[PATCH] amd64: 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/x86_64/ia32/ia32_binfmt.c

@@ -197,8 +197,7 @@ static inline void elf_core_copy_regs(elf_gregset_t *elfregs, struct pt_regs *re
 
 static inline int elf_core_copy_task_regs(struct task_struct *t, elf_gregset_t* elfregs)
 {	
-	struct pt_regs *pp = (struct pt_regs *)(t->thread.rsp0);
-	--pp;
+	struct pt_regs *pp = task_pt_regs(t);
 	ELF_CORE_COPY_REGS((*elfregs), pp);
 	/* fix wrong segments */ 
 	(*elfregs)[7] = t->thread.ds; 
@@ -217,7 +216,7 @@ elf_core_copy_task_fpregs(struct task_struct *tsk, struct pt_regs *regs, elf_fpr
 	if (!tsk_used_math(tsk))
 		return 0;
 	if (!regs)
-		regs = ((struct pt_regs *)tsk->thread.rsp0) - 1;
+		regs = task_pt_regs(tsk);
 	if (tsk == current)
 		unlazy_fpu(tsk);
 	set_fs(KERNEL_DS); 
@@ -233,7 +232,7 @@ elf_core_copy_task_fpregs(struct task_struct *tsk, struct pt_regs *regs, elf_fpr
 static inline int 
 elf_core_copy_task_xfpregs(struct task_struct *t, elf_fpxregset_t *xfpu)
 {
-	struct pt_regs *regs = ((struct pt_regs *)(t->thread.rsp0))-1; 
+	struct pt_regs *regs = task_pt_regs(t);
 	if (!tsk_used_math(t))
 		return 0;
 	if (t == current)

arch/x86_64/ia32/ptrace32.c

@@ -41,7 +41,7 @@
 static int putreg32(struct task_struct *child, unsigned regno, u32 val)
 {
 	int i;
-	__u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs)); 
+	__u64 *stack = (__u64 *)task_pt_regs(child);
 
 	switch (regno) {
 	case offsetof(struct user32, regs.fs):
@@ -137,7 +137,7 @@ static int putreg32(struct task_struct *child, unsigned regno, u32 val)
 
 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
 {
-	__u64 *stack = (__u64 *)(child->thread.rsp0 - sizeof(struct pt_regs)); 
+	__u64 *stack = (__u64 *)task_pt_regs(child);
 
 	switch (regno) {
 	case offsetof(struct user32, regs.fs):
@@ -238,7 +238,7 @@ asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
 	if (ret < 0)
 		goto out;
 
-	childregs = (struct pt_regs *)(child->thread.rsp0 - sizeof(struct pt_regs)); 
+	childregs = task_pt_regs(child);
 
 	switch (request) {
 	case PTRACE_PEEKDATA:

arch/x86_64/kernel/process.c

@@ -822,8 +822,7 @@ int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
 {
 	struct pt_regs *pp, ptregs;
 
-	pp = (struct pt_regs *)(tsk->thread.rsp0);
-	--pp; 
+	pp = task_pt_regs(tsk);
 
 	ptregs = *pp; 
 	ptregs.cs &= 0xffff;

arch/x86_64/kernel/ptrace.c

@@ -67,12 +67,6 @@ static inline unsigned long get_stack_long(struct task_struct *task, int offset)
 	return (*((unsigned long *)stack));
 }
 
-static inline struct pt_regs *get_child_regs(struct task_struct *task)
-{
-	struct pt_regs *regs = (void *)task->thread.rsp0;
-	return regs - 1;
-}
-
 /*
  * this routine will put a word on the processes privileged stack. 
  * the offset is how far from the base addr as stored in the TSS.  
@@ -170,7 +164,7 @@ static int is_at_popf(struct task_struct *child, struct pt_regs *regs)
 
 static void set_singlestep(struct task_struct *child)
 {
-	struct pt_regs *regs = get_child_regs(child);
+	struct pt_regs *regs = task_pt_regs(child);
 
 	/*
 	 * Always set TIF_SINGLESTEP - this guarantees that
@@ -208,7 +202,7 @@ static void clear_singlestep(struct task_struct *child)
 
 	/* But touch TF only if it was set by us.. */
 	if (child->ptrace & PT_DTRACE) {
-		struct pt_regs *regs = get_child_regs(child);
+		struct pt_regs *regs = task_pt_regs(child);
 		regs->eflags &= ~TRAP_FLAG;
 		child->ptrace &= ~PT_DTRACE;
 	}

arch/x86_64/kernel/traps.c

@@ -666,7 +666,7 @@ asmlinkage struct pt_regs *sync_regs(struct pt_regs *eregs)
 		;
 	/* Exception from user space */
 	else if (user_mode(eregs))
-		regs = ((struct pt_regs *)current->thread.rsp0) - 1;
+		regs = task_pt_regs(current);
 	/* Exception from kernel and interrupts are enabled. Move to
  	   kernel process stack. */
 	else if (eregs->eflags & X86_EFLAGS_IF)

include/asm-x86_64/compat.h

@@ -198,7 +198,7 @@ static inline compat_uptr_t ptr_to_compat(void __user *uptr)
 
 static __inline__ void __user *compat_alloc_user_space(long len)
 {
-	struct pt_regs *regs = (void *)current->thread.rsp0 - sizeof(struct pt_regs); 
+	struct pt_regs *regs = task_pt_regs(current);
 	return (void __user *)regs->rsp - len; 
 }
 

include/asm-x86_64/processor.h

@@ -321,8 +321,8 @@ extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
 #define thread_saved_pc(t) (*(unsigned long *)((t)->thread.rsp - 8))
 
 extern unsigned long get_wchan(struct task_struct *p);
-#define KSTK_EIP(tsk) \
-	(((struct pt_regs *)(tsk->thread.rsp0 - sizeof(struct pt_regs)))->rip)
+#define task_pt_regs(tsk) ((struct pt_regs *)(tsk)->thread.rsp0 - 1)
+#define KSTK_EIP(tsk) (task_pt_regs(tsk)->rip)
 #define KSTK_ESP(tsk) -1 /* sorry. doesn't work for syscall. */