* [PATCH 6.12 118/265] LoongArch/orc: Use RCU in all users of __module_address(). [not found] <20260312201018.128816016@linuxfoundation.org> @ 2026-03-12 20:08 ` Greg Kroah-Hartman 2026-04-06 12:27 ` Harshit Mogalapalli 0 siblings, 1 reply; 3+ messages in thread From: Greg Kroah-Hartman @ 2026-03-12 20:08 UTC (permalink / raw) To: stable Cc: Greg Kroah-Hartman, patches, Huacai Chen, WANG Xuerui, loongarch, Sebastian Andrzej Siewior, Peter Zijlstra (Intel), Petr Pavlu, Sasha Levin 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; err: state->error = true; end: - preempt_enable(); state->stack_info.type = STACK_TYPE_UNKNOWN; return false; } -- 2.51.0 ^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH 6.12 118/265] LoongArch/orc: Use RCU in all users of __module_address(). 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 0 siblings, 1 reply; 3+ messages in thread From: Harshit Mogalapalli @ 2026-04-06 12:27 UTC (permalink / raw) To: Greg Kroah-Hartman, stable, Huacai Chen, Sebastian Andrzej Siewior, Sasha Levin Cc: patches, WANG Xuerui, loongarch, Peter Zijlstra (Intel), Petr Pavlu, Vegard Nossum 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/ Thanks, Harshit > err: > state->error = true; > > end: > - preempt_enable(); > state->stack_info.type = STACK_TYPE_UNKNOWN; > return false; > } ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH 6.12 118/265] LoongArch/orc: Use RCU in all users of __module_address(). 2026-04-06 12:27 ` Harshit Mogalapalli @ 2026-04-07 12:46 ` Huacai Chen 0 siblings, 0 replies; 3+ messages in thread From: Huacai Chen @ 2026-04-07 12:46 UTC (permalink / raw) To: Harshit Mogalapalli Cc: Greg Kroah-Hartman, stable, Sebastian Andrzej Siewior, Sasha Levin, patches, WANG Xuerui, loongarch, Peter Zijlstra (Intel), Petr Pavlu, Vegard Nossum 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; > > } > ^ permalink raw reply [flat|nested] 3+ messages in thread
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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
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