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[PATCH] kretprobe spinlock deadlock patch

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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>
This commit is contained in:
bibo,mao
2006-10-02 02:17:35 -07:00
committed by Linus Torvalds
parent f2aa85a0cc
commit 99219a3fbc
7 changed files with 47 additions and 15 deletions
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15
kernel/kprobes.c
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@ -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)