File linux-2.6-kprobes-deadlock-fixes.patch of Package kernel
Date: Fri, 13 Oct 2006 11:42:31 -0700
From: Anil S Keshavamurthy <akeshava@redhat.com>
Subject: [PATCH RHEL5] BZ 21055- Kprobes - fixes some dead lock issues
BZ 210555
The attached patch fixes some serious Kprobe deadlock issues.
Back ported directly from 2.6.19-rc1.
Here is the link to the mainline acceptance.
1) [PATCH] kretprobe spinlock deadlock patch
http://kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=99219a3fbc2dcf2eaa954f7b2ac27299fd7894cd
2) [PATCH] disallow kprobes on notifier_call_chain
http://kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=f2aa85a0ccd90110e76c6375535adc3ae358f971
Please apply.
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 +++++++++++----
kernel/sys.c | 2 +-
8 files changed, 48 insertions(+), 16 deletions(-)
Index: linux-2.6.18.ia64/arch/i386/kernel/kprobes.c
===================================================================
--- linux-2.6.18.ia64.orig/arch/i386/kernel/kprobes.c 2006-10-11 11:21:27.000000000 -0700
+++ linux-2.6.18.ia64/arch/i386/kernel/kprobes.c 2006-10-11 11:25:49.000000000 -0700
@@ -396,11 +396,12 @@
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 @@
}
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 @@
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;
}
Index: linux-2.6.18.ia64/arch/ia64/kernel/kprobes.c
===================================================================
--- linux-2.6.18.ia64.orig/arch/ia64/kernel/kprobes.c 2006-10-11 11:21:27.000000000 -0700
+++ linux-2.6.18.ia64/arch/ia64/kernel/kprobes.c 2006-10-11 11:25:49.000000000 -0700
@@ -338,12 +338,13 @@
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);
@@ -369,7 +370,7 @@
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)
/*
@@ -387,6 +388,10 @@
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
Index: linux-2.6.18.ia64/arch/powerpc/kernel/kprobes.c
===================================================================
--- linux-2.6.18.ia64.orig/arch/powerpc/kernel/kprobes.c 2006-10-11 11:21:27.000000000 -0700
+++ linux-2.6.18.ia64/arch/powerpc/kernel/kprobes.c 2006-10-11 11:25:49.000000000 -0700
@@ -260,11 +260,12 @@
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 @@
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)
/*
@@ -360,6 +361,10 @@
out:
preempt_enable_no_resched();
+ hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
+ hlist_del(&ri->hlist);
+ kfree(ri);
+ }
/*
* if somebody else is singlestepping across a probe point, msr
* will have SE set, in which case, continue the remaining processing
Index: linux-2.6.18.ia64/arch/s390/kernel/kprobes.c
===================================================================
--- linux-2.6.18.ia64.orig/arch/s390/kernel/kprobes.c 2006-10-11 11:21:27.000000000 -0700
+++ linux-2.6.18.ia64/arch/s390/kernel/kprobes.c 2006-10-11 11:25:49.000000000 -0700
@@ -394,11 +394,12 @@
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);
@@ -424,7 +425,7 @@
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) {
/*
@@ -442,6 +443,10 @@
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
Index: linux-2.6.18.ia64/arch/x86_64/kernel/kprobes.c
===================================================================
--- linux-2.6.18.ia64.orig/arch/x86_64/kernel/kprobes.c 2006-10-11 11:21:27.000000000 -0700
+++ linux-2.6.18.ia64/arch/x86_64/kernel/kprobes.c 2006-10-11 11:25:49.000000000 -0700
@@ -406,11 +406,12 @@
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);
@@ -436,7 +437,7 @@
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)
/*
@@ -564,6 +565,10 @@
out:
preempt_enable_no_resched();
+ hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
+ hlist_del(&ri->hlist);
+ kfree(ri);
+ }
/*
* if somebody else is singlestepping across a probe point, eflags
* will have TF set, in which case, continue the remaining processing
Index: linux-2.6.18.ia64/include/linux/kprobes.h
===================================================================
--- linux-2.6.18.ia64.orig/include/linux/kprobes.h 2006-10-11 11:21:27.000000000 -0700
+++ linux-2.6.18.ia64/include/linux/kprobes.h 2006-10-11 11:25:49.000000000 -0700
@@ -202,7 +202,7 @@
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 /**/
Index: linux-2.6.18.ia64/kernel/kprobes.c
===================================================================
--- linux-2.6.18.ia64.orig/kernel/kprobes.c 2006-10-11 11:21:27.000000000 -0700
+++ linux-2.6.18.ia64/kernel/kprobes.c 2006-10-11 11:25:49.000000000 -0700
@@ -319,7 +319,8 @@
}
/* 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 @@
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 @@
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)
Index: linux-2.6.18.ia64/kernel/sys.c
===================================================================
--- linux-2.6.18.ia64.orig/kernel/sys.c 2006-10-11 16:03:57.000000000 -0700
+++ linux-2.6.18.ia64/kernel/sys.c 2006-10-11 11:26:26.000000000 -0700
@@ -220,7 +220,7 @@
* of the last notifier function called.
*/
-int atomic_notifier_call_chain(struct atomic_notifier_head *nh,
+int __kprobes atomic_notifier_call_chain(struct atomic_notifier_head *nh,
unsigned long val, void *v)
{
int ret;
