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

Daniel Borkmann says:

====================
pull-request: bpf-next 2022-09-05

The following pull-request contains BPF updates for your *net-next* tree.

We've added 106 non-merge commits during the last 18 day(s) which contain
a total of 159 files changed, 5225 insertions(+), 1358 deletions(-).

There are two small merge conflicts, resolve them as follows:

1) tools/testing/selftests/bpf/DENYLIST.s390x

  Commit 27e23836ce22 ("selftests/bpf: Add lru_bug to s390x deny list") in
  bpf tree was needed to get BPF CI green on s390x, but it conflicted with
  newly added tests on bpf-next. Resolve by adding both hunks, result:

  [...]
  lru_bug                                  # prog 'printk': failed to auto-attach: -524
  setget_sockopt                           # attach unexpected error: -524                                               (trampoline)
  cb_refs                                  # expected error message unexpected error: -524                               (trampoline)
  cgroup_hierarchical_stats                # JIT does not support calling kernel function                                (kfunc)
  htab_update                              # failed to attach: ERROR: strerror_r(-524)=22                                (trampoline)
  [...]

2) net/core/filter.c

  Commit 1227c1771dd2 ("net: Fix data-races around sysctl_[rw]mem_(max|default).")
  from net tree conflicts with commit 29003875bd5b ("bpf: Change bpf_setsockopt(SOL_SOCKET)
  to reuse sk_setsockopt()") from bpf-next tree. Take the code as it is from
  bpf-next tree, result:

  [...]
	if (getopt) {
		if (optname == SO_BINDTODEVICE)
			return -EINVAL;
		return sk_getsockopt(sk, SOL_SOCKET, optname,
				     KERNEL_SOCKPTR(optval),
				     KERNEL_SOCKPTR(optlen));
	}

	return sk_setsockopt(sk, SOL_SOCKET, optname,
			     KERNEL_SOCKPTR(optval), *optlen);
  [...]

The main changes are:

1) Add any-context BPF specific memory allocator which is useful in particular for BPF
   tracing with bonus of performance equal to full prealloc, from Alexei Starovoitov.

2) Big batch to remove duplicated code from bpf_{get,set}sockopt() helpers as an effort
   to reuse the existing core socket code as much as possible, from Martin KaFai Lau.

3) Extend BPF flow dissector for BPF programs to just augment the in-kernel dissector
   with custom logic. In other words, allow for partial replacement, from Shmulik Ladkani.

4) Add a new cgroup iterator to BPF with different traversal options, from Hao Luo.

5) Support for BPF to collect hierarchical cgroup statistics efficiently through BPF
   integration with the rstat framework, from Yosry Ahmed.

6) Support bpf_{g,s}et_retval() under more BPF cgroup hooks, from Stanislav Fomichev.

7) BPF hash table and local storages fixes under fully preemptible kernel, from Hou Tao.

8) Add various improvements to BPF selftests and libbpf for compilation with gcc BPF
   backend, from James Hilliard.

9) Fix verifier helper permissions and reference state management for synchronous
   callbacks, from Kumar Kartikeya Dwivedi.

10) Add support for BPF selftest's xskxceiver to also be used against real devices that
    support MAC loopback, from Maciej Fijalkowski.

11) Various fixes to the bpf-helpers(7) man page generation script, from Quentin Monnet.

12) Document BPF verifier's tnum_in(tnum_range(), ...) gotchas, from Shung-Hsi Yu.

13) Various minor misc improvements all over the place.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (106 commits)
  bpf: Optimize rcu_barrier usage between hash map and bpf_mem_alloc.
  bpf: Remove usage of kmem_cache from bpf_mem_cache.
  bpf: Remove prealloc-only restriction for sleepable bpf programs.
  bpf: Prepare bpf_mem_alloc to be used by sleepable bpf programs.
  bpf: Remove tracing program restriction on map types
  bpf: Convert percpu hash map to per-cpu bpf_mem_alloc.
  bpf: Add percpu allocation support to bpf_mem_alloc.
  bpf: Batch call_rcu callbacks instead of SLAB_TYPESAFE_BY_RCU.
  bpf: Adjust low/high watermarks in bpf_mem_cache
  bpf: Optimize call_rcu in non-preallocated hash map.
  bpf: Optimize element count in non-preallocated hash map.
  bpf: Relax the requirement to use preallocated hash maps in tracing progs.
  samples/bpf: Reduce syscall overhead in map_perf_test.
  selftests/bpf: Improve test coverage of test_maps
  bpf: Convert hash map to bpf_mem_alloc.
  bpf: Introduce any context BPF specific memory allocator.
  selftest/bpf: Add test for bpf_getsockopt()
  bpf: Change bpf_getsockopt(SOL_IPV6) to reuse do_ipv6_getsockopt()
  bpf: Change bpf_getsockopt(SOL_IP) to reuse do_ip_getsockopt()
  bpf: Change bpf_getsockopt(SOL_TCP) to reuse do_tcp_getsockopt()
  ...
====================

Link: https://lore.kernel.org/r/20220905161136.9150-1-daniel@iogearbox.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

1 files changed, 71 insertions, 7 deletions

diff --git a/scripts/bpf_doc.py b/scripts/bpf_doc.py
index dfb260de17a8..d5c389df6045 100755
--- a/scripts/bpf_doc.py
+++ b/scripts/bpf_doc.py
@@ -10,6 +10,9 @@ from __future__ import print_function
 import argparse
 import re
 import sys, os
+import subprocess
+
+helpersDocStart = 'Start of BPF helper function descriptions:'
 
 class NoHelperFound(BaseException):
     pass
@@ -47,6 +50,10 @@ class Helper(APIElement):
     @desc: textual description of the helper function
     @ret: description of the return value of the helper function
     """
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.enum_val = None
+
     def proto_break_down(self):
         """
         Break down helper function protocol into smaller chunks: return type,
@@ -89,6 +96,7 @@ class HeaderParser(object):
         self.commands = []
         self.desc_unique_helpers = set()
         self.define_unique_helpers = []
+        self.helper_enum_vals = {}
         self.desc_syscalls = []
         self.enum_syscalls = []
 
@@ -233,7 +241,7 @@ class HeaderParser(object):
         self.enum_syscalls = re.findall('(BPF\w+)+', bpf_cmd_str)
 
     def parse_desc_helpers(self):
-        self.seek_to('* Start of BPF helper function descriptions:',
+        self.seek_to(helpersDocStart,
                      'Could not find start of eBPF helper descriptions list')
         while True:
             try:
@@ -245,30 +253,54 @@ class HeaderParser(object):
                 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.
+        # 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)',
                      '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\(\w+\))+|\\\\')
+        # Searches for one FN(\w+) define or a backslash for newline
+        p = re.compile('\s*FN\((\w+)\)|\\\\')
         fn_defines_str = ''
+        i = 1  # 'unspec' is skipped as mentioned above
         while True:
             capture = p.match(self.line)
             if capture:
                 fn_defines_str += self.line
+                self.helper_enum_vals[capture.expand(r'bpf_\1')] = 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)
 
+    def assign_helper_values(self):
+        seen_helpers = set()
+        for helper in self.helpers:
+            proto = helper.proto_break_down()
+            name = proto['name']
+            try:
+                enum_val = self.helper_enum_vals[name]
+            except KeyError:
+                raise Exception("Helper %s is missing from enum bpf_func_id" % name)
+
+            # Enforce current practice of having the descriptions ordered
+            # by enum value.
+            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))
+
+            helper.enum_val = enum_val
+
     def run(self):
         self.parse_desc_syscall()
         self.parse_enum_syscall()
         self.parse_desc_helpers()
         self.parse_define_helpers()
+        self.assign_helper_values()
         self.reader.close()
 
 ###############################################################################
@@ -357,6 +389,31 @@ class PrinterRST(Printer):
 
         print('')
 
+    def get_kernel_version(self):
+        try:
+            version = subprocess.run(['git', 'describe'], cwd=linuxRoot,
+                                     capture_output=True, check=True)
+            version = version.stdout.decode().rstrip()
+        except:
+            try:
+                version = subprocess.run(['make', 'kernelversion'], cwd=linuxRoot,
+                                         capture_output=True, check=True)
+                version = version.stdout.decode().rstrip()
+            except:
+                return 'Linux'
+        return 'Linux {version}'.format(version=version)
+
+    def get_last_doc_update(self, delimiter):
+        try:
+            cmd = ['git', 'log', '-1', '--pretty=format:%cs', '--no-patch',
+                   '-L',
+                   '/{}/,/\*\//:include/uapi/linux/bpf.h'.format(delimiter)]
+            date = subprocess.run(cmd, cwd=linuxRoot,
+                                  capture_output=True, check=True)
+            return date.stdout.decode().rstrip()
+        except:
+            return ''
+
 class PrinterHelpersRST(PrinterRST):
     """
     A printer for dumping collected information about helpers as a ReStructured
@@ -378,6 +435,8 @@ list of eBPF helper functions
 -------------------------------------------------------------------------------
 
 :Manual section: 7
+:Version: {version}
+{date_field}{date}
 
 DESCRIPTION
 ===========
@@ -410,8 +469,13 @@ kernel at the top).
 HELPERS
 =======
 '''
+        kernelVersion = self.get_kernel_version()
+        lastUpdate = self.get_last_doc_update(helpersDocStart)
+
         PrinterRST.print_license(self)
-        print(header)
+        print(header.format(version=kernelVersion,
+                            date_field = ':Date: ' if lastUpdate else '',
+                            date=lastUpdate))
 
     def print_footer(self):
         footer = '''
@@ -761,7 +825,7 @@ class PrinterHelpers(Printer):
             comma = ', '
             print(one_arg, end='')
 
-        print(') = (void *) %d;' % len(self.seen_helpers))
+        print(') = (void *) %d;' % helper.enum_val)
         print('')
 
 ###############################################################################