https://bugzilla.kernel.org/show_bug.cgi?id=215769 Коренберг Марк (socketpair@xxxxxxxxx) changed: What |Removed |Added ---------------------------------------------------------------------------- Component|man-pages |Other Version|unspecified |2.5 Product|Documentation |Other --- Comment #13 from Коренберг Марк (socketpair@xxxxxxxxx) --- Please help me to change Bugzilla fields in the issue. This is a kernel bug as I think. Nothing should be changed in documentation. And also, please stop discussing how to correctly use vfork() (regarding modifying stack, glibc and so on). This issue is actually about vfork() + CLONE_NEWTIME. Regarding CLONE_VM. We have no problems for, say, PID namespace. Suppose we have parent process with two threads. Let's second thread calls vfork() and is stopped as expected. So children process is running and the first thread of parent process too. They share VM, but getpid() will give different values in them, right ? If YES, I don't see any stoppers for doing the same for CLONE_NEWTIME. If NO, this is a bug. Actually, yes: #define _GNU_SOURCE 1 #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <syscall.h> #include <sys/types.h> #include <sys/wait.h> #include <err.h> #include <pthread.h> static void *showpid (void *restrict arg) { (void) arg; for (int i = 0; i < 25; i++) { printf ("thr pid=%lu\n", (unsigned long) syscall (SYS_getpid)); struct timespec ts = { 0, 100000000 };<---->// 0.1 sec nanosleep (&ts, NULL); } return NULL; } int main (void) { pthread_t thr; if (pthread_create (&thr, NULL, showpid, NULL)) abort (); if (unshare (CLONE_NEWPID) == -1) err (EXIT_FAILURE, "unshare(newpid)"); sleep (1);<--><------><------>// allow the thread to work for 1 second pid_t p = vfork (); if (!p) { static char qwe[100]; static struct timespec ts = { 1, 0 }; syscall (SYS_write, 1, qwe, sprintf (qwe, "child: %lu\n", (unsigned long) syscall (SYS_getpid))); syscall (SYS_clock_nanosleep, CLOCK_MONOTONIC, 0, &ts, NULL); syscall (SYS_write, 1, qwe, sprintf (qwe, "child sleep complete\n")); _exit (0); } if (p == -1) err (EXIT_FAILURE, "vfork"); printf("Waiting for child\n"); waitpid (p, NULL, 0); pthread_join (thr, NULL); } $ sudo ./a.out thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 child: 1 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 child sleep complete Waiting for child thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 thr pid=46371 -- You may reply to this email to add a comment. You are receiving this mail because: You are watching the assignee of the bug.
