1 files changed, 59 insertions, 6 deletions

diff --git a/arch/x86/include/asm/ptrace.h b/arch/x86/include/asm/ptrace.h
index 0f0d908349aa..69a686a7dff0 100644
--- a/arch/x86/include/asm/ptrace.h
+++ b/arch/x86/include/asm/ptrace.h
@@ -7,6 +7,7 @@
 
 #ifdef __KERNEL__
 #include <asm/segment.h>
+#include <asm/page_types.h>
 #endif
 
 #ifndef __ASSEMBLY__
@@ -216,20 +217,72 @@ static inline unsigned long user_stack_pointer(struct pt_regs *regs)
         return regs->sp;
 }
 
-/*
- * These are defined as per linux/ptrace.h, which see.
+/* Query offset/name of register from its name/offset */
+extern int regs_query_register_offset(const char *name);
+extern const char *regs_query_register_name(unsigned int offset);
+#define MAX_REG_OFFSET (offsetof(struct pt_regs, ss))
+
+/**
+ * regs_get_register() - get register value from its offset
+ * @regs:       pt_regs from which register value is gotten.
+ * @offset:     offset number of the register.
+ *
+ * regs_get_register returns the value of a register. The @offset is the
+ * offset of the register in struct pt_regs address which specified by @regs.
+ * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
  */
-#define arch_has_single_step()  (1)
-extern void user_enable_single_step(struct task_struct *);
-extern void user_disable_single_step(struct task_struct *);
+static inline unsigned long regs_get_register(struct pt_regs *regs,
+                                              unsigned int offset)
+{
+        if (unlikely(offset > MAX_REG_OFFSET))
+                return 0;
+        return *(unsigned long *)((unsigned long)regs + offset);
+}
+
+/**
+ * regs_within_kernel_stack() - check the address in the stack
+ * @regs:       pt_regs which contains kernel stack pointer.
+ * @addr:       address which is checked.
+ *
+ * regs_within_kernel_stack() checks @addr is within the kernel stack page(s).
+ * If @addr is within the kernel stack, it returns true. If not, returns false.
+ */
+static inline int regs_within_kernel_stack(struct pt_regs *regs,
+                                           unsigned long addr)
+{
+        return ((addr & ~(THREAD_SIZE - 1))  ==
+                (kernel_stack_pointer(regs) & ~(THREAD_SIZE - 1)));
+}
 
-extern void user_enable_block_step(struct task_struct *);
+/**
+ * regs_get_kernel_stack_nth() - get Nth entry of the stack
+ * @regs:       pt_regs which contains kernel stack pointer.
+ * @n:          stack entry number.
+ *
+ * regs_get_kernel_stack_nth() returns @n th entry of the kernel stack which
+ * is specified by @regs. If the @n th entry is NOT in the kernel stack,
+ * this returns 0.
+ */
+static inline unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
+                                                      unsigned int n)
+{
+        unsigned long *addr = (unsigned long *)kernel_stack_pointer(regs);
+        addr += n;
+        if (regs_within_kernel_stack(regs, (unsigned long)addr))
+                return *addr;
+        else
+                return 0;
+}
+
+#define arch_has_single_step()  (1)
 #ifdef CONFIG_X86_DEBUGCTLMSR
 #define arch_has_block_step()   (1)
 #else
 #define arch_has_block_step()   (boot_cpu_data.x86 >= 6)
 #endif
 
+#define ARCH_HAS_USER_SINGLE_STEP_INFO
+
 struct user_desc;
 extern int do_get_thread_area(struct task_struct *p, int idx,
                               struct user_desc __user *info);