[POWERPC] user_regset PTRACE_SETREGS regression fix

The PTRACE_SETREGS request was only recently added on powerpc,
and gdb does not use it.  So it slipped through without getting
all the testing it should have had.

The user_regset changes had a simple bug in storing to all of
the 32-bit general registers block on 64-bit kernels.  This bug
only comes up with PTRACE_SETREGS, not PPC_PTRACE_SETREGS.
It causes a BUG_ON to hit, so this fix needs to go in ASAP.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 8 insertions, 2 deletions

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 7673e9865733..2a9fe97e4521 100644
--- a/arch/powerpc/kernel/ptrace.c
+++ b/arch/powerpc/kernel/ptrace.c
@@ -530,15 +530,21 @@ static int gpr32_set(struct task_struct *target,
                 --count;
         }
 
-        if (kbuf)
+        if (kbuf) {
                 for (; count > 0 && pos <= PT_MAX_PUT_REG; --count)
                         regs[pos++] = *k++;
-        else
+                for (; count > 0 && pos < PT_TRAP; --count, ++pos)
+                        ++k;
+        } else {
                 for (; count > 0 && pos <= PT_MAX_PUT_REG; --count) {
                         if (__get_user(reg, u++))
                                 return -EFAULT;
                         regs[pos++] = reg;
                 }
+                for (; count > 0 && pos < PT_TRAP; --count, ++pos)
+                        if (__get_user(reg, u++))
+                                return -EFAULT;
+        }
 
         if (count > 0 && pos == PT_TRAP) {
                 if (kbuf)