linux-stable.git/tools/bpf, branch v6.6.37

bpf: Fix potential integer overflow in resolve_btfids

2024-06-12T09:12:54+00:00

[ Upstream commit 44382b3ed6b2787710c8ade06c0e97f5970a47c8 ]

err is a 32-bit integer, but elf_update returns an off_t, which is 64-bit
at least on 64-bit platforms. If symbols_patch is called on a binary between
2-4GB in size, the result will be negative when cast to a 32-bit integer,
which the code assumes means an error occurred. This can wrongly trigger
build failures when building very large kernel images.

Fixes: fbbb68de80a4 ("bpf: Add resolve_btfids tool to resolve BTF IDs in ELF object")
Signed-off-by: Friedrich Vock 
Signed-off-by: Daniel Borkmann 
Acked-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20240514070931.199694-1-friedrich.vock@gmx.de
Signed-off-by: Sasha Levin

bpftool: Mount bpffs on provided dir instead of parent dir

2024-06-12T09:11:38+00:00

[ Upstream commit 478a535ae54ad3831371904d93b5dfc403222e17 ]

When pinning programs/objects under PATH (eg: during "bpftool prog
loadall") the bpffs is mounted on the parent dir of PATH in the
following situations:
- the given dir exists but it is not bpffs.
- the given dir doesn't exist and the parent dir is not bpffs.

Mounting on the parent dir can also have the unintentional side-
effect of hiding other files located under the parent dir.

If the given dir exists but is not bpffs, then the bpffs should
be mounted on the given dir and not its parent dir.

Similarly, if the given dir doesn't exist and its parent dir is not
bpffs, then the given dir should be created and the bpffs should be
mounted on this new dir.

Fixes: 2a36c26fe3b8 ("bpftool: Support bpffs mountpoint as pin path for prog loadall")
Signed-off-by: Sahil Siddiq 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/2da44d24-74ae-a564-1764-afccf395eeec@isovalent.com/T/#t
Link: https://lore.kernel.org/bpf/20240404192219.52373-1-icegambit91@gmail.com

Closes: https://github.com/libbpf/bpftool/issues/100

Changes since v1:
 - Split "mount_bpffs_for_pin" into two functions.
   This is done to improve maintainability and readability.

Changes since v2:
- mount_bpffs_for_pin: rename to "create_and_mount_bpffs_dir".
- mount_bpffs_given_file: rename to "mount_bpffs_given_file".
- create_and_mount_bpffs_dir:
  - introduce "dir_exists" boolean.
  - remove new dir if "mnt_fs" fails.
- improve error handling and error messages.

Changes since v3:
- Rectify function name.
- Improve error messages and formatting.
- mount_bpffs_for_file:
  - Check if dir exists before block_mount check.

Changes since v4:
- Use strdup instead of strcpy.
- create_and_mount_bpffs_dir:
  - Use S_IRWXU instead of 0700.
- Improve error handling and formatting.

Signed-off-by: Sasha Levin

bpftool: Fix missing pids during link show

2024-06-12T09:11:35+00:00

[ Upstream commit fe879bb42f8a6513ed18e9d22efb99cb35590201 ]

Current 'bpftool link' command does not show pids, e.g.,
  $ tools/build/bpftool/bpftool link
  ...
  4: tracing  prog 23
        prog_type lsm  attach_type lsm_mac
        target_obj_id 1  target_btf_id 31320

Hack the following change to enable normal libbpf debug output,
#  --- a/tools/bpf/bpftool/pids.c
#  +++ b/tools/bpf/bpftool/pids.c
#  @@ -121,9 +121,9 @@ int build_obj_refs_table(struct hashmap **map, enum bpf_obj_type type)
#          /* we don't want output polluted with libbpf errors if bpf_iter is not
#           * supported
#           */
#  -       default_print = libbpf_set_print(libbpf_print_none);
#  +       /* default_print = libbpf_set_print(libbpf_print_none); */
#          err = pid_iter_bpf__load(skel);
#  -       libbpf_set_print(default_print);
#  +       /* libbpf_set_print(default_print); */

Rerun the above bpftool command:
  $ tools/build/bpftool/bpftool link
  libbpf: prog 'iter': BPF program load failed: Permission denied
  libbpf: prog 'iter': -- BEGIN PROG LOAD LOG --
  0: R1=ctx() R10=fp0
  ; struct task_struct *task = ctx->task; @ pid_iter.bpf.c:69
  0: (79) r6 = *(u64 *)(r1 +8)          ; R1=ctx() R6_w=ptr_or_null_task_struct(id=1)
  ; struct file *file = ctx->file; @ pid_iter.bpf.c:68
  ...
  ; struct bpf_link *link = (struct bpf_link *) file->private_data; @ pid_iter.bpf.c:103
  80: (79) r3 = *(u64 *)(r8 +432)       ; R3_w=scalar() R8=ptr_file()
  ; if (link->type == bpf_core_enum_value(enum bpf_link_type___local, @ pid_iter.bpf.c:105
  81: (61) r1 = *(u32 *)(r3 +12)
  R3 invalid mem access 'scalar'
  processed 39 insns (limit 1000000) max_states_per_insn 0 total_states 3 peak_states 3 mark_read 2
  -- END PROG LOAD LOG --
  libbpf: prog 'iter': failed to load: -13
  ...

The 'file->private_data' returns a 'void' type and this caused subsequent 'link->type'
(insn #81) failed in verification.

To fix the issue, restore the previous BPF_CORE_READ so old kernels can also work.
With this patch, the 'bpftool link' runs successfully with 'pids'.
  $ tools/build/bpftool/bpftool link
  ...
  4: tracing  prog 23
        prog_type lsm  attach_type lsm_mac
        target_obj_id 1  target_btf_id 31320
        pids systemd(1)

Fixes: 44ba7b30e84f ("bpftool: Use a local copy of BPF_LINK_TYPE_PERF_EVENT in pid_iter.bpf.c")
Signed-off-by: Yonghong Song 
Signed-off-by: Andrii Nakryiko 
Tested-by: Quentin Monnet 
Reviewed-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20240312023249.3776718-1-yonghong.song@linux.dev
Signed-off-by: Sasha Levin

tools/resolve_btfids: Fix cross-compilation to non-host endianness

2024-03-26T22:19:27+00:00

[ Upstream commit 903fad4394666bc23975c93fb58f137ce64b5192 ]

The .BTF_ids section is pre-filled with zeroed BTF ID entries during the
build and afterwards patched by resolve_btfids with correct values.
Since resolve_btfids always writes in host-native endianness, it relies
on libelf to do the translation when the target ELF is cross-compiled to
a different endianness (this was introduced in commit 61e8aeda9398
("bpf: Fix libelf endian handling in resolv_btfids")).

Unfortunately, the translation will corrupt the flags fields of SET8
entries because these were written during vmlinux compilation and are in
the correct endianness already. This will lead to numerous selftests
failures such as:

    $ sudo ./test_verifier 502 502
    #502/p sleepable fentry accept FAIL
    Failed to load prog 'Invalid argument'!
    bpf_fentry_test1 is not sleepable
    verification time 34 usec
    stack depth 0
    processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0 peak_states 0 mark_read 0
    Summary: 0 PASSED, 0 SKIPPED, 1 FAILED

Since it's not possible to instruct libelf to translate just certain
values, let's manually bswap the flags (both global and entry flags) in
resolve_btfids when needed, so that libelf then translates everything
correctly.

Fixes: ef2c6f370a63 ("tools/resolve_btfids: Add support for 8-byte BTF sets")
Signed-off-by: Viktor Malik 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/7b6bff690919555574ce0f13d2a5996cacf7bf69.1707223196.git.vmalik@redhat.com
Signed-off-by: Sasha Levin

tools/resolve_btfids: Refactor set sorting with types from btf_ids.h

2024-03-26T22:19:27+00:00

[ Upstream commit 9707ac4fe2f5bac6406d2403f8b8a64d7b3d8e43 ]

Instead of using magic offsets to access BTF ID set data, leverage types
from btf_ids.h (btf_id_set and btf_id_set8) which define the actual
layout of the data. Thanks to this change, set sorting should also
continue working if the layout changes.

This requires to sync the definition of 'struct btf_id_set8' from
include/linux/btf_ids.h to tools/include/linux/btf_ids.h. We don't sync
the rest of the file at the moment, b/c that would require to also sync
multiple dependent headers and we don't need any other defs from
btf_ids.h.

Signed-off-by: Viktor Malik 
Signed-off-by: Andrii Nakryiko 
Acked-by: Daniel Xu 
Link: https://lore.kernel.org/bpf/ff7f062ddf6a00815fda3087957c4ce667f50532.1707223196.git.vmalik@redhat.com
Stable-dep-of: 903fad439466 ("tools/resolve_btfids: Fix cross-compilation to non-host endianness")
Signed-off-by: Sasha Levin

bpftool: Silence build warning about calloc()

2024-03-26T22:19:22+00:00

[ Upstream commit f5f30386c78105cba520e443a6a9ee945ec1d066 ]

There exists the following warning when building bpftool:

  CC      prog.o
prog.c: In function ‘profile_open_perf_events’:
prog.c:2301:24: warning: ‘calloc’ sizes specified with ‘sizeof’ in the earlier argument and not in the later argument [-Wcalloc-transposed-args]
 2301 |                 sizeof(int), obj->rodata->num_cpu * obj->rodata->num_metric);
      |                        ^~~
prog.c:2301:24: note: earlier argument should specify number of elements, later size of each element

Tested with the latest upstream GCC which contains a new warning option
-Wcalloc-transposed-args. The first argument to calloc is documented to
be number of elements in array, while the second argument is size of each
element, just switch the first and second arguments of calloc() to silence
the build warning, compile tested only.

Fixes: 47c09d6a9f67 ("bpftool: Introduce "prog profile" command")
Signed-off-by: Tiezhu Yang 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20240116061920.31172-1-yangtiezhu@loongson.cn
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

bpftool: Align output skeleton ELF code

2024-01-10T16:16:54+00:00

[ Upstream commit 23671f4dfd10b48b4a2fee4768886f0d8ec55b7e ]

libbpf accesses the ELF data requiring at least 8 byte alignment,
however, the data is generated into a C string that doesn't guarantee
alignment. Fix this by assigning to an aligned char array. Use sizeof
on the array, less one for the \0 terminator, rather than generating a
constant.

Fixes: a6cc6b34b93e ("bpftool: Provide a helper method for accessing skeleton's embedded ELF data")
Signed-off-by: Ian Rogers 
Signed-off-by: Andrii Nakryiko 
Reviewed-by: Alan Maguire 
Acked-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20231007044439.25171-1-irogers@google.com
Signed-off-by: Sasha Levin

bpftool: Fix -Wcast-qual warning

2024-01-10T16:16:54+00:00

[ Upstream commit ebc8484d0e6da9e6c9e8cfa1f40bf94e9c6fc512 ]

This cast was made by purpose for older libbpf where the
bpf_object_skeleton field is void * instead of const void *
to eliminate a warning (as i understand
-Wincompatible-pointer-types-discards-qualifiers) but this
cast introduces another warning (-Wcast-qual) for libbpf
where data field is const void *

It makes sense for bpftool to be in sync with libbpf from
kernel sources

Signed-off-by: Denys Zagorui 
Signed-off-by: Andrii Nakryiko 
Acked-by: Quentin Monnet 
Link: https://lore.kernel.org/bpf/20230907090210.968612-1-dzagorui@cisco.com
Stable-dep-of: 23671f4dfd10 ("bpftool: Align output skeleton ELF code")
Signed-off-by: Sasha Levin

bpftool: Fix build warnings with -Wtype-limits

2023-08-30T06:39:00+00:00

Quentin reported build warnings when building bpftool :

    link.c: In function ‘perf_config_hw_cache_str’:
    link.c:86:18: warning: comparison of unsigned expression in ‘>= 0’ is always true [-Wtype-limits]
       86 |         if ((id) >= 0 && (id) < ARRAY_SIZE(array))      \
          |                  ^~
    link.c:320:20: note: in expansion of macro ‘perf_event_name’
      320 |         hw_cache = perf_event_name(evsel__hw_cache, config & 0xff);
          |                    ^~~~~~~~~~~~~~~
    [... more of the same for the other calls to perf_event_name ...]

He also pointed out the reason and the solution:

  We're always passing unsigned, so it should be safe to drop the check on
  (id) >= 0.

Fixes: 62b57e3ddd64 ("bpftool: Add perf event names")
Reported-by: Quentin Monnet 
Suggested-by: Quentin Monnet 
Signed-off-by: Yafang Shao 
Signed-off-by: Daniel Borkmann 
Acked-by: Quentin Monnet 
Closes: https://lore.kernel.org/bpf/a35d9a2d-54a0-49ec-9ed1-8fcf1369d3cc@isovalent.com
Link: https://lore.kernel.org/bpf/20230830030325.3786-1-laoar.shao@gmail.com

bpftool: Implement link show support for xdp

2023-08-16T17:14:17+00:00

Add support to dump XDP link information to bpftool. This reuses the
recently added show_link_ifindex_{plain,json}(). The XDP link info only
exposes the ifindex.

Below shows an example link dump output, and a cgroup link is included
for comparison, too:

  # bpftool link
  [...]
  10: cgroup  prog 2466
        cgroup_id 1  attach_type cgroup_inet6_post_bind
  [...]
  16: xdp  prog 2477
        ifindex enp5s0(3)
  [...]

Equivalent json output:

  # bpftool link --json
  [...]
  {
    "id": 10,
    "type": "cgroup",
    "prog_id": 2466,
    "cgroup_id": 1,
    "attach_type": "cgroup_inet6_post_bind"
  },
  [...]
  {
    "id": 16,
    "type": "xdp",
    "prog_id": 2477,
    "devname": "enp5s0",
    "ifindex": 3
  }
  [...]

Signed-off-by: Daniel Borkmann 
Reviewed-by: Quentin Monnet 
Link: https://lore.kernel.org/r/20230816095651.10014-2-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau