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| author | Mykyta Yatsenko <yatsenko@meta.com> | 2026-07-30 17:17:39 -0700 |
|---|---|---|
| committer | Steven Rostedt <rostedt@goodmis.org> | 2026-08-05 22:02:29 -0400 |
| commit | d5b201ed4feb7a11da242a97669424efeb724031 (patch) | |
| tree | 4d42d8fd6abb228e89fa0a37eb9e9b20139bf839 /include/trace | |
| parent | efdcfd9b4f4f07aa70663ee02a79dbdf980bf582 (diff) | |
| download | linux-d5b201ed4feb7a11da242a97669424efeb724031.tar.gz linux-d5b201ed4feb7a11da242a97669424efeb724031.zip | |
tracing: Make per-template BTF id lists file-local
DECLARE_EVENT_CLASS emitted __bpf_trace_btf_ids_<call> through
BTF_ID_LIST_GLOBAL, i.e. a global symbol named after the event class.
The class name is not unique across the kernel, so the symbol
multiply-defines whenever two translation units instantiate the same
class.
Switch to the file-local BTF_ID_LIST: the list is reached
only through the event_class_<call>.btf_ids pointer, initialised in the
same unit, so tracefs readers never reference the symbol by name and
resolve_btfids still fills the now-local .BTF_ids entries.
The handcrafted syscall classes are the one cross-unit consumer: give
them their own local BTF_ID_LIST rather than importing the generated
sys_{enter,exit} lists.
Link: https://patch.msgid.link/20260730-b4-fix_btf_tracefs-v2-1-6b66da8dc103@meta.com
Fixes: eadc0725ab8d3 ("tracing: Expose tracepoint BTF ids via tracefs")
Reported-by: Mark Brown <broonie@kernel.org>
Closes: https://lore.kernel.org/all/ff58b01c-3f5e-4d55-be82-609d2faaf12e@sirena.org.uk/
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include/trace')
| -rw-r--r-- | include/trace/trace_events.h | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/include/trace/trace_events.h b/include/trace/trace_events.h index 09ad57ac4b73..93011f800d0f 100644 --- a/include/trace/trace_events.h +++ b/include/trace/trace_events.h @@ -398,7 +398,7 @@ static inline notrace int trace_event_get_offsets_##call( \ #define _TRACE_PERF_INIT(call) #endif /* CONFIG_PERF_EVENTS */ -#ifdef CONFIG_BPF_EVENTS +#if defined(CONFIG_BPF_EVENTS) && defined(CONFIG_DEBUG_INFO_BTF) /* * Per-template BTF id list, populated at link time by resolve_btfids: * [0] FUNC __bpf_trace_<call> (the BPF dispatcher) @@ -406,8 +406,7 @@ static inline notrace int trace_event_get_offsets_##call( \ * Exposed via the events/<sys>/<name>/btf_ids tracefs file. */ #define _TRACE_BTF_IDS_DECLARE(call) \ - extern u32 __bpf_trace_btf_ids_##call[]; \ - BTF_ID_LIST_GLOBAL(__bpf_trace_btf_ids_##call, 2) \ + BTF_ID_LIST(__bpf_trace_btf_ids_##call) \ BTF_ID(func, __bpf_trace_##call) \ BTF_ID(struct, trace_event_raw_##call) @@ -417,7 +416,7 @@ static inline notrace int trace_event_get_offsets_##call( \ #else #define _TRACE_BTF_IDS_DECLARE(call) #define _TRACE_BTF_IDS_INIT(call) -#endif /* CONFIG_BPF_EVENTS */ +#endif /* CONFIG_BPF_EVENTS && CONFIG_DEBUG_INFO_BTF */ #include "stages/stage6_event_callback.h" |