diff options
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 17 |
1 files changed, 14 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index c2a6ab38a67f..4c1702423676 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -261,9 +261,20 @@ static int try_to_emulate(struct kprobe *p, struct pt_regs *regs) */ printk("Can't step on instruction %x\n", insn); BUG(); - } else - /* This instruction can't be boosted */ - p->ainsn.boostable = -1; + } else { + /* + * If we haven't previously emulated this instruction, then it + * can't be boosted. Note it down so we don't try to do so again. + * + * If, however, we had emulated this instruction in the past, + * then this is just an error with the current run (for + * instance, exceptions due to a load/store). We return 0 so + * that this is now single-stepped, but continue to try + * emulating it in subsequent probe hits. + */ + if (unlikely(p->ainsn.boostable != 1)) + p->ainsn.boostable = -1; + } return ret; } |