X-Git-Url: https://git.kernelconcepts.de/?a=blobdiff_plain;f=mm%2Futil.c;h=55012d786a3545bc415d30b4774bf9b62dbf27ac;hb=2d4de05aac6be83cf69b7ec29244d10ec1dd8701;hp=68ff8a5361e79a30233fe9ecc4b26b09e614e1b8;hpb=0581276deb9c2578a17d9f4463e7b5172da99eb9;p=karo-tx-linux.git

diff --git a/mm/util.c b/mm/util.c
index 68ff8a5361e7..55012d786a35 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -3,6 +3,7 @@
 #include <linux/string.h>
 #include <linux/compiler.h>
 #include <linux/export.h>
+#include <linux/ctype.h>
 #include <linux/err.h>
 #include <linux/sched.h>
 #include <linux/security.h>
@@ -99,6 +100,35 @@ char *kstrndup(const char *s, size_t max, gfp_t gfp)
 }
 EXPORT_SYMBOL(kstrndup);
 
+/**
+ * kstrimdup - Trim and copy a %NUL terminated string.
+ * @s: the string to trim and duplicate
+ * @gfp: the GFP mask used in the kmalloc() call when allocating memory
+ *
+ * Returns an address, which the caller must kfree, containing
+ * a duplicate of the passed string with leading and/or trailing
+ * whitespace (as defined by isspace) removed.
+ */
+char *kstrimdup(const char *s, gfp_t gfp)
+{
+	char *buf;
+	char *begin = skip_spaces(s);
+	size_t len = strlen(begin);
+
+	while (len && isspace(begin[len - 1]))
+		len--;
+
+	buf = kmalloc_track_caller(len + 1, gfp);
+	if (!buf)
+		return NULL;
+
+	memcpy(buf, begin, len);
+	buf[len] = '\0';
+
+	return buf;
+}
+EXPORT_SYMBOL(kstrimdup);
+
 /**
  * kmemdup - duplicate region of memory
  *
@@ -309,7 +339,7 @@ unsigned long vm_mmap(struct file *file, unsigned long addr,
 {
 	if (unlikely(offset + PAGE_ALIGN(len) < offset))
 		return -EINVAL;
-	if (unlikely(offset & ~PAGE_MASK))
+	if (unlikely(offset_in_page(offset)))
 		return -EINVAL;
 
 	return vm_mmap_pgoff(file, addr, len, prot, flag, offset >> PAGE_SHIFT);
@@ -355,7 +385,9 @@ struct anon_vma *page_anon_vma(struct page *page)
 
 struct address_space *page_mapping(struct page *page)
 {
-	unsigned long mapping;
+	struct address_space *mapping;
+
+	page = compound_head(page);
 
 	/* This happens if someone calls flush_dcache_page on slab page */
 	if (unlikely(PageSlab(page)))
@@ -368,10 +400,10 @@ struct address_space *page_mapping(struct page *page)
 		return swap_address_space(entry);
 	}
 
-	mapping = (unsigned long)page->mapping;
-	if (mapping & PAGE_MAPPING_FLAGS)
+	mapping = page->mapping;
+	if ((unsigned long)mapping & PAGE_MAPPING_FLAGS)
 		return NULL;
-	return page->mapping;
+	return mapping;
 }
 
 int overcommit_ratio_handler(struct ctl_table *table, int write,