Commit 726f177c authored by Anton Blanchard's avatar Anton Blanchard Committed by Sasha Levin

powerpc: Fix emulation of mfocrf in emulate_step()

[ Upstream commit 64e756c5 ]

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: 6888199f ("[POWERPC] Emulate more instructions in software")
Cc: stable@vger.kernel.org # v2.6.22+
Signed-off-by: default avatarAnton Blanchard <anton@samba.org>
Acked-by: default avatarNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Signed-off-by: default avatarSasha Levin <alexander.levin@verizon.com>
parent fb556d25
......@@ -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;
......
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