[PATCH] Use rs->buf after getpkt

[PATCH] Use rs->buf after getpkt

[Yao Qi]

Hi,
The following code snippet looks wrong to me

 char *buf = rs->buf;

 getpkt (&rs->buf, &rs->buf_size, 0);
 packet_ok (buf, );

if rs->buf is reallocated in getpkt, buf points to an out of dated
memory.  This patch removes local 'buf' and uses rs->buf.

Regression tested on x86_64-linux.  Is it OK?

gdb:

2014-01-25  Yao Qi  <yao@codesourcery.com>

	* remote.c (remote_pass_signals): Remove local 'buf' and use
	rs->buf.
	(remote_program_signals): Likewise.
---
 gdb/remote.c |    8 ++------
 1 files changed, 2 insertions(+), 6 deletions(-)

diff --git a/gdb/remote.c b/gdb/remote.c
index 7297df0..ece05d1 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -1732,11 +1732,9 @@ remote_pass_signals (int numsigs, unsigned char *pass_signals)
       *p = 0;
       if (!rs->last_pass_packet || strcmp (rs->last_pass_packet, pass_packet))
 	{
-	  char *buf = rs->buf;
-
 	  putpkt (pass_packet);
 	  getpkt (&rs->buf, &rs->buf_size, 0);
-	  packet_ok (buf, &remote_protocol_packets[PACKET_QPassSignals]);
+	  packet_ok (rs->buf, &remote_protocol_packets[PACKET_QPassSignals]);
 	  if (rs->last_pass_packet)
 	    xfree (rs->last_pass_packet);
 	  rs->last_pass_packet = pass_packet;
@@ -1785,11 +1783,9 @@ remote_program_signals (int numsigs, unsigned char *signals)
       if (!rs->last_program_signals_packet
 	  || strcmp (rs->last_program_signals_packet, packet) != 0)
 	{
-	  char *buf = rs->buf;
-
 	  putpkt (packet);
 	  getpkt (&rs->buf, &rs->buf_size, 0);
-	  packet_ok (buf, &remote_protocol_packets[PACKET_QProgramSignals]);
+	  packet_ok (rs->buf, &remote_protocol_packets[PACKET_QProgramSignals]);
 	  xfree (rs->last_program_signals_packet);
 	  rs->last_program_signals_packet = packet;
 	}
-- 
1.7.7.6

Re: [PATCH] Use rs->buf after getpkt

[Pedro Alves]

On 01/25/2014 12:16 PM, Yao Qi wrote:
> Hi,
> The following code snippet looks wrong to me
> 
>  char *buf = rs->buf;
> 
>  getpkt (&rs->buf, &rs->buf_size, 0);
>  packet_ok (buf, );
> 
> if rs->buf is reallocated in getpkt, buf points to an out of dated
> memory. 

Indeed.

> This patch removes local 'buf' and uses rs->buf.
> 
> Regression tested on x86_64-linux.  Is it OK?

OK.

-- 
Pedro Alves

Re: [PATCH] Use rs->buf after getpkt

[Yao Qi]

On 02/05/2014 03:25 AM, Pedro Alves wrote:
> On 01/25/2014 12:16 PM, Yao Qi wrote:
>> Hi,
>> The following code snippet looks wrong to me
>>
>>  char *buf = rs->buf;
>>
>>  getpkt (&rs->buf, &rs->buf_size, 0);
>>  packet_ok (buf, );
>>
>> if rs->buf is reallocated in getpkt, buf points to an out of dated
>> memory. 
> 
> Indeed.
> 
>> This patch removes local 'buf' and uses rs->buf.
>>
>> Regression tested on x86_64-linux.  Is it OK?
> 
> OK.
> 

Thanks for the review.  Patch is pushed.

-- 
Yao (齐尧)