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authorHao Sun <sunhao.th@gmail.com>2022-12-21 15:42:45 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-01-19 02:12:47 +0100
commit0b7b8704ddcee372099a2bc6781db6ab273a85d5 (patch)
treec1c8de77ddf39a5db49b97611c4b7f019aa81990 /mm/util.c
parentmm/swap: convert deactivate_page() to folio_deactivate() (diff)
downloadlinux-0b7b8704ddcee372099a2bc6781db6ab273a85d5.tar.xz
linux-0b7b8704ddcee372099a2bc6781db6ab273a85d5.zip
mm: new primitive kvmemdup()
Similar to kmemdup(), but support large amount of bytes with kvmalloc() and does *not* guarantee that the result will be physically contiguous. Use only in cases where kvmalloc() is needed and free it with kvfree(). Also adapt policy_unpack.c in case someone bisect into this. Link: https://lkml.kernel.org/r/20221221144245.27164-1-sunhao.th@gmail.com Signed-off-by: Hao Sun <sunhao.th@gmail.com> Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Nick Terrell <terrelln@fb.com> Cc: John Johansen <john.johansen@canonical.com> Cc: Paul Moore <paul@paul-moore.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/util.c')
-rw-r--r--mm/util.c24
1 files changed, 23 insertions, 1 deletions
diff --git a/mm/util.c b/mm/util.c
index b56c92fb910f..cec9327b27b4 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -120,7 +120,8 @@ EXPORT_SYMBOL(kstrndup);
* @len: memory region length
* @gfp: GFP mask to use
*
- * Return: newly allocated copy of @src or %NULL in case of error
+ * Return: newly allocated copy of @src or %NULL in case of error,
+ * result is physically contiguous. Use kfree() to free.
*/
void *kmemdup(const void *src, size_t len, gfp_t gfp)
{
@@ -134,6 +135,27 @@ void *kmemdup(const void *src, size_t len, gfp_t gfp)
EXPORT_SYMBOL(kmemdup);
/**
+ * kvmemdup - duplicate region of memory
+ *
+ * @src: memory region to duplicate
+ * @len: memory region length
+ * @gfp: GFP mask to use
+ *
+ * Return: newly allocated copy of @src or %NULL in case of error,
+ * result may be not physically contiguous. Use kvfree() to free.
+ */
+void *kvmemdup(const void *src, size_t len, gfp_t gfp)
+{
+ void *p;
+
+ p = kvmalloc(len, gfp);
+ if (p)
+ memcpy(p, src, len);
+ return p;
+}
+EXPORT_SYMBOL(kvmemdup);
+
+/**
* kmemdup_nul - Create a NUL-terminated string from unterminated data
* @s: The data to stringify
* @len: The size of the data