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| author | Ananth N Mavinakayanahalli <ananth@in.ibm.com> | 2010-05-27 19:19:20 +0000 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2010-06-02 17:50:37 +1000 |
| commit | db97bc7f9997fef41b24c91f61c2f776d32d7ce3 (patch) | |
| tree | ae35f82cc63a624966934efb63f30d7c2a8ab746 /arch/powerpc/kernel/kprobes.c | |
| parent | 83aea945c21c646184a494a32ad5524248b60226 (diff) | |
| download | lwn-db97bc7f9997fef41b24c91f61c2f776d32d7ce3.tar.gz lwn-db97bc7f9997fef41b24c91f61c2f776d32d7ce3.zip | |
powerpc/kprobes: Remove resume_execution() in kprobes
emulate_step() in kprobe_handler() would've already determined if the
probed instruction can be emulated. We single-step in hardware only if
the instruction couldn't be emulated. resume_execution() therefore is
superfluous -- all we need is to fix up the instruction pointer after
single-stepping.
Thanks to Paul Mackerras for catching this.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel/kprobes.c')
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 14 |
1 files changed, 2 insertions, 12 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index c533525ca56a..bc47352deb1f 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -378,17 +378,6 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, * single-stepped a copy of the instruction. The address of this * copy is p->ainsn.insn. */ -static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) -{ - int ret; - unsigned int insn = *p->ainsn.insn; - - regs->nip = (unsigned long)p->addr; - ret = emulate_step(regs, insn); - if (ret == 0) - regs->nip = (unsigned long)p->addr + 4; -} - static int __kprobes post_kprobe_handler(struct pt_regs *regs) { struct kprobe *cur = kprobe_running(); @@ -406,7 +395,8 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs) cur->post_handler(cur, regs, 0); } - resume_execution(cur, regs); + /* Adjust nip to after the single-stepped instruction */ + regs->nip = (unsigned long)cur->addr + 4; regs->msr |= kcb->kprobe_saved_msr; /*Restore back the original saved kprobes variables and continue. */ |