* [PATCH] ftrace: fix address for jmp mode in t_show
@ 2025-12-16 3:45 Menglong Dong
2025-12-16 16:28 ` Steven Rostedt
0 siblings, 1 reply; 3+ messages in thread
From: Menglong Dong @ 2025-12-16 3:45 UTC (permalink / raw)
To: rostedt
Cc: mhiramat, mark.rutland, mathieu.desnoyers, menglong8.dong, ast,
jiang.biao, linux-kernel, linux-trace-kernel
The address from ftrace_find_rec_direct() is printed directly in t_show().
This can mislead symbol offsets if it has the "jmp" bit in the last bit.
Fix this by printing the address that returned by ftrace_jmp_get().
Fixes: 25e4e3565d45 ("ftrace: Introduce FTRACE_OPS_FL_JMP")
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
---
kernel/trace/ftrace.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
index bbb37c0f8c6c..d4c41fb76a25 100644
--- a/kernel/trace/ftrace.c
+++ b/kernel/trace/ftrace.c
@@ -4492,8 +4492,12 @@ static int t_show(struct seq_file *m, void *v)
unsigned long direct;
direct = ftrace_find_rec_direct(rec->ip);
- if (direct)
- seq_printf(m, "\n\tdirect-->%pS", (void *)direct);
+ if (direct) {
+ seq_printf(m, ftrace_is_jmp(direct) ?
+ "\n\tdirect(jmp)-->%pS" :
+ "\n\tdirect-->%pS",
+ (void *)ftrace_jmp_get(direct));
+ }
}
}
--
2.52.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] ftrace: fix address for jmp mode in t_show
2025-12-16 3:45 [PATCH] ftrace: fix address for jmp mode in t_show Menglong Dong
@ 2025-12-16 16:28 ` Steven Rostedt
2025-12-17 1:32 ` Menglong Dong
0 siblings, 1 reply; 3+ messages in thread
From: Steven Rostedt @ 2025-12-16 16:28 UTC (permalink / raw)
To: Menglong Dong
Cc: mhiramat, mark.rutland, mathieu.desnoyers, ast, jiang.biao,
linux-kernel, linux-trace-kernel
On Tue, 16 Dec 2025 11:45:33 +0800
Menglong Dong <menglong8.dong@gmail.com> wrote:
> diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> index bbb37c0f8c6c..d4c41fb76a25 100644
> --- a/kernel/trace/ftrace.c
> +++ b/kernel/trace/ftrace.c
> @@ -4492,8 +4492,12 @@ static int t_show(struct seq_file *m, void *v)
> unsigned long direct;
>
> direct = ftrace_find_rec_direct(rec->ip);
> - if (direct)
> - seq_printf(m, "\n\tdirect-->%pS", (void *)direct);
> + if (direct) {
> + seq_printf(m, ftrace_is_jmp(direct) ?
> + "\n\tdirect(jmp)-->%pS" :
> + "\n\tdirect-->%pS",
> + (void *)ftrace_jmp_get(direct));
A little cleaner way to do the above:
seq_printf(m, "\n\tdirect%s-->%pS",
ftrace_is_jmp(direct) ? "(jmp)" : "",
(void *)ftrace_jmp_get(direct));
-- Steve
> + }
> }
> }
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: [PATCH] ftrace: fix address for jmp mode in t_show
2025-12-16 16:28 ` Steven Rostedt
@ 2025-12-17 1:32 ` Menglong Dong
0 siblings, 0 replies; 3+ messages in thread
From: Menglong Dong @ 2025-12-17 1:32 UTC (permalink / raw)
To: Menglong Dong, Steven Rostedt
Cc: mhiramat, mark.rutland, mathieu.desnoyers, ast, jiang.biao,
linux-kernel, linux-trace-kernel
On 2025/12/17 00:28 Steven Rostedt <rostedt@goodmis.org> write:
> On Tue, 16 Dec 2025 11:45:33 +0800
> Menglong Dong <menglong8.dong@gmail.com> wrote:
>
> > diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c
> > index bbb37c0f8c6c..d4c41fb76a25 100644
> > --- a/kernel/trace/ftrace.c
> > +++ b/kernel/trace/ftrace.c
> > @@ -4492,8 +4492,12 @@ static int t_show(struct seq_file *m, void *v)
> > unsigned long direct;
> >
> > direct = ftrace_find_rec_direct(rec->ip);
> > - if (direct)
> > - seq_printf(m, "\n\tdirect-->%pS", (void *)direct);
> > + if (direct) {
> > + seq_printf(m, ftrace_is_jmp(direct) ?
> > + "\n\tdirect(jmp)-->%pS" :
> > + "\n\tdirect-->%pS",
> > + (void *)ftrace_jmp_get(direct));
>
> A little cleaner way to do the above:
>
> seq_printf(m, "\n\tdirect%s-->%pS",
> ftrace_is_jmp(direct) ? "(jmp)" : "",
> (void *)ftrace_jmp_get(direct));
Yeah, looks better. I'll send a V2 later.
Thanks!
Menglong Dong
>
>
> -- Steve
>
> > + }
> > }
> > }
>
>
^ permalink raw reply [flat|nested] 3+ messages in thread
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2025-12-16 3:45 [PATCH] ftrace: fix address for jmp mode in t_show Menglong Dong
2025-12-16 16:28 ` Steven Rostedt
2025-12-17 1:32 ` Menglong Dong
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