summaryrefslogtreecommitdiff
path: root/arch/powerpc
diff options
context:
space:
mode:
authorAnton Blanchard <anton@samba.org>2017-06-15 09:46:39 +1000
committerBen Hutchings <ben@decadent.org.uk>2017-10-12 15:27:16 +0100
commit8712783ddcba8851207e852b6acd2e0950e496b5 (patch)
treed3b4ca2058011470d5dfebacb30b870e44de05ae /arch/powerpc
parent19660de3f6528fba95eaaf322a997fbb1f241c1b (diff)
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") Signed-off-by: Anton Blanchard <anton@samba.org> Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'arch/powerpc')
-rw-r--r--arch/powerpc/lib/sstep.c13
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 9a52349874ee..6ca7fe0bd420 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;