X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Futil.c;h=cb00b748ce47886446975d96466c2154f4d52fa3;hb=3bda12589646caa22b2ed4ef7cf82d17ea59d7a6;hp=bf340d80686884bf765dc696a73f7fd840842e8f;hpb=b981d8b3f5e008ff10d993be633ad00564fc22cd;p=linux-2.6

diff --git a/mm/util.c b/mm/util.c
index bf340d8068..cb00b748ce 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -1,7 +1,9 @@
+#include <linux/mm.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/module.h>
 #include <linux/err.h>
+#include <linux/sched.h>
 #include <asm/uaccess.h>
 
 /**
@@ -67,6 +69,38 @@ void *kmemdup(const void *src, size_t len, gfp_t gfp)
 }
 EXPORT_SYMBOL(kmemdup);
 
+/**
+ * __krealloc - like krealloc() but don't free @p.
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * This function is like krealloc() except it never frees the originally
+ * allocated buffer. Use this if you don't want to free the buffer immediately
+ * like, for example, with RCU.
+ */
+void *__krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+	void *ret;
+	size_t ks = 0;
+
+	if (unlikely(!new_size))
+		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);
+
+	return ret;
+}
+EXPORT_SYMBOL(__krealloc);
+
 /**
  * krealloc - reallocate memory. The contents will remain unchanged.
  * @p: object to reallocate memory for.
@@ -81,22 +115,16 @@ EXPORT_SYMBOL(kmemdup);
 void *krealloc(const void *p, size_t new_size, gfp_t flags)
 {
 	void *ret;
-	size_t ks;
 
 	if (unlikely(!new_size)) {
 		kfree(p);
 		return ZERO_SIZE_PTR;
 	}
 
-	ks = ksize(p);
-	if (ks >= new_size)
-		return (void *)p;
-
-	ret = kmalloc_track_caller(new_size, flags);
-	if (ret) {
-		memcpy(ret, p, min(new_size, ks));
+	ret = __krealloc(p, new_size, flags);
+	if (ret && p != ret)
 		kfree(p);
-	}
+
 	return ret;
 }
 EXPORT_SYMBOL(krealloc);
@@ -134,3 +162,27 @@ char *strndup_user(const char __user *s, long n)
 	return p;
 }
 EXPORT_SYMBOL(strndup_user);
+
+#ifndef HAVE_ARCH_PICK_MMAP_LAYOUT
+void arch_pick_mmap_layout(struct mm_struct *mm)
+{
+	mm->mmap_base = TASK_UNMAPPED_BASE;
+	mm->get_unmapped_area = arch_get_unmapped_area;
+	mm->unmap_area = arch_unmap_area;
+}
+#endif
+
+int __attribute__((weak)) get_user_pages_fast(unsigned long start,
+				int nr_pages, int write, struct page **pages)
+{
+	struct mm_struct *mm = current->mm;
+	int ret;
+
+	down_read(&mm->mmap_sem);
+	ret = get_user_pages(current, mm, start, nr_pages,
+					write, 0, pages, NULL);
+	up_read(&mm->mmap_sem);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(get_user_pages_fast);