[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>
This commit is contained in:
Dan Williams 2007-02-13 17:11:34 +01:00 committed by Russell King
parent 6df26700c0
commit dfc544c721

View File

@ -282,7 +282,10 @@ asmlinkage void do_undefinstr(struct pt_regs *regs)
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);