From: Kartik <kkartik@nvidia.com>
Date: Tue, 17 Oct 2023 05:23:15 +0000 (+0530)
Subject: mm/util: Introduce kmemdup_array()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7092e9b3bed1252c7d3f5812b9fb9d82375b73a6;p=linux.git

mm/util: Introduce kmemdup_array()

Introduce kmemdup_array() API to duplicate `n` number of elements
from a given array. This internally uses kmemdup to allocate and duplicate
the `src` array.

Signed-off-by: Kartik <kkartik@nvidia.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
---

diff --git a/include/linux/string.h b/include/linux/string.h
index ab148d8dbfc14..4795ee5c50c66 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -217,6 +217,7 @@ extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
 extern void *kmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2);
 extern void *kvmemdup(const void *src, size_t len, gfp_t gfp) __realloc_size(2);
 extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
+extern void *kmemdup_array(const void *src, size_t element_size, size_t count, gfp_t gfp);
 
 extern char **argv_split(gfp_t gfp, const char *str, int *argcp);
 extern void argv_free(char **argv);
diff --git a/mm/util.c b/mm/util.c
index 5a6a9802583b1..5faf3adc6f433 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -135,6 +135,23 @@ void *kmemdup(const void *src, size_t len, gfp_t gfp)
 }
 EXPORT_SYMBOL(kmemdup);
 
+/**
+ * kmemdup_array - duplicate a given array.
+ *
+ * @src: array to duplicate.
+ * @element_size: size of each element of array.
+ * @count: number of elements to duplicate from array.
+ * @gfp: GFP mask to use.
+ *
+ * Return: duplicated array of @src or %NULL in case of error,
+ * result is physically contiguous. Use kfree() to free.
+ */
+void *kmemdup_array(const void *src, size_t element_size, size_t count, gfp_t gfp)
+{
+	return kmemdup(src, size_mul(element_size, count), gfp);
+}
+EXPORT_SYMBOL(kmemdup_array);
+
 /**
  * kvmemdup - duplicate region of memory
  *