diff options
| author | bibo,mao <bibo.mao@intel.com> | 2006-10-02 02:17:35 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-10-02 07:57:16 -0700 |
| commit | 99219a3fbc2dcf2eaa954f7b2ac27299fd7894cd (patch) | |
| tree | 895abde156c9fbeea9c5a87cfaaa411d4ad175c6 /kernel/kprobes.c | |
| parent | f2aa85a0ccd90110e76c6375535adc3ae358f971 (diff) | |
| download | lwn-99219a3fbc2dcf2eaa954f7b2ac27299fd7894cd.tar.gz lwn-99219a3fbc2dcf2eaa954f7b2ac27299fd7894cd.zip | |
[PATCH] kretprobe spinlock deadlock patch
kprobe_flush_task() possibly calls kfree function during holding
kretprobe_lock spinlock, if kfree function is probed by kretprobe that will
incur spinlock deadlock. This patch moves kfree function out scope of
kretprobe_lock.
Signed-off-by: bibo, mao <bibo.mao@intel.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'kernel/kprobes.c')
| -rw-r--r-- | kernel/kprobes.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 41dfda50e22a..610c837ad9e0 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -319,7 +319,8 @@ void __kprobes add_rp_inst(struct kretprobe_instance *ri) } /* Called with kretprobe_lock held */ -void __kprobes recycle_rp_inst(struct kretprobe_instance *ri) +void __kprobes recycle_rp_inst(struct kretprobe_instance *ri, + struct hlist_head *head) { /* remove rp inst off the rprobe_inst_table */ hlist_del(&ri->hlist); @@ -331,7 +332,7 @@ void __kprobes recycle_rp_inst(struct kretprobe_instance *ri) hlist_add_head(&ri->uflist, &ri->rp->free_instances); } else /* Unregistering */ - kfree(ri); + hlist_add_head(&ri->hlist, head); } struct hlist_head __kprobes *kretprobe_inst_table_head(struct task_struct *tsk) @@ -348,17 +349,23 @@ struct hlist_head __kprobes *kretprobe_inst_table_head(struct task_struct *tsk) void __kprobes kprobe_flush_task(struct task_struct *tk) { struct kretprobe_instance *ri; - struct hlist_head *head; + struct hlist_head *head, empty_rp; struct hlist_node *node, *tmp; unsigned long flags = 0; + INIT_HLIST_HEAD(&empty_rp); spin_lock_irqsave(&kretprobe_lock, flags); head = kretprobe_inst_table_head(tk); hlist_for_each_entry_safe(ri, node, tmp, head, hlist) { if (ri->task == tk) - recycle_rp_inst(ri); + recycle_rp_inst(ri, &empty_rp); } spin_unlock_irqrestore(&kretprobe_lock, flags); + + hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { + hlist_del(&ri->hlist); + kfree(ri); + } } static inline void free_rp_inst(struct kretprobe *rp) |