[PATCH 2d] utrace: avr32 regset support

From: Haavard Skinnemoen <hskinnemoen@atmel.com>

Rip out most of the ptrace code for AVR32 and replace it with the much
nicer utrace stuff.

CC: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Roland McGrath <roland@redhat.com>

---

 arch/avr32/kernel/ptrace.c |  111 +++++++++++++++++---------------------------
 1 files changed, 44 insertions(+), 67 deletions(-)

--- linux-2.6/arch/avr32/kernel/ptrace.c
+++ linux-2.6/arch/avr32/kernel/ptrace.c
@@ -14,10 +14,14 @@
 #include <linux/ptrace.h>
 #include <linux/errno.h>
 #include <linux/user.h>
+#include <linux/tracehook.h>
 
+#include <asm/tracehook.h>
 #include <asm/mmu_context.h>
 #include <linux/kdebug.h>
 
+#ifdef CONFIG_UTRACE
+
 static struct pt_regs *get_user_regs(struct task_struct *tsk)
 {
 	return (struct pt_regs *)((unsigned long)task_stack_page(tsk) +
@@ -57,86 +61,59 @@ void ptrace_disable(struct task_struct *
 	clear_tsk_thread_flag(child, TIF_BREAKPOINT);
 }
 
-/*
- * Read the word at offset "offset" into the task's "struct user". We
- * actually access the pt_regs struct stored on the kernel stack.
- */
-static int ptrace_read_user(struct task_struct *tsk, unsigned long offset,
-			    unsigned long __user *data)
+static int genregs_get(struct task_struct *target,
+		       const struct utrace_regset *regset,
+		       unsigned int pos, unsigned int count,
+		       void *kbuf, void __user *ubuf)
 {
-	unsigned long *regs;
-	unsigned long value;
-
-	if (offset & 3 || offset >= sizeof(struct user)) {
-		printk("ptrace_read_user: invalid offset 0x%08lx\n", offset);
-		return -EIO;
-	}
-
-	regs = (unsigned long *)get_user_regs(tsk);
-
-	value = 0;
-	if (offset < sizeof(struct pt_regs))
-		value = regs[offset / sizeof(regs[0])];
+	struct pt_regs *regs = get_user_regs(target);
 
-	pr_debug("ptrace_read_user(%s[%u], %#lx, %p) -> %#lx\n",
-		 tsk->comm, tsk->pid, offset, data, value);
-
-	return put_user(value, data);
+	return utrace_regset_copyout(&pos, &count, &kbuf, &ubuf,
+				     regs, 0, -1);
 }
 
-/*
- * Write the word "value" to offset "offset" into the task's "struct
- * user". We actually access the pt_regs struct stored on the kernel
- * stack.
- */
-static int ptrace_write_user(struct task_struct *tsk, unsigned long offset,
-			     unsigned long value)
+static int genregs_set(struct task_struct *target,
+		       const struct utrace_regset *regset,
+		       unsigned int pos, unsigned int count,
+		       const void *kbuf, const void __user *ubuf)
 {
-	unsigned long *regs;
-
-	pr_debug("ptrace_write_user(%s[%u], %#lx, %#lx)\n",
-			tsk->comm, tsk->pid, offset, value);
-
-	if (offset & 3 || offset >= sizeof(struct user)) {
-		pr_debug("  invalid offset 0x%08lx\n", offset);
-		return -EIO;
-	}
-
-	if (offset >= sizeof(struct pt_regs))
-		return 0;
+	struct pt_regs *regs = get_user_regs(target);
 
-	regs = (unsigned long *)get_user_regs(tsk);
-	regs[offset / sizeof(regs[0])] = value;
-
-	return 0;
+	return utrace_regset_copyin(&pos, &count, &kbuf, &ubuf,
+				    regs, 0, -1);
 }
 
-static int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
-{
-	struct pt_regs *regs = get_user_regs(tsk);
+static const struct utrace_regset native_regsets[] = {
+	{
+		.core_note_type = NT_PRSTATUS,
+		.n	= ELF_NGREG,
+		.size	= sizeof(long),
+		.align	= sizeof(long),
+		.get	= genregs_get,
+		.set	= genregs_set,
+	},
+	/*
+	 * Other register sets that probably would make sense:
+	 *   - Coprocessor registers (8 coprocs with 16 registers each)
+	 *   - TLS stuff
+	 */
+};
 
-	return copy_to_user(uregs, regs, sizeof(*regs)) ? -EFAULT : 0;
-}
+static const struct utrace_regset_view utrace_avr32_native_view = {
+	.name		= UTS_MACHINE,
+	.e_machine	= ELF_ARCH,
+	.regsets	= native_regsets,
+	.n		= ARRAY_SIZE(native_regsets),
+};
 
-static int ptrace_setregs(struct task_struct *tsk, const void __user *uregs)
+const struct utrace_regset_view *utrace_native_view(struct task_struct *tsk)
 {
-	struct pt_regs newregs;
-	int ret;
-
-	ret = -EFAULT;
-	if (copy_from_user(&newregs, uregs, sizeof(newregs)) == 0) {
-		struct pt_regs *regs = get_user_regs(tsk);
-
-		ret = -EINVAL;
-		if (valid_user_regs(&newregs)) {
-			*regs = newregs;
-			ret = 0;
-		}
-	}
-
-	return ret;
+	return &utrace_avr32_native_view;
 }
+#endif /* CONFIG_UTRACE */
+
 
+#if 0
 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 {
 	int ret;