Description of problem: strace hangs when -f option is specified Version-Release number of selected component (if applicable): FAIL: kernel-2.6.18-8.el5.ia64 FAIL: kernel-2.6.18-20.el5.ia64 FAIL: kernel-utrace-2.6.21-2.6.22.rc2.986.1.3190.fc7.ia64 but PASS: kernel-upstream-2.6.21-2.6.22.rc2.137.1.3190.fc7.ia64 PASS: kernel-vanilla-2.6.21-1.3190.fc7.ia64.rpm How reproducible: Always. Steps to Reproduce: 1. gcc -o fork fork.c -Wall -ggdb2 2. strace -f ./fork Actual results: clone2(Process 5514 attached child_stack=0, stack_size=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCH LD, child_tidptr=0x2000000000318090) = 5514 [pid 5513] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0 [pid 5513] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0 [pid 5513] rt_sigprocmask(SIG_SETMASK, [], NULL, 8) = 0 [pid 5513] rt_sigprocmask(SIG_BLOCK, [CHLD], [], 8) = 0 [pid 5513] rt_sigaction(SIGINT, {0x400000000015c560, [], 0}, {SIG_DFL}, 8) = 0 [pid 5513] wait4(-1, Process 5513 suspended Expected results: clone2(Process 4323 attached child_stack=0, stack_size=0, flags=CLONE_CHILD_CLEARTID|CLONE_CHILD_SETTID|SIGCHLD, child_tidptr=0x200000000004ecd0) = 4323 [pid 4322] wait4(-1, Process 4322 suspended <unfinished ...> [pid 4323] exit_group(0) = ? Process 4322 resumed Process 4323 detached <... wait4 resumed> NULL, 0, NULL) = 4323 --- SIGCHLD (Child exited) @ a000000000010621 (10e3) --- exit_group(0) = ? Process 4322 detached Additional info: Problem is that strace patches the FLAGS parameter of __clone2 () by: flags |= CLONE_PTRACE; but this parameter change gets ignored by the kernel. The testcase submits there the CLONE_PTRACE on its own and so works: strace -f ./clone The parameter is found from BSP+CFM by PTRACE_PEEKUSER and retrieved/patched by PTRACE_PEEKDATA/PTRACE_POKEDATA. This Bug is ia64 specific and the utrace.ia64 author is listed as: Anil S Keshavamurthy <anil.s.keshavamurthy>
Created attachment 155237 [details] Minimal real code reproducer `fork.c': fork() && wait()
Created attachment 155238 [details] Testcase workarounding the CLONE_PTRACE kernel bug.
Based on the date this bug was created, it appears to have been reported against rawhide during the development of a Fedora release that is no longer maintained. In order to refocus our efforts as a project we are flagging all of the open bugs for releases which are no longer maintained. If this bug remains in NEEDINFO thirty (30) days from now, we will automatically close it. If you can reproduce this bug in a maintained Fedora version (7, 8, or rawhide), please change this bug to the respective version and change the status to ASSIGNED. (If you're unable to change the bug's version or status, add a comment to the bug and someone will change it for you.) Thanks for your help, and we apologize again that we haven't handled these issues to this point. The process we're following is outlined here: http://fedoraproject.org/wiki/BugZappers/F9CleanUp We will be following the process here: http://fedoraproject.org/wiki/BugZappers/HouseKeeping to ensure this doesn't happen again.
This bug has been in NEEDINFO for more than 30 days since feedback was first requested. As a result we are closing it. If you can reproduce this bug in the future against a maintained Fedora version please feel free to reopen it against that version. The process we're following is outlined here: http://fedoraproject.org/wiki/BugZappers/F9CleanUp