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From: Borislav Petkov <bp@alien8.de>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
	"Jason A. Donenfeld" <Jason@zx2c4.com>,
	pbonzini@redhat.com, ebiggers@kernel.org, x86@kernel.org,
	linux-kernel@vger.kernel.org, qemu-devel@nongnu.org,
	kraxel@redhat.com, philmd@linaro.org
Subject: Re: [PATCH qemu] x86: don't let decompressed kernel image clobber setup_data
Date: Mon, 2 Jan 2023 14:36:52 +0100	[thread overview]
Message-ID: <Y7Ld9MVZC3/fsj9Y@zn.tnic> (raw)
In-Reply-To: <CAMj1kXHDw5p5yX25TnKiQ7sgqVbhEjB+=fu=7Oz67shQD-fL6Q@mail.gmail.com>

On Mon, Jan 02, 2023 at 10:32:03AM +0100, Ard Biesheuvel wrote:
> So instead of appending data to the compressed image and assuming that
> it will stay in place, create or extend a memory reservation
> elsewhere, and refer to its absolute address in setup_data.

From my limited experience with all those boot protocols, I'd say hardcoding
stuff is always a bad idea. But, we already more or less hardcode, or rather
codify through the setup header contract how stuff needs to get accessed.

And yeah, maybe specifying an absolute address and size for a blob of data and
putting that address and size in the setup header so that all the parties
involved are where what is, is probably better.

But WTH do I know...

-- 
Regards/Gruss,
    Boris.

https://people.kernel.org/tglx/notes-about-netiquette

  reply	other threads:[~2023-01-02 13:37 UTC|newest]

Thread overview: 46+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-12-28 14:38 Jason A. Donenfeld
2022-12-28 16:02 ` Philippe Mathieu-Daudé
2022-12-28 16:30   ` Jason A. Donenfeld
2022-12-28 16:57     ` Jason A. Donenfeld
2022-12-28 23:58       ` H. Peter Anvin
2022-12-29  2:13         ` H. Peter Anvin
2022-12-29  2:31         ` Jason A. Donenfeld
2022-12-29  7:28           ` Philippe Mathieu-Daudé
2022-12-29  7:30           ` H. Peter Anvin
2022-12-29  7:31           ` H. Peter Anvin
2022-12-29 12:47             ` Borislav Petkov
2022-12-30 15:54               ` Jason A. Donenfeld
2022-12-30 17:01                 ` Borislav Petkov
2022-12-30 17:07                   ` Jason A. Donenfeld
2022-12-30 19:54                     ` Borislav Petkov
2022-12-30 21:58                       ` H. Peter Anvin
2022-12-30 22:10                         ` Jason A. Donenfeld
2022-12-31  1:06                           ` H. Peter Anvin
2022-12-31  1:14                             ` H. Peter Anvin
2022-12-31 12:55                             ` Jason A. Donenfeld
2022-12-31 13:40                             ` Borislav Petkov
2022-12-31 13:44                               ` Jason A. Donenfeld
2022-12-31 13:48                                 ` Borislav Petkov
2022-12-31 13:51                                   ` Jason A. Donenfeld
2022-12-31 14:24                                     ` Borislav Petkov
2022-12-31 18:22                                       ` Jason A. Donenfeld
2022-12-31 19:00                                         ` Borislav Petkov
2023-01-01  3:21                                           ` H. Peter Anvin
2023-01-01  3:31                                             ` H. Peter Anvin
2023-01-02  6:01                                               ` Borislav Petkov
2023-01-02  6:17                                                 ` Borislav Petkov
2023-01-02  9:32                                                   ` Ard Biesheuvel
2023-01-02 13:36                                                     ` Borislav Petkov [this message]
2023-01-02 15:03                                                       ` Ard Biesheuvel
2023-01-02  5:50                                             ` Borislav Petkov
2023-01-01  4:33                                         ` H. Peter Anvin
2023-01-01  4:55                                           ` Mika Penttilä
2023-01-01  5:13                                             ` H. Peter Anvin
2022-12-30 15:59             ` Jason A. Donenfeld
2022-12-30 16:21               ` Jason A. Donenfeld
2022-12-30 19:13               ` H. Peter Anvin
2022-12-31  9:48               ` Borislav Petkov
2022-12-31 12:54                 ` Jason A. Donenfeld
2022-12-31 13:35                   ` Borislav Petkov
2022-12-31 13:42                     ` Jason A. Donenfeld
2022-12-30 18:30 ` Jason A. Donenfeld

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