Hi In the kernel 4.9-rc1, the x32 support is seriously broken, a x32 process is killed with SIGKILL after returning from any signal handler. I use Debian sid x64-64 distribution with x32 architecture added from debian-ports. I bisected the bug and found out that it is caused by the patch 6846351052e685c2d1428e80ead2d7ca3d7ed913 ("x86/signal: Add SA_{X32,IA32}_ABI sa_flags"). example (strace of a process after receiving the SIGWINCH signal): epoll_wait(10, 0xef6890, 32, -1) = -1 EINTR (Interrupted system call) --- SIGWINCH {si_signo=SIGWINCH, si_code=SI_USER, si_pid=1772, si_uid=0} --- poll([{fd=4, events=POLLOUT}], 1, 0) = 1 ([{fd=4, revents=POLLOUT}]) write(4, "\0", 1) = 1 rt_sigreturn({mask=[INT QUIT ILL TRAP BUS KILL SEGV USR2 PIPE ALRM STKFLT TSTP TTOU URG XCPU XFSZ VTALRM IO PWR SYS RTMIN]}) = 0 --- SIGSEGV {si_signo=SIGSEGV, si_code=SI_KERNEL, si_addr=NULL} --- +++ killed by SIGSEGV +++ Neoprávnìný pøístup do pamìti (SIGSEGV) Mikulas