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powerpc: Fix ptrace compat wrapper for FPU register access

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The ptrace compat wrapper mishandles access to the fpu registers.  The
PTRACE_PEEKUSR and PTRACE_POKEUSR requests miscalculate the index into
the fpr array due to the broken FPINDEX macro.  The
PPC_PTRACE_PEEKUSR_3264 request needs to use the same formula that the
native ptrace interface uses when operating on the register number (as
opposed to the 4-byte offset).  The PPC_PTRACE_POKEUSR_3264 request
didn't take TS_FPRWIDTH into account.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Michael Neuling 2009-04-05 20:59:39 +00:00 committed by Paul Mackerras
parent c7d07fdd5a
commit bc826666e4
1 changed files with 11 additions and 4 deletions
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15
arch/powerpc/kernel/ptrace32.c
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@ -67,7 +67,8 @@ static long compat_ptrace_old(struct task_struct *child, long request,
/* Macros to workout the correct index for the FPR in the thread struct */
#define FPRNUMBER(i) (((i) - PT_FPR0) >> 1)
#define FPRHALF(i) (((i) - PT_FPR0) & 1)
#define FPRINDEX(i) TS_FPRWIDTH * FPRNUMBER(i) + FPRHALF(i)
#define FPRINDEX(i) TS_FPRWIDTH * FPRNUMBER(i) * 2 + FPRHALF(i)
#define FPRINDEX_3264(i) (TS_FPRWIDTH * ((i) - PT_FPR0))
long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
compat_ulong_t caddr, compat_ulong_t cdata)
@ -168,8 +169,9 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
CHECK_FULL_REGS(child->thread.regs);
if (numReg >= PT_FPR0) {
flush_fp_to_thread(child);
tmp = ((unsigned long int *)child->thread.fpr)
[FPRINDEX(numReg)];
/* get 64 bit FPR */
tmp = ((u64 *)child->thread.fpr)
[FPRINDEX_3264(numReg)];
} else { /* register within PT_REGS struct */
tmp = ptrace_get_reg(child, numReg);
}
@ -262,8 +264,13 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
freg = (freg & 0xfffffffful) | (data << 32);
ret = ptrace_put_reg(child, numReg, freg);
} else {
u64 *tmp;
flush_fp_to_thread(child);
((unsigned int *)child->thread.regs)[index] = data;
/* get 64 bit FPR ... */
tmp = &(((u64 *)child->thread.fpr)
[FPRINDEX_3264(numReg)]);
/* ... write the 32 bit part we want */
((u32 *)tmp)[index % 2] = data;
ret = 0;
}
break;