sh: Fixup __strnlen_user() behaviour.
Drop TIF_USERSPACE and add addr_limit to the thread_info struct.
Subsequently, use that for address checking in strnlen_user() to
ward off bogus -EFAULTs.
Make __strnlen_user() return 0 on exception, rather than -EFAULT.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/kernel/process.c b/arch/sh/kernel/process.c
index f203131..4a32550 100644
--- a/arch/sh/kernel/process.c
+++ b/arch/sh/kernel/process.c
@@ -263,6 +263,7 @@
unsigned long unused,
struct task_struct *p, struct pt_regs *regs)
{
+ struct thread_info *ti = task_thread_info(p);
struct pt_regs *childregs;
#if defined(CONFIG_SH_FPU)
struct task_struct *tsk = current;
@@ -277,8 +278,10 @@
if (user_mode(regs)) {
childregs->regs[15] = usp;
+ ti->addr_limit = USER_DS;
} else {
childregs->regs[15] = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+ ti->addr_limit = KERNEL_DS;
}
if (clone_flags & CLONE_SETTLS) {
childregs->gbr = childregs->regs[0];