On Tue, May 11, 2021 at 9:24 PM Olivier Langlois <olivier@xxxxxxxxxxxxxx> wrote: > > I have reported an issue that I have with a user process using io_uring > where when it core dumps, the dump fails to be generated. > https://github.com/axboe/liburing/issues/346 I suspect most kernel developers don't have github notifications enabled. I know I have them disabled because it would be *way* too noisy not to. But maybe Jens does for that libiouring part. > Pavel did comment to my report and he did point out this thread as > possibly a related issue. I don't think this is related. The gdb confusion wouldn't affect core dump generation. I don't see why a core-dump shouldn't work from an IO thread these days - the signal struct and synchronization should all be the same as for a regular user thread. That said, I do wonder if we should avoid generating core dumps from the IO worker thread itself. The IO thread itself should never get a SIGSEGV/SIGBUS anyway, it should have been turned into -EFAULT. So maybe the if (current->flags & PF_IO_WORKER) goto out; in kernel/signal.c should be moved up above the do_coredump() logic regardless. Jens, have you played with core-dumping when there are active io_uring threads? There's a test-program in that github issue report.. Linus
