Commit dfc544c7 authored Feb 13, 2007 by Dan Williams Committed by Russell King Feb 14, 2007

[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>

parent 6df26700

arch/arm/kernel/traps.c

+4 −1

Original line number	Diff line number	Diff line
		@@ -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);

Admin message