X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=include%2Flinux%2Fregset.h;h=8abee65562230fe05174d2ded6bc8ec50249348b;hb=03cf1e0c3b4ee4ef51dc7eb197a4d098ad4873af;hp=85d0fb0a014db61f723a7930fbb971c4289c35de;hpb=bdf88217b70dbb18c4ee27a6c497286e040a6705;p=safe%2Fjmp%2Flinux-2.6

diff --git a/include/linux/regset.h b/include/linux/regset.h
index 85d0fb0..8abee65 100644
--- a/include/linux/regset.h
+++ b/include/linux/regset.h
@@ -15,6 +15,7 @@
 
 #include <linux/compiler.h>
 #include <linux/types.h>
+#include <linux/uaccess.h>
 struct task_struct;
 struct user_regset;
 
@@ -203,4 +204,165 @@ struct user_regset_view {
 const struct user_regset_view *task_user_regset_view(struct task_struct *tsk);
 
 
+/*
+ * These are helpers for writing regset get/set functions in arch code.
+ * Because @start_pos and @end_pos are always compile-time constants,
+ * these are inlined into very little code though they look large.
+ *
+ * Use one or more calls sequentially for each chunk of regset data stored
+ * contiguously in memory.  Call with constants for @start_pos and @end_pos,
+ * giving the range of byte positions in the regset that data corresponds
+ * to; @end_pos can be -1 if this chunk is at the end of the regset layout.
+ * Each call updates the arguments to point past its chunk.
+ */
+
+static inline int user_regset_copyout(unsigned int *pos, unsigned int *count,
+				      void **kbuf,
+				      void __user **ubuf, const void *data,
+				      const int start_pos, const int end_pos)
+{
+	if (*count == 0)
+		return 0;
+	BUG_ON(*pos < start_pos);
+	if (end_pos < 0 || *pos < end_pos) {
+		unsigned int copy = (end_pos < 0 ? *count
+				     : min(*count, end_pos - *pos));
+		data += *pos - start_pos;
+		if (*kbuf) {
+			memcpy(*kbuf, data, copy);
+			*kbuf += copy;
+		} else if (__copy_to_user(*ubuf, data, copy))
+			return -EFAULT;
+		else
+			*ubuf += copy;
+		*pos += copy;
+		*count -= copy;
+	}
+	return 0;
+}
+
+static inline int user_regset_copyin(unsigned int *pos, unsigned int *count,
+				     const void **kbuf,
+				     const void __user **ubuf, void *data,
+				     const int start_pos, const int end_pos)
+{
+	if (*count == 0)
+		return 0;
+	BUG_ON(*pos < start_pos);
+	if (end_pos < 0 || *pos < end_pos) {
+		unsigned int copy = (end_pos < 0 ? *count
+				     : min(*count, end_pos - *pos));
+		data += *pos - start_pos;
+		if (*kbuf) {
+			memcpy(data, *kbuf, copy);
+			*kbuf += copy;
+		} else if (__copy_from_user(data, *ubuf, copy))
+			return -EFAULT;
+		else
+			*ubuf += copy;
+		*pos += copy;
+		*count -= copy;
+	}
+	return 0;
+}
+
+/*
+ * These two parallel the two above, but for portions of a regset layout
+ * that always read as all-zero or for which writes are ignored.
+ */
+static inline int user_regset_copyout_zero(unsigned int *pos,
+					   unsigned int *count,
+					   void **kbuf, void __user **ubuf,
+					   const int start_pos,
+					   const int end_pos)
+{
+	if (*count == 0)
+		return 0;
+	BUG_ON(*pos < start_pos);
+	if (end_pos < 0 || *pos < end_pos) {
+		unsigned int copy = (end_pos < 0 ? *count
+				     : min(*count, end_pos - *pos));
+		if (*kbuf) {
+			memset(*kbuf, 0, copy);
+			*kbuf += copy;
+		} else if (__clear_user(*ubuf, copy))
+			return -EFAULT;
+		else
+			*ubuf += copy;
+		*pos += copy;
+		*count -= copy;
+	}
+	return 0;
+}
+
+static inline int user_regset_copyin_ignore(unsigned int *pos,
+					    unsigned int *count,
+					    const void **kbuf,
+					    const void __user **ubuf,
+					    const int start_pos,
+					    const int end_pos)
+{
+	if (*count == 0)
+		return 0;
+	BUG_ON(*pos < start_pos);
+	if (end_pos < 0 || *pos < end_pos) {
+		unsigned int copy = (end_pos < 0 ? *count
+				     : min(*count, end_pos - *pos));
+		if (*kbuf)
+			*kbuf += copy;
+		else
+			*ubuf += copy;
+		*pos += copy;
+		*count -= copy;
+	}
+	return 0;
+}
+
+/**
+ * copy_regset_to_user - fetch a thread's user_regset data into user memory
+ * @target:	thread to be examined
+ * @view:	&struct user_regset_view describing user thread machine state
+ * @setno:	index in @view->regsets
+ * @offset:	offset into the regset data, in bytes
+ * @size:	amount of data to copy, in bytes
+ * @data:	user-mode pointer to copy into
+ */
+static inline int copy_regset_to_user(struct task_struct *target,
+				      const struct user_regset_view *view,
+				      unsigned int setno,
+				      unsigned int offset, unsigned int size,
+				      void __user *data)
+{
+	const struct user_regset *regset = &view->regsets[setno];
+
+	if (!access_ok(VERIFY_WRITE, data, size))
+		return -EIO;
+
+	return regset->get(target, regset, offset, size, NULL, data);
+}
+
+/**
+ * copy_regset_from_user - store into thread's user_regset data from user memory
+ * @target:	thread to be examined
+ * @view:	&struct user_regset_view describing user thread machine state
+ * @setno:	index in @view->regsets
+ * @offset:	offset into the regset data, in bytes
+ * @size:	amount of data to copy, in bytes
+ * @data:	user-mode pointer to copy from
+ */
+static inline int copy_regset_from_user(struct task_struct *target,
+					const struct user_regset_view *view,
+					unsigned int setno,
+					unsigned int offset, unsigned int size,
+					const void __user *data)
+{
+	const struct user_regset *regset = &view->regsets[setno];
+
+	if (!access_ok(VERIFY_READ, data, size))
+		return -EIO;
+
+	return regset->set(target, regset, offset, size, NULL, data);
+}
+
+
 #endif	/* <linux/regset.h> */