[PATCH 1/2] string: make kmemdup_nul take and return void*, not char*

[PATCH 1/2] string: make kmemdup_nul take and return void*, not char*

[Rasmus Villemoes]

This allows kmemdup_nul to be used in cases where the source pointer is
not a char* or const char*, but the result should nevertheless have a
nul char after the memcpy'ed data.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/string.h | 2 +-
 mm/util.c              | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/string.h b/include/linux/string.h
index 4a5a0eb7df51..b44a2254bc6b 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -169,7 +169,7 @@ extern char *kstrdup(const char *s, gfp_t gfp) __malloc;
 extern const char *kstrdup_const(const char *s, gfp_t gfp);
 extern char *kstrndup(const char *s, size_t len, gfp_t gfp);
 extern void *kmemdup(const void *src, size_t len, gfp_t gfp);
-extern char *kmemdup_nul(const char *s, size_t len, gfp_t gfp);
+extern void *kmemdup_nul(const void *s, size_t len, 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 9e3ebd2ef65f..15ef23f1176e 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -128,7 +128,7 @@ EXPORT_SYMBOL(kmemdup);
  * @len: The size of the data
  * @gfp: the GFP mask used in the kmalloc() call when allocating memory
  */
-char *kmemdup_nul(const char *s, size_t len, gfp_t gfp)
+void *kmemdup_nul(const void *s, size_t len, gfp_t gfp)
 {
 	char *buf;
 
-- 
2.16.4

[PATCH 2/2] rxrpc: use kmemdup_nul in rxrpc_krb5_decode_principal

[Rasmus Villemoes]

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
This depends on patch 1/2.

 net/rxrpc/key.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/net/rxrpc/key.c b/net/rxrpc/key.c
index e7f6b8823eb6..42f0ca9265c2 100644
--- a/net/rxrpc/key.c
+++ b/net/rxrpc/key.c
@@ -252,11 +252,9 @@ static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
 		paddedlen = (tmp + 3) & ~3;
 		if (paddedlen > toklen)
 			return -EINVAL;
-		princ->name_parts[loop] = kmalloc(tmp + 1, GFP_KERNEL);
+		princ->name_parts[loop] = kmemdup_nul(xdr, tmp, GFP_KERNEL);
 		if (!princ->name_parts[loop])
 			return -ENOMEM;
-		memcpy(princ->name_parts[loop], xdr, tmp);
-		princ->name_parts[loop][tmp] = 0;
 		toklen -= paddedlen;
 		xdr += paddedlen >> 2;
 	}
@@ -270,11 +268,9 @@ static int rxrpc_krb5_decode_principal(struct krb5_principal *princ,
 	paddedlen = (tmp + 3) & ~3;
 	if (paddedlen > toklen)
 		return -EINVAL;
-	princ->realm = kmalloc(tmp + 1, GFP_KERNEL);
+	princ->realm = kmemdup_nul(xdr, tmp, GFP_KERNEL);
 	if (!princ->realm)
 		return -ENOMEM;
-	memcpy(princ->realm, xdr, tmp);
-	princ->realm[tmp] = 0;
 	toklen -= paddedlen;
 	xdr += paddedlen >> 2;
 
-- 
2.16.4

Re: [PATCH 1/2] string: make kmemdup_nul take and return void*, not char*

[Rasmus Villemoes]

On 7 September 2018 at 09:46, Rasmus Villemoes <linux@rasmusvillemoes.dk> wrote:
> This allows kmemdup_nul to be used in cases where the source pointer is
> not a char* or const char*, but the result should nevertheless have a
> nul char after the memcpy'ed data.

ping