linux-kernel - Re: [PATCH v2] printf: convert test

lists.openwall.net		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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <aW3pgf4FQHFCC9Bm@smile.fi.intel.com>
Date: Mon, 19 Jan 2026 10:21:21 +0200
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Tamir Duberstein <tamird@...nel.org>
Cc: Petr Mladek <pmladek@...e.com>, Steven Rostedt <rostedt@...dmis.org>,
	Rasmus Villemoes <linux@...musvillemoes.dk>,
	Sergey Senozhatsky <senozhatsky@...omium.org>,
	Nathan Chancellor <nathan@...nel.org>,
	Nick Desaulniers <nick.desaulniers+lkml@...il.com>,
	Bill Wendling <morbo@...gle.com>,
	Justin Stitt <justinstitt@...gle.com>, Kees Cook <kees@...nel.org>,
	linux-kernel@...r.kernel.org, oe-kbuild-all@...ts.linux.dev,
	llvm@...ts.linux.dev, kernel test robot <lkp@...el.com>
Subject: Re: [PATCH v2] printf: convert test_hashed into macro

On Fri, Jan 16, 2026 at 11:27:03AM -0500, Tamir Duberstein wrote:
> This allows the compiler to check the arguments against the __printf

__printf() since it takes parameters, OTOH it's an attribute at the end,
so I have no strong opinion on how to spell it.

> attribute on __test. This produces better diagnostics when incorrect

__test()

*This is reference to a function.

> inputs are passed.

...

> +/*
> + * This is a macro so that the compiler can compare its arguments to the
> + * __printf attribute on __test. This cannot be a function with a __printf
> + * attribute because GCC requires __printf functions to be variadic.

As per commit message remarks.

> + */
> +#define test_hashed(kunittest, fmt, p)                                   \
> +	do {                                                             \
> +		char buf[PLAIN_BUF_SIZE];                                \
> +		plain_hash_to_buffer(kunittest, p, buf, PLAIN_BUF_SIZE); \
> +		test(buf, fmt, p);                                       \
> +	} while (0)

Make sure you used tabs to indent the \:s.

...

The downside of a macro is a killing of compile-time type checks.

-- 
With Best Regards,
Andy Shevchenko