Commit 14daa3bc authored by Sebastian Andrzej Siewior's avatar Sebastian Andrzej Siewior Committed by Petr Pavlu
Browse files

x86: Use RCU in all users of __module_address(). 



__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: H. Peter Anvin <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20250108090457.512198-23-bigeasy@linutronix.de


Signed-off-by: default avatarPetr Pavlu <petr.pavlu@suse.com>
parent e151955b

arch/x86/kernel/callthunks.c

+1 −2
Original line number Diff line number Diff line
@@ -98,11 +98,10 @@ static inline bool within_module_coretext(void *addr) 
#ifdef CONFIG_MODULES

	struct module *mod;



	preempt_disable();

	guard(rcu)();

	mod = __module_address((unsigned long)addr);

	if (mod && within_module_core((unsigned long)addr, mod))

		ret = true;

	preempt_enable();

#endif

	return ret;

}

arch/x86/kernel/unwind_orc.c

+1 −3
Original line number Diff line number Diff line
@@ -476,7 +476,7 @@ 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)();



	/* End-of-stack check for user tasks: */

	if (state->regs && user_mode(state->regs))
@@ -669,14 +669,12 @@ bool unwind_next_frame(struct unwind_state *state) 
		goto err;

	}



	preempt_enable();

	return true;



err:

	state->error = true;



the_end:

	preempt_enable();

	state->stack_info.type = STACK_TYPE_UNKNOWN;

	return false;

}