From b03a5b7559563dafdbe52f8b5d8e453a914db941 Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 11 Aug 2008 12:27:16 +0100 Subject: [PATCH] [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: Russell King --- arch/arm/kernel/traps.c | 31 ++++++++++++++++++------------- 1 file changed, 18 insertions(+), 13 deletions(-) diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c index 7277aef83098..872f1f8fbb57 100644 --- a/arch/arm/kernel/traps.c +++ b/arch/arm/kernel/traps.c @@ -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); - return; - } - } - } - spin_unlock_irqrestore(&undef_lock, flags); + if (call_undef_hook(regs, instr) == 0) + return; #ifdef CONFIG_DEBUG_USER if (user_debug & UDBG_UNDEFINED) { -- 2.20.1