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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 15:08:00 -0700
commit5e35ee249e26e36cae641bee8d212fba0e1bb6e6 (patch)
tree9d315e0e898d38c375d315a3f674c9989f9d9d4b /arch
parent53a28216131762700d10eb4755562b10c8d2685b (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>
Diffstat (limited to 'arch')
-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 b6e4eca6e4a4..776c1a1f9bc2 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -970,6 +970,19 @@ 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;