The quilt patch titled Subject: mm/util: deduplicate code in {kstrdup,kstrndup,kmemdup_nul} has been removed from the -mm tree. Its filename was mm-util-deduplicate-code-in-kstrdupkstrndupkmemdup_nul.patch This patch was dropped because it was merged into the mm-nonmm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Yafang Shao <laoar.shao@xxxxxxxxx> Subject: mm/util: deduplicate code in {kstrdup,kstrndup,kmemdup_nul} Date: Mon, 7 Oct 2024 22:49:10 +0800 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@xxxxxxxxx Suggested-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Yafang Shao <laoar.shao@xxxxxxxxx> Cc: Simon Horman <horms@xxxxxxxxxx> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> Cc: Alejandro Colomar <alx@xxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Alexei Starovoitov <alexei.starovoitov@xxxxxxxxx> Cc: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Christian Brauner <brauner@xxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: David Airlie <airlied@xxxxxxxxx> Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx> Cc: Eric Paris <eparis@xxxxxxxxxx> Cc: James Morris <jmorris@xxxxxxxxx> Cc: Jan Kara <jack@xxxxxxx> Cc: Justin Stitt <justinstitt@xxxxxxxxxx> Cc: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx> Cc: Matus Jokay <matus.jokay@xxxxxxxx> Cc: Maxime Ripard <mripard@xxxxxxxxxx> Cc: Ondrej Mosnacek <omosnace@xxxxxxxxxx> Cc: Paul Moore <paul@xxxxxxxxxxxxxx> Cc: Quentin Monnet <qmo@xxxxxxxxxx> Cc: "Serge E. Hallyn" <serge@xxxxxxxxxx> Cc: Stephen Smalley <stephen.smalley.work@xxxxxxxxx> Cc: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx> Cc: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/util.c | 69 ++++++++++++++++++++-------------------------------- 1 file changed, 27 insertions(+), 42 deletions(-) --- a/mm/util.c~mm-util-deduplicate-code-in-kstrdupkstrndupkmemdup_nul +++ a/mm/util.c @@ -45,34 +45,41 @@ void kfree_const(const void *x) EXPORT_SYMBOL(kfree_const); /** - * kstrdup - allocate space for and copy an existing string - * @s: the string to duplicate + * __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 or %NULL in case of error + * Return: newly allocated copy of @s with NUL-termination or %NULL in + * case of error */ -noinline -char *kstrdup(const char *s, gfp_t gfp) +static __always_inline char *__kmemdup_nul(const char *s, size_t len, gfp_t gfp) { - size_t len; char *buf; - if (!s) + /* '+1' for the NUL terminator */ + buf = kmalloc_track_caller(len + 1, gfp); + if (!buf) 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'; - } + 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 + * @gfp: the GFP mask used in the kmalloc() call when allocating memory + * + * Return: newly allocated copy of @s or %NULL in case of error + */ +noinline +char *kstrdup(const char *s, gfp_t gfp) +{ + 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); _ Patches currently in -mm which might be from laoar.shao@xxxxxxxxx are