hence module dependency will not be added. Nor CRCs can be added. Currently, external module builds check only $(objtree)/Module.symvers, but it should check files specified by KBUILD_EXTRA_SYMBOLS as well. Move the warning message from the top Makefile to scripts/Makefile.modpost and print the warning if any dump file is missing. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: show warning if vmlinux is not found when processing modulesMasahiro Yamada1-2/+7
check_exports() does not print warnings about unresolved symbols if vmlinux is missing because there would be too many. This situation happens when you do 'make modules' from the clean tree, or compile external modules against a kernel tree that has not been completely built. It is dangerous to not check unresolved symbols because you might be building useless modules. At least it should be warned. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: invoke modpost only when input files are updatedMasahiro Yamada2-15/+37
Currently, the second pass of modpost is always invoked when you run 'make' or 'make modules' even if none of modules is changed. Use if_changed to invoke it only when it is necessary. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: generate vmlinux.symvers and reuse it for the second modpostMasahiro Yamada5-6/+7
The full build runs modpost twice, first for vmlinux.o and second for modules. The first pass dumps all the vmlinux symbols into Module.symvers, but the second pass parses vmlinux again instead of reusing the dump file, presumably because it needs to avoid accumulating stale symbols. Loading symbol info from a dump file is faster than parsing an ELF object. Besides, modpost deals with various issues to parse vmlinux in the second pass. A solution is to make the first pass dumps symbols into a separate file, vmlinux.symvers. The second pass reads it, and parses module .o files. The merged symbol information is dumped into Module.symvers in the same way as before. This makes further modpost cleanups possible. Also, it fixes the problem of 'make vmlinux', which previously overwrote Module.symvers, throwing away module symbols. I slightly touched scripts/link-vmlinux.sh so that vmlinux is re-linked when you cross this commit. Otherwise, vmlinux.symvers would not be generated. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: refactor -i option calculationMasahiro Yamada1-4/+2
Prepare to use -i for in-tree modpost as well. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: print symbol dump file as the build target in short logMasahiro Yamada1-13/+20
The symbol dump *.symvers is the output of modpost. Print it in the short log. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: re-add -e to set external_module flagMasahiro Yamada2-2/+8
Previously, the -i option had two functions; load a symbol dump file, and set the external_module flag. I want to assign a dedicate option for each of them. Going forward, the -i is used to load a symbol dump file, and the -e to set the external_module flag. With this, we will be able to use -i for loading in-kernel symbols. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: rename ext_sym_list to dump_listMasahiro Yamada1-13/+14
The -i option is used to include Modules.symver as well as files from $(KBUILD_EXTRA_SYMBOLS). Make the struct and variable names more generic. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: allow to pass -i option multiple times to remove -e optionMasahiro Yamada2-9/+2
Now that there is no difference between -i and -e, they can be unified. Make modpost accept the -i option multiple times, then remove -e. I will reuse -e for a different purpose. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-06modpost: track if the symbol origin is a dump file or ELF objectMasahiro Yamada2-10/+6
The meaning of sym->kernel is obscure; it is set for in-kernel symbols loaded from Modules.symvers. This happens only when we are building external modules, and it is used to determine whether to dump symbols to $(KBUILD_EXTMOD)/Modules.symvers It is clearer to remember whether the symbol or module came from a dump file or ELF object. This changes the KBUILD_EXTRA_SYMBOLS behavior. Previously, symbols loaded from KBUILD_EXTRA_SYMBOLS are accumulated into the current $(KBUILD_EXTMOD)/Modules.symvers Going forward, they will be only used to check symbol references, but not dumped into the current $(KBUILD_EXTMOD)/Modules.symvers. I believe this makes more sense. sym->vmlinux will have no user. Remove it too. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-03modpost: load KBUILD_EXTRA_SYMBOLS files in orderMasahiro Yamada1-8/+8
Currently, modpost reads extra symbol dump files in the reverse order. If '-e foo -e bar' is given, modpost reads bar, foo, in this order. This is probably not a big deal, but there is no good reason to reverse the order. Read files in the given order. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-03modpost: pass -N option only for modules modpostMasahiro Yamada1-1/+4
The built-in only code is not required to have MODULE_IMPORT_NS() to use symbols. So, the namespace is not checked for vmlinux(.o). Do not pass the meaningless -N option to the first pass of modpost. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-03modpost: move -T option close to the modpost commandMasahiro Yamada1-2/+2
The '-T -' option reads the file list from stdin. It is clearer to put it close to the piped command. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-03modpost: fix -i (--ignore-errors) MAKEFLAGS detectionMasahiro Yamada1-1/+6
$(filter -i,$(MAKEFLAGS)) works only in limited use-cases. The representation of $(MAKEFLAGS) depends on various factors: - GNU Make version (version 3.8x or version 4.x) - The presence of other flags like -j In my experiments, $(MAKEFLAGS) is expanded as follows: * GNU Make 3.8x: * without -j option: --no-print-directory -Rri * with -j option: --no-print-directory -Rr --jobserver-fds=3,4 -j -i * GNU Make 4.x: * without -j option: irR --no-print-directory * with -j option: irR -j --jobserver-fds=3,4 --no-print-directory For GNU Make 4.x, the flags are grouped as 'irR', which does not work. For the single thread build with GNU Make 3.8x, the flags are grouped as '-Rri', which does not work either. To make it work for all cases, do likewise as commit 6f0fa58e4596 ("kbuild: simplify silent build (-s) detection"). BTW, since commit ff9b45c55b26 ("kbuild: modpost: read modules.order instead of $(MODVERDIR)/*.mod"), you also need to pass -k option to build final *.ko files. 'make -i -k' ignores compile errors in modules, and build as many remaining *.ko as possible. Please note this feature is kind of dangerous if other modules depend on the broken module because the generated modules will lack the correct module dependency or CRC. Honestly, I am not a big fan of it, but I am keeping this feature. Fixes: eed380f3f593 ("modpost: Optionally ignore secondary errors seen if a single module build fails") Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-03kbuild: update modules.order only when contained modules are updatedMasahiro Yamada3-24/+38
Make modules.order depend on $(obj-m), and use if_changed to build it. This will avoid unneeded update of modules.order, which will be useful to optimize the modpost stage. Currently, the second pass of modpost is always invoked. By checking the timestamp of modules.order, we can avoid the unneeded modpost. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-03kbuild: refactor KBUILD_VMLINUX_{OBJS,LIBS} calculationMasahiro Yamada1-9/+8
Do not overwrite core-y or drivers-y. Remove libs-y1 and libs-y2. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-01kbuild: merge net-y and virt-y into drivers-yMasahiro Yamada1-8/+4
This will slightly change the link order; drivers-y from arch Makefile will be linked after virt/built-in.a, but I guess this is not a big deal. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-01kbuild: merge init-y into core-yMasahiro Yamada1-6/+4
No arch Makefile specifies init-y. Merge init-y into core-y. This does not change the link order. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-01kbuild: refactor tagets caluculation for KBUILD_{BUILTIN,KBUILD_MODULES}Masahiro Yamada1-13/+12
Remove lib-target, builtin-target, modorder-target, and modtargets. Instead, add targets-for-builtin and targets-for-modules. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-01kbuild: refactor subdir-ym calculationMasahiro Yamada1-9/+4
Remove the unneeded variables, __subdir-y and __subdir-m. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-01kbuild: merge two 'ifdef CONFIG_TRIM_UNUSED_KSYMS' blocksMasahiro Yamada1-7/+5
This hunk has two 'ifdef CONFIG_TRIM_UNUSED_KSYMS ... endif' blocks with no other code interleaved. Merge them. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-01kbuild: force to build vmlinux if CONFIG_MODVERSION=yMasahiro Yamada1-5/+8
This code does not work as stated in the comment. $(CONFIG_MODVERSIONS) is always empty because it is expanded before include/config/auto.conf is included. Hence, 'make modules' with CONFIG_MODVERSION=y cannot record the version CRCs. This has been broken since 2003, commit ("kbuild: Enable modules to be build using the "make dir/" syntax"). [1] [1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=15c6240cdc44bbeef3c4797ec860f9765ef4f1a7 Cc: linux-stable <stable@vger.kernel.org> # v2.5.71+ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-28Makefile: support compressed debug infoNick Desaulniers2-0/+23
As debug information gets larger and larger, it helps significantly save the size of vmlinux images to compress the information in the debug information sections. Note: this debug info is typically split off from the final compressed kernel image, which is why vmlinux is what's used in conjunction with GDB. Minimizing the debug info size should have no impact on boot times, or final compressed kernel image size. All of the debug sections will have a `C` flag set. $ readelf -S <object file> $ bloaty vmlinux.gcc75.compressed.dwarf4 -- \ vmlinux.gcc75.uncompressed.dwarf4 FILE SIZE VM SIZE -------------- -------------- +0.0% +18 [ = ] 0 [Unmapped] -73.3% -114Ki [ = ] 0 .debug_aranges -76.2% -2.01Mi [ = ] 0 .debug_frame -73.6% -2.89Mi [ = ] 0 .debug_str -80.7% -4.66Mi [ = ] 0 .debug_abbrev -82.9% -4.88Mi [ = ] 0 .debug_ranges -70.5% -9.04Mi [ = ] 0 .debug_line -79.3% -10.9Mi [ = ] 0 .debug_loc -39.5% -88.6Mi [ = ] 0 .debug_info -18.2% -123Mi [ = ] 0 TOTAL $ bloaty vmlinux.clang11.compressed.dwarf4 -- \ vmlinux.clang11.uncompressed.dwarf4 FILE SIZE VM SIZE -------------- -------------- +0.0% +23 [ = ] 0 [Unmapped] -65.6% -871 [ = ] 0 .debug_aranges -77.4% -1.84Mi [ = ] 0 .debug_frame -82.9% -2.33Mi [ = ] 0 .debug_abbrev -73.1% -2.43Mi [ = ] 0 .debug_str -84.8% -3.07Mi [ = ] 0 .debug_ranges -65.9% -8.62Mi [ = ] 0 .debug_line -86.2% -40.0Mi [ = ] 0 .debug_loc -42.0% -64.1Mi [ = ] 0 .debug_info -22.1% -122Mi [ = ] 0 TOTAL For x86_64 defconfig + LLVM=1 (before): Elapsed (wall clock) time (h:mm:ss or m:ss): 3:22.03 Maximum resident set size (kbytes): 43856 For x86_64 defconfig + LLVM=1 (after): Elapsed (wall clock) time (h:mm:ss or m:ss): 3:32.52 Maximum resident set size (kbytes): 1566776 Thanks to: Nick Clifton helped us to provide the minimal binutils version. Sedat Dilek found an increase in size of debug .deb package. Cc: Nick Clifton <nickc@redhat.com> Suggested-by: David Blaikie <blaikie@google.com> Reviewed-by: Fangrui Song <maskray@google.com> Tested-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-28modpost: refactor sech_name()Masahiro Yamada1-12/+11
Use sym_get_data_by_offset() helper to get access to the .shstrtab section data. No functional change is intended because elf->sechdrs[elf->secindex_strings].sh_addr is 0 for both ET_REL and ET_EXEC object types. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-28modpost: fix potential segmentation fault for addend_i386_rel()Masahiro Yamada1-9/+9
This may not be a practical problem, but the second pass of ARCH=i386 modpost causes segmentation fault if the -s option is not passed. MODPOST 12 modules Segmentation fault (core dumped) make[2]: *** [scripts/Makefile.modpost:94: __modpost] Error 139 make[1]: *** [Makefile:1339: modules] Error 2 make[1]: *** Waiting for unfinished jobs.... The segmentation fault occurs when section_rel() is called for vmlinux, which is untested in regular builds. The cause of the problem is reloc_location() returning a wrong pointer for ET_EXEC object type. In this case, you need to subtract sechdr->sh_addr, otherwise it would get access beyond the mmap'ed memory. Add sym_get_data_by_offset() helper to avoid code duplication. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-28kbuild: disallow multi-word in M= or KBUILD_EXTMODMasahiro Yamada2-1/+4
$(firstword ...) in scripts/Makefile.modpost was added by commit 3f3fd3c05585 ("[PATCH] kbuild: allow multi-word $M in Makefile.modpost") to build multiple external module directories. It was a solution to resolve symbol dependencies when an external module depends on another external module. Commit 0d96fb20b7ed ("kbuild: Add new Kbuild variable KBUILD_EXTRA_SYMBOLS") introduced another solution by passing symbol info via KBUILD_EXTRA_SYMBOLS, then broke the multi-word M= support. include $(if $(wildcard $(KBUILD_EXTMOD)/Kbuild), \ $(KBUILD_EXTMOD)/Kbuild, $(KBUILD_EXTMOD)/Makefile) ... does not work if KBUILD_EXTMOD contains multiple words. This feature has been broken for more than a decade. Remove the bitrotten code, and stop parsing if M or KBUILD_EXTMOD contains multiple words. As Documentation/kbuild/modules.rst explains, if your module depends on another one, there are two solutions: - add a common top-level Kbuild file - use KBUILD_EXTRA_SYMBOLS Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: make modules.order rule consistent with built-in.aMasahiro Yamada2-4/+8
built-in.a contains the built-in object paths from the current and sub directories. module.order collects the module paths from the current and sub directories. Make their build rules look more symmetrical. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: rename subdir-obj-y to subdir-builtinMasahiro Yamada1-4/+5
I think subdir-builtin is clearer. While I was here, I made its build rule explicit. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: move subdir-obj-y to scripts/Makefile.buildMasahiro Yamada2-5/+2
Save $(addprefix ...) for subdir-obj-y. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: clear KBUILD_MODULES in top Makefile if CONFIG_MODULES=nMasahiro Yamada2-1/+5
Do not try to build any module-related artifacts when CONFIG_MODULES is disabled. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: remove ifdef builtin-target / lib-targetMasahiro Yamada1-8/+2
I do not see a good reason to add ifdef here. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: doc: remove documentation about copying Module.symvers aroundMasahiro Yamada1-12/+0
This is a left-over of commit 39808e451fdf ("kbuild: do not read $(KBUILD_EXTMOD)/Module.symvers"). Kbuild no longer supports this way. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: make module name conflict fatal errorMasahiro Yamada2-5/+18
I think all the warnings have been fixed by now. Make it a fatal error. Check it before modpost because we need to stop building *.ko files. Also, pass modules.order via a script parameter. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: error out if targets prefixed with '__' are directly runMasahiro Yamada1-10/+13
Some targets are internal-use only. It is tedious to care about "what if __build_one_by_one is contained in $(MAKECMDGOALS)?" etc. Prefix internal targets with double underscores. Stop parsing Makefile if they are directly run. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: add this-makefile as a shorthand for $(lastword $(MAKEFILE_LIST))Masahiro Yamada1-2/+4
Make it clearer, and self-documenting. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25gcc-plugins: remove always-false $(if ...) in MakefileMasahiro Yamada1-1/+1
This is the remnant of commit c17d6179ad5a ("gcc-plugins: remove unused GCC_PLUGIN_SUBDIR"). The conditional $(if $(findstring /,$(p)),...) is always false because none of plugins contains '/' in the file name. Clean up the code. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Kees Cook <keescook@chromium.org>
2020-05-25bpfilter: document build requirements for bpfilter_umhValdis Kl ē tnieks1-0/+4
It's not intuitively obvious that bpfilter_umh is a statically linked binary. Mention the toolchain requirement in the Kconfig help, so people have an easier time figuring out what's needed. Signed-off-by: Valdis Kletnieks <valdis.kletnieks@vt.edu> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25scripts/checkstack.pl: fix arm sp regexManinder Singh1-1/+1
if objdump has below entries; c01ed608 <X>: c01ed614: e24ddff7 sub sp, sp, #120 ; 0x78 c01f0d50 <Y>: c01f0d50: e24dd094 sub sp, sp, #140 ; 0x8c scripts fails to read stack usage. so making regex $re for ARM similar to aarch64 Co-developed-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25scripts/checkstack.pl: add arm push handling for stack usageManinder Singh1-1/+27
To count stack usage of push {*, fp, ip, lr, pc} instruction in ARM, if FRAME POINTER is enabled. e.g. c01f0d48: e92ddff0 push {r4, r5, r6, r7, r8, r9, sl, fp, ip, lr, pc} c01f0d50 <Y>: c01f0d44: e1a0c00d mov ip, sp c01f0d48: e92ddff0 push {r4, r5, r6, r7, r8, r9, sl, fp, ip, lr, pc} c01f0d4c: e24cb004 sub fp, ip, #4 c01f0d50: e24dd094 sub sp, sp, #448 ; 0x1C0 $ cat dump | scripts/checkstack.pl arm 0xc01f0d50 Y []: 448 added subroutine frame work for this. After change: 0xc01f0d500 Y []: 492 Co-developed-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25scripts/checkstack.pl: Add argument to print stacks greather than value.Maninder Singh1-3/+8
Add arguments support to print stacks which are greater than argument value only. Co-developed-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25scripts/checkstack.pl: don't display $dre as different entityManinder Singh1-27/+27
currently script prints stack usage for functions in two ways:($re and $dre) dre breaks sorting mechanism. 0xffffa00011f26f88 sunxi_mux_clk_setup.isra.0 [vmlinux]:Dynamic (0x140) .. 0xffffa00011f27210 sunxi_divs_clk_setup [vmlinux]: Dynamic (0x1d0) so we can print it in decimal only. Also address before function name is changed to function start address rather than stack consumption address. Because in next patch, arm has two ways to use stack which can be clubbed and printed in one function only. All symbols whose stack by adding(re and dre) is greater than 100, will be printed. 0xffffa00011f2720c0 sunxi_divs_clk_setup [vmlinux]: 464 ... 0xffffa00011f26f840 sunxi_mux_clk_setup.isra.0 [vmlinux]:320 Co-developed-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Vaneet Narang <v.narang@samsung.com> Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25modpost,fixdep: Replace zero-length array with flexible-arrayGustavo A. R. Silva3-3/+3
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25scripts: headers_install: Exit with error on config leakSiddharth Gupta1-5/+6
Misuse of CONFIG_* in UAPI headers should result in an error. These config options can be set in userspace by the user application which includes these headers to control the APIs and structures being used in a kernel which supports multiple targets. Signed-off-by: Siddharth Gupta <sidgup@codeaurora.org> Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: remove {CLEAN,MRPROPER,DISTCLEAN}_DIRSMasahiro Yamada2-17/+7
Merge {CLEAN,MRPROPER,DISTCLEAN}_DIRS into {CLEAN,MRPROPER,DISTCLEAN}_FILES because the difference is just the -r option passed to the 'rm' command. Do likewise as commit 1634f2bfdb84 ("kbuild: remove clean-dirs syntax"). Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-05-25kbuild: remove misleading stale FIXME commentMasahiro Yamada1-3/+0
This comment was added by commit ("kbuild: Restore build nr, improve vmlinux link") [1]. It was talking about if_changed_rule at that time. Now, it is unclear what to fix. [1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=ea52ca1b3e3882b499cc6c043f384958b88b62ff Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>