linux-kernel - [PATCH 3.16 255/366] string: drop __must

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Date:   Sun, 11 Nov 2018 19:49:05 +0000
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "Tejun Heo" <tj@...nel.org>
Subject: [PATCH 3.16 255/366] string: drop __must_check from strscpy()

3.16.61-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Ben Hutchings <ben@...adent.org.uk>

This was done as part of commit 08a77676f9c5 upstream, from which
the following description is taken:

> strlcpy() is worse than strlcpy() because it unconditionally runs
> strlen() on the source string, and the only reason we switched to
> strlcpy() here was because it was lacking __must_check, which doesn't
> reflect any material differences between the two function.  It's just
> that someone added __must_check to strscpy() and not to strlcpy().
> 
> These basic string copy operations are used in variety of ways, and
> one of not-so-uncommon use cases is safely handling truncated copies,
> where the caller naturally doesn't care about the return value.  The
> __must_check doesn't match the actual use cases and forces users to
> opt for inferior variants which lack __must_check by happenstance or
> spread ugly (void) casts.

Cc: Tejun Heo <tj@...nel.org>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
--- a/include/linux/string.h
+++ b/include/linux/string.h
@@ -26,7 +26,7 @@ extern char * strncpy(char *,const char
 size_t strlcpy(char *, const char *, size_t);
 #endif
 #ifndef __HAVE_ARCH_STRSCPY
-ssize_t __must_check strscpy(char *, const char *, size_t);
+ssize_t strscpy(char *, const char *, size_t);
 #endif
 #ifndef __HAVE_ARCH_STRCAT
 extern char * strcat(char *, const char *);