All of lore.kernel.org
 help / color / mirror / Atom feed
From: "bibo,mao" <bibo.mao@intel.com>
To: Andrew Morton <akpm@osdl.org>
Cc: linux-kernel@vger.kernel.org,
	Ananth N Mavinakayanahalli <ananth@in.ibm.com>,
	Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
	"Keshavamurthy, Anil S" <anil.s.keshavamurthy@intel.com>
Subject: [PATCH 3/3] kretprobe spinlock deadlock patch
Date: Tue, 26 Sep 2006 13:02:38 +0800	[thread overview]
Message-ID: <4518B46E.3050206@intel.com> (raw)

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);
 	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)

             reply	other threads:[~2006-09-26  5:06 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2006-09-26  5:02 bibo,mao [this message]
2006-09-26  6:54 ` [PATCH 3/3] kretprobe spinlock deadlock patch Jiri Slaby

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4518B46E.3050206@intel.com \
    --to=bibo.mao@intel.com \
    --cc=akpm@osdl.org \
    --cc=ananth@in.ibm.com \
    --cc=anil.s.keshavamurthy@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=masami.hiramatsu.pt@hitachi.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.