This is a note to let you know that I've just added the patch titled
libbpf: fix return value for PERF_EVENT __arg_ctx type fix up check
to the 6.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
libbpf-fix-return-value-for-perf_event-__arg_ctx-typ.patch
and it can be found in the queue-6.8 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 290afa9bd207e61ad0a214d794af1f075a08eafe
Author: Andrii Nakryiko <andrii@xxxxxxxxxx>
Date: Mon Feb 5 16:22:43 2024 -0800
libbpf: fix return value for PERF_EVENT __arg_ctx type fix up check
[ Upstream commit d7bc416aa5cc183691287e8f0b1d5b182a7ce9c3 ]
If PERF_EVENT program has __arg_ctx argument with matching
architecture-specific pt_regs/user_pt_regs/user_regs_struct pointer
type, libbpf should still perform type rewrite for old kernels, but not
emit the warning. Fix copy/paste from kernel code where 0 is meant to
signify "no error" condition. For libbpf we need to return "true" to
proceed with type rewrite (which for PERF_EVENT program will be
a canonical `struct bpf_perf_event_data *` type).
Fixes: 9eea8fafe33e ("libbpf: fix __arg_ctx type enforcement for perf_event programs")
Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240206002243.1439450-1-andrii@xxxxxxxxxx
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c
index 910f72c9e6a49..92bca96587a4a 100644
--- a/tools/lib/bpf/libbpf.c
+++ b/tools/lib/bpf/libbpf.c
@@ -6755,13 +6755,13 @@ static bool need_func_arg_type_fixup(const struct btf *btf, const struct bpf_pro
case BPF_PROG_TYPE_PERF_EVENT:
if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct pt_regs) &&
btf_is_struct(t) && strcmp(tname, "pt_regs") == 0)
- return 0;
+ return true;
if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct user_pt_regs) &&
btf_is_struct(t) && strcmp(tname, "user_pt_regs") == 0)
- return 0;
+ return true;
if (__builtin_types_compatible_p(bpf_user_pt_regs_t, struct user_regs_struct) &&
btf_is_struct(t) && strcmp(tname, "user_regs_struct") == 0)
- return 0;
+ return true;
break;
case BPF_PROG_TYPE_RAW_TRACEPOINT:
case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
