[Mesa-dev] [PATCH 2/2] gallium/util: libunwind support

[Thomas Hellstrom]

On 04/03/2017 07:33 PM, Thomas Hellstrom wrote:
> On 04/03/2017 07:13 PM, Rob Clark wrote:
>> On Mon, Apr 3, 2017 at 12:56 PM, Thomas Hellstrom <thellstrom at vmware.com> wrote:
>>> Hi, Rob,
>>>
>>> On 03/24/2017 10:21 PM, Rob Clark wrote:
>>>> It's kinda sad that (a) we don't have debug_backtrace support on !X86
>>>> and that (b) we re-invent our own crude backtrace support in the first
>>>> place.  If available, use libunwind instead.  The backtrace format is
>>>> based on what xserver and weston use, since it is nice not to have to
>>>> figure out a different format.
>>>>
>>>> Signed-off-by: Rob Clark <robdclark at gmail.com>
>>> Did you consider glibc "backtrace()", I think it's also available on ARM...
>> I had not.. although xserver and weston are already using libunwind.
>> I'm not sure about portability of libunwind to other libc
>> implementations (but I guess it is at least not worse than using a
>> glibc specific API).
>>
>> I suppose we could always add a fallback to backtrace().
>>
Hmm. This commit (bisected) appears to break svga/vmwgfx in DEBUG mode:

*** Error in `glxgears': malloc(): memory corruption: 0x00000000025c09c0 ***
Aborted (core dumped)

The svga linux winsys makes extensive use of the backtrace functionality
using u_debug_flush.c

/Thomas