From 733c88d4da7984ec1ce65d6628ad0da25816b7a2 Mon Sep 17 00:00:00 2001 From: Anton Blanchard Date: Thu, 15 Jun 2017 09:46:39 +1000 Subject: [PATCH] powerpc: Fix emulation of mfocrf in emulate_step() commit 64e756c55aa46fc18fd53e8f3598b73b528d8637 upstream. From POWER4 onwards, mfocrf() only places the specified CR field into the destination GPR, and the rest of it is set to 0. The PowerPC AS from version 3.0 now requires this behaviour. The emulation code currently puts the entire CR into the destination GPR. Fix it. Fixes: 6888199f7fe5 ("[POWERPC] Emulate more instructions in software") Cc: stable@vger.kernel.org # v2.6.22+ Signed-off-by: Anton Blanchard Acked-by: Naveen N. Rao Signed-off-by: Michael Ellerman Signed-off-by: Willy Tarreau --- arch/powerpc/lib/sstep.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 08490ecc465e..23da15ff7796 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -863,6 +863,19 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) goto instr_done; #endif case 19: /* mfcr */ + if ((instr >> 20) & 1) { + imm = 0xf0000000UL; + for (sh = 0; sh < 8; ++sh) { + if (instr & (0x80000 >> sh)) { + regs->gpr[rd] = regs->ccr & imm; + break; + } + imm >>= 4; + } + + goto instr_done; + } + regs->gpr[rd] = regs->ccr; regs->gpr[rd] &= 0xffffffffUL; goto instr_done; -- 2.20.1