src/patches/suse-2.6.27.25/patches.arch/ppc32-fix-ptrace-compat-wrapper-for-fpu-register-access

   1 From: Michael Neuling <mikey@neuling.org>
   2 Subject: powerpc: Fix ptrace compat wrapper for FPU register access
   3 Patch-mainline: 2.6.30-rc4
   4 Git-commit: bc826666e4252f78d2b144af3b7d699ff5efce0a
   5 References: bnc#496027
   6
   7 powerpc: Fix ptrace compat wrapper for FPU register access
   8
   9 The ptrace compat wrapper mishandles access to the fpu registers.  The
  10 PTRACE_PEEKUSR and PTRACE_POKEUSR requests miscalculate the index into
  11 the fpr array due to the broken FPINDEX macro.  The
  12 PPC_PTRACE_PEEKUSR_3264 request needs to use the same formula that the
  13 native ptrace interface uses when operating on the register number (as
  14 opposed to the 4-byte offset).  The PPC_PTRACE_POKEUSR_3264 request
  15 didn't take TS_FPRWIDTH into account.
  16
  17 Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
  18 Signed-off-by: Michael Neuling <mikey@neuling.org>
  19 Signed-off-by: Paul Mackerras <paulus@samba.org>
  20 Acked-by: Jeff Mahoney <jeffm@suse.com>
  21 ---
  22  arch/powerpc/kernel/ptrace32.c |   15 +++++++++++----
  23  1 file changed, 11 insertions(+), 4 deletions(-)
  24
  25 --- a/arch/powerpc/kernel/ptrace32.c
  26 +++ b/arch/powerpc/kernel/ptrace32.c
  27 @@ -70,7 +70,8 @@ static long compat_ptrace_old(struct tas
  28  /* Macros to workout the correct index for the FPR in the thread struct */
  29  #define FPRNUMBER(i) (((i) - PT_FPR0) >> 1)
  30  #define FPRHALF(i) (((i) - PT_FPR0) & 1)
  31 -#define FPRINDEX(i) TS_FPRWIDTH * FPRNUMBER(i) + FPRHALF(i)
  32 +#define FPRINDEX(i) TS_FPRWIDTH * FPRNUMBER(i) * 2 + FPRHALF(i)
  33 +#define FPRINDEX_3264(i) (TS_FPRWIDTH * ((i) - PT_FPR0))
  34
  35  static int compat_ptrace_getsiginfo(struct task_struct *child, compat_siginfo_t __user *data)
  36  {
  37 @@ -192,8 +193,9 @@ long compat_arch_ptrace(struct task_stru
  38                 CHECK_FULL_REGS(child->thread.regs);
  39                 if (numReg >= PT_FPR0) {
  40                         flush_fp_to_thread(child);
  41 -                       tmp = ((unsigned long int *)child->thread.fpr)
  42 -                               [FPRINDEX(numReg)];
  43 +                       /* get 64 bit FPR */
  44 +                       tmp = ((u64 *)child->thread.fpr)
  45 +                               [FPRINDEX_3264(numReg)];
  46                 } else { /* register within PT_REGS struct */
  47                         tmp = ptrace_get_reg(child, numReg);
  48                 }
  49 @@ -286,8 +288,13 @@ long compat_arch_ptrace(struct task_stru
  50                                 freg = (freg & 0xfffffffful) | (data << 32);
  51                         ret = ptrace_put_reg(child, numReg, freg);
  52                 } else {
  53 +                       u64 *tmp;
  54                         flush_fp_to_thread(child);
  55 -                       ((unsigned int *)child->thread.regs)[index] = data;
  56 +                       /* get 64 bit FPR ... */
  57 +                       tmp = &(((u64 *)child->thread.fpr)
  58 +                               [FPRINDEX_3264(numReg)]);
  59 +                       /* ... write the 32 bit part we want */
  60 +                       ((u32 *)tmp)[index % 2] = data;
  61                         ret = 0;
  62                 }
  63                 break;