Initialize status in gdbserver/linux-low.c

Initialize status in gdbserver/linux-low.c

[Sterling Augustine]

[-- Attachment #1: Type: text/plain, Size: 372 bytes --]

Hi,

As the code for handle_extended_wait exists today, status can be used
uninitialized on line 486 if pull_pid_from_list on line 451 returns
true.

This near-trivial patch initializes it to zero at the declaration.

OK for mainline?

Sterling


2012-07-07  Sterling Augustine  <saugustine@google.com>

	* gdbserver/linux-low.c (handle_extended_wait): Initialize status.

[-- Attachment #2: patch --]
[-- Type: application/octet-stream, Size: 492 bytes --]

Index: linux-low.c
===================================================================
RCS file: /cvs/src/src/gdb/gdbserver/linux-low.c,v
retrieving revision 1.226
diff -d -u -r1.226 linux-low.c
--- linux-low.c	7 Jul 2012 12:13:57 -0000	1.226
+++ linux-low.c	16 Jul 2012 15:50:12 -0000
@@ -443,7 +443,7 @@
     {
       ptid_t ptid;
       unsigned long new_pid;
-      int ret, status;
+      int ret, status = 0;
 
       ptrace (PTRACE_GETEVENTMSG, lwpid_of (event_child), 0, &new_pid);
 

Re: Initialize status in gdbserver/linux-low.c

[Pedro Alves]

On 07/16/2012 04:54 PM, Sterling Augustine wrote:
> Hi,
> 
> As the code for handle_extended_wait exists today, status can be used
> uninitialized on line 486 if pull_pid_from_list on line 451 returns
> true.

If pull_pid_from_list returns true, then it has written to status.
Sounds like you're getting a false positive warning?

> 
> This near-trivial patch initializes it to zero at the declaration.
> 
> OK for mainline?

If this is indeed a false warning, then this is okay with
a "Avoid GCC false warning" comment or some such.

-- 
Pedro Alves

Re: Initialize status in gdbserver/linux-low.c

[Sterling Augustine]

On Mon, Jul 16, 2012 at 9:06 AM, Pedro Alves <palves@redhat.com> wrote:
> On 07/16/2012 04:54 PM, Sterling Augustine wrote:
>> Hi,
>>
>> As the code for handle_extended_wait exists today, status can be used
>> uninitialized on line 486 if pull_pid_from_list on line 451 returns
>> true.
>
> If pull_pid_from_list returns true, then it has written to status.
> Sounds like you're getting a false positive warning?
>
>>
>> This near-trivial patch initializes it to zero at the declaration.
>>
>> OK for mainline?
>
> If this is indeed a false warning, then this is okay with
> a "Avoid GCC false warning" comment or some such.

My mistake. I was compiling an older version of gdb where
pull_pid_from_list didn't include the third parameter. Then forward
ported the fix.

Sterling