Red Hat Bugzilla – Bug 110121
XFree86 memory permissions not backwards compatible
Last modified: 2007-11-30 17:06:53 EST
Memory permissions not backwards compatible with OEM driver
requirements. chatr "hack" was removed post-QU2 and replaced
with different patch. PROT_EXEC patch not sufficient for
OEM drivers (nvidia-2.4.18.e.31_4431-1.ia64.rpm) that were
tested and released by HP. Customer used up2date and
experienced unresolvable system breakage when version
XFree86-4.1.0-50.EL applied to IPF system.
XFree86 seg faults when used with an OEM driver.
When chatr (from 4.1.0-46 revision) was applied to executable,
functionality returned to package when using graphics package
Additional behavior seems to be that before this memory
attribute was changed, X server did not properly export
symbols to the OEM driver, either.
While we would not make any change to XFree86 or the kernel that
would knowingly break a 3rd party driver without good cause, and
without notifying relevant vendors and partners ahead of time,
Red Hat does not test XFree86 with 3rd party video drivers at all,
and we do not certify or guarantee XFree86 will work with 3rd
party video drivers, and we do not support systems that are running
3rd party drivers, so it is entirely possible that a kernel update
or an XFree86 update might cause 3rd party uncertified drivers to
break at any time.
The chatr hack we had previously was only a quick hack to make the
server work properly until the proper and better solution could be
found, which is what we have currently.
Nvidia's driver may need to be recompiled by Nvidia with the
proper bits to ensure PROT_EXEC is used inside the driver
I don't consider this to be a bug in our XFree86 package, but
rather a bug in the proprietary driver.