在2024年1月24日一月 上午10:42，Xi Ruoyao写道： > Hi, > > When I'm testing Glibc master branch for upcoming 2.39 release, I > noticed an alarming test failure on mips64el: So apparently it should be tracked as a regression. #regzbot ^introduced 4bce37a68ff884e821a02a731897a8119e0c37b7 Should we revert it for now? Thanks - Jiaxun > > FAIL: stdlib/tst-arc4random-thread > > I've gathered some info about it and pasted my findings into > https://sourceware.org/glibc/wiki/Testing/Tests/stdlib/tst-arc4random-thread. > > Finally I was able to reduce the test case into: > > #include <stdlib.h> > #include <errno.h> > #include <pthread.h> > #include <unistd.h> > #include <fcntl.h> > > void * > test_thread (void *) > { > char buf[16] = {}; > int fd = open("/dev/zero", O_RDONLY); > while (1) > { > ssize_t ret = read (fd, buf, 7); > if (ret == -1 && errno == EFAULT) > abort (); > } > } > > void * > fork_thread (void *) > { > while (1) > { > if (!fork ()) > _exit (0); > } > } > > int > main (void) > { > pthread_t test_th; > pthread_t fork_th; > > pthread_create (&test_th, NULL, test_thread, NULL); > pthread_create (&fork_th, NULL, fork_thread, NULL); > pthread_join (test_th, NULL); > pthread_join (fork_th, NULL); > } > > When running this on the mainline kernel (revision 6.8.0-rc1+- > g7ed2632ec7d72e926b9e8bcc9ad1bb0cd37274bf) it fails in milliseconds. > Some "interesting" aspects: > > 1. This is related to the size parameter passed to read (). When it's > less than 8 it fails, but when it's 8 or greater there is no failure. > 2. This is not related to if "buf" is initialized or not. > > Now I'm suspecting this might be a kernel bug. Any pointer to further > triage? > > -- > Xi Ruoyao <xry111@xxxxxxxxxxx> > School of Aerospace Science and Technology, Xidian University -- - Jiaxun
