32bit processes at compatbility mode on x86_64 machines fail to restart syscall after processing a signal

[Zhang, Yanmin]

The test case at
http://cvs.sourceforge.net/viewcvs.py/posixtest/posixtestsuite/conforman
ce/interfaces/clock_nanosleep/1-5.c fails if it runs as a 32bit process
on x86_86 machines.

The root cause is the sub 32bit process fails to restart the syscall
after it is interrupted
by a signal.

The syscall number of sys_restart_syscall in table sys_call_table is 
__NR_restart_syscall (219) while it's __NR_ia32_restart_syscall (0) in
ia32_sys_call_table. When regs->rax==(unsigned
long)-ERESTART_RESTARTBLOCK,
function do_signal doesn't distinguish if the process is 64bit or 32bit,
and always sets
restart syscall number as __NR_restart_syscall (219).

Here is a patch against kernel 2.6.12-rc4.

Signed-off-by: Zhang Yanmin <yanmin.zhang@xxxxxxxxx>

Attachment: 32bit_process_fail_restart_syscall.patch
Description: 32bit_process_fail_restart_syscall.patch