Merge tag 'for-netdev' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2022-10-18

We've added 33 non-merge commits during the last 14 day(s) which contain
a total of 31 files changed, 874 insertions(+), 538 deletions(-).

The main changes are:

1) Add RCU grace period chaining to BPF to wait for the completion
   of access from both sleepable and non-sleepable BPF programs,
   from Hou Tao & Paul E. McKenney.

2) Improve helper UAPI by explicitly defining BPF_FUNC_xxx integer
   values. In the wild we have seen OS vendors doing buggy backports
   where helper call numbers mismatched. This is an attempt to make
   backports more foolproof, from Andrii Nakryiko.

3) Add libbpf *_opts API-variants for bpf_*_get_fd_by_id() functions,
   from Roberto Sassu.

4) Fix libbpf's BTF dumper for structs with padding-only fields,
   from Eduard Zingerman.

5) Fix various libbpf bugs which have been found from fuzzing with
   malformed BPF object files, from Shung-Hsi Yu.

6) Clean up an unneeded check on existence of SSE2 in BPF x86-64 JIT,
   from Jie Meng.

7) Fix various ASAN bugs in both libbpf and selftests when running
   the BPF selftest suite on arm64, from Xu Kuohai.

8) Fix missing bpf_iter_vma_offset__destroy() call in BPF iter selftest
   and use in-skeleton link pointer to remove an explicit bpf_link__destroy(),
   from Jiri Olsa.

9) Fix BPF CI breakage by pointing to iptables-legacy instead of relying
   on symlinked iptables which got upgraded to iptables-nft,
   from Martin KaFai Lau.

10) Minor BPF selftest improvements all over the place, from various others.

* tag 'for-netdev' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (33 commits)
  bpf/docs: Update README for most recent vmtest.sh
  bpf: Use rcu_trace_implies_rcu_gp() for program array freeing
  bpf: Use rcu_trace_implies_rcu_gp() in local storage map
  bpf: Use rcu_trace_implies_rcu_gp() in bpf memory allocator
  rcu-tasks: Provide rcu_trace_implies_rcu_gp()
  selftests/bpf: Use sys_pidfd_open() helper when possible
  libbpf: Fix null-pointer dereference in find_prog_by_sec_insn()
  libbpf: Deal with section with no data gracefully
  libbpf: Use elf_getshdrnum() instead of e_shnum
  selftest/bpf: Fix error usage of ASSERT_OK in xdp_adjust_tail.c
  selftests/bpf: Fix error failure of case test_xdp_adjust_tail_grow
  selftest/bpf: Fix memory leak in kprobe_multi_test
  selftests/bpf: Fix memory leak caused by not destroying skeleton
  libbpf: Fix memory leak in parse_usdt_arg()
  libbpf: Fix use-after-free in btf_dump_name_dups
  selftests/bpf: S/iptables/iptables-legacy/ in the bpf_nf and xdp_synproxy test
  selftests/bpf: Alphabetize DENYLISTs
  selftests/bpf: Add tests for _opts variants of bpf_*_get_fd_by_id()
  libbpf: Introduce bpf_link_get_fd_by_id_opts()
  libbpf: Introduce bpf_btf_get_fd_by_id_opts()
  ...
====================

Link: https://lore.kernel.org/r/20221018210631.11211-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 32 insertions, 14 deletions

diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py
index d5c389df6045..c0e6690be82a 100755
--- a/scripts/bpf_doc.py
+++ b/scripts/bpf_doc.py
@@ -97,6 +97,7 @@ class HeaderParser(object):
         self.desc_unique_helpers = set()
         self.define_unique_helpers = []
         self.helper_enum_vals = {}
+        self.helper_enum_pos = {}
         self.desc_syscalls = []
         self.enum_syscalls = []
 
@@ -253,54 +254,71 @@ class HeaderParser(object):
                 break
 
     def parse_define_helpers(self):
-        # Parse FN(...) in #define __BPF_FUNC_MAPPER to compare later with the
+        # Parse FN(...) in #define ___BPF_FUNC_MAPPER to compare later with the
         # number of unique function names present in description and use the
         # correct enumeration value.
         # 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)',
+        # resulting in FN(unspec, 0, ##ctx) being skipped and not added to
+        # self.define_unique_helpers.
+        self.seek_to('#define ___BPF_FUNC_MAPPER(FN, ctx...)',
                      'Could not find start of eBPF helper definition list')
         # Searches for one FN(\w+) define or a backslash for newline
-        p = re.compile('\s*FN\((\w+)\)|\\\\')
+        p = re.compile('\s*FN\((\w+), (\d+), ##ctx\)|\\\\')
         fn_defines_str = ''
-        i = 1  # 'unspec' is skipped as mentioned above
+        i = 0
         while True:
             capture = p.match(self.line)
             if capture:
                 fn_defines_str += self.line
-                self.helper_enum_vals[capture.expand(r'bpf_\1')] = i
+                helper_name = capture.expand(r'bpf_\1')
+                self.helper_enum_vals[helper_name] = int(capture[2])
+                self.helper_enum_pos[helper_name] = i
                 i += 1
             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)
+        self.define_unique_helpers = re.findall('FN\(\w+, \d+, ##ctx\)', fn_defines_str)
 
-    def assign_helper_values(self):
+    def validate_helpers(self):
+        last_helper = ''
         seen_helpers = set()
+        seen_enum_vals = set()
+        i = 0
         for helper in self.helpers:
             proto = helper.proto_break_down()
             name = proto['name']
             try:
                 enum_val = self.helper_enum_vals[name]
+                enum_pos = self.helper_enum_pos[name]
             except KeyError:
                 raise Exception("Helper %s is missing from enum bpf_func_id" % name)
 
+            if name in seen_helpers:
+                if last_helper != name:
+                    raise Exception("Helper %s has multiple descriptions which are not grouped together" % name)
+                continue
+
             # Enforce current practice of having the descriptions ordered
             # by enum value.
+            if enum_pos != i:
+                raise Exception("Helper %s (ID %d) comment order (#%d) must be aligned with its position (#%d) in enum bpf_func_id" % (name, enum_val, i + 1, enum_pos + 1))
+            if enum_val in seen_enum_vals:
+                raise Exception("Helper %s has duplicated value %d" % (name, enum_val))
+
             seen_helpers.add(name)
-            desc_val = len(seen_helpers)
-            if desc_val != enum_val:
-                raise Exception("Helper %s comment order (#%d) must be aligned with its position (#%d) in enum bpf_func_id" % (name, desc_val, enum_val))
+            last_helper = name
+            seen_enum_vals.add(enum_val)
 
             helper.enum_val = enum_val
+            i += 1
 
     def run(self):
         self.parse_desc_syscall()
         self.parse_enum_syscall()
         self.parse_desc_helpers()
         self.parse_define_helpers()
-        self.assign_helper_values()
+        self.validate_helpers()
         self.reader.close()
 
 ###############################################################################
@@ -423,7 +441,7 @@ 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')
+        self.elem_number_check(parser.desc_unique_helpers, parser.define_unique_helpers, 'helper', '___BPF_FUNC_MAPPER')
 
     def print_header(self):
         header = '''\
@@ -636,7 +654,7 @@ 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')
+        self.elem_number_check(parser.desc_unique_helpers, parser.define_unique_helpers, 'helper', '___BPF_FUNC_MAPPER')
 
     type_fwds = [
             'struct bpf_fib_lookup',