Re: libbacktrace patch committed: Call munmap after memory test

[Ian Lance Taylor <iant at golang dot org>]

On Tue, Apr 17, 2018 at 10:21 AM, Tom de Vries <Tom_deVries@mentor.com> wrote:
> On 04/17/2018 03:59 PM, Ian Lance Taylor wrote:
>>
>> The bug report https://github.com/ianlancetaylor/libbacktrace/issues/13
>> points out that when backtrace_full checks whether memory is
>> available, it doesn't necessarily release that memory.  It will stay
>> on the free list, so libbacktrace will use more and more memory over
>> time.  This patch fixes that problem by explicitly calling munmap.
>> Bootstrapped and ran libbacktrace and Go tests on x86_64-pc-linux-gnu.
>> Committed to mainline.
>>
>> Ian
>>
>>
>> 2018-04-17  Ian Lance Taylor  <iant@golang.org>
>>
>> * backtrace.c (backtrace_full): When testing whether we can
>> allocate memory, call mmap directly, and munmap the memory.
>>
>>
>> patch.txt
>>
>>
>> Index: backtrace.c
>> ===================================================================
>> --- backtrace.c (revision 259359)
>> +++ backtrace.c (working copy)
>> @@ -32,12 +32,26 @@ POSSIBILITY OF SUCH DAMAGE.  */
>>     #include "config.h"
>>   +#include <unistd.h>
>>   #include <sys/types.h>
>>   +#if !BACKTRACE_USES_MALLOC
>> +#include <sys/mman.h>
>> +#endif
>> +
>
>
> Hi,
>
> this breaks the nvptx build:
> ...
> libbacktrace/backtrace.c:39:10: fatal error: sys/mman.h: No such file or
> directory
>  #include <sys/mman.h>
>           ^~~~~~~~~~~~
> compilation terminated.

Sorry about that.  Committed this patch, which should fix that problem.

Ian


2018-04-17  Ian Lance Taylor  <iant@golang.org>

* backtrace.c: Include backtrace-supported.h before checking
BACKTRACE_USES_MALLOC.

Attachment: patch.txt
Description: Text document