Some discussion with the glibc mailing lists revealed that this was
necessary for 64-bit platforms with MIPS-like sign-extension rules
for 32-bit values. The original symptom was that passing (uid_t)-1 to
setreuid() was failing in programs linked -pthread because of the "setxid"
mechanism for passing setxid-type function arguments to the syscall code.
SYSCALL_WRAPPERS handles ensuring that all syscall arguments end up with
proper sign-extension and is thus the appropriate fix for this problem.
On other platforms (s390, powerpc, sparc64, and mips) this was fixed
in 2.6.28.6. The general issue is tracked as CVE-2009-0029.
Cc: <stable@vger.kernel.org>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
e6d9668e11