On Thu, 14 Nov 2024 13:55:36 +0100 Christian Franke wrote: > After enabling the usage of pthread_sigqueue() in stress-ng, 'stress-ng > --pthread ...' occasionally reports that child processes failed with > SIGSEGV. > > The problem is unrelated to the recent fix of the signature of > pthread_sigqueue(): > https://cygwin.com/git/?p=newlib-cygwin.git;a=commit;h=1e8c92e > > It could be reproduced with Cygwin 3.5.4-1 and with current 3.6.0 TEST > release if the signature is adjusted. > > Testcase (attached): > > $ gcc -O2 -o sigfault sigfault.c # Add -DBETA if compiling for a TEST > release > > $ strace -o trace.log ./sigfault > pthread_create({0xa000188d0}, ...)=0 > pthread_sigqueue(0xa000188d0, SIGUSR1, .) > sigtimedwait(...)=30 (errno=0) > ... > sigtimedwait(...)=30 (errno=0) > pthread_sigqueue(0xa000188d0, SIGUSR1, .)=0 > pthread_join(0xa000188d0, .)=0 > pthread_create({0xa000188d0}, ...)=0 > pthread_sigqueue(0xa000188d0, SIGUSR1, .) > sigtimedwait(...)=30 (errno=0) > pthread_sigqueue(0xa000188d0, SIGUSR1, .)=0 > pthread_join(0xa000188d0, .)=0 > pthread_create({0xa000188d0}, ...)=0 > pthread_sigqueue(0xa000188d0, SIGUSR1, .) > Segmentation fault > > $ cat trace.log > ... > 78 103937 [main] sigfault 2074 sig_send: Waiting for pack.wakeup 0x21C > 80 104017 [sig] sigfault 2074 sigpacket::process: signal 30 processing > 147 104164 [sigfault] sigfault 2074 __set_errno: int > sigwait_common(const sigset_t*, siginfo_t*, PLARGE_INTEGER):643 setting > errno 11 > 103 104267 [sig] sigfault 2074 sigpacket::process: signal 30, signal > handler 0x1 > 84 104351 [sigfault] sigfault 2074 sigwait_common: returning signal -1 > 81 104432 [sig] sigfault 2074 sigpacket::setup_handler: controlled > interrupt. stackptr 0x7FFDFE220, stack 0x7FFDFE218, stackptr[-1] 0x100401109 > 78 104510 [sig] sigfault 2074 proc_subproc: args: 4, 1 > 74 104584 [sig] sigfault 2074 proc_subproc: clear waiting threads > 71 104655 [sig] sigfault 2074 proc_subproc: finished clearing > 70 104725 [sig] sigfault 2074 proc_subproc: returning 1 > 125 104850 [sig] sigfault 2074 _cygtls::interrupt_setup: armed > signal_arrived 0x24C, signal 30 > 74 104924 [sig] sigfault 2074 sigpacket::setup_handler: signal 30 > delivered > 83 105007 [sigfault] sigfault 2074 set_process_mask_delta: oldmask > 0, newmask 20000000, deltamask 20000000 > --- Process 9568 (pid: 2074), exception c0000005 at 0000000000000001 > 80 105087 [sig] sigfault 2074 sigpacket::process: returning 1 > --- Process 9568 (pid: 2074) thread 7320 exited with status 0xc0000005 > --- Process 9568 (pid: 2074) thread 8928 exited with status 0xc0000005 > --- Process 9568 (pid: 2074) thread 6792 exited with status 0xc0000005 > --- Process 9568 (pid: 2074) thread 5020 exited with status 0xc0000005 > --- Process 9568 thread 9020 exited with status 0xc0000005 > --- Process 9568 exited with status 0xc0000005 > > I guess the problem occurs because pthread_sigqueue() is sometimes > issued after the thread function already returned. The thread pointer > should be valid until pthread_join() is called. Sorry if I missed something.
Thansk for the report and especially for the test case. I could reporduce the problem using your test case. I'll look into this. -- Takashi Yano <takashi.y...@nifty.ne.jp> -- Problem reports: https://cygwin.com/problems.html FAQ: https://cygwin.com/faq/ Documentation: https://cygwin.com/docs.html Unsubscribe info: https://cygwin.com/ml/#unsubscribe-simple
