If kip->nused is not zero, collect_one_slot() return false, otherwise do
a lot of linked list operations, reverse the processing order to make the
code if nesting more concise. __disable_kprobe() is the same as well.
Signed-off-by: Jinjie Ruan <ruanjin...@huawei.com>
---
kernel/kprobes.c | 79 ++++++++++++++++++++++++------------------------
1 file changed, 40 insertions(+), 39 deletions(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index ca3fa8652c49..98d71a5acb72 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -206,29 +206,29 @@ static bool collect_one_slot(struct kprobe_insn_page
*kip, int idx)
{
kip->slot_used[idx] = SLOT_CLEAN;
kip->nused--;
- if (kip->nused == 0) {
+ if (kip->nused != 0)
+ return false;
+
+ /*
+ * Page is no longer in use. Free it unless
+ * it's the last one. We keep the last one
+ * so as not to have to set it up again the
+ * next time somebody inserts a probe.
+ */
+ if (!list_is_singular(&kip->list)) {
/*
- * Page is no longer in use. Free it unless
- * it's the last one. We keep the last one
- * so as not to have to set it up again the
- * next time somebody inserts a probe.
+ * Record perf ksymbol unregister event before removing
+ * the page.
*/
- if (!list_is_singular(&kip->list)) {
- /*
- * Record perf ksymbol unregister event before removing
- * the page.
- */
- perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
- (unsigned long)kip->insns,
PAGE_SIZE, true,
- kip->cache->sym);
- list_del_rcu(&kip->list);
- synchronize_rcu();
- kip->cache->free(kip->insns);
- kfree(kip);
- }
- return true;
+ perf_event_ksymbol(PERF_RECORD_KSYMBOL_TYPE_OOL,
+ (unsigned long)kip->insns, PAGE_SIZE, true,
+ kip->cache->sym);
+ list_del_rcu(&kip->list);
+ synchronize_rcu();
+ kip->cache->free(kip->insns);
+ kfree(kip);
}
- return false;
+ return true;
}
static int collect_garbage_slots(struct kprobe_insn_cache *c)
@@ -1725,28 +1725,29 @@ static struct kprobe *__disable_kprobe(struct kprobe *p)
if (unlikely(orig_p == NULL))
return ERR_PTR(-EINVAL);
- if (!kprobe_disabled(p)) {
- /* Disable probe if it is a child probe */
- if (p != orig_p)
- p->flags |= KPROBE_FLAG_DISABLED;
+ if (kprobe_disabled(p))
+ return orig_p;
- /* Try to disarm and disable this/parent probe */
- if (p == orig_p || aggr_kprobe_disabled(orig_p)) {
- /*
- * Don't be lazy here. Even if 'kprobes_all_disarmed'
- * is false, 'orig_p' might not have been armed yet.
- * Note arm_all_kprobes() __tries__ to arm all kprobes
- * on the best effort basis.
- */
- if (!kprobes_all_disarmed && !kprobe_disabled(orig_p)) {
- ret = disarm_kprobe(orig_p, true);
- if (ret) {
- p->flags &= ~KPROBE_FLAG_DISABLED;
- return ERR_PTR(ret);
- }
+ /* Disable probe if it is a child probe */
+ if (p != orig_p)
+ p->flags |= KPROBE_FLAG_DISABLED;
+
+ /* Try to disarm and disable this/parent probe */
+ if (p == orig_p || aggr_kprobe_disabled(orig_p)) {
+ /*
+ * Don't be lazy here. Even if 'kprobes_all_disarmed'
+ * is false, 'orig_p' might not have been armed yet.
+ * Note arm_all_kprobes() __tries__ to arm all kprobes
+ * on the best effort basis.
+ */
+ if (!kprobes_all_disarmed && !kprobe_disabled(orig_p)) {
+ ret = disarm_kprobe(orig_p, true);
+ if (ret) {
+ p->flags &= ~KPROBE_FLAG_DISABLED;
+ return ERR_PTR(ret);
}
- orig_p->flags |= KPROBE_FLAG_DISABLED;
}
+ orig_p->flags |= KPROBE_FLAG_DISABLED;
}
return orig_p;
--
2.34.1
