[PATCH] powerpc: user_regset PTRACE_SETREGS regression fix

From: Roland McGrath
Date: Thu Mar 13 2008 - 04:26:54 EST



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@xxxxxxxxxx>
---
arch/powerpc/kernel/ptrace.c | 10 ++++++++--
1 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/ptrace.c b/arch/powerpc/kernel/ptrace.c
index 7673e98..2a9fe97 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)
--
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