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authorAnton Blanchard <anton@samba.org>2017-06-15 09:46:38 +1000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-27 15:06:05 -0700
commit397722322954dcac604dac53de2a84d963eac517 (patch)
tree179fc333263d06a05537557fe14046376e77b42b /arch
parent3f888d1e40ad42783fd02366f04480642bed1f30 (diff)
powerpc: Fix emulation of mcrf in emulate_step()
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>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/lib/sstep.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
index 4014881e9843..8bf5c0bf9795 100644
--- a/arch/powerpc/lib/sstep.c
+++ b/arch/powerpc/lib/sstep.c
@@ -687,8 +687,10 @@ int __kprobes analyse_instr(struct instruction_op *op, struct pt_regs *regs,
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;