The Linux/BSD DF kernel bug
fgouget at free.fr
Wed Mar 19 09:59:56 CDT 2008
So I've just read the following article:
GCC 4.3.0 exposes a kernel bug
And my question is: could this be relevant to Wine?
And I don't mean about GCC 4.3.0 but about MSVC.
Here's the core of the issue:
The problem revolves around the x86 direction flag (DF), which
governs whether block memory operations operate forward through
memory or backwards. GCC [...] 4.3.0, assumes that the direction flag
has been cleared [...] at the entry of each function, as is specified
by the ABI [...] Prior to 4.3, GCC would emit a cld (clear direction
flag) opcode before doing inline string or memory operations.
So any compiler that not clear the direction flag at the start of each
function can cause kernel crashes when running on a buggy Linux or BSD
So the questions are:
Does anyone know if MSVC does a cld in the right places?
What about other popular compilers used to compile Windows
Mac OS X being (loosely) based on the BSD kernels, does it have
this issue too?
Francois Gouget <fgouget at free.fr> http://fgouget.free.fr/
tcA thgirypoC muinelliM latigiD eht detaloiv tsuj evah uoY
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