[PATCH 6.12 118/265] LoongArch/orc: Use RCU in all users of __module_address().

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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