linux-kernel - "eliminate warn_on_slowpath()" change causes many gcc-3.2.3 warnings

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: Windows password security audit tool. GUI, reports in PDF.

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

Message-Id: <200901171519.n0HFJZuf028704@harpo.it.uu.se>
Date:	Sat, 17 Jan 2009 16:19:35 +0100 (MET)
From:	Mikael Pettersson <mikpe@...uu.se>
To:	mingo@...e.hu
Cc:	linux-kernel@...r.kernel.org
Subject: "eliminate warn_on_slowpath()" change causes many gcc-3.2.3 warnings

Commit ec5679e513305f1411753e5f5489935bd638af23 "eliminate warn_on_slowpath()"
changed __WARN() to call warn_slowpath() with a NULL value for the format
string parameter. Now every WARN_ON() triggers a warning from gcc-3.2.3:

In file included from include/linux/kmod.h:22,
                 from include/linux/module.h:13,
                 from include/linux/crypto.h:21,
                 from arch/x86/kernel/asm-offsets_32.c:7,
                 from arch/x86/kernel/asm-offsets.c:2:
include/linux/gfp.h: In function `allocflags_to_migratetype':
include/linux/gfp.h:104: warning: null format string

Compiling kernel 2.6.29-rc2 with a minimalistic .config for my 486
generates 1767 'null format string' warnings.

warn_slowpath() is declared with attribute((format(printf, 3, 4))),
and gcc-3.2.3 warns if the format string parameter is NULL. gcc-3.3
and newer do not warn in that case.

Since gcc-3.2 is still a supported compiler for the kernel, this is
a regression.

(Just FYI. I don't consider this serious enough to warrant reverting
that cleanup patch or declaring gcc-3.2.3 too old. I can always update
my 486 to gcc-3.3.6 if the warnings start to bug me too much.)

/Mikael
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/