MN10300: Save frame pointer in thread_info struct rather than global var

Save the current exception frame pointer in the thread_info struct rather than
in a global variable as the latter makes SMP tricky, especially when preemption
is also enabled.

This also replaces __frame with current_frame() and rearranges header file
inclusions to make it all compile.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>

1 files changed, 11 insertions, 9 deletions

diff --git a/arch/mn10300/kernel/process.c b/arch/mn10300/kernel/process.c
index b2e85ed73a54..0d0f8049a17b 100644
--- a/arch/mn10300/kernel/process.c
+++ b/arch/mn10300/kernel/process.c
@@ -228,6 +228,7 @@ int copy_thread(unsigned long clone_flags,
                 unsigned long c_usp, unsigned long ustk_size,
                 struct task_struct *p, struct pt_regs *kregs)
 {
+        struct thread_info *ti = task_thread_info(p);
         struct pt_regs *c_uregs, *c_kregs, *uregs;
         unsigned long c_ksp;
 
@@ -248,7 +249,7 @@ int copy_thread(unsigned long clone_flags,
 
         /* the new TLS pointer is passed in as arg #5 to sys_clone() */
         if (clone_flags & CLONE_SETTLS)
-                c_uregs->e2 = __frame->d3;
+                c_uregs->e2 = current_frame()->d3;
 
         /* set up the return kernel frame if called from kernel_thread() */
         c_kregs = c_uregs;
@@ -266,7 +267,7 @@ int copy_thread(unsigned long clone_flags,
         }
 
         /* set up things up so the scheduler can start the new task */
-        p->thread.frame = c_kregs;
+        ti->frame       = c_kregs;
         p->thread.a3    = (unsigned long) c_kregs;
         p->thread.sp    = c_ksp;
         p->thread.pc    = (unsigned long) ret_from_fork;
@@ -278,25 +279,26 @@ int copy_thread(unsigned long clone_flags,
 
 /*
  * clone a process
- * - tlsptr is retrieved by copy_thread() from __frame->d3
+ * - tlsptr is retrieved by copy_thread() from current_frame()->d3
  */
 asmlinkage long sys_clone(unsigned long clone_flags, unsigned long newsp,
                           int __user *parent_tidptr, int __user *child_tidptr,
                           int __user *tlsptr)
 {
-        return do_fork(clone_flags, newsp ?: __frame->sp, __frame, 0,
-                       parent_tidptr, child_tidptr);
+        return do_fork(clone_flags, newsp ?: current_frame()->sp,
+                       current_frame(), 0, parent_tidptr, child_tidptr);
 }
 
 asmlinkage long sys_fork(void)
 {
-        return do_fork(SIGCHLD, __frame->sp, __frame, 0, NULL, NULL);
+        return do_fork(SIGCHLD, current_frame()->sp,
+                       current_frame(), 0, NULL, NULL);
 }
 
 asmlinkage long sys_vfork(void)
 {
-        return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, __frame->sp, __frame,
-                       0, NULL, NULL);
+        return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, current_frame()->sp,
+                       current_frame(), 0, NULL, NULL);
 }
 
 asmlinkage long sys_execve(const char __user *name,
@@ -310,7 +312,7 @@ asmlinkage long sys_execve(const char __user *name,
         error = PTR_ERR(filename);
         if (IS_ERR(filename))
                 return error;
-        error = do_execve(filename, argv, envp, __frame);
+        error = do_execve(filename, argv, envp, current_frame());
         putname(filename);
         return error;
 }