mempolicy: use MPOL_PREFERRED for system-wide default policy

[safe/jmp/linux-2.6] / mm / util.c

diff --git a/mm/util.c b/mm/util.c
index 5f4bb59..8f18683 100644 (file)
--- a/mm/util.c
+++ b/mm/util.c
@@ -1,24 +1,11 @@
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/module.h>
+#include <linux/err.h>
+#include <asm/uaccess.h>
 
 /**
- * kzalloc - allocate memory. The memory is set to zero.
- * @size: how many bytes of memory are required.
- * @flags: the type of memory to allocate.
- */
-void *kzalloc(size_t size, gfp_t flags)
-{
-       void *ret = kmalloc(size, flags);
-       if (ret)
-               memset(ret, 0, size);
-       return ret;
-}
-EXPORT_SYMBOL(kzalloc);
-
-/*
  * kstrdup - allocate space for and copy an existing string
- *
  * @s: the string to duplicate
  * @gfp: the GFP mask used in the kmalloc() call when allocating memory
  */
@@ -31,9 +18,121 @@ char *kstrdup(const char *s, gfp_t gfp)
                return NULL;
 
        len = strlen(s) + 1;
-       buf = kmalloc(len, gfp);
+       buf = kmalloc_track_caller(len, gfp);
        if (buf)
                memcpy(buf, s, len);
        return buf;
 }
 EXPORT_SYMBOL(kstrdup);
+
+/**
+ * kstrndup - allocate space for and copy an existing string
+ * @s: the string to duplicate
+ * @max: read at most @max chars from @s
+ * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ */
+char *kstrndup(const char *s, size_t max, gfp_t gfp)
+{
+       size_t len;
+       char *buf;
+
+       if (!s)
+               return NULL;
+
+       len = strnlen(s, max);
+       buf = kmalloc_track_caller(len+1, gfp);
+       if (buf) {
+               memcpy(buf, s, len);
+               buf[len] = '\0';
+       }
+       return buf;
+}
+EXPORT_SYMBOL(kstrndup);
+
+/**
+ * kmemdup - duplicate region of memory
+ *
+ * @src: memory region to duplicate
+ * @len: memory region length
+ * @gfp: GFP mask to use
+ */
+void *kmemdup(const void *src, size_t len, gfp_t gfp)
+{
+       void *p;
+
+       p = kmalloc_track_caller(len, gfp);
+       if (p)
+               memcpy(p, src, len);
+       return p;
+}
+EXPORT_SYMBOL(kmemdup);
+
+/**
+ * krealloc - reallocate memory. The contents will remain unchanged.
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * The contents of the object pointed to are preserved up to the
+ * lesser of the new and old sizes.  If @p is %NULL, krealloc()
+ * behaves exactly like kmalloc().  If @size is 0 and @p is not a
+ * %NULL pointer, the object pointed to is freed.
+ */
+void *krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+       void *ret;
+       size_t ks = 0;
+
+       if (unlikely(!new_size)) {
+               kfree(p);
+               return ZERO_SIZE_PTR;
+       }
+
+       if (p)
+               ks = ksize(p);
+
+       if (ks >= new_size)
+               return (void *)p;
+
+       ret = kmalloc_track_caller(new_size, flags);
+       if (ret && p) {
+               memcpy(ret, p, ks);
+               kfree(p);
+       }
+       return ret;
+}
+EXPORT_SYMBOL(krealloc);
+
+/*
+ * strndup_user - duplicate an existing string from user space
+ * @s: The string to duplicate
+ * @n: Maximum number of bytes to copy, including the trailing NUL.
+ */
+char *strndup_user(const char __user *s, long n)
+{
+       char *p;
+       long length;
+
+       length = strnlen_user(s, n);
+
+       if (!length)
+               return ERR_PTR(-EFAULT);
+
+       if (length > n)
+               return ERR_PTR(-EINVAL);
+
+       p = kmalloc(length, GFP_KERNEL);
+
+       if (!p)
+               return ERR_PTR(-ENOMEM);
+
+       if (copy_from_user(p, s, length)) {
+               kfree(p);
+               return ERR_PTR(-EFAULT);
+       }
+
+       p[length - 1] = '\0';
+
+       return p;
+}
+EXPORT_SYMBOL(strndup_user);