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Date: Thu, 25 Jun 2015 14:48:40 -0300
From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>, linux-kernel@vger.kernel.org,
        Jiri Olsa <jolsa@kernel.org>, Adrian Hunter <adrian.hunter@intel.com>,
        Andi Kleen <ak@linux.intel.com>, David Ahern <dsahern@gmail.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Peter Zijlstra <a.p.zijlstra@chello.nl>,
        Stephane Eranian <eranian@google.com>
Subject: Re: [PATCH 12/13] perf thread_map: Change map entries into a struct
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Em Thu, Jun 25, 2015 at 10:45:05AM -0300, Arnaldo Carvalho de Melo escreveu:
> Em Thu, Jun 25, 2015 at 10:38:41AM +0200, Jiri Olsa escreveu:
> > and you missed following hunk:

> > ---
> >  static struct thread_map *thread_map__realloc(struct thread_map *map, int nr)
> >  {
> > -       size_t size = sizeof(*map) + sizeof(pid_t) * nr;
> > +       size_t size = sizeof(*map) + sizeof(struct thread_map_data) * nr;
> > ---

> > shouldn't be fatal, it probably has the same or biggger size ATM
> > I'll include the fix in the next version
> 
> Yeah, sorry about that, should have noticed that, but as you said, code
> wise it is harmless.

Adding this fix for it, should have been there since when I implemented
thread_map...

 static struct thread_map *thread_map__realloc(struct thread_map *map,
int nr)
 {
-       size_t size = sizeof(*map) + sizeof(pid_t) * nr;
+       size_t size = sizeof(*map) + sizeof(map->map[0]) * nr;

-----------

[acme@zoo ~]$ cat thread_map.c 
#include <sys/types.h>
#include <stdio.h>

struct thread_map_data {
        pid_t    pid;
};

struct thread_map {
        int nr;
        struct thread_map_data map[];
};

int main(void)
{
	struct thread_map *map;

	printf("sizeof(map->map[0]:\t\t%zd\n", sizeof(map->map[0]));
	printf("sizeof(struct thread_map_data):\t%zd\n", sizeof(struct thread_map_data));
	printf("sizeof(pid_t):\t\t\t%zd\n", sizeof(pid_t));
	return 0;
}
[acme@zoo ~]$ make thread_map
cc     thread_map.c   -o thread_map
[acme@zoo ~]$ ./thread_map 
sizeof(map->map[0]:		4
sizeof(struct thread_map_data):	4
sizeof(pid_t):			4
[acme@zoo ~]$ file thread_map
thread_map: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.32, BuildID[sha1]=a6a9894fb6127e23621ef02e1110ff6635082bcd, not stripped
[acme@zoo ~]$

- Arnaldo