diff options
| author | Jiri Olsa <jolsa@kernel.org> | 2026-01-12 13:11:56 +0100 |
|---|---|---|
| committer | Andrii Nakryiko <andrii@kernel.org> | 2026-01-15 16:15:25 -0800 |
| commit | 276f3b6daf6024ae2742afd161e7418a5584a660 (patch) | |
| tree | 1f93c852b612aee28bf0979890e8d3b792787485 /kernel/trace | |
| parent | 9a403a4aea32f1801a7f29b2385ec345d4faaf78 (diff) | |
| download | linux-next-276f3b6daf6024ae2742afd161e7418a5584a660.tar.gz linux-next-276f3b6daf6024ae2742afd161e7418a5584a660.zip | |
arm64/ftrace,bpf: Fix partial regs after bpf_prog_run
Mahe reported issue with bpf_override_return helper not working when
executed from kprobe.multi bpf program on arm.
The problem is that on arm we use alternate storage for pt_regs object
that is passed to bpf_prog_run and if any register is changed (which
is the case of bpf_override_return) it's not propagated back to actual
pt_regs object.
Fixing this by introducing and calling ftrace_partial_regs_update function
to propagate the values of changed registers (ip and stack).
Reported-by: Mahe Tardy <mahe.tardy@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/bpf/20260112121157.854473-1-jolsa@kernel.org
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 6e076485bf70..3a17f79b20c2 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -2564,6 +2564,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); err = bpf_prog_run(link->link.prog, regs); bpf_reset_run_ctx(old_run_ctx); + ftrace_partial_regs_update(fregs, bpf_kprobe_multi_pt_regs_ptr()); rcu_read_unlock(); out: |