Re: [Qemu-devel] [PATCH V2] colo-proxy: fix memory leak

[Eric Blake <eblake@redhat.com>]

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On 10/11/2016 02:33 AM, Zhang Chen wrote:
> Fix memory leak in colo-compare.c and filter-rewriter.c
> Report by Coverity.

This part is fine.

> 
> v2:
>   - use traces instead of fprintf in colo-compare.c
> 
> v1:
>   - initial patch

...but this part should live...

> 
> Signed-off-by: Zhang Chen <zhangchen.fnst@cn.fujitsu.com>
> ---

...here, after the --- separator, where 'git am' will ignore it.  It is
useful information to list readers, but will make no sense in qemu.git
history a year from now (we don't care how many versions it took to get
to the version that was committed).  The maintainer can fix it, so by
itself, that's not a reason to send a v3.

>  net/colo-compare.c    | 11 +++--------
>  net/filter-rewriter.c | 17 +++++------------
>  trace-events          |  1 +
>  3 files changed, 9 insertions(+), 20 deletions(-)
> 

> @@ -219,11 +218,9 @@ static int colo_packet_compare_tcp(Packet *spkt, Packet *ppkt)
>                  (spkt->size - ETH_HLEN));
>  
>      if (res != 0 && trace_event_get_state(TRACE_COLO_COMPARE_MISCOMPARE)) {
> -        sdebug = strdup(inet_ntoa(ppkt->ip->ip_src));
> -        ddebug = strdup(inet_ntoa(ppkt->ip->ip_dst));
> -        fprintf(stderr, "%s: src/dst: %s/%s p: seq/ack=%u/%u"
> -                " s: seq/ack=%u/%u res=%d flags=%x/%x\n",
> -                __func__, sdebug, ddebug,
> +        trace_colo_compare_pkt_info(__func__,

net/filter-rewriter.c is the only file that currently uses
trace_...(__func__), that's because the trace mechanism itself already
expands the trace_* call to something with enough context that manually
adding __func__ just gives redundant information.  I'd rather see
__func__ removed from the trace call.

> +                inet_ntoa(ppkt->ip->ip_src),
> +                inet_ntoa(ppkt->ip->ip_dst),
>                  (unsigned int)ntohl(ptcp->th_seq),
>                  (unsigned int)ntohl(ptcp->th_ack),
>                  (unsigned int)ntohl(stcp->th_seq),

Are these casts still needed?

> +++ b/trace-events
> @@ -149,6 +149,7 @@ colo_compare_icmp_miscompare(const char *sta, int size) ": %s = %d"
>  colo_compare_ip_info(int psize, const char *sta, const char *stb, int ssize, const char *stc, const char *std) "ppkt size = %d, ip_src = %s, ip_dst = %s, spkt size = %d, ip_src = %s, ip_dst = %s"
>  colo_old_packet_check_found(int64_t old_time) "%" PRId64
>  colo_compare_miscompare(void) ""
> +colo_compare_pkt_info(const char *func, const char *src, const char *dst, uint32_t pseq, uint32_t pack, uint32_t sseq, uint32_t sack, int res, uint32_t pflag, uint32_t sflag) "%s: src/dst: %s/%s p: seq/ack=%u/%u   s: seq/ack=%u/%u res=%d flags=%x/%x\n"

Again, the 'const char *func' portion is not needed.

Looking forward to v3.

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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