diff options
| author | Song Liu <songliubraving@fb.com> | 2021-09-10 11:33:51 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2021-09-13 10:53:50 -0700 |
| commit | 856c02dbce4f8d6a5644083db22c11750aa11481 (patch) | |
| tree | 3c3230ddfc3a5e7a03b30614b3da5aa2cc6cfe86 /kernel/bpf/trampoline.c | |
| parent | c22ac2a3d4bd83411ebf0b1726e9e5fc4f5e7ebf (diff) | |
bpf: Introduce helper bpf_get_branch_snapshot
Introduce bpf_get_branch_snapshot(), which allows tracing pogram to get
branch trace from hardware (e.g. Intel LBR). To use the feature, the
user need to create perf_event with proper branch_record filtering
on each cpu, and then calls bpf_get_branch_snapshot in the bpf function.
On Intel CPUs, VLBR event (raw event 0x1b00) can be use for this.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210910183352.3151445-3-songliubraving@fb.com
Diffstat (limited to 'kernel/bpf/trampoline.c')
| -rw-r--r-- | kernel/bpf/trampoline.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index fe1e857324e6..39eaaff81953 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -10,6 +10,7 @@ #include <linux/rcupdate_trace.h> #include <linux/rcupdate_wait.h> #include <linux/module.h> +#include <linux/static_call.h> /* dummy _ops. The verifier will operate on target program's ops. */ const struct bpf_verifier_ops bpf_extension_verifier_ops = { @@ -526,7 +527,7 @@ out: } #define NO_START_TIME 1 -static u64 notrace bpf_prog_start_time(void) +static __always_inline u64 notrace bpf_prog_start_time(void) { u64 start = NO_START_TIME; |