MN10300: Fix ret_from_kernel_thread

ret_from_kernel_thread needs to set A2 to the thread_info pointer before
jumping to syscall_exit.

Without this, we never correctly start userspace.

This was caused by the rejuggling of the fork/exec paths in commit
ddf23e87a804 ("mn10300: switch to saner kernel_execve() semantics")

Reported-by: Ken Cox <jkc@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Ken Cox <jkc@redhat.com>
Acked-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/mn10300/kernel/entry.S b/arch/mn10300/kernel/entry.S
index 68fcab8..9420057 100644 (file)
--- a/arch/mn10300/kernel/entry.S
+++ b/arch/mn10300/kernel/entry.S
@@ -60,6 +60,7 @@ ENTRY(ret_from_kernel_thread)
        mov     (REG_D0,fp),d0
        mov     (REG_A0,fp),a0
        calls   (a0)
+       GET_THREAD_INFO a2              # A2 must be set on return from sys_exit()
        clr     d0
        mov     d0,(REG_D0,fp)
        jmp     syscall_exit