Blackfin: simplify PTRACE_{PEEK,POKE}USR in preperation for regset support

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/arch/blackfin/include/asm/ptrace.h b/arch/blackfin/include/asm/ptrace.h
index b33a448..c1aebdb 100644 (file)
--- a/arch/blackfin/include/asm/ptrace.h
+++ b/arch/blackfin/include/asm/ptrace.h
@@ -173,4 +173,6 @@ extern void show_regs(struct pt_regs *);
 #define PT_FDPIC_EXEC 232
 #define PT_FDPIC_INTERP 236
 
+#define PT_LAST_PSEUDO PT_FDPIC_INTERP
+
 #endif                         /* _BFIN_PTRACE_H */

diff --git a/arch/blackfin/kernel/ptrace.c b/arch/blackfin/kernel/ptrace.c
index 14118e4..9536c1e 100644 (file)
--- a/arch/blackfin/kernel/ptrace.c
+++ b/arch/blackfin/kernel/ptrace.c
@@ -25,7 +25,6 @@
 #include <asm/cacheflush.h>
 #include <asm/mem_map.h>
 
-#define TEXT_OFFSET 0
 /*
  * does not yet catch signals sent when the child dies.
  * in exit.c or in signal.c.
@@ -43,7 +42,7 @@
  * 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)
+static inline struct pt_regs *task_pt_regs(struct task_struct *task)
 {
        return (struct pt_regs *)
            ((unsigned long)task_stack_page(task) +
@@ -56,7 +55,7 @@ static inline struct pt_regs *get_user_regs(struct task_struct *task)
 static inline int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
 {
        struct pt_regs regs;
-       memcpy(&regs, get_user_regs(tsk), sizeof(regs));
+       memcpy(&regs, task_pt_regs(tsk), sizeof(regs));
        regs.usp = tsk->thread.usp;
        return copy_to_user(uregs, &regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
 }
@@ -69,40 +68,49 @@ static inline int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
 /*
  * Get contents of register REGNO in task TASK.
  */
-static inline long get_reg(struct task_struct *task, int regno)
+static inline long
+get_reg(struct task_struct *task, long regno, unsigned long __user *datap)
 {
-       unsigned char *reg_ptr;
+       long tmp;
+       struct pt_regs *regs = task_pt_regs(task);
 
-       struct pt_regs *regs =
-           (struct pt_regs *)((unsigned long)task_stack_page(task) +
-                              (THREAD_SIZE - sizeof(struct pt_regs)));
-       reg_ptr = (char *)regs;
+       if (regno & 3 || regno > PT_LAST_PSEUDO || regno < 0)
+               return -EIO;
 
        switch (regno) {
+       case PT_TEXT_ADDR:
+               tmp = task->mm->start_code;
+               break;
+       case PT_TEXT_END_ADDR:
+               tmp = task->mm->end_code;
+               break;
+       case PT_DATA_ADDR:
+               tmp = task->mm->start_data;
+               break;
        case PT_USP:
-               return task->thread.usp;
+               tmp = task->thread.usp;
+               break;
        default:
-               if (regno <= 216)
-                       return *(long *)(reg_ptr + regno);
+               if (regno < sizeof(*regs)) {
+                       void *reg_ptr = regs;
+                       tmp = *(long *)(reg_ptr + regno);
+               } else
+                       return -EIO;
        }
-       /* slight mystery ... never seems to come here but kernel misbehaves without this code! */
 
-       printk(KERN_WARNING "Request to get for unknown register %d\n", regno);
-       return 0;
+       return put_user(tmp, datap);
 }
 
 /*
  * Write contents of register REGNO in task TASK.
  */
 static inline int
-put_reg(struct task_struct *task, int regno, unsigned long data)
+put_reg(struct task_struct *task, long regno, unsigned long data)
 {
-       char *reg_ptr;
+       struct pt_regs *regs = task_pt_regs(task);
 
-       struct pt_regs *regs =
-           (struct pt_regs *)((unsigned long)task_stack_page(task) +
-                              (THREAD_SIZE - sizeof(struct pt_regs)));
-       reg_ptr = (char *)regs;
+       if (regno & 3 || regno > PT_LAST_PSEUDO || regno < 0)
+               return -EIO;
 
        switch (regno) {
        case PT_PC:
@@ -119,10 +127,18 @@ put_reg(struct task_struct *task, int regno, unsigned long data)
                regs->usp = data;
                task->thread.usp = data;
                break;
+       case PT_SYSCFG: /* don't let userspace screw with this */
+               if ((data & ~1) != 0x6)
+                       pr_warning("ptrace: ignore syscfg write of %#lx\n", data);
+               break;          /* regs->syscfg = data; break; */
        default:
-               if (regno <= 216)
-                       *(long *)(reg_ptr + regno) = data;
+               if (regno < sizeof(*regs)) {
+                       void *reg_offset = regs;
+                       *(long *)(reg_offset + regno) = data;
+               }
+               /* Ignore writes to pseudo registers */
        }
+
        return 0;
 }
 
@@ -231,40 +247,6 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                        break;
                }
 
-               /* read the word at location addr in the USER area. */
-       case PTRACE_PEEKUSR:
-               {
-                       unsigned long tmp;
-                       ret = -EIO;
-                       tmp = 0;
-                       if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
-                               printk(KERN_WARNING "ptrace error : PEEKUSR : temporarily returning "
-                                                   "0 - %x sizeof(pt_regs) is %lx\n",
-                                    (int)addr, sizeof(struct pt_regs));
-                               break;
-                       }
-                       if (addr == sizeof(struct pt_regs)) {
-                               /* PT_TEXT_ADDR */
-                               tmp = child->mm->start_code + TEXT_OFFSET;
-                       } else if (addr == (sizeof(struct pt_regs) + 4)) {
-                               /* PT_TEXT_END_ADDR */
-                               tmp = child->mm->end_code;
-                       } else if (addr == (sizeof(struct pt_regs) + 8)) {
-                               /* PT_DATA_ADDR */
-                               tmp = child->mm->start_data;
-#ifdef CONFIG_BINFMT_ELF_FDPIC
-                       } else if (addr == (sizeof(struct pt_regs) + 12)) {
-                               goto case_PTRACE_GETFDPIC_EXEC;
-                       } else if (addr == (sizeof(struct pt_regs) + 16)) {
-                               goto case_PTRACE_GETFDPIC_INTERP;
-#endif
-                       } else {
-                               tmp = get_reg(child, addr);
-                       }
-                       ret = put_user(tmp, datap);
-                       break;
-               }
-
 #ifdef CONFIG_BINFMT_ELF_FDPIC
        case PTRACE_GETFDPIC: {
                unsigned long tmp = 0;
@@ -327,19 +309,21 @@ long arch_ptrace(struct task_struct *child, long request, long addr, long data)
                        break;
                }
 
-       case PTRACE_POKEUSR:    /* write the word at location addr in the USER area */
-               ret = -EIO;
-               if ((addr & 3) || (addr > (sizeof(struct pt_regs) + 16))) {
-                       printk(KERN_WARNING "ptrace error : POKEUSR: temporarily returning 0\n");
-                       break;
+       case PTRACE_PEEKUSR:
+               switch (addr) {
+#ifdef CONFIG_BINFMT_ELF_FDPIC /* backwards compat */
+               case PT_FDPIC_EXEC:   goto case_PTRACE_GETFDPIC_EXEC;
+               case PT_FDPIC_INTERP: goto case_PTRACE_GETFDPIC_INTERP;
+#endif
+               default:
+                       ret = get_reg(child, addr, datap);
                }
+               pr_debug("ptrace: PEEKUSR reg %li with %#lx = %i\n", addr, data, ret);
+               break;
 
-               /* Ignore writes to SYSCFG and other pseudo regs */
-               if (addr >= PT_SYSCFG) {
-                       ret = 0;
-                       break;
-               }
+       case PTRACE_POKEUSR:
                ret = put_reg(child, addr, data);
+               pr_debug("ptrace: POKEUSR reg %li with %li = %i\n", addr, data, ret);
                break;
 
        case PTRACE_GETREGS: