Re: [PATCH 2/2] tracing: fprobe: Fix to remove recorded module addresses from filter

Masami Hiramatsu
2025-09-24T08:11:00Z

On Wed, 24 Sep 2025 11:49:39 +0800
menglong.dong@linux.dev wrote:

> On 2025/9/24 08:26 Masami Hiramatsu (Google) <mhiramat@kernel.org> write:
> > From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> >
> > Even if there is a memory allocation failure in fprobe_addr_list_add(),
> > there is a partial list of module addresses. So remove the recorded
> > addresses from filter if exists.
> > This also removes the redundant ret local variable.
> >
> > Fixes: a3dc2983ca7b ("tracing: fprobe: Cleanup fprobe hash when module unloading")
> > Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> > ---
> > kernel/trace/fprobe.c | 7 ++++---
> > 1 file changed, 4 insertions(+), 3 deletions(-)
>
> Hi, Masami. Should I send the V2 of the patch:
>
> tracing: fprobe: optimization for entry only case
>
> after this series applied?

Yeah, I'll push this [2/2] to stable tonight. and
push [1/2] to probes/for-next too. I'll rebase probes/for-next
so that it will have both patch.

Thank you,

>
> Thanks!
> Menglong Dong
>
> >
> > diff --git a/kernel/trace/fprobe.c b/kernel/trace/fprobe.c
> > index 12ec194fdfed..95e43814b85b 100644
> > --- a/kernel/trace/fprobe.c
> > +++ b/kernel/trace/fprobe.c
> > @@ -434,8 +434,9 @@ static int fprobe_addr_list_add(struct fprobe_addr_list *alist, unsigned long ad
> > {
> > unsigned long *addrs;
> >
> > - if (alist->index >= alist->size)
> > - return -ENOMEM;
> > + /* Previously we failed to expand the list. */
> > + if (alist->index == alist->size)
> > + return -ENOSPC;
> >
> > alist->addrs[alist->index++] = addr;
> > if (alist->index < alist->size)
> > @@ -497,7 +498,7 @@ static int fprobe_module_callback(struct notifier_block *nb,
> > } while (node == ERR_PTR(-EAGAIN));
> > rhashtable_walk_exit(&iter);
> >
> > - if (alist.index < alist.size && alist.index > 0)
> > + if (alist.index > 0)
> > ftrace_set_filter_ips(&fprobe_graph_ops.ops,
> > alist.addrs, alist.index, 1, 0);
> > mutex_unlock(&fprobe_mutex);
> >
> >
> >
>
>
>
>

--
Masami Hiramatsu (Google) <mhiramat@kernel.org>