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powerpc: Fix bugs in emulate_step()

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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 <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
This commit is contained in:
Paul Mackerras 2014-07-19 17:47:57 +10:00 committed by Benjamin Herrenschmidt
parent bd6ba3518f
commit e698b96678
1 changed files with 5 additions and 5 deletions
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10
arch/powerpc/lib/sstep.c
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@ -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;