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From: Kees Cook <kees@kernel.org>
To: Borislav Petkov <bp@alien8.de>
Cc: Jeff Johnson <quic_jjohnson@quicinc.com>,
	Nikolay Borisov <nik.borisov@suse.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
	linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org,
	kernel-janitors@vger.kernel.org
Subject: Re: [PATCH] x86/boot: add prototype for __fortify_panic()
Date: Fri, 31 May 2024 13:46:37 -0700	[thread overview]
Message-ID: <202405311345.D91BF6E9@keescook> (raw)
In-Reply-To: <20240531190816.GLZlogIGgpc5maOeLN@fat_crate.local>

On Fri, May 31, 2024 at 09:08:16PM +0200, Borislav Petkov wrote:
> On Fri, May 31, 2024 at 09:53:28AM -0700, Kees Cook wrote:
> > Under CONFIG_FORTIFY_SOURCE, the boot code *does* still uses
> > fortify-string.h. It lets us both catch mistakes we can discover at
> > compile and will catch egregious runtime mistakes, though the reporting
> > is much simpler in the boot code.
> 
> From where I'm standing, we're not catching anything in the
> decompressor:
> 
> $  objdump -D arch/x86/boot/compressed/vmlinux | grep __fortify_panic
> 0000000001bec250 <__fortify_panic>:
> $
> 
> Sure, in vmlinux proper (allmodconfig) we do:
> 
> objdump -D vmlinux | grep __fortify_panic | wc -l
> 1417
> 
> but not in the decompressor which is special anyway.
> 
> So we can just as well disable CONFIG_FORTIFY_SOURCE in the decompressor
> and not do silly prototypes.

Please do not do this. It still benefits from compile-time sanity
checking.

-- 
Kees Cook

  reply	other threads:[~2024-05-31 20:46 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-05-29 18:09 [PATCH] x86/boot: add prototype for __fortify_panic() Jeff Johnson
2024-05-30 15:42 ` Nikolay Borisov
2024-05-30 16:23   ` Jeff Johnson
2024-05-30 16:46     ` Borislav Petkov
2024-05-31 16:53       ` Kees Cook
2024-05-31 19:08         ` Borislav Petkov
2024-05-31 20:46           ` Kees Cook [this message]
2024-05-31 20:49             ` Borislav Petkov
2024-05-31 21:06               ` Kees Cook
2024-05-31 21:20                 ` Borislav Petkov
2024-05-31 21:34                   ` Kees Cook
2024-05-31 21:45                     ` Borislav Petkov
2024-05-31 22:20                       ` Jeff Johnson
2024-05-31 16:28     ` Kees Cook
2024-05-31 18:28       ` Jeff Johnson
2024-05-31 18:34         ` Dan Carpenter
2024-06-01  7:27       ` Nikolay Borisov
2024-06-10  7:08         ` Nikolay Borisov

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