On Fri, Oct 29, 2021 at 5:34 PM Stefano Brivio <sbrivio(a)redhat.com> wrote:On Fri, 29 Oct 2021 16:54:47 +0800 Li Feng <fengli(a)smartx.com> wrote:I made a mistake in the previous mail, using `./passt -f` works, but if running in background, it still exits without any output. This is the strace output. ``` $ strace -f ./passt ... ... accept(6, NULL, NULL) = 7 epoll_ctl(5, EPOLL_CTL_ADD, 7, {events=EPOLLIN|EPOLLRDHUP|EPOLLET, data={u32=7, u64=7}}) = 0 getrandom("\x40\xfc\xc5\x4a\x29\x3e\xdb\xcd\x25\x92\xc6\xc3\xc7\xcb\x57\x5a", 16, GRND_RANDOM) = 16 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 8 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 9 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 10 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 11 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 12 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 13 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 14 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 15 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 16 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 17 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 18 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 19 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 20 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 21 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 22 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 23 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 24 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 25 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 26 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 27 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 28 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 29 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 30 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 31 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 32 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 33 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 34 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 35 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 36 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 37 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 38 socket(AF_INET, SOCK_STREAM|SOCK_NONBLOCK, IPPROTO_TCP) = 39 clone(child_stack=NULL, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLDstrace: Process 172939 attached , child_tidptr=0x7f7b89b1da10) = 172939 [pid 172921] exit_group(0 <unfinished ...> [pid 172939] set_robust_list(0x7f7b89b1da20, 24 <unfinished ...> [pid 172921] <... exit_group resumed>) = ? [pid 172921] +++ exited with 0 +++ <... set_robust_list resumed>) = ? +++ killed by SIGSYS (core dumped) +++ ``` Which is the bad syscall?[...] Thanks for the detailed explanation. I finally found out that the `qrap` was the root cause. I patched the qemu, and it works well.Have you found out what was the offending syscall? I'll probably hit this later too, but that would help me double checking what the problem was.[...] This background knowledge helped me a lot. The seccomp works well with Fedora 35 without the `qrap`. Thanks again for your great work.You're welcome, I'm glad to hear it works for you! -- Stefano