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authorbibo,mao <bibo.mao@intel.com>2006-10-02 02:17:35 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-10-02 07:57:16 -0700
commit99219a3fbc2dcf2eaa954f7b2ac27299fd7894cd (patch)
tree895abde156c9fbeea9c5a87cfaaa411d4ad175c6 /kernel/kprobes.c
parentf2aa85a0ccd90110e76c6375535adc3ae358f971 (diff)
[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.c15
1 files changed, 11 insertions, 4 deletions
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 41dfda50e22..610c837ad9e 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)