lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Date:   Thu, 30 Sep 2021 16:57:54 -0700
From:   Kees Cook <>
To:     Jonathan Corbet <>
Cc:     Kees Cook <>,
        Randy Dunlap <>,
        Joe Perches <>,
        Alexey Dobriyan <>,
        Nick Desaulniers <>,
        Linus Torvalds <>,
        Rasmus Villemoes <>,
        Andrew Morton <>,,,
Subject: [PATCH v4] docs: Explain the desired position of function attributes

While discussing how to format the addition of various function
attributes, some "unwritten rules" of ordering surfaced[1]. Capture as
close as possible to Linus's preferences for future reference.

(Though I note the dissent voiced by Joe Perches, Alexey Dobriyan, and
others that would prefer all attributes live on a separate leading line.)


Signed-off-by: Kees Cook <>
- fix another stray "void"! This is why code needs a compiler... (thx randy)
 Documentation/process/coding-style.rst | 30 ++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst
index 42969ab37b34..45b48510f5ec 100644
--- a/Documentation/process/coding-style.rst
+++ b/Documentation/process/coding-style.rst
@@ -487,6 +487,36 @@ because it is a simple way to add valuable information for the reader.
 Do not use the ``extern`` keyword with function prototypes as this makes
 lines longer and isn't strictly necessary.
+When writing a function declarations, please keep the `order of elements regular
+For example::
+ extern __init void * __must_check action(enum magic value, size_t size, u8 count,
+ 					  char *fmt, ...) __printf(4, 5) __malloc;
+The preferred order of elements for a function prototype is:
+- storage class (here, ``extern``, and things like ``static __always_inline`` even though
+  ``__always_inline`` is technically an attribute, it is treated like ``inline``)
+- storage class attributes (here, ``__init`` -- i.e. section declarations, but also things like ``__cold``)
+- return type (here, ``void *``)
+- return type attributes (here, ``__must_check``)
+- function name (here, ``action``)
+- function parameters (here, ``(enum magic value, size_t size, u8 count, char *fmt, ...)``, noting that parameter names should always be included)
+- function parameter attributes (here, ``__printf(4, 5)``)
+- function behavior attributes (here, ``__malloc``)
+Note that for a function definition (e.g. ``static inline``), the compiler does
+not allow function parameter attributes after the function parameters. In these
+cases, they should go after the storage class attributes (e.g. note the changed
+position of ``__printf(4, 5)``)::
+ static __always_inline __init __printf(4, 5) void * __must_check action(enum magic value,
+ 		size_t size, u8 count, char *fmt, ...)
+ 		__malloc
+ {
+ 	...
+ }
 7) Centralized exiting of functions

Powered by blists - more mailing lists