The patch titled
kretprobe spinlock deadlock patch
has been added to the -mm tree. Its filename is
kretprobe-spinlock-deadlock-patch.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: kretprobe spinlock deadlock patch
From: "bibo,mao" <bibo.mao@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
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 -puN arch/i386/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch arch/i386/kernel/kprobes.c
--- a/arch/i386/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch
+++ a/arch/i386/kernel/kprobes.c
@@ -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 -puN arch/ia64/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch arch/ia64/kernel/kprobes.c
--- a/arch/ia64/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch
+++ a/arch/ia64/kernel/kprobes.c
@@ -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 -puN arch/powerpc/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch arch/powerpc/kernel/kprobes.c
--- a/arch/powerpc/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch
+++ a/arch/powerpc/kernel/kprobes.c
@@ -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 -puN arch/s390/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch arch/s390/kernel/kprobes.c
--- a/arch/s390/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch
+++ a/arch/s390/kernel/kprobes.c
@@ -369,11 +369,12 @@ 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);
@@ -399,7 +400,7 @@ 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) {
/*
@@ -417,6 +418,10 @@ 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 -puN arch/x86_64/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch arch/x86_64/kernel/kprobes.c
--- a/arch/x86_64/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch
+++ a/arch/x86_64/kernel/kprobes.c
@@ -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 -puN include/linux/kprobes.h~kretprobe-spinlock-deadlock-patch include/linux/kprobes.h
--- a/include/linux/kprobes.h~kretprobe-spinlock-deadlock-patch
+++ a/include/linux/kprobes.h
@@ -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 -puN kernel/kprobes.c~kretprobe-spinlock-deadlock-patch kernel/kprobes.c
--- a/kernel/kprobes.c~kretprobe-spinlock-deadlock-patch
+++ a/kernel/kprobes.c
@@ -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);
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)
_
Patches currently in -mm which might be from bibo.mao@xxxxxxxxx are
kprobe-whitespace-cleanup.patch
disallow-kprobes-on-notifier_call_chain.patch
kretprobe-spinlock-deadlock-patch.patch
-
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