[bpf-next,v2,0/3] bpf: bpf trampoline improvements

Message

Yafang Shao May 15, 2023, 1:08 p.m. UTC

When we run fexit bpf programs (e.g. attaching tcp_recvmsg) on our servers
which were running old kernels, some of these servers crashed. Finally we
figured out that it was caused by the same issue resolved by
commit e21aa341785c ("bpf: Fix fexit trampoline."). After we backported
that commit, the crash disappears. However new issues are introduced by
that commit. This patchset fixes them.

PATCH #1: Fix a memory leak found on our server
PATCH #2: Remove bpf trampoline selector and also fix the issue in perf
          caused by the name change in bpf trampoline
PATCH #3: Show target_{obj,btf}_id when link to a bpf trampoline

v1->v2:
- Reuse the common code between __bpf_tramp_image_put_deferred and
  bpf_tramp_image_free (Song)
- Add fixes tag in patch #1 (Song)
- Restore the old bpf trampoline name format (Song)
- Jiri pointed out a issue in perf
- Show btf information in the tracing link info

Yafang Shao (3):
  bpf: Fix memleak due to fentry attach failure
  bpf: Remove bpf trampoline selector
  bpf: Show target_{obj,btf}_id in tracing link info

 include/linux/bpf.h      |  1 -
 kernel/bpf/syscall.c     | 12 ++++++++++--
 kernel/bpf/trampoline.c  | 32 +++++++++++++++++++-------------
 tools/bpf/bpftool/link.c |  4 ++++
 4 files changed, 33 insertions(+), 16 deletions(-)