From: Andrew Morton Date: Tue, 5 Feb 2008 06:27:22 +0000 (-0800) Subject: clone: prepare to recycle CLONE_STOPPED X-Git-Tag: firefly_0821_release~23542 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=bdff746a3915;p=firefly-linux-kernel-4.4.55.git clone: prepare to recycle CLONE_STOPPED Ulrich says that we never used this clone flags and that nothing should be using it. As we're down to only a single bit left in clone's flags argument, let's add a warning to check that no userspace is actually using it. Hopefully we will be able to recycle it. Roland said: CLONE_STOPPED was previously used by some NTPL versions when under thread_db (i.e. only when being actively debugged by gdb), but not for a long time now, and it never worked reliably when it was used. Removing it seems fine to me. [akpm@linux-foundation.org: it looks like CLONE_DETACHED is being used] Cc: Ulrich Drepper Cc: Ingo Molnar Cc: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/kernel/fork.c b/kernel/fork.c index 05e0b6f4365b..6caf4f23206b 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -1450,6 +1450,23 @@ long do_fork(unsigned long clone_flags, int trace = 0; long nr; + /* + * We hope to recycle these flags after 2.6.26 + */ + if (unlikely(clone_flags & CLONE_STOPPED)) { + static int __read_mostly count = 100; + + if (count > 0 && printk_ratelimit()) { + char comm[TASK_COMM_LEN]; + + count--; + printk(KERN_INFO "fork(): process `%s' used deprecated " + "clone flags 0x%lx\n", + get_task_comm(comm, current), + clone_flags & CLONE_STOPPED); + } + } + if (unlikely(current->ptrace)) { trace = fork_traceflag (clone_flags); if (trace)