Re: [rfc-patch 07/11] Text Edit Lock - kprobes architecture independent support

2007-11-17 Thread Mathieu Desnoyers
* Roel Kluin ([EMAIL PROTECTED]) wrote:
[...]
> > for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
> > head = _table[i];
> > +   kernel_text_lock();
> > hlist_for_each_entry_rcu(p, node, head, hlist)
> > arch_arm_kprobe(p);
> > +   kernel_text_unlock();
> > }
> 
> isn't it better to put the kernel_text_lock around the for loop?
> 
> >  
> > kprobe_enabled = true;
> > @@ -969,10 +974,12 @@ static void __kprobes disable_all_kprobe
> > printk(KERN_INFO "Kprobes globally disabled\n");
> > for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
> > head = _table[i];
> > +   kernel_text_lock();
> > hlist_for_each_entry_rcu(p, node, head, hlist) {
> > if (!arch_trampoline_kprobe(p))
> > arch_disarm_kprobe(p);
> > }
> > +   kernel_text_unlock();
> > }
> 
> same question here
> 

Yes, you are right, although it does not have to be fast. Here is the
updated patch.

Text Edit Lock - kprobes architecture independent support

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.

Signed-off-by: Mathieu Desnoyers <[EMAIL PROTECTED]>
Acked-by: Ananth N Mavinakayanahalli <[EMAIL PROTECTED]>
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: Roel Kluin <[EMAIL PROTECTED]>
---
 kernel/kprobes.c |   19 +--
 1 file changed, 13 insertions(+), 6 deletions(-)

Index: linux-2.6-lttng/kernel/kprobes.c
===
--- linux-2.6-lttng.orig/kernel/kprobes.c   2007-11-16 13:40:06.0 
-0500
+++ linux-2.6-lttng/kernel/kprobes.c2007-11-17 10:00:23.0 -0500
@@ -43,6 +43,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include 
 #include 
@@ -568,9 +569,10 @@ static int __kprobes __register_kprobe(s
goto out;
}
 
+   kernel_text_lock();
ret = arch_prepare_kprobe(p);
if (ret)
-   goto out;
+   goto out_unlock_text;
 
INIT_HLIST_NODE(>hlist);
hlist_add_head_rcu(>hlist,
@@ -578,7 +580,8 @@ static int __kprobes __register_kprobe(s
 
if (kprobe_enabled)
arch_arm_kprobe(p);
-
+out_unlock_text:
+   kernel_text_unlock();
 out:
mutex_unlock(_mutex);
 
@@ -621,8 +624,11 @@ valid_p:
 * enabled - otherwise, the breakpoint would already have
 * been removed. We save on flushing icache.
 */
-   if (kprobe_enabled)
+   if (kprobe_enabled) {
+   kernel_text_lock();
arch_disarm_kprobe(p);
+   kernel_text_unlock();
+   }
hlist_del_rcu(_p->hlist);
cleanup_p = 1;
} else {
@@ -644,9 +650,7 @@ valid_p:
list_del_rcu(>list);
kfree(old_p);
}
-   mutex_lock(_mutex);
arch_remove_kprobe(p);
-   mutex_unlock(_mutex);
} else {
mutex_lock(_mutex);
if (p->break_handler)
@@ -717,7 +721,6 @@ static int __kprobes pre_handler_kretpro
ri->rp = rp;
ri->task = current;
arch_prepare_kretprobe(ri, regs);
-
/* XXX(hch): why is there no hlist_move_head? */
hlist_del(>uflist);
hlist_add_head(>uflist, >rp->used_instances);
@@ -938,11 +941,13 @@ static void __kprobes enable_all_kprobes
if (kprobe_enabled)
goto already_enabled;
 
+   kernel_text_lock();
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = _table[i];
hlist_for_each_entry_rcu(p, node, head, hlist)
arch_arm_kprobe(p);
}
+   kernel_text_unlock();
 
kprobe_enabled = true;
printk(KERN_INFO "Kprobes globally enabled\n");
@@ -967,6 +972,7 @@ static void __kprobes disable_all_kprobe
 
kprobe_enabled = false;
printk(KERN_INFO "Kprobes globally disabled\n");
+   kernel_text_lock();
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = _table[i];
hlist_for_each_entry_rcu(p, node, head, hlist) {
@@ -974,6 +980,7 @@ static void __kprobes disable_all_kprobe
arch_disarm_kprobe(p);
}
}
+   kernel_text_unlock();
 
mutex_unlock(_mutex);
/* Allow all currently running kprobes to complete */

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
-
To unsubscribe from this list: send the line 

Re: [rfc-patch 07/11] Text Edit Lock - kprobes architecture independent support

2007-11-17 Thread Roel Kluin
Mathieu Desnoyers wrote:
> 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.
> 
> Signed-off-by: Mathieu Desnoyers <[EMAIL PROTECTED]>
> Acked-by: Ananth N Mavinakayanahalli <[EMAIL PROTECTED]>
> CC: [EMAIL PROTECTED]
> CC: [EMAIL PROTECTED]
> CC: [EMAIL PROTECTED]
> CC: [EMAIL PROTECTED]
> ---
>  kernel/kprobes.c |   19 +--
>  1 file changed, 13 insertions(+), 6 deletions(-)
> 
> Index: linux-2.6-lttng/kernel/kprobes.c
> ===
> --- linux-2.6-lttng.orig/kernel/kprobes.c 2007-09-07 10:12:06.0 
> -0400
> +++ linux-2.6-lttng/kernel/kprobes.c  2007-09-07 10:13:09.0 -0400
> @@ -43,6 +43,7 @@
>  #include 
>  #include 
>  #include 
> +#include 
>  
>  #include 
>  #include 
> @@ -568,9 +569,10 @@ static int __kprobes __register_kprobe(s
>   goto out;
>   }
>  
> + kernel_text_lock();
>   ret = arch_prepare_kprobe(p);
>   if (ret)
> - goto out;
> + goto out_unlock_text;
>  
>   INIT_HLIST_NODE(>hlist);
>   hlist_add_head_rcu(>hlist,
> @@ -578,7 +580,8 @@ static int __kprobes __register_kprobe(s
>  
>   if (kprobe_enabled)
>   arch_arm_kprobe(p);
> -
> +out_unlock_text:
> + kernel_text_unlock();
>  out:
>   mutex_unlock(_mutex);
>  
> @@ -621,8 +624,11 @@ valid_p:
>* enabled - otherwise, the breakpoint would already have
>* been removed. We save on flushing icache.
>*/
> - if (kprobe_enabled)
> + if (kprobe_enabled) {
> + kernel_text_lock();
>   arch_disarm_kprobe(p);
> + kernel_text_unlock();
> + }
>   hlist_del_rcu(_p->hlist);
>   cleanup_p = 1;
>   } else {
> @@ -644,9 +650,7 @@ valid_p:
>   list_del_rcu(>list);
>   kfree(old_p);
>   }
> - mutex_lock(_mutex);
>   arch_remove_kprobe(p);
> - mutex_unlock(_mutex);
>   } else {
>   mutex_lock(_mutex);
>   if (p->break_handler)
> @@ -717,7 +721,6 @@ static int __kprobes pre_handler_kretpro
>   ri->rp = rp;
>   ri->task = current;
>   arch_prepare_kretprobe(ri, regs);
> -
>   /* XXX(hch): why is there no hlist_move_head? */
>   hlist_del(>uflist);
>   hlist_add_head(>uflist, >rp->used_instances);
> @@ -940,8 +943,10 @@ static void __kprobes enable_all_kprobes
>  
>   for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
>   head = _table[i];
> + kernel_text_lock();
>   hlist_for_each_entry_rcu(p, node, head, hlist)
>   arch_arm_kprobe(p);
> + kernel_text_unlock();
>   }

isn't it better to put the kernel_text_lock around the for loop?

>  
>   kprobe_enabled = true;
> @@ -969,10 +974,12 @@ static void __kprobes disable_all_kprobe
>   printk(KERN_INFO "Kprobes globally disabled\n");
>   for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
>   head = _table[i];
> + kernel_text_lock();
>   hlist_for_each_entry_rcu(p, node, head, hlist) {
>   if (!arch_trampoline_kprobe(p))
>   arch_disarm_kprobe(p);
>   }
> + kernel_text_unlock();
>   }

same question here

>  
>   mutex_unlock(_mutex);
> 

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Re: [rfc-patch 07/11] Text Edit Lock - kprobes architecture independent support

2007-11-17 Thread Roel Kluin
Mathieu Desnoyers wrote:
 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.
 
 Signed-off-by: Mathieu Desnoyers [EMAIL PROTECTED]
 Acked-by: Ananth N Mavinakayanahalli [EMAIL PROTECTED]
 CC: [EMAIL PROTECTED]
 CC: [EMAIL PROTECTED]
 CC: [EMAIL PROTECTED]
 CC: [EMAIL PROTECTED]
 ---
  kernel/kprobes.c |   19 +--
  1 file changed, 13 insertions(+), 6 deletions(-)
 
 Index: linux-2.6-lttng/kernel/kprobes.c
 ===
 --- linux-2.6-lttng.orig/kernel/kprobes.c 2007-09-07 10:12:06.0 
 -0400
 +++ linux-2.6-lttng/kernel/kprobes.c  2007-09-07 10:13:09.0 -0400
 @@ -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
 @@ -568,9 +569,10 @@ static int __kprobes __register_kprobe(s
   goto out;
   }
  
 + kernel_text_lock();
   ret = arch_prepare_kprobe(p);
   if (ret)
 - goto out;
 + goto out_unlock_text;
  
   INIT_HLIST_NODE(p-hlist);
   hlist_add_head_rcu(p-hlist,
 @@ -578,7 +580,8 @@ static int __kprobes __register_kprobe(s
  
   if (kprobe_enabled)
   arch_arm_kprobe(p);
 -
 +out_unlock_text:
 + kernel_text_unlock();
  out:
   mutex_unlock(kprobe_mutex);
  
 @@ -621,8 +624,11 @@ valid_p:
* enabled - otherwise, the breakpoint would already have
* been removed. We save on flushing icache.
*/
 - if (kprobe_enabled)
 + if (kprobe_enabled) {
 + kernel_text_lock();
   arch_disarm_kprobe(p);
 + kernel_text_unlock();
 + }
   hlist_del_rcu(old_p-hlist);
   cleanup_p = 1;
   } else {
 @@ -644,9 +650,7 @@ valid_p:
   list_del_rcu(p-list);
   kfree(old_p);
   }
 - mutex_lock(kprobe_mutex);
   arch_remove_kprobe(p);
 - mutex_unlock(kprobe_mutex);
   } else {
   mutex_lock(kprobe_mutex);
   if (p-break_handler)
 @@ -717,7 +721,6 @@ static int __kprobes pre_handler_kretpro
   ri-rp = rp;
   ri-task = current;
   arch_prepare_kretprobe(ri, regs);
 -
   /* XXX(hch): why is there no hlist_move_head? */
   hlist_del(ri-uflist);
   hlist_add_head(ri-uflist, ri-rp-used_instances);
 @@ -940,8 +943,10 @@ static void __kprobes enable_all_kprobes
  
   for (i = 0; i  KPROBE_TABLE_SIZE; i++) {
   head = kprobe_table[i];
 + kernel_text_lock();
   hlist_for_each_entry_rcu(p, node, head, hlist)
   arch_arm_kprobe(p);
 + kernel_text_unlock();
   }

isn't it better to put the kernel_text_lock around the for loop?

  
   kprobe_enabled = true;
 @@ -969,10 +974,12 @@ static void __kprobes disable_all_kprobe
   printk(KERN_INFO Kprobes globally disabled\n);
   for (i = 0; i  KPROBE_TABLE_SIZE; i++) {
   head = kprobe_table[i];
 + kernel_text_lock();
   hlist_for_each_entry_rcu(p, node, head, hlist) {
   if (!arch_trampoline_kprobe(p))
   arch_disarm_kprobe(p);
   }
 + kernel_text_unlock();
   }

same question here

  
   mutex_unlock(kprobe_mutex);
 

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Re: [rfc-patch 07/11] Text Edit Lock - kprobes architecture independent support

2007-11-17 Thread Mathieu Desnoyers
* Roel Kluin ([EMAIL PROTECTED]) wrote:
[...]
  for (i = 0; i  KPROBE_TABLE_SIZE; i++) {
  head = kprobe_table[i];
  +   kernel_text_lock();
  hlist_for_each_entry_rcu(p, node, head, hlist)
  arch_arm_kprobe(p);
  +   kernel_text_unlock();
  }
 
 isn't it better to put the kernel_text_lock around the for loop?
 
   
  kprobe_enabled = true;
  @@ -969,10 +974,12 @@ static void __kprobes disable_all_kprobe
  printk(KERN_INFO Kprobes globally disabled\n);
  for (i = 0; i  KPROBE_TABLE_SIZE; i++) {
  head = kprobe_table[i];
  +   kernel_text_lock();
  hlist_for_each_entry_rcu(p, node, head, hlist) {
  if (!arch_trampoline_kprobe(p))
  arch_disarm_kprobe(p);
  }
  +   kernel_text_unlock();
  }
 
 same question here
 

Yes, you are right, although it does not have to be fast. Here is the
updated patch.

Text Edit Lock - kprobes architecture independent support

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.

Signed-off-by: Mathieu Desnoyers [EMAIL PROTECTED]
Acked-by: Ananth N Mavinakayanahalli [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: Roel Kluin [EMAIL PROTECTED]
---
 kernel/kprobes.c |   19 +--
 1 file changed, 13 insertions(+), 6 deletions(-)

Index: linux-2.6-lttng/kernel/kprobes.c
===
--- linux-2.6-lttng.orig/kernel/kprobes.c   2007-11-16 13:40:06.0 
-0500
+++ linux-2.6-lttng/kernel/kprobes.c2007-11-17 10:00:23.0 -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
@@ -568,9 +569,10 @@ static int __kprobes __register_kprobe(s
goto out;
}
 
+   kernel_text_lock();
ret = arch_prepare_kprobe(p);
if (ret)
-   goto out;
+   goto out_unlock_text;
 
INIT_HLIST_NODE(p-hlist);
hlist_add_head_rcu(p-hlist,
@@ -578,7 +580,8 @@ static int __kprobes __register_kprobe(s
 
if (kprobe_enabled)
arch_arm_kprobe(p);
-
+out_unlock_text:
+   kernel_text_unlock();
 out:
mutex_unlock(kprobe_mutex);
 
@@ -621,8 +624,11 @@ valid_p:
 * enabled - otherwise, the breakpoint would already have
 * been removed. We save on flushing icache.
 */
-   if (kprobe_enabled)
+   if (kprobe_enabled) {
+   kernel_text_lock();
arch_disarm_kprobe(p);
+   kernel_text_unlock();
+   }
hlist_del_rcu(old_p-hlist);
cleanup_p = 1;
} else {
@@ -644,9 +650,7 @@ valid_p:
list_del_rcu(p-list);
kfree(old_p);
}
-   mutex_lock(kprobe_mutex);
arch_remove_kprobe(p);
-   mutex_unlock(kprobe_mutex);
} else {
mutex_lock(kprobe_mutex);
if (p-break_handler)
@@ -717,7 +721,6 @@ static int __kprobes pre_handler_kretpro
ri-rp = rp;
ri-task = current;
arch_prepare_kretprobe(ri, regs);
-
/* XXX(hch): why is there no hlist_move_head? */
hlist_del(ri-uflist);
hlist_add_head(ri-uflist, ri-rp-used_instances);
@@ -938,11 +941,13 @@ static void __kprobes enable_all_kprobes
if (kprobe_enabled)
goto already_enabled;
 
+   kernel_text_lock();
for (i = 0; i  KPROBE_TABLE_SIZE; i++) {
head = kprobe_table[i];
hlist_for_each_entry_rcu(p, node, head, hlist)
arch_arm_kprobe(p);
}
+   kernel_text_unlock();
 
kprobe_enabled = true;
printk(KERN_INFO Kprobes globally enabled\n);
@@ -967,6 +972,7 @@ static void __kprobes disable_all_kprobe
 
kprobe_enabled = false;
printk(KERN_INFO Kprobes globally disabled\n);
+   kernel_text_lock();
for (i = 0; i  KPROBE_TABLE_SIZE; i++) {
head = kprobe_table[i];
hlist_for_each_entry_rcu(p, node, head, hlist) {
@@ -974,6 +980,7 @@ static void __kprobes disable_all_kprobe
arch_disarm_kprobe(p);
}
}
+   kernel_text_unlock();
 
mutex_unlock(kprobe_mutex);
/* Allow all currently running kprobes to complete */

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 

[rfc-patch 07/11] Text Edit Lock - kprobes architecture independent support

2007-11-16 Thread Mathieu Desnoyers
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.

Signed-off-by: Mathieu Desnoyers <[EMAIL PROTECTED]>
Acked-by: Ananth N Mavinakayanahalli <[EMAIL PROTECTED]>
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
---
 kernel/kprobes.c |   19 +--
 1 file changed, 13 insertions(+), 6 deletions(-)

Index: linux-2.6-lttng/kernel/kprobes.c
===
--- linux-2.6-lttng.orig/kernel/kprobes.c   2007-09-07 10:12:06.0 
-0400
+++ linux-2.6-lttng/kernel/kprobes.c2007-09-07 10:13:09.0 -0400
@@ -43,6 +43,7 @@
 #include 
 #include 
 #include 
+#include 
 
 #include 
 #include 
@@ -568,9 +569,10 @@ static int __kprobes __register_kprobe(s
goto out;
}
 
+   kernel_text_lock();
ret = arch_prepare_kprobe(p);
if (ret)
-   goto out;
+   goto out_unlock_text;
 
INIT_HLIST_NODE(>hlist);
hlist_add_head_rcu(>hlist,
@@ -578,7 +580,8 @@ static int __kprobes __register_kprobe(s
 
if (kprobe_enabled)
arch_arm_kprobe(p);
-
+out_unlock_text:
+   kernel_text_unlock();
 out:
mutex_unlock(_mutex);
 
@@ -621,8 +624,11 @@ valid_p:
 * enabled - otherwise, the breakpoint would already have
 * been removed. We save on flushing icache.
 */
-   if (kprobe_enabled)
+   if (kprobe_enabled) {
+   kernel_text_lock();
arch_disarm_kprobe(p);
+   kernel_text_unlock();
+   }
hlist_del_rcu(_p->hlist);
cleanup_p = 1;
} else {
@@ -644,9 +650,7 @@ valid_p:
list_del_rcu(>list);
kfree(old_p);
}
-   mutex_lock(_mutex);
arch_remove_kprobe(p);
-   mutex_unlock(_mutex);
} else {
mutex_lock(_mutex);
if (p->break_handler)
@@ -717,7 +721,6 @@ static int __kprobes pre_handler_kretpro
ri->rp = rp;
ri->task = current;
arch_prepare_kretprobe(ri, regs);
-
/* XXX(hch): why is there no hlist_move_head? */
hlist_del(>uflist);
hlist_add_head(>uflist, >rp->used_instances);
@@ -940,8 +943,10 @@ static void __kprobes enable_all_kprobes
 
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = _table[i];
+   kernel_text_lock();
hlist_for_each_entry_rcu(p, node, head, hlist)
arch_arm_kprobe(p);
+   kernel_text_unlock();
}
 
kprobe_enabled = true;
@@ -969,10 +974,12 @@ static void __kprobes disable_all_kprobe
printk(KERN_INFO "Kprobes globally disabled\n");
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = _table[i];
+   kernel_text_lock();
hlist_for_each_entry_rcu(p, node, head, hlist) {
if (!arch_trampoline_kprobe(p))
arch_disarm_kprobe(p);
}
+   kernel_text_unlock();
}
 
mutex_unlock(_mutex);

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
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 [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/


[rfc-patch 07/11] Text Edit Lock - kprobes architecture independent support

2007-11-16 Thread Mathieu Desnoyers
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.

Signed-off-by: Mathieu Desnoyers [EMAIL PROTECTED]
Acked-by: Ananth N Mavinakayanahalli [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
CC: [EMAIL PROTECTED]
---
 kernel/kprobes.c |   19 +--
 1 file changed, 13 insertions(+), 6 deletions(-)

Index: linux-2.6-lttng/kernel/kprobes.c
===
--- linux-2.6-lttng.orig/kernel/kprobes.c   2007-09-07 10:12:06.0 
-0400
+++ linux-2.6-lttng/kernel/kprobes.c2007-09-07 10:13:09.0 -0400
@@ -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
@@ -568,9 +569,10 @@ static int __kprobes __register_kprobe(s
goto out;
}
 
+   kernel_text_lock();
ret = arch_prepare_kprobe(p);
if (ret)
-   goto out;
+   goto out_unlock_text;
 
INIT_HLIST_NODE(p-hlist);
hlist_add_head_rcu(p-hlist,
@@ -578,7 +580,8 @@ static int __kprobes __register_kprobe(s
 
if (kprobe_enabled)
arch_arm_kprobe(p);
-
+out_unlock_text:
+   kernel_text_unlock();
 out:
mutex_unlock(kprobe_mutex);
 
@@ -621,8 +624,11 @@ valid_p:
 * enabled - otherwise, the breakpoint would already have
 * been removed. We save on flushing icache.
 */
-   if (kprobe_enabled)
+   if (kprobe_enabled) {
+   kernel_text_lock();
arch_disarm_kprobe(p);
+   kernel_text_unlock();
+   }
hlist_del_rcu(old_p-hlist);
cleanup_p = 1;
} else {
@@ -644,9 +650,7 @@ valid_p:
list_del_rcu(p-list);
kfree(old_p);
}
-   mutex_lock(kprobe_mutex);
arch_remove_kprobe(p);
-   mutex_unlock(kprobe_mutex);
} else {
mutex_lock(kprobe_mutex);
if (p-break_handler)
@@ -717,7 +721,6 @@ static int __kprobes pre_handler_kretpro
ri-rp = rp;
ri-task = current;
arch_prepare_kretprobe(ri, regs);
-
/* XXX(hch): why is there no hlist_move_head? */
hlist_del(ri-uflist);
hlist_add_head(ri-uflist, ri-rp-used_instances);
@@ -940,8 +943,10 @@ static void __kprobes enable_all_kprobes
 
for (i = 0; i  KPROBE_TABLE_SIZE; i++) {
head = kprobe_table[i];
+   kernel_text_lock();
hlist_for_each_entry_rcu(p, node, head, hlist)
arch_arm_kprobe(p);
+   kernel_text_unlock();
}
 
kprobe_enabled = true;
@@ -969,10 +974,12 @@ static void __kprobes disable_all_kprobe
printk(KERN_INFO Kprobes globally disabled\n);
for (i = 0; i  KPROBE_TABLE_SIZE; i++) {
head = kprobe_table[i];
+   kernel_text_lock();
hlist_for_each_entry_rcu(p, node, head, hlist) {
if (!arch_trampoline_kprobe(p))
arch_disarm_kprobe(p);
}
+   kernel_text_unlock();
}
 
mutex_unlock(kprobe_mutex);

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
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