mbox series

[bpf-next,0/2] BPF static linker: fix failure when encountering duplicate extern functions

Message ID 20240929-libbpf-dup-extern-funcs-v1-0-df15fbd6525b@hack3r.moe (mailing list archive)
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Series BPF static linker: fix failure when encountering duplicate extern functions | expand

Message

Eric Long via B4 Relay Sept. 29, 2024, 8:47 a.m. UTC 
Currently, if `bpftool gen object` tries to link two objects that
contains the same extern function prototype, libbpf will try to get
their (non-existent) size by calling bpf__resolve_size like extern
variables and fail with:

	libbpf: global 'whatever': failed to resolve size of underlying type: -22

This should not be the case, and this series adds conditions to update
size only when the BTF kind is not function.

Fixes: a46349227cd8 ("libbpf: Add linker extern resolution support for functions and global variables")
Signed-off-by: Eric Long <i@hack3r.moe>
---
Eric Long (2):
      libbpf: do not resolve size on duplicate FUNCs
      selftests/bpf: make sure linking objects with duplicate extern functions doesn't fail

 tools/lib/bpf/linker.c                             | 24 +++++++++++++---------
 tools/testing/selftests/bpf/Makefile               |  3 ++-
 .../selftests/bpf/prog_tests/dup_extern_funcs.c    |  9 ++++++++
 .../selftests/bpf/progs/dup_extern_funcs1.c        | 20 ++++++++++++++++++
 .../selftests/bpf/progs/dup_extern_funcs2.c        | 18 ++++++++++++++++
 5 files changed, 63 insertions(+), 11 deletions(-)
---
base-commit: 93eeaab4563cc7fc0309bc1c4d301139762bbd60
change-id: 20240929-libbpf-dup-extern-funcs-871f4bad2122

Best regards,