* [PATCH bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del
@ 2026-03-02 8:16 Jiri Olsa
2026-03-02 15:58 ` Alexei Starovoitov
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Jiri Olsa @ 2026-03-02 8:16 UTC (permalink / raw)
To: Steven Rostedt, Alexei Starovoitov
Cc: Ihor Solodrai, Kumar Kartikeya Dwivedi, bpf, linux-kernel,
linux-trace-kernel, Daniel Borkmann, Andrii Nakryiko,
Menglong Dong, Song Liu
Ihor and Kumar reported splat from ftrace_get_addr_curr [1], which happened
because of the missing ftrace_lock in update_ftrace_direct_add/del functions
allowing concurrent access to ftrace internals.
The ftrace_update_ops function must be guarded by ftrace_lock, adding that.
Fixes: 05dc5e9c1fe1 ("ftrace: Add update_ftrace_direct_add function")
Fixes: 8d2c1233f371 ("ftrace: Add update_ftrace_direct_del function")
Reported-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Closes: https://lore.kernel.org/bpf/1b58ffb2-92ae-433a-ba46-95294d6edea2@linux.dev/
Tested-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
kernel/trace/ftrace.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index 827fb9a0bf0d..8baf61c9be6d 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -6404,6 +6404,7 @@ int update_ftrace_direct_add(struct ftrace_ops *ops, struct ftrace_hash *hash)
new_filter_hash = old_filter_hash;
}
} else {
+ guard(mutex)(&ftrace_lock);
err = ftrace_update_ops(ops, new_filter_hash, EMPTY_HASH);
/*
* new_filter_hash is dup-ed, so we need to release it anyway,
@@ -6530,6 +6531,7 @@ int update_ftrace_direct_del(struct ftrace_ops *ops, struct ftrace_hash *hash)
ops->func_hash->filter_hash = NULL;
}
} else {
+ guard(mutex)(&ftrace_lock);
err = ftrace_update_ops(ops, new_filter_hash, EMPTY_HASH);
/*
* new_filter_hash is dup-ed, so we need to release it anyway,
--
2.53.0
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del
2026-03-02 8:16 [PATCH bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del Jiri Olsa
@ 2026-03-02 15:58 ` Alexei Starovoitov
2026-03-02 17:47 ` Steven Rostedt
2026-03-02 16:12 ` Steven Rostedt
2026-03-02 18:00 ` patchwork-bot+netdevbpf
2 siblings, 1 reply; 6+ messages in thread
From: Alexei Starovoitov @ 2026-03-02 15:58 UTC (permalink / raw)
To: Jiri Olsa
Cc: Steven Rostedt, Alexei Starovoitov, Ihor Solodrai,
Kumar Kartikeya Dwivedi, bpf, LKML, linux-trace-kernel,
Daniel Borkmann, Andrii Nakryiko, Menglong Dong, Song Liu
On Mon, Mar 2, 2026 at 12:16 AM Jiri Olsa <jolsa@kernel.org> wrote:
>
> Ihor and Kumar reported splat from ftrace_get_addr_curr [1], which happened
> because of the missing ftrace_lock in update_ftrace_direct_add/del functions
> allowing concurrent access to ftrace internals.
>
> The ftrace_update_ops function must be guarded by ftrace_lock, adding that.
>
> Fixes: 05dc5e9c1fe1 ("ftrace: Add update_ftrace_direct_add function")
> Fixes: 8d2c1233f371 ("ftrace: Add update_ftrace_direct_del function")
> Reported-by: Ihor Solodrai <ihor.solodrai@linux.dev>
> Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> Closes: https://lore.kernel.org/bpf/1b58ffb2-92ae-433a-ba46-95294d6edea2@linux.dev/
> Tested-by: Ihor Solodrai <ihor.solodrai@linux.dev>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
lgtm.
Steven,
should it land through ftrace tree?
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del
2026-03-02 15:58 ` Alexei Starovoitov
@ 2026-03-02 17:47 ` Steven Rostedt
2026-03-02 17:53 ` Alexei Starovoitov
0 siblings, 1 reply; 6+ messages in thread
From: Steven Rostedt @ 2026-03-02 17:47 UTC (permalink / raw)
To: Alexei Starovoitov
Cc: Jiri Olsa, Alexei Starovoitov, Ihor Solodrai,
Kumar Kartikeya Dwivedi, bpf, LKML, linux-trace-kernel,
Daniel Borkmann, Andrii Nakryiko, Menglong Dong, Song Liu
On Mon, 2 Mar 2026 07:58:11 -0800
Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> Steven,
> should it land through ftrace tree?
I added my review by tag. It's small enough that you can take it through
your tree.
Thanks,
-- Steve
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del
2026-03-02 17:47 ` Steven Rostedt
@ 2026-03-02 17:53 ` Alexei Starovoitov
0 siblings, 0 replies; 6+ messages in thread
From: Alexei Starovoitov @ 2026-03-02 17:53 UTC (permalink / raw)
To: Steven Rostedt
Cc: Jiri Olsa, Alexei Starovoitov, Ihor Solodrai,
Kumar Kartikeya Dwivedi, bpf, LKML, linux-trace-kernel,
Daniel Borkmann, Andrii Nakryiko, Menglong Dong, Song Liu
On Mon, Mar 2, 2026 at 9:47 AM Steven Rostedt <rostedt@kernel.org> wrote:
>
> On Mon, 2 Mar 2026 07:58:11 -0800
> Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
>
> > Steven,
> > should it land through ftrace tree?
>
> I added my review by tag. It's small enough that you can take it through
> your tree.
Ok. Applied.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del
2026-03-02 8:16 [PATCH bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del Jiri Olsa
2026-03-02 15:58 ` Alexei Starovoitov
@ 2026-03-02 16:12 ` Steven Rostedt
2026-03-02 18:00 ` patchwork-bot+netdevbpf
2 siblings, 0 replies; 6+ messages in thread
From: Steven Rostedt @ 2026-03-02 16:12 UTC (permalink / raw)
To: Jiri Olsa
Cc: Alexei Starovoitov, Ihor Solodrai, Kumar Kartikeya Dwivedi, bpf,
linux-kernel, linux-trace-kernel, Daniel Borkmann,
Andrii Nakryiko, Menglong Dong, Song Liu
On Mon, 2 Mar 2026 09:16:22 +0100
Jiri Olsa <jolsa@kernel.org> wrote:
> Ihor and Kumar reported splat from ftrace_get_addr_curr [1], which happened
> because of the missing ftrace_lock in update_ftrace_direct_add/del functions
> allowing concurrent access to ftrace internals.
>
> The ftrace_update_ops function must be guarded by ftrace_lock, adding that.
>
> Fixes: 05dc5e9c1fe1 ("ftrace: Add update_ftrace_direct_add function")
> Fixes: 8d2c1233f371 ("ftrace: Add update_ftrace_direct_del function")
> Reported-by: Ihor Solodrai <ihor.solodrai@linux.dev>
> Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> Closes: https://lore.kernel.org/bpf/1b58ffb2-92ae-433a-ba46-95294d6edea2@linux.dev/
> Tested-by: Ihor Solodrai <ihor.solodrai@linux.dev>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
-- Steve
> ---
> kernel/trace/ftrace.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index 827fb9a0bf0d..8baf61c9be6d 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -6404,6 +6404,7 @@ int update_ftrace_direct_add(struct ftrace_ops *ops, struct ftrace_hash *hash)
> new_filter_hash = old_filter_hash;
> }
> } else {
> + guard(mutex)(&ftrace_lock);
> err = ftrace_update_ops(ops, new_filter_hash, EMPTY_HASH);
> /*
> * new_filter_hash is dup-ed, so we need to release it anyway,
> @@ -6530,6 +6531,7 @@ int update_ftrace_direct_del(struct ftrace_ops *ops, struct ftrace_hash *hash)
> ops->func_hash->filter_hash = NULL;
> }
> } else {
> + guard(mutex)(&ftrace_lock);
> err = ftrace_update_ops(ops, new_filter_hash, EMPTY_HASH);
> /*
> * new_filter_hash is dup-ed, so we need to release it anyway,
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del
2026-03-02 8:16 [PATCH bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del Jiri Olsa
2026-03-02 15:58 ` Alexei Starovoitov
2026-03-02 16:12 ` Steven Rostedt
@ 2026-03-02 18:00 ` patchwork-bot+netdevbpf
2 siblings, 0 replies; 6+ messages in thread
From: patchwork-bot+netdevbpf @ 2026-03-02 18:00 UTC (permalink / raw)
To: Jiri Olsa
Cc: rostedt, ast, ihor.solodrai, memxor, bpf, linux-kernel,
linux-trace-kernel, daniel, andrii, menglong8.dong, song
Hello:
This patch was applied to bpf/bpf.git (master)
by Alexei Starovoitov <ast@kernel.org>:
On Mon, 2 Mar 2026 09:16:22 +0100 you wrote:
> Ihor and Kumar reported splat from ftrace_get_addr_curr [1], which happened
> because of the missing ftrace_lock in update_ftrace_direct_add/del functions
> allowing concurrent access to ftrace internals.
>
> The ftrace_update_ops function must be guarded by ftrace_lock, adding that.
>
> Fixes: 05dc5e9c1fe1 ("ftrace: Add update_ftrace_direct_add function")
> Fixes: 8d2c1233f371 ("ftrace: Add update_ftrace_direct_del function")
> Reported-by: Ihor Solodrai <ihor.solodrai@linux.dev>
> Reported-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> Closes: https://lore.kernel.org/bpf/1b58ffb2-92ae-433a-ba46-95294d6edea2@linux.dev/
> Tested-by: Ihor Solodrai <ihor.solodrai@linux.dev>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
>
> [...]
Here is the summary with links:
- [bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del
https://git.kernel.org/bpf/bpf/c/3ebc98c1ae7e
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 6+ messages in thread
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2026-03-02 8:16 [PATCH bpf] ftrace: Add missing ftrace_lock to update_ftrace_direct_add/del Jiri Olsa
2026-03-02 15:58 ` Alexei Starovoitov
2026-03-02 17:47 ` Steven Rostedt
2026-03-02 17:53 ` Alexei Starovoitov
2026-03-02 16:12 ` Steven Rostedt
2026-03-02 18:00 ` patchwork-bot+netdevbpf
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