From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
To: kernel-hardening@lists.openwall.com
Cc: linux-kernel@vger.kernel.org,
Andrew Morton <akpm@linux-foundation.org>,
Kees Cook <keescook@chromium.org>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>
Subject: [RFC 3/6] compiler.h: add __attribute__((format_arg)) shorthand
Date: Wed, 8 Nov 2017 23:30:17 +0100 [thread overview]
Message-ID: <20171108223020.24487-4-linux@rasmusvillemoes.dk> (raw)
In-Reply-To: <20171108223020.24487-1-linux@rasmusvillemoes.dk>
The __format_arg attribute tells gcc that it can use a specific
argument to the annotated function as the format string for the
purpose of type-checking a surrounding __printf function call, e.g.
sprintf(buf, fmtcheck(what->ever, "%d %lx", 0), i, m)
makes gcc check that i and m are indeed an int and a long; with
sprintf(buf, what->ever, i, m)
the compiler cannot do any type checking.
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
include/linux/compiler-gcc.h | 1 +
include/linux/compiler.h | 4 ++++
2 files changed, 5 insertions(+)
diff --git a/include/linux/compiler-gcc.h b/include/linux/compiler-gcc.h
index bb78e5bdff26..69a233f9fa26 100644
--- a/include/linux/compiler-gcc.h
+++ b/include/linux/compiler-gcc.h
@@ -128,6 +128,7 @@
#define __maybe_unused __attribute__((unused))
#define __always_unused __attribute__((unused))
#define __mode(x) __attribute__((mode(x)))
+#define __format_arg(n) __attribute__((format_arg(n)))
/* gcc version specific checks */
diff --git a/include/linux/compiler.h b/include/linux/compiler.h
index 478914ad280b..2c8793f72fb0 100644
--- a/include/linux/compiler.h
+++ b/include/linux/compiler.h
@@ -631,4 +631,8 @@ static __always_inline void __write_once_size(volatile void *p, void *res, int s
#define __format_template(x)
#endif
+#ifndef __format_arg
+#define __format_arg(n)
+#endif
+
#endif /* __LINUX_COMPILER_H */
--
2.11.0
next prev parent reply other threads:[~2017-11-08 22:30 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-08 22:30 [RFC 0/6] some compile- and run-time format checking Rasmus Villemoes
2017-11-08 22:30 ` [RFC 1/6] plugins: implement format_template attribute Rasmus Villemoes
2017-11-08 22:30 ` [RFC 2/6] compiler.h: add __format_template Rasmus Villemoes
2017-11-08 22:30 ` Rasmus Villemoes [this message]
2017-11-08 22:30 ` [RFC 4/6] lib/vsprintf.c: add fmtcheck utility Rasmus Villemoes
2017-11-09 1:08 ` Kees Cook
2017-11-08 22:30 ` [RFC 5/6] kernel.h: implement fmtmatch() wrapper around fmtcheck() Rasmus Villemoes
2017-11-08 22:30 ` [RFC 6/6] lib/test_printf.c: add a few fmtcheck() test cases Rasmus Villemoes
2017-11-09 1:11 ` [RFC 0/6] some compile- and run-time format checking Kees Cook
2017-11-09 14:08 ` Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 0/7] runtime format string checking Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 1/7] compiler_attributes.h: add __attribute__((format_arg)) shorthand Rasmus Villemoes
2018-10-27 12:06 ` Miguel Ojeda
2018-10-29 10:20 ` Rasmus Villemoes
2018-10-29 19:17 ` Miguel Ojeda
2018-11-02 10:36 ` Miguel Ojeda
2018-11-02 10:43 ` Rasmus Villemoes
2019-01-09 10:57 ` Miguel Ojeda
2018-10-26 23:24 ` [RFC PATCH 2/7] lib/vsprintf.c: add fmtcheck utility Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 3/7] kernel.h: implement fmtmatch() wrapper around fmtcheck() Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 4/7] lib/test_printf.c: add a few fmtcheck() test cases Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 5/7] kernel/kthread.c: do runtime check of format string in kthread_create_on_cpu() Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 6/7] nfs: use fmtcheck() in root_nfs_data Rasmus Villemoes
2018-10-26 23:24 ` [RFC PATCH 7/7] drivers: hwmon: add runtime format string checking Rasmus Villemoes
2018-10-27 17:44 ` Guenter Roeck
2018-10-30 20:58 ` [RFC PATCH 0/7] " Kees Cook
2018-11-01 22:06 ` Rasmus Villemoes
2018-11-01 22:57 ` Kees Cook
2018-11-02 20:09 ` Rasmus Villemoes
2018-11-02 20:46 ` Kees Cook
2018-11-05 9:33 ` Rasmus Villemoes
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