ptrace: cleanup arch_ptrace() on sh

Remove unnecessary castings and get rid of dummy pointer in favor of
offsetof() macro in ptrace_32.c. Also use temporary variables and
break long lines in order to improve readability.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 21 insertions, 17 deletions

diff --git a/arch/sh/kernel/ptrace_32.c b/arch/sh/kernel/ptrace_32.c
index 34bf0374..90a15d2 100644
--- a/arch/sh/kernel/ptrace_32.c
+++ b/arch/sh/kernel/ptrace_32.c
@@ -368,7 +368,6 @@ const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 long arch_ptrace(struct task_struct *child, long request,
 		 unsigned long addr, unsigned long data)
 {
-	struct user * dummy = NULL;
 	unsigned long __user *datap = (unsigned long __user *)data;
 	int ret;
 
@@ -384,17 +383,20 @@ long arch_ptrace(struct task_struct *child, long request,
 
 		if (addr < sizeof(struct pt_regs))
 			tmp = get_stack_long(child, addr);
-		else if (addr >= (unsigned long) &dummy->fpu &&
-			 addr < (unsigned long) &dummy->u_fpvalid) {
+		else if (addr >= offsetof(struct user, fpu) &&
+			 addr < offsetof(struct user, u_fpvalid)) {
 			if (!tsk_used_math(child)) {
-				if (addr == (unsigned long)&dummy->fpu.fpscr)
+				if (addr == offsetof(struct user, fpu.fpscr))
 					tmp = FPSCR_INIT;
 				else
 					tmp = 0;
-			} else
+			} else {
+				unsigned long index;
+				index = addr - offsetof(struct user, fpu);
 				tmp = ((unsigned long *)child->thread.xstate)
-					[(addr - (long)&dummy->fpu) >> 2];
-		} else if (addr == (unsigned long) &dummy->u_fpvalid)
+					[index >> 2];
+			}
+		} else if (addr == offsetof(struct user, u_fpvalid))
 			tmp = !!tsk_used_math(child);
 		else if (addr == PT_TEXT_ADDR)
 			tmp = child->mm->start_code;
@@ -418,13 +420,15 @@ long arch_ptrace(struct task_struct *child, long request,
 
 		if (addr < sizeof(struct pt_regs))
 			ret = put_stack_long(child, addr, data);
-		else if (addr >= (unsigned long) &dummy->fpu &&
-			 addr < (unsigned long) &dummy->u_fpvalid) {
+		else if (addr >= offsetof(struct user, fpu) &&
+			 addr < offsetof(struct user, u_fpvalid)) {
+			unsigned long index;
+			index = addr - offsetof(struct user, fpu);
 			set_stopped_child_used_math(child);
 			((unsigned long *)child->thread.xstate)
-				[(addr - (long)&dummy->fpu) >> 2] = data;
+				[index >> 2] = data;
 			ret = 0;
-		} else if (addr == (unsigned long) &dummy->u_fpvalid) {
+		} else if (addr == offsetof(struct user, u_fpvalid)) {
 			conditional_stopped_child_used_math(data, child);
 			ret = 0;
 		}
@@ -434,35 +438,35 @@ long arch_ptrace(struct task_struct *child, long request,
 		return copy_regset_to_user(child, &user_sh_native_view,
 					   REGSET_GENERAL,
 					   0, sizeof(struct pt_regs),
-					   (void __user *)data);
+					   datap);
 	case PTRACE_SETREGS:
 		return copy_regset_from_user(child, &user_sh_native_view,
 					     REGSET_GENERAL,
 					     0, sizeof(struct pt_regs),
-					     (const void __user *)data);
+					     datap);
 #ifdef CONFIG_SH_FPU
 	case PTRACE_GETFPREGS:
 		return copy_regset_to_user(child, &user_sh_native_view,
 					   REGSET_FPU,
 					   0, sizeof(struct user_fpu_struct),
-					   (void __user *)data);
+					   datap);
 	case PTRACE_SETFPREGS:
 		return copy_regset_from_user(child, &user_sh_native_view,
 					     REGSET_FPU,
 					     0, sizeof(struct user_fpu_struct),
-					     (const void __user *)data);
+					     datap);
 #endif
 #ifdef CONFIG_SH_DSP
 	case PTRACE_GETDSPREGS:
 		return copy_regset_to_user(child, &user_sh_native_view,
 					   REGSET_DSP,
 					   0, sizeof(struct pt_dspregs),
-					   (void __user *)data);
+					   datap);
 	case PTRACE_SETDSPREGS:
 		return copy_regset_from_user(child, &user_sh_native_view,
 					     REGSET_DSP,
 					     0, sizeof(struct pt_dspregs),
-					     (const void __user *)data);
+					     datap);
 #endif
 	default:
 		ret = ptrace_request(child, request, addr, data);