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 <drepper@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/fork.c b/kernel/fork.c
index 05e0b6f..6caf4f2 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1450,6 +1450,23 @@
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)