Kernel/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-12-29 09:16:33 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

mm/util: deduplicate code in {kstrdup,kstrndup,kmemdup_nul}

Browse Source 
These three functions follow the same pattern.  To deduplicate the code,
let's introduce a common helper __kmemdup_nul().

Link: https://lkml.kernel.org/r/20241007144911.27693-7-laoar.shao@gmail.com
Suggested-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Alejandro Colomar <alx@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Eric Paris <eparis@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Matus Jokay <matus.jokay@stuba.sk>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Quentin Monnet <qmo@kernel.org>
Cc: "Serge E. Hallyn" <serge@hallyn.com>
Cc: Stephen Smalley <stephen.smalley.work@gmail.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Yafang Shao 2024-10-07 22:49:10 +08:00 committed by Andrew Morton
parent 44ff630170
commit 43731516fa
1 changed files with 27 additions and 42 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

69
mm/util.c
View File

@ -44,6 +44,30 @@ void kfree_const(const void *x)
}
EXPORT_SYMBOL(kfree_const);
/**
* __kmemdup_nul - Create a NUL-terminated string from @s, which might be unterminated.
* @s: The data to copy
* @len: The size of the data, not including the NUL terminator
* @gfp: the GFP mask used in the kmalloc() call when allocating memory
*
* Return: newly allocated copy of @s with NUL-termination or %NULL in
* case of error
*/
static __always_inline char *__kmemdup_nul(const char *s, size_t len, gfp_t gfp)
{
char *buf;
/* '+1' for the NUL terminator */
buf = kmalloc_track_caller(len + 1, gfp);
if (!buf)
return NULL;
memcpy(buf, s, len);
/* Ensure the buf is always NUL-terminated, regardless of @s. */
buf[len] = '\0';
return buf;
}
/**
* kstrdup - allocate space for and copy an existing string
* @s: the string to duplicate
@ -54,24 +78,7 @@ EXPORT_SYMBOL(kfree_const);
noinline
char *kstrdup(const char *s, gfp_t gfp)
{
size_t len;
char *buf;
if (!s)
return NULL;
len = strlen(s) + 1;
buf = kmalloc_track_caller(len, gfp);
if (buf) {
memcpy(buf, s, len);
/*
* During memcpy(), the string might be updated to a new value,
* which could be longer than the string when strlen() is
* called. Therefore, we need to add a NUL terminator.
*/
buf[len - 1] = '\0';
}
return buf;
return s ? __kmemdup_nul(s, strlen(s), gfp) : NULL;
}
EXPORT_SYMBOL(kstrdup);
@ -107,19 +114,7 @@ EXPORT_SYMBOL(kstrdup_const);
*/
char *kstrndup(const char *s, size_t max, gfp_t gfp)
{
size_t len;
char *buf;
if (!s)
return NULL;
len = strnlen(s, max);
buf = kmalloc_track_caller(len+1, gfp);
if (buf) {
memcpy(buf, s, len);
buf[len] = '\0';
}
return buf;
return s ? __kmemdup_nul(s, strnlen(s, max), gfp) : NULL;
}
EXPORT_SYMBOL(kstrndup);
@ -193,17 +188,7 @@ EXPORT_SYMBOL(kvmemdup);
*/
char *kmemdup_nul(const char *s, size_t len, gfp_t gfp)
{
char *buf;
if (!s)
return NULL;
buf = kmalloc_track_caller(len + 1, gfp);
if (buf) {
memcpy(buf, s, len);
buf[len] = '\0';
}
return buf;
return s ? __kmemdup_nul(s, len, gfp) : NULL;
}
EXPORT_SYMBOL(kmemdup_nul);