[PATCH] uml: clear SKAS0/3 flags when running in TT mode

SEGV_MAYBE_FIXABLE tests ptrace_faultinfo, and depends on it being 1 only in
SKAS3 mode, while currently when running with mode=tt it will be 1 anyway.
Fix this, and do the same for proc_mm.

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

2 files changed, 6 insertions, 0 deletions

diff --git a/arch/um/include/os.h b/arch/um/include/os.h
index 583329d0a539..6f766e1faecc 100644
--- a/arch/um/include/os.h
+++ b/arch/um/include/os.h
@@ -157,6 +157,10 @@ extern int os_lock_file(int fd, int excl);
 extern void os_early_checks(void);
 extern int can_do_skas(void);
 
+/* Make sure they are clear when running in TT mode. Required by
+ * SEGV_MAYBE_FIXABLE */
+#define clear_can_do_skas() do { ptrace_faultinfo = proc_mm = 0; } while (0)
+
 /* mem.c */
 extern int create_mem_file(unsigned long len);
 
diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index f0a275947d34..93dc782dc1cc 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -334,6 +334,8 @@ int linux_main(int argc, char **argv)
                 add_arg(DEFAULT_COMMAND_LINE);
 
         os_early_checks();
+        if (force_tt)
+                clear_can_do_skas();
         mode_tt = force_tt ? 1 : !can_do_skas();
 #ifndef CONFIG_MODE_TT
         if (mode_tt) {