From 521c646108ed199d19c5c73978aaca3e18ca8f81 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Thu, 9 Feb 2017 15:19:20 +0000 Subject: [PATCH] arm64: cpufeature: correctly handle MRS to XZR In emulate_mrs() we may erroneously write back to the user SP rather than XZR if we trap an MRS instruction where Xt == 31. Use the new pt_regs_write_reg() helper to handle this correctly. Signed-off-by: Mark Rutland Fixes: 77c97b4ee21290f5 ("arm64: cpufeature: Expose CPUID registers by emulation") Cc: Andre Przywara Cc: Catalin Marinas Cc: Marc Zyngier Cc: Suzuki K Poulose Cc: Will Deacon Signed-off-by: Will Deacon --- arch/arm64/kernel/cpufeature.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index 1ee5357d0c6a..abda8e861865 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1214,7 +1214,7 @@ static int emulate_mrs(struct pt_regs *regs, u32 insn) rc = emulate_sys_reg(sys_reg, &val); if (!rc) { dst = aarch64_insn_decode_register(AARCH64_INSN_REGTYPE_RT, insn); - regs->user_regs.regs[dst] = val; + pt_regs_write_reg(regs, dst, val); regs->pc += 4; }