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authorMasami Hiramatsu <mhiramat@kernel.org>2018-09-11 19:20:40 +0900
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-11-13 11:16:50 -0800
commit6c8b1db819e6948f27d1aa03c111965b3db73362 (patch)
tree5aca726ef212f52d123f48ea7f7de9ba201c39aa /kernel/kprobes.c
parentd5b19a43871343bedf6524a1e69c2e4c8970b9a0 (diff)
kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()
[ Upstream commit 819319fc93461c07b9cdb3064f154bd8cfd48172 ] Make reuse_unused_kprobe() to return error code if it fails to reuse unused kprobe for optprobe instead of calling BUG_ON(). Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: David S . Miller <davem@davemloft.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naveen N . Rao <naveen.n.rao@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/153666124040.21306.14150398706331307654.stgit@devbox Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel/kprobes.c')
-rw-r--r--kernel/kprobes.c27
1 files changed, 20 insertions, 7 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index b9e966bcdd20..f580352cc6e5 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -665,9 +665,10 @@ static void unoptimize_kprobe(struct kprobe *p, bool force)
}
/* Cancel unoptimizing for reusing */
-static void reuse_unused_kprobe(struct kprobe *ap)
+static int reuse_unused_kprobe(struct kprobe *ap)
{
struct optimized_kprobe *op;
+ int ret;
BUG_ON(!kprobe_unused(ap));
/*
@@ -681,8 +682,12 @@ static void reuse_unused_kprobe(struct kprobe *ap)
/* Enable the probe again */
ap->flags &= ~KPROBE_FLAG_DISABLED;
/* Optimize it again (remove from op->list) */
- BUG_ON(!kprobe_optready(ap));
+ ret = kprobe_optready(ap);
+ if (ret)
+ return ret;
+
optimize_kprobe(ap);
+ return 0;
}
/* Remove optimized instructions */
@@ -894,11 +899,16 @@ static void __disarm_kprobe(struct kprobe *p, bool reopt)
#define kprobe_disarmed(p) kprobe_disabled(p)
#define wait_for_kprobe_optimizer() do {} while (0)
-/* There should be no unused kprobes can be reused without optimization */
-static void reuse_unused_kprobe(struct kprobe *ap)
+static int reuse_unused_kprobe(struct kprobe *ap)
{
+ /*
+ * If the optimized kprobe is NOT supported, the aggr kprobe is
+ * released at the same time that the last aggregated kprobe is
+ * unregistered.
+ * Thus there should be no chance to reuse unused kprobe.
+ */
printk(KERN_ERR "Error: There should be no unused kprobe here.\n");
- BUG_ON(kprobe_unused(ap));
+ return -EINVAL;
}
static void free_aggr_kprobe(struct kprobe *p)
@@ -1276,9 +1286,12 @@ static int register_aggr_kprobe(struct kprobe *orig_p, struct kprobe *p)
goto out;
}
init_aggr_kprobe(ap, orig_p);
- } else if (kprobe_unused(ap))
+ } else if (kprobe_unused(ap)) {
/* This probe is going to die. Rescue it */
- reuse_unused_kprobe(ap);
+ ret = reuse_unused_kprobe(ap);
+ if (ret)
+ goto out;
+ }
if (kprobe_gone(ap)) {
/*