Christophe Leroy wrote:
if (a) {
if (b)
do_something();
}
Is equivalent to
if (a & b)
do_something();
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
arch/powerpc/kernel/kprobes.c | 58 +++++++++++++++++------------------
1 file changed, 28 insertions(+), 30 deletions(-)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 7a925eb76ec0..d7c80a078c1e 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -277,38 +277,36 @@ int kprobe_handler(struct pt_regs *regs)
/* Check we're not actually recursing */
p = get_kprobe(addr);
- if (kprobe_running()) {
- if (p) {
- kprobe_opcode_t insn = *p->ainsn.insn;
- if (kcb->kprobe_status == KPROBE_HIT_SS &&
- is_trap(insn)) {
- /* Turn off 'trace' bits */
- regs->msr &= ~MSR_SINGLESTEP;
- regs->msr |= kcb->kprobe_saved_msr;
- goto no_kprobe;
- }
- /* We have reentered the kprobe_handler(), since
- * another probe was hit while within the handler.
- * We here save the original kprobes variables and
- * just single step on the instruction of the new probe
- * without calling any user handlers.
- */
- save_previous_kprobe(kcb);
- set_current_kprobe(p, regs, kcb);
- kprobes_inc_nmissed_count(p);
- kcb->kprobe_status = KPROBE_REENTER;
- if (p->ainsn.boostable >= 0) {
- ret = try_to_emulate(p, regs);
-
- if (ret > 0) {
- restore_previous_kprobe(kcb);
- preempt_enable_no_resched();
- return 1;
- }
+ if (kprobe_running() && p) {
+ kprobe_opcode_t insn = *p->ainsn.insn;
+
+ if (kcb->kprobe_status == KPROBE_HIT_SS && is_trap(insn)) {
+ /* Turn off 'trace' bits */
+ regs->msr &= ~MSR_SINGLESTEP;
+ regs->msr |= kcb->kprobe_saved_msr;
+ goto no_kprobe;
+ }
+ /* We have reentered the kprobe_handler(), since
+ * another probe was hit while within the handler.
+ * We here save the original kprobes variables and
+ * just single step on the instruction of the new probe
+ * without calling any user handlers.
+ */
+ save_previous_kprobe(kcb);
+ set_current_kprobe(p, regs, kcb);
+ kprobes_inc_nmissed_count(p);
+ kcb->kprobe_status = KPROBE_REENTER;
+ if (p->ainsn.boostable >= 0) {
+ ret = try_to_emulate(p, regs);
+
+ if (ret > 0) {
+ restore_previous_kprobe(kcb);
+ preempt_enable_no_resched();
+ return 1;
}
- prepare_singlestep(p, regs);
- return 1;
}
+ prepare_singlestep(p, regs);
+ return 1;
}
If we move the below !p case before the check for kprobe_running() right
after get_kprobe(), we won't need to check for (p) above and we won't
have any change in logic from Patch 1.
if (!p) {
- Naveen
