From 592201a9f154cdd5db59304d1369e94d8b551803 Mon Sep 17 00:00:00 2001 From: Jon Medhurst Date: Sat, 26 Mar 2011 19:19:07 +0000 Subject: ARM: Thumb-2: Support Thumb-2 in undefined instruction handler This patch allows undef_hook's to be specified for 32-bit Thumb instructions and also to be used for thumb kernel-side code. 32-bit Thumb instructions are specified in the form: ((first_half << 16 ) | second_half) which matches the layout used by the ARM ARM. ptrace was handling 32-bit Thumb instructions by hooking the first halfword and manually checking the second half. This method would be broken by this patch so it is migrated to make use of the new Thumb-2 support. Signed-off-by: Jon Medhurst Acked-by: Nicolas Pitre --- arch/arm/kernel/ptrace.c | 28 +++------------------------- 1 file changed, 3 insertions(+), 25 deletions(-) (limited to 'arch/arm/kernel/ptrace.c') diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c index 97260060bf26..897ade059f58 100644 --- a/arch/arm/kernel/ptrace.c +++ b/arch/arm/kernel/ptrace.c @@ -228,34 +228,12 @@ static struct undef_hook thumb_break_hook = { .fn = break_trap, }; -static int thumb2_break_trap(struct pt_regs *regs, unsigned int instr) -{ - unsigned int instr2; - void __user *pc; - - /* Check the second half of the instruction. */ - pc = (void __user *)(instruction_pointer(regs) + 2); - - if (processor_mode(regs) == SVC_MODE) { - instr2 = *(u16 *) pc; - } else { - get_user(instr2, (u16 __user *)pc); - } - - if (instr2 == 0xa000) { - ptrace_break(current, regs); - return 0; - } else { - return 1; - } -} - static struct undef_hook thumb2_break_hook = { - .instr_mask = 0xffff, - .instr_val = 0xf7f0, + .instr_mask = 0xffffffff, + .instr_val = 0xf7f0a000, .cpsr_mask = PSR_T_BIT, .cpsr_val = PSR_T_BIT, - .fn = thumb2_break_trap, + .fn = break_trap, }; static int __init ptrace_break_init(void) -- cgit v1.2.3