Messages in this thread | | | Date | Tue, 26 Sep 2006 08:54:18 +0200 | From | Jiri Slaby <> | Subject | Re: [PATCH 3/3] kretprobe spinlock deadlock patch |
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bibo,mao wrote: > Hi, > Function 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> > thanks > bibo,mao > > arch/i386/kernel/kprobes.c | 9 +++++++-- > arch/ia64/kernel/kprobes.c | 9 +++++++-- > arch/powerpc/kernel/kprobes.c | 9 +++++++-- > arch/s390/kernel/kprobes.c | 9 +++++++-- > arch/x86_64/kernel/kprobes.c | 9 +++++++-- > include/linux/kprobes.h | 2 +- > kernel/kprobes.c | 15 +++++++++++---- > 7 files changed, 47 insertions(+), 15 deletions(-) > diff -Nruap 2.6.18-mm1.org/arch/i386/kernel/kprobes.c > 2.6.18-mm1/arch/i386/kernel/kprobes.c > --- 2.6.18-mm1.org/arch/i386/kernel/kprobes.c 2006-09-26 > 10:49:26.000000000 +0800 > +++ 2.6.18-mm1/arch/i386/kernel/kprobes.c 2006-09-26 > 10:53:16.000000000 +0800 > @@ -396,11 +396,12 @@ no_kprobe: > fastcall void *__kprobes trampoline_handler(struct pt_regs *regs) > { > struct kretprobe_instance *ri = NULL; > - struct hlist_head *head; > + struct hlist_head *head, empty_rp; > struct hlist_node *node, *tmp; > unsigned long flags, orig_ret_address = 0; > unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline; > > + INIT_HLIST_HEAD(&empty_rp); > spin_lock_irqsave(&kretprobe_lock, flags); > head = kretprobe_inst_table_head(current); > > @@ -429,7 +430,7 @@ fastcall void *__kprobes trampoline_hand > } > > orig_ret_address = (unsigned long)ri->ret_addr; > - recycle_rp_inst(ri); > + recycle_rp_inst(ri, &empty_rp); > > if (orig_ret_address != trampoline_address) > /* > @@ -444,6 +445,10 @@ fastcall void *__kprobes trampoline_hand > > spin_unlock_irqrestore(&kretprobe_lock, flags); > > + hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { > + hlist_del(&ri->hlist); > + kfree(ri); > + } > return (void*)orig_ret_address; > } > > diff -Nruap 2.6.18-mm1.org/arch/ia64/kernel/kprobes.c > 2.6.18-mm1/arch/ia64/kernel/kprobes.c > --- 2.6.18-mm1.org/arch/ia64/kernel/kprobes.c 2006-09-26 > 10:49:26.000000000 +0800 > +++ 2.6.18-mm1/arch/ia64/kernel/kprobes.c 2006-09-26 > 10:53:16.000000000 +0800 > @@ -340,12 +340,13 @@ static void kretprobe_trampoline(void) > int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs > *regs) > { > struct kretprobe_instance *ri = NULL; > - struct hlist_head *head; > + struct hlist_head *head, empty_rp; > struct hlist_node *node, *tmp; > unsigned long flags, orig_ret_address = 0; > unsigned long trampoline_address = > ((struct fnptr *)kretprobe_trampoline)->ip; > > + INIT_HLIST_HEAD(&empty_rp); > spin_lock_irqsave(&kretprobe_lock, flags); > head = kretprobe_inst_table_head(current); > > @@ -371,7 +372,7 @@ int __kprobes trampoline_probe_handler(s > ri->rp->handler(ri, regs); > > orig_ret_address = (unsigned long)ri->ret_addr; > - recycle_rp_inst(ri); > + recycle_rp_inst(ri, &empty_rp); > > if (orig_ret_address != trampoline_address) > /* > @@ -389,6 +390,10 @@ int __kprobes trampoline_probe_handler(s > spin_unlock_irqrestore(&kretprobe_lock, flags); > preempt_enable_no_resched(); > > + hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { > + hlist_del(&ri->hlist); > + kfree(ri); > + } > /* > * By returning a non-zero value, we are telling > * kprobe_handler() that we don't want the post_handler > diff -Nruap 2.6.18-mm1.org/arch/powerpc/kernel/kprobes.c > 2.6.18-mm1/arch/powerpc/kernel/kprobes.c > --- 2.6.18-mm1.org/arch/powerpc/kernel/kprobes.c 2006-09-26 > 10:49:26.000000000 +0800 > +++ 2.6.18-mm1/arch/powerpc/kernel/kprobes.c 2006-09-26 > 10:53:16.000000000 +0800 > @@ -260,11 +260,12 @@ void kretprobe_trampoline_holder(void) > int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs > *regs) > { > struct kretprobe_instance *ri = NULL; > - struct hlist_head *head; > + struct hlist_head *head, empty_rp; > struct hlist_node *node, *tmp; > unsigned long flags, orig_ret_address = 0; > unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline; > > + INIT_HLIST_HEAD(&empty_rp); > spin_lock_irqsave(&kretprobe_lock, flags); > head = kretprobe_inst_table_head(current); > > @@ -290,7 +291,7 @@ int __kprobes trampoline_probe_handler(s > ri->rp->handler(ri, regs); > > orig_ret_address = (unsigned long)ri->ret_addr; > - recycle_rp_inst(ri); > + recycle_rp_inst(ri, &empty_rp); > > if (orig_ret_address != trampoline_address) > /* > @@ -308,6 +309,10 @@ int __kprobes trampoline_probe_handler(s > spin_unlock_irqrestore(&kretprobe_lock, flags); > preempt_enable_no_resched(); > > + hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { > + hlist_del(&ri->hlist); > + kfree(ri); > + } > /* > * By returning a non-zero value, we are telling > * kprobe_handler() that we don't want the post_handler > diff -Nruap 2.6.18-mm1.org/arch/s390/kernel/kprobes.c > 2.6.18-mm1/arch/s390/kernel/kprobes.c > --- 2.6.18-mm1.org/arch/s390/kernel/kprobes.c 2006-09-25 > 16:11:56.000000000 +0800 > +++ 2.6.18-mm1/arch/s390/kernel/kprobes.c 2006-09-26 > 10:53:16.000000000 +0800 > @@ -368,11 +368,12 @@ void __kprobes kretprobe_trampoline_hold > int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs > *regs) > { > struct kretprobe_instance *ri = NULL; > - struct hlist_head *head; > + struct hlist_head *head, empty_rp; > struct hlist_node *node, *tmp; > unsigned long flags, orig_ret_address = 0; > unsigned long trampoline_address = (unsigned > long)&kretprobe_trampoline; > > + INIT_HLIST_HEAD(&empty_rp); > spin_lock_irqsave(&kretprobe_lock, flags); > head = kretprobe_inst_table_head(current); > > @@ -398,7 +399,7 @@ int __kprobes trampoline_probe_handler(s > ri->rp->handler(ri, regs); > > orig_ret_address = (unsigned long)ri->ret_addr; > - recycle_rp_inst(ri); > + recycle_rp_inst(ri, &empty_rp); > > if (orig_ret_address != trampoline_address) { > /* > @@ -416,6 +417,10 @@ int __kprobes trampoline_probe_handler(s > spin_unlock_irqrestore(&kretprobe_lock, flags); > preempt_enable_no_resched(); > > + hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { > + hlist_del(&ri->hlist); > + kfree(ri); > + } > /* > * By returning a non-zero value, we are telling > * kprobe_handler() that we don't want the post_handler > diff -Nruap 2.6.18-mm1.org/arch/x86_64/kernel/kprobes.c > 2.6.18-mm1/arch/x86_64/kernel/kprobes.c > --- 2.6.18-mm1.org/arch/x86_64/kernel/kprobes.c 2006-09-26 > 10:49:26.000000000 +0800 > +++ 2.6.18-mm1/arch/x86_64/kernel/kprobes.c 2006-09-26 > 10:53:16.000000000 +0800 > @@ -405,11 +405,12 @@ no_kprobe: > int __kprobes trampoline_probe_handler(struct kprobe *p, struct pt_regs > *regs) > { > struct kretprobe_instance *ri = NULL; > - struct hlist_head *head; > + struct hlist_head *head, empty_rp; > struct hlist_node *node, *tmp; > unsigned long flags, orig_ret_address = 0; > unsigned long trampoline_address =(unsigned long)&kretprobe_trampoline; > > + INIT_HLIST_HEAD(&empty_rp); > spin_lock_irqsave(&kretprobe_lock, flags); > head = kretprobe_inst_table_head(current); > > @@ -435,7 +436,7 @@ int __kprobes trampoline_probe_handler(s > ri->rp->handler(ri, regs); > > orig_ret_address = (unsigned long)ri->ret_addr; > - recycle_rp_inst(ri); > + recycle_rp_inst(ri, &empty_rp); > > if (orig_ret_address != trampoline_address) > /* > @@ -453,6 +454,10 @@ int __kprobes trampoline_probe_handler(s > spin_unlock_irqrestore(&kretprobe_lock, flags); > preempt_enable_no_resched(); > > + hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) { > + hlist_del(&ri->hlist); > + kfree(ri); > + } > /* > * By returning a non-zero value, we are telling > * kprobe_handler() that we don't want the post_handler > diff -Nruap 2.6.18-mm1.org/include/linux/kprobes.h > 2.6.18-mm1/include/linux/kprobes.h > --- 2.6.18-mm1.org/include/linux/kprobes.h 2006-09-25 > 16:12:04.000000000 +0800 > +++ 2.6.18-mm1/include/linux/kprobes.h 2006-09-26 10:53:16.000000000 > +0800 > @@ -202,7 +202,7 @@ void unregister_kretprobe(struct kretpro > struct kretprobe_instance *get_free_rp_inst(struct kretprobe *rp); > void add_rp_inst(struct kretprobe_instance *ri); > void kprobe_flush_task(struct task_struct *tk); > -void recycle_rp_inst(struct kretprobe_instance *ri); > +void recycle_rp_inst(struct kretprobe_instance *ri, struct hlist_head > *head); > #else /* CONFIG_KPROBES */ > > #define __kprobes /**/ > diff -Nruap 2.6.18-mm1.org/kernel/kprobes.c 2.6.18-mm1/kernel/kprobes.c > --- 2.6.18-mm1.org/kernel/kprobes.c 2006-09-26 10:49:26.000000000 +0800 > +++ 2.6.18-mm1/kernel/kprobes.c 2006-09-26 10:53:16.000000000 +0800 > @@ -319,7 +319,8 @@ void __kprobes add_rp_inst(struct kretpr > } > > /* 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 kr > 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_i > 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);
HLIST_HEAD(empty_rp); instead of that 2 changes?
> 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)
regards, -- http://www.fi.muni.cz/~xslaby/ Jiri Slaby faculty of informatics, masaryk university, brno, cz e-mail: jirislaby gmail com, gpg pubkey fingerprint: B674 9967 0407 CE62 ACC8 22A0 32CC 55C3 39D4 7A7E - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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