From: Huacai Chen <chenhuacai@kernel.org>
To: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org,
Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
Sasha Levin <sashal@kernel.org>,
patches@lists.linux.dev, WANG Xuerui <kernel@xen0n.name>,
loongarch@lists.linux.dev,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Petr Pavlu <petr.pavlu@suse.com>,
Vegard Nossum <vegard.nossum@oracle.com>
Subject: Re: [PATCH 6.12 118/265] LoongArch/orc: Use RCU in all users of __module_address().
Date: Tue, 7 Apr 2026 20:46:40 +0800 [thread overview]
Message-ID: <CAAhV-H6Jihemh01mXx1wWU4QBw2-x5XwV=a7rUD5ZoJiQ56FDw@mail.gmail.com> (raw)
In-Reply-To: <28a3e1fc-b6e7-4d92-b949-7218a74b7231@oracle.com>
On Mon, Apr 6, 2026 at 8:28 PM Harshit Mogalapalli
<harshit.m.mogalapalli@oracle.com> wrote:
>
> Hi all,
>
> On 13/03/26 01:38, Greg Kroah-Hartman wrote:
> > 6.12-stable review patch. If anyone has any objections, please let me know.
> >
> > ------------------
> >
> > From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> >
> > [ Upstream commit f99d27d9feb755aee9350fc89f57814d7e1b4880 ]
> >
> > __module_address() can be invoked within a RCU section, there is no
> > requirement to have preemption disabled.
> >
> > Replace the preempt_disable() section around __module_address() with
> > RCU.
> >
> > Cc: Huacai Chen <chenhuacai@kernel.org>
> > Cc: WANG Xuerui <kernel@xen0n.name>
> > Cc: loongarch@lists.linux.dev
> > Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> > Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
> > Link: https://lore.kernel.org/r/20250108090457.512198-19-bigeasy@linutronix.de
> > Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
> > Stable-dep-of: 055c7e75190e ("LoongArch: Handle percpu handler address for ORC unwinder")
> > Signed-off-by: Sasha Levin <sashal@kernel.org>
> > ---
> > arch/loongarch/kernel/unwind_orc.c | 4 +---
> > 1 file changed, 1 insertion(+), 3 deletions(-)
> >
> > diff --git a/arch/loongarch/kernel/unwind_orc.c b/arch/loongarch/kernel/unwind_orc.c
> > index 471652c0c8653..59809c3406c03 100644
> > --- a/arch/loongarch/kernel/unwind_orc.c
> > +++ b/arch/loongarch/kernel/unwind_orc.c
> > @@ -399,7 +399,7 @@ bool unwind_next_frame(struct unwind_state *state)
> > return false;
> >
> > /* Don't let modules unload while we're reading their ORC data. */
> > - preempt_disable();
> > + guard(rcu)();
> >
> > if (is_entry_func(state->pc))
> > goto end;
> > @@ -514,14 +514,12 @@ bool unwind_next_frame(struct unwind_state *state)
> > if (!__kernel_text_address(state->pc))
> > goto err;
> >
> > - preempt_enable();
> > return true;
> >
>
>
> Looks like this is dependent on commit: 7d9dda6f628f ("module: Allow
> __module_address() to be called from RCU section."), so I feel pulling
> in this patch without the mentioned missing prerequisite is wrong. Can
> you please help review this ?
>
> This is also part of a feature series in
> https://lore.kernel.org/all/20250108090457.512198-13-bigeasy@linutronix.de/
Yes, I have also asked about this:
https://lore.kernel.org/stable/CAAhV-H7GxtWRZyAT=kedLEMu=C5wH--NUzRjwi3DKXzUq+QZjA@mail.gmail.com/
However, no answer and no action for this. I don't know what happened
to Greg and Sasha. Recently, similar accidents happen again and again.
Huacai
>
> Thanks,
> Harshit
>
> > err:
> > state->error = true;
> >
> > end:
> > - preempt_enable();
> > state->stack_info.type = STACK_TYPE_UNKNOWN;
> > return false;
> > }
>
prev parent reply other threads:[~2026-04-07 12:46 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20260312201018.128816016@linuxfoundation.org>
2026-03-12 20:08 ` [PATCH 6.12 118/265] LoongArch/orc: Use RCU in all users of __module_address() Greg Kroah-Hartman
2026-04-06 12:27 ` Harshit Mogalapalli
2026-04-07 12:46 ` Huacai Chen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAAhV-H6Jihemh01mXx1wWU4QBw2-x5XwV=a7rUD5ZoJiQ56FDw@mail.gmail.com' \
--to=chenhuacai@kernel.org \
--cc=bigeasy@linutronix.de \
--cc=gregkh@linuxfoundation.org \
--cc=harshit.m.mogalapalli@oracle.com \
--cc=kernel@xen0n.name \
--cc=loongarch@lists.linux.dev \
--cc=patches@lists.linux.dev \
--cc=peterz@infradead.org \
--cc=petr.pavlu@suse.com \
--cc=sashal@kernel.org \
--cc=stable@vger.kernel.org \
--cc=vegard.nossum@oracle.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).