s390: fix system call restart with multiple signals
commit fc66127d upstream. glibc complained with "The futex facility returned an unexpected error code.". It turned out that the futex syscall returned -ERESTARTSYS because a signal is pending. arch_do_signal_or_restart() restored the syscall parameters (nameley regs->gprs[2]) and set PIF_SYSCALL_RESTART. When another signal is made pending later in the exit loop arch_do_signal_or_restart() is called again. This function clears PIF_SYSCALL_RESTART and checks the return code which is set in regs->gprs[2]. However, regs->gprs[2] was restored in the previous run and no longer contains -ERESTARTSYS, so PIF_SYSCALL_RESTART isn't set again and the syscall is skipped. Fix this by not clearing PIF_SYSCALL_RESTART - it is already cleared in __do_syscall() when the syscall is restarted. Reported-by:Bjoern Walk <bwalk@linux.ibm.com> Signed-off-by:
Sven Schnelle <svens@linux.ibm.com> Reviewed-by:
Heiko Carstens <hca@linux.ibm.com> Fixes: 56e62a73 ("s390: convert to generic entry") Cc: <stable@vger.kernel.org> # 5.12 Signed-off-by:
Vasily Gorbik <gor@linux.ibm.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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24b8aa8c
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