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asan: support for globals in kernel

Message ID CACT4Y+bZAni-M9Pc+po2OoGc7xu6JJGazi0VwGGKOoaD6Dbstg@mail.gmail.com
State New
Headers show

Commit Message

Dmitry Vyukov Dec. 2, 2014, 6:12 p.m. UTC 
On Tue, Dec 2, 2014 at 9:04 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Tue, Dec 02, 2014 at 09:56:36PM +0400, Dmitry Vyukov wrote:
>> --- gcc/ChangeLog (revision 218280)
>> +++ gcc/ChangeLog (working copy)
>> @@ -1,3 +1,8 @@
>> +2014-12-02  Dmitry Vyukov  <dvyukov@google.com>
>> +
>> + * asan.c: (asan_finish_file): Use default priority for constructors
>> + in kernel mode.
>
> Seems your MUA is eating tabs, I'll assume they are where I'd expect them to
> be.
>
>> @@ -2440,6 +2442,7 @@
>>  {
>>    varpool_node *vnode;
>>    unsigned HOST_WIDE_INT gcount = 0;
>> +  int priority;
>>
>>    if (shadow_ptr_types[0] == NULL_TREE)
>>      asan_init_shadow_ptr_types ();
>
> No need to declare this separately,
>
>> @@ -2448,6 +2451,13 @@
>>       nor after .LASAN* array.  */
>>    flag_sanitize &= ~SANITIZE_ADDRESS;
>>
>> +  /* For user-space we want asan constructors to run first.
>> +     Linux kernel does not support priorities other than default, and the only
>> +     other user of constructors is coverage. So we run with the default
>> +     priority.  */
>> +  priority = flag_sanitize & SANITIZE_USER_ADDRESS ?
>> +      MAX_RESERVED_INIT_PRIORITY - 1 : DEFAULT_INIT_PRIORITY;
>
> formatting plus declare it here too.  This should be
>   int priority = flag_sanitize & SANITIZE_USER_ADDRESS
>                  ? MAX_RESERVED_INIT_PRIORITY - 1 : DEFAULT_INIT_PRIORITY;
> (? should be on the second line and aligned below flag_sanitize).
>
> Ok for trunk with that change.
>
> Shall we backport it to 4.9 branch too?

If it's doable, it would be nice. Thanks.
When do we expect next 4.9 release?

Yes, my mail client eats tabs, here is proper version:
https://codereview.appspot.com/176570043/diff/20001/gcc/ChangeLog
Sorry.


And here is updated text version with eaten tabs:

Comments

Jakub Jelinek Dec. 2, 2014, 6:17 p.m. UTC | #1 
On Tue, Dec 02, 2014 at 10:12:30PM +0400, Dmitry Vyukov wrote:
> > Shall we backport it to 4.9 branch too?
> 
> If it's doable, it would be nice. Thanks.

Bet the same patch will just apply there.

> When do we expect next 4.9 release?

Probably in March/April timeframe or so, 4.9.2 has been released
just a month ago.

> And here is updated text version with eaten tabs:

Ok.

	Jakub
Dmitry Vyukov Dec. 2, 2014, 6:59 p.m. UTC | #2 
On Tue, Dec 2, 2014 at 9:17 PM, Jakub Jelinek <jakub@redhat.com> wrote:
> On Tue, Dec 02, 2014 at 10:12:30PM +0400, Dmitry Vyukov wrote:
>> > Shall we backport it to 4.9 branch too?
>>
>> If it's doable, it would be nice. Thanks.
>
> Bet the same patch will just apply there.

Do I need to do anything additional for this? Or you will backport it?


Committed in revision 218281.


>> When do we expect next 4.9 release?
>
> Probably in March/April timeframe or so, 4.9.2 has been released
> just a month ago.
>
>> And here is updated text version with eaten tabs:
>
> Ok.
>
>         Jakub
diff mbox

Patch

Index: gcc/ChangeLog
===================================================================
--- gcc/ChangeLog (revision 218280)
+++ gcc/ChangeLog (working copy)
@@ -1,3 +1,8 @@ 
+2014-12-02  Dmitry Vyukov  <dvyukov@google.com>
+
+ * asan.c: (asan_finish_file): Use default priority for constructors
+ in kernel mode.
+
 2014-12-02  Ulrich Weigand  <Ulrich.Weigand@de.ibm.com>

  PR target/64115
Index: gcc/asan.c
===================================================================
--- gcc/asan.c (revision 218280)
+++ gcc/asan.c (working copy)
@@ -1348,7 +1348,9 @@ 
  the var that is selected by the linker will have
  padding or not.  */
       || DECL_ONE_ONLY (decl)
-      /* Similarly for common vars.  People can use -fno-common.  */
+      /* Similarly for common vars.  People can use -fno-common.
+ Note: Linux kernel is built with -fno-common, so we do instrument
+ globals there even if it is C.  */
       || (DECL_COMMON (decl) && TREE_PUBLIC (decl))
       /* Don't protect if using user section, often vars placed
  into user section from multiple TUs are then assumed
@@ -2448,6 +2450,13 @@ 
      nor after .LASAN* array.  */
   flag_sanitize &= ~SANITIZE_ADDRESS;

+  /* For user-space we want asan constructors to run first.
+     Linux kernel does not support priorities other than default, and the only
+     other user of constructors is coverage. So we run with the default
+     priority.  */
+  int priority = flag_sanitize & SANITIZE_USER_ADDRESS
+                 ? MAX_RESERVED_INIT_PRIORITY - 1 : DEFAULT_INIT_PRIORITY;
+
   if (flag_sanitize & SANITIZE_USER_ADDRESS)
     {
       tree fn = builtin_decl_implicit (BUILT_IN_ASAN_INIT);
@@ -2503,12 +2512,10 @@ 
  build_fold_addr_expr (var),
  gcount_tree),
  &dtor_statements);
-      cgraph_build_static_cdtor ('D', dtor_statements,
- MAX_RESERVED_INIT_PRIORITY - 1);
+      cgraph_build_static_cdtor ('D', dtor_statements, priority);
     }
   if (asan_ctor_statements)
-    cgraph_build_static_cdtor ('I', asan_ctor_statements,
-       MAX_RESERVED_INIT_PRIORITY - 1);
+    cgraph_build_static_cdtor ('I', asan_ctor_statements, priority);
   flag_sanitize |= SANITIZE_ADDRESS;
 }