[PATCH] arm26: task_pt_regs()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/arm26/kernel/process.c

@@ -278,9 +278,8 @@ copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start,
 	    unsigned long unused, struct task_struct *p, struct pt_regs *regs)
 {
 	struct thread_info *thread = task_thread_info(p);
-	struct pt_regs *childregs;
+	struct pt_regs *childregs = task_pt_regs(p);
 
-	childregs = __get_user_regs(thread);
 	*childregs = *regs;
 	childregs->ARM_r0 = 0;
 	childregs->ARM_sp = stack_start;

arch/arm26/kernel/ptrace.c

@@ -39,21 +39,6 @@
  */
 #define BREAKINST_ARM	0xef9f0001
 
-/*
- * Get the address of the live pt_regs for the specified task.
- * These are saved onto the top kernel stack when the process
- * is not running.
- *
- * Note: if a user thread is execve'd from kernel space, the
- * kernel stack will not be empty on entry to the kernel, so
- * ptracing these tasks will fail.
- */
-static inline struct pt_regs *
-get_user_regs(struct task_struct *task)
-{
-	return __get_user_regs(task->thread_info);
-}
-
 /*
  * this routine will get a word off of the processes privileged stack.
  * the offset is how far from the base addr as stored in the THREAD.
@@ -62,7 +47,7 @@ get_user_regs(struct task_struct *task)
  */
 static inline long get_user_reg(struct task_struct *task, int offset)
 {
-	return get_user_regs(task)->uregs[offset];
+	return task_pt_regs(task)->uregs[offset];
 }
 
 /*
@@ -74,7 +59,7 @@ static inline long get_user_reg(struct task_struct *task, int offset)
 static inline int
 put_user_reg(struct task_struct *task, int offset, long data)
 {
-	struct pt_regs newregs, *regs = get_user_regs(task);
+	struct pt_regs newregs, *regs = task_pt_regs(task);
 	int ret = -EINVAL;
 
 	newregs = *regs;
@@ -377,7 +362,7 @@ void ptrace_set_bpt(struct task_struct *child)
 	u32 insn;
 	int res;
 
-	regs = get_user_regs(child);
+	regs = task_pt_regs(child);
 	pc = instruction_pointer(regs);
 
 	res = read_instr(child, pc, &insn);
@@ -500,7 +485,7 @@ static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
  */
 static int ptrace_getregs(struct task_struct *tsk, void *uregs)
 {
-	struct pt_regs *regs = get_user_regs(tsk);
+	struct pt_regs *regs = task_pt_regs(tsk);
 
 	return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
 }
@@ -515,7 +500,7 @@ static int ptrace_setregs(struct task_struct *tsk, void *uregs)
 
 	ret = -EFAULT;
 	if (copy_from_user(&newregs, uregs, sizeof(struct pt_regs)) == 0) {
-		struct pt_regs *regs = get_user_regs(tsk);
+		struct pt_regs *regs = task_pt_regs(tsk);
 
 		ret = -EINVAL;
 		if (valid_user_regs(&newregs)) {

include/asm-arm26/thread_info.h

@@ -82,7 +82,7 @@ static inline struct thread_info *current_thread_info(void)
 
 /* FIXME - PAGE_SIZE < 32K */
 #define THREAD_SIZE		(8*32768) // FIXME - this needs attention (see kernel/fork.c which gets a nice div by zero if this is lower than 8*32768
-#define __get_user_regs(x) (((struct pt_regs *)((unsigned long)(x) + THREAD_SIZE - 8)) - 1)
+#define task_pt_regs(task) ((struct pt_regs *)((unsigned long)(task)->thread_info + THREAD_SIZE - 8) - 1)
 
 extern struct thread_info *alloc_thread_info(struct task_struct *task);
 extern void free_thread_info(struct thread_info *);