[PATCH v3 18/28] LoongArch/orc: Use RCU in all users of __module_address().

From: Sebastian Andrzej Siewior
Date: Wed Jan 08 2025 - 04:07:54 EST


__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@xxxxxxxxxx>
Cc: WANG Xuerui <kernel@xxxxxxxxxx>
Cc: loongarch@xxxxxxxxxxxxxxx
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
---
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 b257228763317..d623935a75471 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;
}
--
2.47.1