Bug 693268

Summary:	Crash with 478-01.ps
Product:	Ghostscript	Reporter:	Ray Johnston <ray.johnston>
Component:	PS Interpreter	Assignee:	Alex Cherepanov <alex>
Status:	RESOLVED FIXED
Severity:	critical
Priority:	P4
Version:	master
Hardware:	PC
OS:	Windows 7
Customer:		Word Size:	---

Description Ray Johnston 2012-08-12 18:09:55 UTC

I started trying to look at the shading regression bug with this file and find
that HEAD crashes.

I ran git bisect and Alex's commit:
   86f9af6937e76e10a7adad201b06c337b1a9240b
was the cause.

Note I am using VS 2008 (MSVC_VER=9) building 32-bit binaries. The command
line is:

gswin32c -q -r300 -dNOPAUSE -dBATCH tests_private/comparefiles/478-01.ps

and also segfaults with:

gswin32c -q -r300 -sDEVICE=ppmraw -o x.ppm tests_private/comparefiles/478-01.ps

I haven't looked into it much, but it is failing during GC.

I suggest considering reversion of the patch until this is found/fixed.

Comment 1 Alex Cherepanov 2012-08-12 22:01:20 UTC

The problem is reproduced on Windows but the file works fine on
32 and 64 bit Linux.

We need regression testing on every platform we support.

Comment 2 Marcos H. Woehrmann 2012-08-14 13:59:06 UTC

(In reply to comment #1)
> We need regression testing on every platform we support.

I agree with Alex's suggestion that we drop support for Windows.

Comment 3 Alex Cherepanov 2012-08-14 14:51:37 UTC

The problem is caused by the fact that on Windows obj_align_mod == 8 but
sizeof(ref) == 12. On Linux x86 obj_align_mod == 4, Linux AMD64 sizeof(ref)==16

We need either
- don't require sizeof(ref) % obj_align_mod == 0
- always use 16-byte ref's or pad the ref when obj_align_mod == 8
- don't set obj_align_mod == 8 on x86 or ppc32

Comment 4 Alex Cherepanov 2012-08-23 06:19:21 UTC

Reinstate big references.
Make them compatible with 8-byte alignment on 32-bit Windows by adding
a dummy uint64_t member to the union that increases the sizeof(ref) to 16.

http://git.ghostscript.com/?p=ghostpdl.git;a=commitdiff;h=2740bef445c51680d831ec40753436291f01760a