Commit b03a5b75 authored by Russell King's avatar Russell King Committed by Russell King
Browse files

[ARM] traps: don't call undef hook functions with spinlock held 



Calling the undefined instruction handler functions with a
spinlock held is a recipe for must_sleep() warnings.  Avoid it.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent f64c0acc

arch/arm/kernel/traps.c

+18 −13
Original line number Diff line number Diff line
@@ -288,14 +288,28 @@ void unregister_undef_hook(struct undef_hook *hook) 
	spin_unlock_irqrestore(&undef_lock, flags);

}



static int call_undef_hook(struct pt_regs *regs, unsigned int instr)

{

	struct undef_hook *hook;

	unsigned long flags;

	int (*fn)(struct pt_regs *regs, unsigned int instr) = NULL;



	spin_lock_irqsave(&undef_lock, flags);

	list_for_each_entry(hook, &undef_hook, node)

		if ((instr & hook->instr_mask) == hook->instr_val &&

		    (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val)

			fn = hook->fn;

	spin_unlock_irqrestore(&undef_lock, flags);



	return fn ? fn(regs, instr) : 1;

}



asmlinkage void __exception do_undefinstr(struct pt_regs *regs)

{

	unsigned int correction = thumb_mode(regs) ? 2 : 4;

	unsigned int instr;

	struct undef_hook *hook;

	siginfo_t info;

	void __user *pc;

	unsigned long flags;



	/*

	 * According to the ARM ARM, PC is 2 or 4 bytes ahead,
@@ -325,17 +339,8 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) 
	}

#endif



	spin_lock_irqsave(&undef_lock, flags);

	list_for_each_entry(hook, &undef_hook, node) {

		if ((instr & hook->instr_mask) == hook->instr_val &&

		    (regs->ARM_cpsr & hook->cpsr_mask) == hook->cpsr_val) {

			if (hook->fn(regs, instr) == 0) {

				spin_unlock_irqrestore(&undef_lock, flags);

	if (call_undef_hook(regs, instr) == 0)

		return;

			}

		}

	}

	spin_unlock_irqrestore(&undef_lock, flags);



#ifdef CONFIG_DEBUG_USER

	if (user_debug & UDBG_UNDEFINED) {