From: tip-bot for Masami Hiramatsu <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: davem@davemloft.net, linux-kernel@vger.kernel.org,
anil.s.keshavamurthy@intel.com, hpa@zytor.com,
naveen.n.rao@linux.vnet.ibm.com, mhiramat@kernel.org,
torvalds@linux-foundation.org, mingo@kernel.org,
tglx@linutronix.de, peterz@infradead.org
Subject: [tip:perf/core] kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()
Date: Tue, 11 Sep 2018 23:53:31 -0700 [thread overview]
Message-ID: <tip-819319fc93461c07b9cdb3064f154bd8cfd48172@git.kernel.org> (raw)
In-Reply-To: <153666124040.21306.14150398706331307654.stgit@devbox>
Commit-ID: 819319fc93461c07b9cdb3064f154bd8cfd48172
Gitweb: https://git.kernel.org/tip/819319fc93461c07b9cdb3064f154bd8cfd48172
Author: Masami Hiramatsu <mhiramat@kernel.org>
AuthorDate: Tue, 11 Sep 2018 19:20:40 +0900
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Wed, 12 Sep 2018 08:01:16 +0200
kprobes: Return error if we fail to reuse kprobe instead of BUG_ON()
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>
---
kernel/kprobes.c | 27 ++++++++++++++++++++-------
1 file changed, 20 insertions(+), 7 deletions(-)
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 277a6cbe83db..63c342e5e6c3 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -700,9 +700,10 @@ 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;
/*
* Unused kprobe MUST be on the way of delayed unoptimizing (means
@@ -713,8 +714,12 @@ 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 */
@@ -939,11 +944,16 @@ 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)
@@ -1315,9 +1325,12 @@ 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)) {
/*
next prev parent reply other threads:[~2018-09-12 6:54 UTC|newest]
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-bot for Masami Hiramatsu [this message]
2018-09-11 10:21 ` [PATCH -tip v2 5/5] kprobes: Don't call BUG_ON if there is a kprobe in use on free list Masami Hiramatsu
2018-09-12 6:54 ` [tip:perf/core] kprobes: Don't call BUG_ON() " tip-bot for Masami Hiramatsu
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