Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2022-01-24

We've added 80 non-merge commits during the last 14 day(s) which contain
a total of 128 files changed, 4990 insertions(+), 895 deletions(-).

The main changes are:

1) Add XDP multi-buffer support and implement it for the mvneta driver,
   from Lorenzo Bianconi, Eelco Chaudron and Toke Høiland-Jørgensen.

2) Add unstable conntrack lookup helpers for BPF by using the BPF kfunc
   infra, from Kumar Kartikeya Dwivedi.

3) Extend BPF cgroup programs to export custom ret value to userspace via
   two helpers bpf_get_retval() and bpf_set_retval(), from YiFei Zhu.

4) Add support for AF_UNIX iterator batching, from Kuniyuki Iwashima.

5) Complete missing UAPI BPF helper description and change bpf_doc.py script
   to enforce consistent & complete helper documentation, from Usama Arif.

6) Deprecate libbpf's legacy BPF map definitions and streamline XDP APIs to
   follow tc-based APIs, from Andrii Nakryiko.

7) Support BPF_PROG_QUERY for BPF programs attached to sockmap, from Di Zhu.

8) Deprecate libbpf's bpf_map__def() API and replace users with proper getters
   and setters, from Christy Lee.

9) Extend libbpf's btf__add_btf() with an additional hashmap for strings to
   reduce overhead, from Kui-Feng Lee.

10) Fix bpftool and libbpf error handling related to libbpf's hashmap__new()
    utility function, from Mauricio Vásquez.

11) Add support to BTF program names in bpftool's program dump, from Raman Shukhau.

12) Fix resolve_btfids build to pick up host flags, from Connor O'Brien.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (80 commits)
  selftests, bpf: Do not yet switch to new libbpf XDP APIs
  selftests, xsk: Fix rx_full stats test
  bpf: Fix flexible_array.cocci warnings
  xdp: disable XDP_REDIRECT for xdp frags
  bpf: selftests: add CPUMAP/DEVMAP selftests for xdp frags
  bpf: selftests: introduce bpf_xdp_{load,store}_bytes selftest
  net: xdp: introduce bpf_xdp_pointer utility routine
  bpf: generalise tail call map compatibility check
  libbpf: Add SEC name for xdp frags programs
  bpf: selftests: update xdp_adjust_tail selftest to include xdp frags
  bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature
  bpf: introduce frags support to bpf_prog_test_run_xdp()
  bpf: move user_size out of bpf_test_init
  bpf: add frags support to xdp copy helpers
  bpf: add frags support to the bpf_xdp_adjust_tail() API
  bpf: introduce bpf_xdp_get_buff_len helper
  net: mvneta: enable jumbo frames if the loaded XDP program support frags
  bpf: introduce BPF_F_XDP_HAS_FRAGS flag in prog_flags loading the ebpf program
  net: mvneta: add frags support to XDP_TX
  xdp: add frags support to xdp_return_{buff/frame}
  ...
====================

Link: https://lore.kernel.org/r/20220124221235.18993-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 104 insertions, 20 deletions

diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py
index a6403ddf5de7..096625242475 100755
--- a/scripts/bpf_doc.py
+++ b/scripts/bpf_doc.py
@@ -87,21 +87,25 @@ class HeaderParser(object):
         self.line = ''
         self.helpers = []
         self.commands = []
+        self.desc_unique_helpers = set()
+        self.define_unique_helpers = []
+        self.desc_syscalls = []
+        self.enum_syscalls = []
 
     def parse_element(self):
         proto    = self.parse_symbol()
-        desc     = self.parse_desc()
-        ret      = self.parse_ret()
+        desc     = self.parse_desc(proto)
+        ret      = self.parse_ret(proto)
         return APIElement(proto=proto, desc=desc, ret=ret)
 
     def parse_helper(self):
         proto    = self.parse_proto()
-        desc     = self.parse_desc()
-        ret      = self.parse_ret()
+        desc     = self.parse_desc(proto)
+        ret      = self.parse_ret(proto)
         return Helper(proto=proto, desc=desc, ret=ret)
 
     def parse_symbol(self):
-        p = re.compile(' \* ?(.+)$')
+        p = re.compile(' \* ?(BPF\w+)$')
         capture = p.match(self.line)
         if not capture:
             raise NoSyscallCommandFound
@@ -127,16 +131,15 @@ class HeaderParser(object):
         self.line = self.reader.readline()
         return capture.group(1)
 
-    def parse_desc(self):
+    def parse_desc(self, proto):
         p = re.compile(' \* ?(?:\t| {5,8})Description$')
         capture = p.match(self.line)
         if not capture:
-            # Helper can have empty description and we might be parsing another
-            # attribute: return but do not consume.
-            return ''
+            raise Exception("No description section found for " + proto)
         # Description can be several lines, some of them possibly empty, and it
         # stops when another subsection title is met.
         desc = ''
+        desc_present = False
         while True:
             self.line = self.reader.readline()
             if self.line == ' *\n':
@@ -145,21 +148,24 @@ class HeaderParser(object):
                 p = re.compile(' \* ?(?:\t| {5,8})(?:\t| {8})(.*)')
                 capture = p.match(self.line)
                 if capture:
+                    desc_present = True
                     desc += capture.group(1) + '\n'
                 else:
                     break
+
+        if not desc_present:
+            raise Exception("No description found for " + proto)
         return desc
 
-    def parse_ret(self):
+    def parse_ret(self, proto):
         p = re.compile(' \* ?(?:\t| {5,8})Return$')
         capture = p.match(self.line)
         if not capture:
-            # Helper can have empty retval and we might be parsing another
-            # attribute: return but do not consume.
-            return ''
+            raise Exception("No return section found for " + proto)
         # Return value description can be several lines, some of them possibly
         # empty, and it stops when another subsection title is met.
         ret = ''
+        ret_present = False
         while True:
             self.line = self.reader.readline()
             if self.line == ' *\n':
@@ -168,44 +174,101 @@ class HeaderParser(object):
                 p = re.compile(' \* ?(?:\t| {5,8})(?:\t| {8})(.*)')
                 capture = p.match(self.line)
                 if capture:
+                    ret_present = True
                     ret += capture.group(1) + '\n'
                 else:
                     break
+
+        if not ret_present:
+            raise Exception("No return found for " + proto)
         return ret
 
-    def seek_to(self, target, help_message):
+    def seek_to(self, target, help_message, discard_lines = 1):
         self.reader.seek(0)
         offset = self.reader.read().find(target)
         if offset == -1:
             raise Exception(help_message)
         self.reader.seek(offset)
         self.reader.readline()
-        self.reader.readline()
+        for _ in range(discard_lines):
+            self.reader.readline()
         self.line = self.reader.readline()
 
-    def parse_syscall(self):
+    def parse_desc_syscall(self):
         self.seek_to('* DOC: eBPF Syscall Commands',
                      'Could not find start of eBPF syscall descriptions list')
         while True:
             try:
                 command = self.parse_element()
                 self.commands.append(command)
+                self.desc_syscalls.append(command.proto)
+
             except NoSyscallCommandFound:
                 break
 
-    def parse_helpers(self):
+    def parse_enum_syscall(self):
+        self.seek_to('enum bpf_cmd {',
+                     'Could not find start of bpf_cmd enum', 0)
+        # Searches for either one or more BPF\w+ enums
+        bpf_p = re.compile('\s*(BPF\w+)+')
+        # Searches for an enum entry assigned to another entry,
+        # for e.g. BPF_PROG_RUN = BPF_PROG_TEST_RUN, which is
+        # not documented hence should be skipped in check to
+        # determine if the right number of syscalls are documented
+        assign_p = re.compile('\s*(BPF\w+)\s*=\s*(BPF\w+)')
+        bpf_cmd_str = ''
+        while True:
+            capture = assign_p.match(self.line)
+            if capture:
+                # Skip line if an enum entry is assigned to another entry
+                self.line = self.reader.readline()
+                continue
+            capture = bpf_p.match(self.line)
+            if capture:
+                bpf_cmd_str += self.line
+            else:
+                break
+            self.line = self.reader.readline()
+        # Find the number of occurences of BPF\w+
+        self.enum_syscalls = re.findall('(BPF\w+)+', bpf_cmd_str)
+
+    def parse_desc_helpers(self):
         self.seek_to('* Start of BPF helper function descriptions:',
                      'Could not find start of eBPF helper descriptions list')
         while True:
             try:
                 helper = self.parse_helper()
                 self.helpers.append(helper)
+                proto = helper.proto_break_down()
+                self.desc_unique_helpers.add(proto['name'])
             except NoHelperFound:
                 break
 
+    def parse_define_helpers(self):
+        # Parse the number of FN(...) in #define __BPF_FUNC_MAPPER to compare
+        # later with the number of unique function names present in description.
+        # Note: seek_to(..) discards the first line below the target search text,
+        # resulting in FN(unspec) being skipped and not added to self.define_unique_helpers.
+        self.seek_to('#define __BPF_FUNC_MAPPER(FN)',
+                     'Could not find start of eBPF helper definition list')
+        # Searches for either one or more FN(\w+) defines or a backslash for newline
+        p = re.compile('\s*(FN\(\w+\))+|\\\\')
+        fn_defines_str = ''
+        while True:
+            capture = p.match(self.line)
+            if capture:
+                fn_defines_str += self.line
+            else:
+                break
+            self.line = self.reader.readline()
+        # Find the number of occurences of FN(\w+)
+        self.define_unique_helpers = re.findall('FN\(\w+\)', fn_defines_str)
+
     def run(self):
-        self.parse_syscall()
-        self.parse_helpers()
+        self.parse_desc_syscall()
+        self.parse_enum_syscall()
+        self.parse_desc_helpers()
+        self.parse_define_helpers()
         self.reader.close()
 
 ###############################################################################
@@ -235,6 +298,25 @@ class Printer(object):
             self.print_one(elem)
         self.print_footer()
 
+    def elem_number_check(self, desc_unique_elem, define_unique_elem, type, instance):
+        """
+        Checks the number of helpers/syscalls documented within the header file
+        description with those defined as part of enum/macro and raise an
+        Exception if they don't match.
+        """
+        nr_desc_unique_elem = len(desc_unique_elem)
+        nr_define_unique_elem = len(define_unique_elem)
+        if nr_desc_unique_elem != nr_define_unique_elem:
+            exception_msg = '''
+The number of unique %s in description (%d) doesn\'t match the number of unique %s defined in %s (%d)
+''' % (type, nr_desc_unique_elem, type, instance, nr_define_unique_elem)
+            if nr_desc_unique_elem < nr_define_unique_elem:
+                # Function description is parsed until no helper is found (which can be due to
+                # misformatting). Hence, only print the first missing/misformatted helper/enum.
+                exception_msg += '''
+The description for %s is not present or formatted correctly.
+''' % (define_unique_elem[nr_desc_unique_elem])
+            raise Exception(exception_msg)
 
 class PrinterRST(Printer):
     """
@@ -295,7 +377,6 @@ class PrinterRST(Printer):
 
         print('')
 
-
 class PrinterHelpersRST(PrinterRST):
     """
     A printer for dumping collected information about helpers as a ReStructured
@@ -305,6 +386,7 @@ class PrinterHelpersRST(PrinterRST):
     """
     def __init__(self, parser):
         self.elements = parser.helpers
+        self.elem_number_check(parser.desc_unique_helpers, parser.define_unique_helpers, 'helper', '__BPF_FUNC_MAPPER')
 
     def print_header(self):
         header = '''\
@@ -478,6 +560,7 @@ class PrinterSyscallRST(PrinterRST):
     """
     def __init__(self, parser):
         self.elements = parser.commands
+        self.elem_number_check(parser.desc_syscalls, parser.enum_syscalls, 'syscall', 'bpf_cmd')
 
     def print_header(self):
         header = '''\
@@ -509,6 +592,7 @@ class PrinterHelpers(Printer):
     """
     def __init__(self, parser):
         self.elements = parser.helpers
+        self.elem_number_check(parser.desc_unique_helpers, parser.define_unique_helpers, 'helper', '__BPF_FUNC_MAPPER')
 
     type_fwds = [
             'struct bpf_fib_lookup',