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authorAnton Blanchard <anton@samba.org>2017-06-15 09:46:39 +1000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-27 15:06:05 -0700
commit79afeb379cf496cad4cb0aefb8ed4f9670a74f18 (patch)
treee96e8efe7e7102c2d61dd082b7906cfbed1c684a
parent397722322954dcac604dac53de2a84d963eac517 (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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-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 8bf5c0bf9795..e37162d356d8 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -969,6 +969,19 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
#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;