[PATCH] mips: 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/mips/kernel/process.c

@@ -229,9 +229,7 @@ void elf_dump_regs(elf_greg_t *gp, struct pt_regs *regs)
 
 int dump_task_regs (struct task_struct *tsk, elf_gregset_t *regs)
 {
-	struct thread_info *ti = tsk->thread_info;
-	long ksp = (unsigned long)ti + THREAD_SIZE - 32;
-	elf_dump_regs(&(*regs)[0], (struct pt_regs *) ksp - 1);
+	elf_dump_regs(*regs, task_pt_regs(tsk));
 	return 1;
 }
 

arch/mips/kernel/ptrace.c

@@ -64,8 +64,7 @@ int ptrace_getregs (struct task_struct *child, __s64 __user *data)
 	if (!access_ok(VERIFY_WRITE, data, 38 * 8))
 		return -EIO;
 
-	regs = (struct pt_regs *) ((unsigned long) child->thread_info +
-	       THREAD_SIZE - 32 - sizeof(struct pt_regs));
+	regs = task_pt_regs(child);
 
 	for (i = 0; i < 32; i++)
 		__put_user (regs->regs[i], data + i);
@@ -92,8 +91,7 @@ int ptrace_setregs (struct task_struct *child, __s64 __user *data)
 	if (!access_ok(VERIFY_READ, data, 38 * 8))
 		return -EIO;
 
-	regs = (struct pt_regs *) ((unsigned long) child->thread_info +
-	       THREAD_SIZE - 32 - sizeof(struct pt_regs));
+	regs = task_pt_regs(child);
 
 	for (i = 0; i < 32; i++)
 		__get_user (regs->regs[i], data + i);
@@ -198,8 +196,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 		struct pt_regs *regs;
 		unsigned long tmp = 0;
 
-		regs = (struct pt_regs *) ((unsigned long) child->thread_info +
-		       THREAD_SIZE - 32 - sizeof(struct pt_regs));
+		regs = task_pt_regs(child);
 		ret = 0;  /* Default return value. */
 
 		switch (addr) {
@@ -314,8 +311,7 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 	case PTRACE_POKEUSR: {
 		struct pt_regs *regs;
 		ret = 0;
-		regs = (struct pt_regs *) ((unsigned long) child->thread_info +
-		       THREAD_SIZE - 32 - sizeof(struct pt_regs));
+		regs = task_pt_regs(child);
 
 		switch (addr) {
 		case 0 ... 31:

arch/mips/kernel/ptrace32.c

@@ -126,8 +126,7 @@ asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
 		struct pt_regs *regs;
 		unsigned int tmp;
 
-		regs = (struct pt_regs *) ((unsigned long) child->thread_info +
-		       THREAD_SIZE - 32 - sizeof(struct pt_regs));
+		regs = task_pt_regs(child);
 		ret = 0;  /* Default return value. */
 
 		switch (addr) {
@@ -259,8 +258,7 @@ asmlinkage int sys32_ptrace(int request, int pid, int addr, int data)
 	case PTRACE_POKEUSR: {
 		struct pt_regs *regs;
 		ret = 0;
-		regs = (struct pt_regs *) ((unsigned long) child->thread_info +
-		       THREAD_SIZE - 32 - sizeof(struct pt_regs));
+		regs = task_pt_regs(child);
 
 		switch (addr) {
 		case 0 ... 31:

include/asm-mips/processor.h

@@ -200,11 +200,11 @@ extern void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long
 
 unsigned long get_wchan(struct task_struct *p);
 
-#define __PT_REG(reg) ((long)&((struct pt_regs *)0)->reg - sizeof(struct pt_regs))
 #define __KSTK_TOS(tsk) ((unsigned long)(tsk->thread_info) + THREAD_SIZE - 32)
-#define KSTK_EIP(tsk) (*(unsigned long *)(__KSTK_TOS(tsk) + __PT_REG(cp0_epc)))
-#define KSTK_ESP(tsk) (*(unsigned long *)(__KSTK_TOS(tsk) + __PT_REG(regs[29])))
-#define KSTK_STATUS(tsk) (*(unsigned long *)(__KSTK_TOS(tsk) + __PT_REG(cp0_status)))
+#define task_pt_regs(tsk) ((struct pt_regs *)__KSTK_TOS(tsk) - 1)
+#define KSTK_EIP(tsk) (task_pt_regs(tsk)->cp0_epc)
+#define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[29])
+#define KSTK_STATUS(tsk) (task_pt_regs(tsk)->cp0_status)
 
 #define cpu_relax()	barrier()
 

include/asm-mips/system.h

@@ -159,7 +159,7 @@ struct task_struct;
 do {									\
 	if (cpu_has_dsp)						\
 		__save_dsp(prev);					\
-	(last) = resume(prev, next, next->thread_info);			\
+	(last) = resume(prev, next, task_thread_info(next));		\
 	if (cpu_has_dsp)						\
 		__restore_dsp(current);					\
 } while(0)