[PATCH] uml: add arch_switch_to for newly forked thread

Newly forked threads have no arch_switch_to_skas() called before their first
run, because when schedule() switches to them they're resumed in the body of
thread_wait() inside fork_handler() rather than in switch_threads() in
switch_to_skas().  Compensate this missing call.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Acked-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 8 insertions, 1 deletions

diff --git a/arch/um/sys-i386/ptrace.c b/arch/um/sys-i386/ptrace.c
index 6a23cc6947c3..6028bc7cc01b 100644
--- a/arch/um/sys-i386/ptrace.c
+++ b/arch/um/sys-i386/ptrace.c
@@ -23,7 +23,14 @@ void arch_switch_to_tt(struct task_struct *from, struct task_struct *to)
 
 void arch_switch_to_skas(struct task_struct *from, struct task_struct *to)
 {
-        arch_switch_tls_skas(from, to);
+        int err = arch_switch_tls_skas(from, to);
+        if (!err)
+                return;
+
+        if (err != -EINVAL)
+                printk(KERN_WARNING "arch_switch_tls_skas failed, errno %d, not EINVAL\n", -err);
+        else
+                printk(KERN_WARNING "arch_switch_tls_skas failed, errno = EINVAL\n");
 }
 
 int is_syscall(unsigned long addr)