RE: commit 6fb8cbcb58a29fff73eb2101b34caa19a7f88eba causes Dialogic DIVA fax to send corrupted image

RE: commit 6fb8cbcb58a29fff73eb2101b34caa19a7f88eba causes Dialogic DIVA fax to send corrupted image

[Lu, Hongjiu]

> 
> I don't know whether this is a Dialogic Diva Fax problem or Glibc
> problem. With this commit, fax sent is corrupted. Reverting the commit
> solves the problem.
> 
> I'm on latest glibc (dbf3a06904168417a05882a871342e7a9ee3b383) and it
> has the same problem, so I bisected to this commit causing the issue.
> I've tried all versions of DIVA including the latest
> Diva4Linux_installer_9.5-110-13.bin and dssdk-gcc4x-110.2555-
> 1.x86_64.rpm
> 
> Linux version is 2.6.33
> gcc version 4.4.5 20100925 (prerelease) (GCC)
> 
> GNU C Library stable release version 2.11.1, by Roland McGrath et al.
> (OK) GNU C Library development release version 2.12.90, by Roland
> McGrath et al. (bad)
> 
> I've attached two images. One good and a corrupted image received.
> 
> 6fb8cbcb58a29fff73eb2101b34caa19a7f88eba is the first bad commit
> commit 6fb8cbcb58a29fff73eb2101b34caa19a7f88eba
> Author: H.J. Lu <hongjiu.lu@intel.com>
> Date:   Wed Jun 30 08:26:11 2010 -0700
> 
>     Improve 64bit memcpy/memmove for Atom, Core 2 and Core i7
> 
>     This patch includes optimized 64bit memcpy/memmove for Atom, Core
> 2 and
>     Core i7.  It improves memcpy by up to 3X on Atom, up to 4X on Core
> 2 and
>     up to 1X on Core i7.  It also improves memmove by up to 3X on Atom,
> up to
>     4X on Core 2 and up to 2X on Core i7.
> 
> 

The new memcpy doesn't work if there is any overlap in destination and
source. Please try to replace memcpy with memmove in Dialogic Diva Fax to
see if the problem goes away. If it is impossible, please write a
memcpy wrapper to check if there is any overlap in destination and
source.


H.J.

Re: commit 6fb8cbcb58a29fff73eb2101b34caa19a7f88eba causes Dialogic DIVA fax to send corrupted image

[Jeff Chua]

On Tue, Oct 26, 2010 at 11:15 PM, Lu, Hongjiu <hongjiu.lu@intel.com> wrote:

> The new memcpy doesn't work if there is any overlap in destination and
> source. Please try to replace memcpy with memmove in Dialogic Diva Fax to
> see if the problem goes away. If it is impossible, please write a
> memcpy wrapper to check if there is any overlap in destination and
> source.

HJ,

The Dialogic software is all binaries and has an API which is pretty
high level, so will be difficult for me to do this change. I'll wait
for Dialogic to see if they can do something on their end.

Thanks for the fast response.

Jeff.