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From: Masami Hiramatsu <mhiramat@kernel.org>
To: Ingo Molnar <mingo@redhat.com>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.vnet.ibm.com>,
	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>,
	"David S . Miller" <davem@davemloft.net>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	linux-kernel@vger.kernel.org
Subject: [PATCH -tip v2 5/5] kprobes: Don't call BUG_ON if there is a kprobe in use on free list
Date: Tue, 11 Sep 2018 19:21:09 +0900
Message-ID: <153666126882.21306.10738207224288507996.stgit@devbox> (raw)
In-Reply-To: <153666112297.21306.4621579144717171778.stgit@devbox>

Instead of calling BUG_ON, if we find a kprobe in use on free kprobe
list, just remove it from the list and keep it on kprobe hash list
as same as other in-use kprobes.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
---
 Changes in v2:
  - Use WARN_ON_ONCE() for unusual case.
---
 kernel/kprobes.c |    8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 63c342e5e6c3..90e98e233647 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -546,8 +546,14 @@ static void do_free_cleaned_kprobes(void)
 	struct optimized_kprobe *op, *tmp;
 
 	list_for_each_entry_safe(op, tmp, &freeing_list, list) {
-		BUG_ON(!kprobe_unused(&op->kp));
 		list_del_init(&op->list);
+		if (WARN_ON_ONCE(!kprobe_unused(&op->kp))) {
+			/*
+			 * This must not happen, but if there is a kprobe
+			 * still in use, keep it on kprobes hash list.
+			 */
+			continue;
+		}
 		free_aggr_kprobe(&op->kp);
 	}
 }


  parent reply index

Thread overview: 11+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-11 10:18 [PATCH -tip v2 0/5] kprobes: Remove BUG_ON from kprobes Masami Hiramatsu
2018-09-11 10:19 ` [PATCH -tip v2 1/5] kprobes: Remove meaningless BUG_ON from disarming process Masami Hiramatsu
2018-09-12  6:51   ` [tip:perf/core] kprobes: Remove pointless BUG_ON() " tip-bot for Masami Hiramatsu
2018-09-11 10:19 ` [PATCH -tip v2 2/5] kprobes: Remove meaningless BUG_ON from add_new_kprobe Masami Hiramatsu
2018-09-12  6:52   ` [tip:perf/core] kprobes: Remove pointless BUG_ON() from add_new_kprobe() tip-bot for Masami Hiramatsu
2018-09-11 10:20 ` [PATCH -tip v2 3/5] kprobes: Remove meaningless BUG_ON from reuse_unused_kprobe Masami Hiramatsu
2018-09-12  6:52   ` [tip:perf/core] kprobes: Remove pointless BUG_ON() from reuse_unused_kprobe() tip-bot for Masami Hiramatsu
2018-09-11 10:20 ` [PATCH -tip v2 4/5] kprobes: Return error if fail to reuse kprobe instead of BUG_ON Masami Hiramatsu
2018-09-12  6:53   ` [tip:perf/core] kprobes: Return error if we fail to reuse kprobe instead of BUG_ON() tip-bot for Masami Hiramatsu
2018-09-11 10:21 ` Masami Hiramatsu [this message]
2018-09-12  6:54   ` [tip:perf/core] kprobes: Don't call BUG_ON() if there is a kprobe in use on free list tip-bot for Masami Hiramatsu

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