From: Anton Blanchard Date: Wed, 14 Jun 2017 23:46:38 +0000 (+1000) Subject: powerpc: Fix emulation of mcrf in emulate_step() X-Git-Tag: C0P2-H0.0--20200415~8098 X-Git-Url: https://git.somdevices.com/?a=commitdiff_plain;h=53a28216131762700d10eb4755562b10c8d2685b;p=linux.git 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 Acked-by: Naveen N. Rao Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 6ca3b902f7b9..b6e4eca6e4a4 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;