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Commit 2bbb3c15 authored by Peng Du's avatar Peng Du Committed by Ruchi Kandoi
Browse files

arm64: kernel: check mode for get_user in undefinstr 



get_user() should be called only for user_mode undef instruction.

Change-Id: Ia654783de0cf72abac6847ac9630236f9f0d6ebb
Signed-off-by: default avatarPeng Du <pdu@nvidia.com>
Reviewed-on: http://git-master/r/441348


Reviewed-by: default avatarThomas Cherry <tcherry@nvidia.com>
Reviewed-by: default avatarBo Yan <byan@nvidia.com>
parent f0bb4ad7

arch/arm64/kernel/traps.c

+15 −11
Original line number Diff line number Diff line
@@ -289,6 +289,7 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) 
	/* check for AArch32 breakpoint instructions */

	if (!aarch32_break_handler(regs))

		return;

	if (user_mode(regs)) {

		if (compat_thumb_mode(regs)) {

			if (get_user(instr, (u16 __user *)pc))

				goto die_sig;
@@ -299,10 +300,13 @@ asmlinkage void __exception do_undefinstr(struct pt_regs *regs) 
				instr <<= 16;

				instr |= instr2;

			}



	} else if ((get_user(instr, (u32 __user *)pc))) {

		} else if (get_user(instr, (u32 __user *)pc)) {

			goto die_sig;

		}

	} else {

		/* kernel mode */

		instr = *((u32 *)pc);

	}



	if (call_undef_hook(regs, instr) == 0)

		return;