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| author | Masami Hiramatsu <mhiramat@kernel.org> | 2018-09-11 19:20:40 +0900 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2018-09-12 08:01:16 +0200 |
| commit | 819319fc93461c07b9cdb3064f154bd8cfd48172 (patch) | |
| tree | 1af8017bac10831354dde691e7fa974f2e6b6358 /kernel/kprobes.c | |
| parent | a6d18e65dff2b73ceeb187c598b48898e36ad7b1 (diff) | |
| download | linux-819319fc93461c07b9cdb3064f154bd8cfd48172.tar.bz2 | |
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>
Diffstat (limited to 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 27 |
1 files 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)) { /* |