| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.12 053/196] powerpc: Fix emulation of mcrf in emulate_step() | Date | Tue, 25 Jul 2017 12:20:52 -0700 |
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4.12-stable review patch. If anyone has any objections, please let me know.
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From: Anton Blanchard <anton@samba.org>
commit 87c4b83e0fe234a1f0eed131ab6fa232036860d5 upstream.
The mcrf emulation code was using the CR field number directly as the shift value, without taking into account that CR fields are numbered from 0-7 starting at the high bits. That meant it was looking at the CR fields in the reverse order.
Fixes: cf87c3f6b647 ("powerpc: Emulate icbi, mcrf and conditional-trap instructions") 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>
--- arch/powerpc/lib/sstep.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
--- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -683,8 +683,10 @@ int analyse_instr(struct instruction_op case 19: switch ((instr >> 1) & 0x3ff) { case 0: /* mcrf */ - rd = (instr >> 21) & 0x1c; - ra = (instr >> 16) & 0x1c; + rd = 7 - ((instr >> 23) & 0x7); + ra = 7 - ((instr >> 18) & 0x7); + rd *= 4; + ra *= 4; val = (regs->ccr >> ra) & 0xf; regs->ccr = (regs->ccr & ~(0xfUL << rd)) | (val << rd); goto instr_done;
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