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authorAnton Blanchard <anton@samba.org>2017-06-14 23:46:38 (GMT)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-07-27 22:07:59 (GMT)
commit53a28216131762700d10eb4755562b10c8d2685b (patch)
tree2e8a740cf793c3e0f5d67f76e9c31978c09c1fc0 /arch
parent99fc5a2254ef6409947e21b7b829cd59eb8234c5 (diff)
downloadlinux-53a28216131762700d10eb4755562b10c8d2685b.tar.xz
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 6ca3b90..b6e4eca 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;