From e698b9667879b79e479cc985f9d74ecf126e343e Mon Sep 17 00:00:00 2001 From: Paul Mackerras Date: Sat, 19 Jul 2014 17:47:57 +1000 Subject: [PATCH] powerpc: Fix bugs in emulate_step() This fixes some bugs in emulate_step(). First, the setting of the carry bit for the arithmetic right-shift instructions was not correct on 64-bit machines because we were masking with a mask of type int rather than unsigned long. Secondly, the sld (shift left doubleword) instruction was using the wrong instruction field for the register containing the shift count. Signed-off-by: Paul Mackerras Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/lib/sstep.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c index 412dd46dd0b7..5c09f365c842 100644 --- a/arch/powerpc/lib/sstep.c +++ b/arch/powerpc/lib/sstep.c @@ -1198,7 +1198,7 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) sh = regs->gpr[rb] & 0x3f; ival = (signed int) regs->gpr[rd]; regs->gpr[ra] = ival >> (sh < 32 ? sh : 31); - if (ival < 0 && (sh >= 32 || (ival & ((1 << sh) - 1)) != 0)) + if (ival < 0 && (sh >= 32 || (ival & ((1ul << sh) - 1)) != 0)) regs->xer |= XER_CA; else regs->xer &= ~XER_CA; @@ -1208,7 +1208,7 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) sh = rb; ival = (signed int) regs->gpr[rd]; regs->gpr[ra] = ival >> sh; - if (ival < 0 && (ival & ((1 << sh) - 1)) != 0) + if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0) regs->xer |= XER_CA; else regs->xer &= ~XER_CA; @@ -1216,7 +1216,7 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) #ifdef __powerpc64__ case 27: /* sld */ - sh = regs->gpr[rd] & 0x7f; + sh = regs->gpr[rb] & 0x7f; if (sh < 64) regs->gpr[ra] = regs->gpr[rd] << sh; else @@ -1235,7 +1235,7 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) sh = regs->gpr[rb] & 0x7f; ival = (signed long int) regs->gpr[rd]; regs->gpr[ra] = ival >> (sh < 64 ? sh : 63); - if (ival < 0 && (sh >= 64 || (ival & ((1 << sh) - 1)) != 0)) + if (ival < 0 && (sh >= 64 || (ival & ((1ul << sh) - 1)) != 0)) regs->xer |= XER_CA; else regs->xer &= ~XER_CA; @@ -1246,7 +1246,7 @@ int __kprobes emulate_step(struct pt_regs *regs, unsigned int instr) sh = rb | ((instr & 2) << 4); ival = (signed long int) regs->gpr[rd]; regs->gpr[ra] = ival >> sh; - if (ival < 0 && (ival & ((1 << sh) - 1)) != 0) + if (ival < 0 && (ival & ((1ul << sh) - 1)) != 0) regs->xer |= XER_CA; else regs->xer &= ~XER_CA; -- 2.11.4.GIT