ARM: 5912/1: Define a 32-bit Thumb-2 breakpoint instruction

Recognize 0xf7f0 0xa000 as a 32-bit breakpoint instruction for
Thumb-2.

Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/kernel/ptrace.c b/arch/arm/kernel/ptrace.c
index a2ea385..bd56673 100644 (file)
--- a/arch/arm/kernel/ptrace.c
+++ b/arch/arm/kernel/ptrace.c
@@ -499,10 +499,41 @@ 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,
+       .cpsr_mask      = PSR_T_BIT,
+       .cpsr_val       = PSR_T_BIT,
+       .fn             = thumb2_break_trap,
+};
+
 static int __init ptrace_break_init(void)
 {
        register_undef_hook(&arm_break_hook);
        register_undef_hook(&thumb_break_hook);
+       register_undef_hook(&thumb2_break_hook);
        return 0;
 }