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-rw-r--r--kernel/kprobes.c60
1 files changed, 30 insertions, 30 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 5016bfb..a55bfad 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -518,20 +518,20 @@ static inline void copy_kprobe(struct kprobe *old_p, struct kprobe *p)
}
/*
-* Add the new probe to old_p->list. Fail if this is the
+* Add the new probe to ap->list. Fail if this is the
* second jprobe at the address - two jprobes can't coexist
*/
-static int __kprobes add_new_kprobe(struct kprobe *old_p, struct kprobe *p)
+static int __kprobes add_new_kprobe(struct kprobe *ap, struct kprobe *p)
{
if (p->break_handler) {
- if (old_p->break_handler)
+ if (ap->break_handler)
return -EEXIST;
- list_add_tail_rcu(&p->list, &old_p->list);
- old_p->break_handler = aggr_break_handler;
+ list_add_tail_rcu(&p->list, &ap->list);
+ ap->break_handler = aggr_break_handler;
} else
- list_add_rcu(&p->list, &old_p->list);
- if (p->post_handler && !old_p->post_handler)
- old_p->post_handler = aggr_post_handler;
+ list_add_rcu(&p->list, &ap->list);
+ if (p->post_handler && !ap->post_handler)
+ ap->post_handler = aggr_post_handler;
return 0;
}
@@ -544,6 +544,7 @@ static inline void add_aggr_kprobe(struct kprobe *ap, struct kprobe *p)
copy_kprobe(p, ap);
flush_insn_slot(ap);
ap->addr = p->addr;
+ ap->flags = p->flags;
ap->pre_handler = aggr_pre_handler;
ap->fault_handler = aggr_fault_handler;
/* We don't care the kprobe which has gone. */
@@ -566,44 +567,43 @@ static int __kprobes register_aggr_kprobe(struct kprobe *old_p,
struct kprobe *p)
{
int ret = 0;
- struct kprobe *ap;
+ struct kprobe *ap = old_p;
- if (kprobe_gone(old_p)) {
+ if (old_p->pre_handler != aggr_pre_handler) {
+ /* If old_p is not an aggr_probe, create new aggr_kprobe. */
+ ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL);
+ if (!ap)
+ return -ENOMEM;
+ add_aggr_kprobe(ap, old_p);
+ }
+
+ if (kprobe_gone(ap)) {
/*
* Attempting to insert new probe at the same location that
* had a probe in the module vaddr area which already
* freed. So, the instruction slot has already been
* released. We need a new slot for the new probe.
*/
- ret = arch_prepare_kprobe(old_p);
+ ret = arch_prepare_kprobe(ap);
if (ret)
+ /*
+ * Even if fail to allocate new slot, don't need to
+ * free aggr_probe. It will be used next time, or
+ * freed by unregister_kprobe.
+ */
return ret;
- }
- if (old_p->pre_handler == aggr_pre_handler) {
- copy_kprobe(old_p, p);
- ret = add_new_kprobe(old_p, p);
- ap = old_p;
- } else {
- ap = kzalloc(sizeof(struct kprobe), GFP_KERNEL);
- if (!ap) {
- if (kprobe_gone(old_p))
- arch_remove_kprobe(old_p);
- return -ENOMEM;
- }
- add_aggr_kprobe(ap, old_p);
- copy_kprobe(ap, p);
- ret = add_new_kprobe(ap, p);
- }
- if (kprobe_gone(old_p)) {
+ /* Clear gone flag to prevent allocating new slot again. */
+ ap->flags &= ~KPROBE_FLAG_GONE;
/*
* If the old_p has gone, its breakpoint has been disarmed.
* We have to arm it again after preparing real kprobes.
*/
- ap->flags &= ~KPROBE_FLAG_GONE;
if (kprobe_enabled)
arch_arm_kprobe(ap);
}
- return ret;
+
+ copy_kprobe(ap, p);
+ return add_new_kprobe(ap, p);
}
static int __kprobes in_kprobes_functions(unsigned long addr)
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