linux-kernel - [PATCH] Text Edit Lock - kprobes architecture independent support (v2)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 2 Mar 2009 20:31:24 -0500
From:	Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>
To:	Ingo Molnar <mingo@...e.hu>
Cc:	Peter Zijlstra <a.p.zijlstra@...llo.nl>,
	Masami Hiramatsu <mhiramat@...hat.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Nick Piggin <npiggin@...e.de>,
	Steven Rostedt <rostedt@...dmis.org>,
	Andi Kleen <andi@...stfloor.org>, linux-kernel@...r.kernel.org,
	Thomas Gleixner <tglx@...utronix.de>,
	Peter Zijlstra <peterz@...radead.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Arjan van de Ven <arjan@...radead.org>,
	Rusty Russell <rusty@...tcorp.com.au>,
	"H. Peter Anvin" <hpa@...or.com>,
	Steven Rostedt <srostedt@...hat.com>
Subject: [PATCH] Text Edit Lock - kprobes architecture independent support
	(v2)

Use the mutual exclusion provided by the text edit lock in the kprobes code. It
allows coherent manipulation of the kernel code by other subsystems.

Changelog:

Move the kernel_text_lock/unlock out of the for loops.
Use text_mutex directly instead of a function.

(applies on 2.6.29-rc6)

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@...ymtl.ca>
Acked-by: Ananth N Mavinakayanahalli <ananth@...ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@...hat.com>
CC: ananth@...ibm.com
CC: anil.s.keshavamurthy@...el.com
CC: davem@...emloft.net
CC: Roel Kluin <12o3l@...cali.nl>
---
 kernel/kprobes.c |   18 +++++++++++++-----
 1 file changed, 13 insertions(+), 5 deletions(-)

Index: linux-2.6-lttng/kernel/kprobes.c
===================================================================
--- linux-2.6-lttng.orig/kernel/kprobes.c	2009-03-02 19:22:51.000000000 -0500
+++ linux-2.6-lttng/kernel/kprobes.c	2009-03-02 19:27:26.000000000 -0500
@@ -43,6 +43,7 @@
 #include <linux/seq_file.h>
 #include <linux/debugfs.h>
 #include <linux/kdebug.h>
+#include <linux/memory.h>
 
 #include <asm-generic/sections.h>
 #include <asm/cacheflush.h>
@@ -699,9 +700,10 @@ int __kprobes register_kprobe(struct kpr
 		goto out;
 	}
 
+	mutex_lock(&text_mutex);
 	ret = arch_prepare_kprobe(p);
 	if (ret)
-		goto out;
+		goto out_unlock_text;
 
 	INIT_HLIST_NODE(&p->hlist);
 	hlist_add_head_rcu(&p->hlist,
@@ -709,7 +711,8 @@ int __kprobes register_kprobe(struct kpr
 
 	if (kprobe_enabled)
 		arch_arm_kprobe(p);
-
+out_unlock_text:
+	mutex_unlock(&text_mutex);
 out:
 	mutex_unlock(&kprobe_mutex);
 
@@ -746,8 +749,11 @@ valid_p:
 		 * enabled and not gone - otherwise, the breakpoint would
 		 * already have been removed. We save on flushing icache.
 		 */
-		if (kprobe_enabled && !kprobe_gone(old_p))
+		if (kprobe_enabled && !kprobe_gone(old_p)) {
+			mutex_lock(&text_mutex);
 			arch_disarm_kprobe(p);
+			mutex_unlock(&text_mutex);
+		}
 		hlist_del_rcu(&old_p->hlist);
 	} else {
 		if (p->break_handler && !kprobe_gone(p))
@@ -918,7 +924,6 @@ static int __kprobes pre_handler_kretpro
 		}
 
 		arch_prepare_kretprobe(ri, regs);
-
 		/* XXX(hch): why is there no hlist_move_head? */
 		INIT_HLIST_NODE(&ri->hlist);
 		kretprobe_table_lock(hash, &flags);
@@ -1280,12 +1285,14 @@ static void __kprobes enable_all_kprobes
 	if (kprobe_enabled)
 		goto already_enabled;
 
+	mutex_lock(&text_mutex);
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
 		hlist_for_each_entry_rcu(p, node, head, hlist)
 			if (!kprobe_gone(p))
 				arch_arm_kprobe(p);
 	}
+	mutex_unlock(&text_mutex);
 
 	kprobe_enabled = true;
 	printk(KERN_INFO "Kprobes globally enabled\n");
@@ -1310,6 +1317,7 @@ static void __kprobes disable_all_kprobe
 
 	kprobe_enabled = false;
 	printk(KERN_INFO "Kprobes globally disabled\n");
+	mutex_lock(&text_mutex);
 	for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
 		head = &kprobe_table[i];
 		hlist_for_each_entry_rcu(p, node, head, hlist) {
@@ -1317,7 +1325,7 @@ static void __kprobes disable_all_kprobe
 				arch_disarm_kprobe(p);
 		}
 	}
-
+	mutex_unlock(&text_mutex);
 	mutex_unlock(&kprobe_mutex);
 	/* Allow all currently running kprobes to complete */
 	synchronize_sched();
-- 
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/