[ARM] 4183/1: do_undefinstr: read svc undefined instructions with svc privileges
do_undefinstr currently does not expect undefined instructions in kernel
code, since it always uses get_user() to read the instruction.
Dereference the 'pc' pointer directly in the SVC case.
Per Nicolas Pitre's note, kernel code is never in thumb mode.
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index 329609b..2409560 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -282,7 +282,10 @@
regs->ARM_pc -= correction;
pc = (void __user *)instruction_pointer(regs);
- if (thumb_mode(regs)) {
+
+ if (processor_mode(regs) == SVC_MODE) {
+ instr = *(u32 *) pc;
+ } else if (thumb_mode(regs)) {
get_user(instr, (u16 __user *)pc);
} else {
get_user(instr, (u32 __user *)pc);