kprobes: support per-kprobe disabling
Add disable_kprobe() and enable_kprobe() to disable/enable kprobes
temporarily.
disable_kprobe() asynchronously disables probe handlers of specified
kprobe. So, after calling it, some handlers can be called at a while.
enable_kprobe() enables specified kprobe.
aggr_pre_handler and aggr_post_handler check disabled probes. On the
other hand aggr_break_handler and aggr_fault_handler don't check it
because these handlers will be called while executing pre or post handlers
and usually those help error handling.
Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 39826a6..1071cfd 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -112,18 +112,28 @@
/* copy of the original instruction */
struct arch_specific_insn ainsn;
- /* Indicates various status flags. Protected by kprobe_mutex. */
+ /*
+ * Indicates various status flags.
+ * Protected by kprobe_mutex after this kprobe is registered.
+ */
u32 flags;
};
/* Kprobe status flags */
#define KPROBE_FLAG_GONE 1 /* breakpoint has already gone */
+#define KPROBE_FLAG_DISABLED 2 /* probe is temporarily disabled */
+/* Has this kprobe gone ? */
static inline int kprobe_gone(struct kprobe *p)
{
return p->flags & KPROBE_FLAG_GONE;
}
+/* Is this kprobe disabled ? */
+static inline int kprobe_disabled(struct kprobe *p)
+{
+ return p->flags & (KPROBE_FLAG_DISABLED | KPROBE_FLAG_GONE);
+}
/*
* Special probe type that uses setjmp-longjmp type tricks to resume
* execution at a specified entry with a matching prototype corresponding
@@ -283,6 +293,9 @@
void kprobe_flush_task(struct task_struct *tk);
void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head *head);
+int disable_kprobe(struct kprobe *kp);
+int enable_kprobe(struct kprobe *kp);
+
#else /* !CONFIG_KPROBES: */
static inline int kprobes_built_in(void)
@@ -349,5 +362,13 @@
static inline void kprobe_flush_task(struct task_struct *tk)
{
}
+static inline int disable_kprobe(struct kprobe *kp)
+{
+ return -ENOSYS;
+}
+static inline int enable_kprobe(struct kprobe *kp)
+{
+ return -ENOSYS;
+}
#endif /* CONFIG_KPROBES */
#endif /* _LINUX_KPROBES_H */