diff options
| author | Ananth N Mavinakayanahalli <ananth@in.ibm.com> | 2006-04-28 17:38:42 +0530 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2006-05-03 23:06:41 +1000 |
| commit | 0ccde0a290b44b8296b82a7683b4c299eb51ba6b (patch) | |
| tree | cc586aa319da07dcda8f91e3ee03d9da960d5fac | |
| parent | 054d8ff37710efaebd1998ce94d366df315a354f (diff) | |
[PATCH] powerpc/kprobes: fix singlestep out-of-line
We currently single-step inline if the instruction on which a kprobe is
inserted is a trap variant.
- variants (such as tdnei, used by BUG()) typically evaluate a condition
and cause a trap only if the condition is satisfied.
- kprobes uses the unconditional "trap" (0x7fe00008) and single-stepping
again on this instruction, resulting in another trap without
evaluating the condition is obviously incorrect.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 856ef1a832b9..f78866367b70 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -90,15 +90,15 @@ void __kprobes arch_remove_kprobe(struct kprobe *p) static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) { - kprobe_opcode_t insn = *p->ainsn.insn; - regs->msr |= MSR_SE; - /* single step inline if it is a trap variant */ - if (is_trap(insn)) - regs->nip = (unsigned long)p->addr; - else - regs->nip = (unsigned long)p->ainsn.insn; + /* + * On powerpc we should single step on the original + * instruction even if the probed insn is a trap + * variant as values in regs could play a part in + * if the trap is taken or not + */ + regs->nip = (unsigned long)p->ainsn.insn; } static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) |