From: Borislav Petkov <bp@alien8.de>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Arvind Sankar <nivedita@alum.mit.edu>,
Sergey Shatunov <me@prok.pw>,
hpa@zytor.com,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
mingo@redhat.com, Thomas Gleixner <tglx@linutronix.de>,
x86@kernel.org, linux-efi <linux-efi@vger.kernel.org>,
initramfs@vger.kernel.org,
Donovan Tremura <neurognostic@protonmail.ch>,
Harald Hoyer <harald@hoyer.xyz>
Subject: Re: [PATCH 1/2] x86/boot/compressed/64: Remove .bss/.pgtable from bzImage
Date: Mon, 6 Apr 2020 10:47:38 +0200 [thread overview]
Message-ID: <20200406084738.GA2520@zn.tnic> (raw)
In-Reply-To: <CAMj1kXEUhyv886CjyKvjw2F12WaZxZRUWF6t_XzP4C2TJPdpeg@mail.gmail.com>
On Mon, Apr 06, 2020 at 09:32:47AM +0200, Ard Biesheuvel wrote:
> The EFI handover protocol strikes again :-(
>
> It seems we did not include any guidance in the documentation in
> Documentation/x86/boot.rst regarding zero-initializing BSS, and come
> to think of it, we don't include any other requirements either, i.e.,
> regarding placement wrt section alignment etc. This is a serious bug.
> Even though EFI usually lays out PE/COFF images in files the exact way
> they appear in memory, this is not actually required by the spec. Most
> notably, the virtual size can be smaller than the file size, and the
> loader is expected to zero-initialize the difference as well.
Is that expectation stated explicitly somewhere?
> Since the EFI handover protocol should be considered deprecated at
> this point (and is never going to be supported in upstream GRUB
> either, for instance), I would recommend the systemd-boot developers
> to start looking into deprecating this as well, and switch to the
> ordinary PE/COFF entry point, and use the new initrd callback protocol
> for initrd loading.
Any pointers to that new initrd callback protocol?
In any case, I'd really appreciate a patch to boot.rst formulating those
requirements so that they're written down and people can find them.
> On the Linux/x86 side, we should at least add some code to the EFI
> handover protocol entry point to zero initialize BSS, and ensure that
> it is either not needed in other places, or add the code to deal with
> those as well.
Sounds like a simple fix, if that would fix it.
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2020-04-06 8:47 UTC|newest]
Thread overview: 130+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-09 15:02 [PATCH 1/2] x86/boot/compressed/64: Remove .bss/.pgtable from bzImage Arvind Sankar
2020-01-09 15:02 ` [PATCH 2/2] x86/boot/compressed: Remove unnecessary sections " Arvind Sankar
2020-02-06 11:44 ` Kees Cook
2020-02-19 16:55 ` [tip: x86/boot] " tip-bot2 for Arvind Sankar
2020-02-22 5:08 ` [PATCH 2/2] " Nathan Chancellor
2020-02-22 6:55 ` Borislav Petkov
2020-02-22 7:02 ` Nathan Chancellor
2020-02-22 7:21 ` Fangrui Song
2020-02-22 7:42 ` Nathan Chancellor
2020-02-22 15:37 ` Arvind Sankar
2020-02-22 16:44 ` Arvind Sankar
2020-02-22 17:18 ` [PATCH] x86/boot/compressed: Fix compressed kernel linking with lld Arvind Sankar
2020-02-22 18:14 ` Nathan Chancellor
2020-02-22 18:58 ` Fangrui Song
2020-02-22 20:17 ` Arvind Sankar
2020-02-22 21:01 ` Fangrui Song
2020-02-22 23:33 ` Nick Desaulniers
2020-02-22 23:57 ` Arvind Sankar
2020-02-23 19:37 ` [PATCH 0/2] Stop generating .eh_frame sections Arvind Sankar
2020-02-24 4:15 ` Nathan Chancellor
2020-02-24 20:49 ` Nick Desaulniers
2020-02-24 21:53 ` Arvind Sankar
2020-02-24 22:01 ` Nick Desaulniers
2020-02-23 19:37 ` [PATCH 1/2] arch/x86: Use -fno-asynchronous-unwind-tables to suppress " Arvind Sankar
2020-02-24 20:33 ` Nick Desaulniers
2020-02-24 21:05 ` Arvind Sankar
2020-02-24 21:12 ` Fangrui Song
2020-02-24 21:17 ` Nick Desaulniers
2020-02-24 21:22 ` Nick Desaulniers
2020-02-23 19:37 ` [PATCH 2/2] arch/x86: Drop unneeded linker script discard of .eh_frame Arvind Sankar
2020-02-24 20:45 ` Nick Desaulniers
2020-02-24 21:33 ` Arvind Sankar
2020-02-24 21:58 ` Nick Desaulniers
2020-02-24 23:21 ` [PATCH v2 0/2] Stop generating .eh_frame sections Arvind Sankar
2020-02-24 23:21 ` [PATCH v2 1/2] arch/x86: Use -fno-asynchronous-unwind-tables to suppress " Arvind Sankar
2020-02-24 23:28 ` Nathan Chancellor
2020-02-24 23:30 ` Nick Desaulniers
2020-02-25 4:10 ` Kees Cook
2020-02-25 16:53 ` [tip: x86/boot] x86/*/Makefile: " tip-bot2 for Arvind Sankar
2020-02-24 23:21 ` [PATCH v2 2/2] arch/x86: Drop unneeded linker script discard of .eh_frame Arvind Sankar
2020-02-24 23:28 ` Nathan Chancellor
2020-02-24 23:33 ` Nick Desaulniers
2020-02-25 4:11 ` Kees Cook
2020-02-25 16:53 ` [tip: x86/boot] x86/vmlinux: " tip-bot2 for Arvind Sankar
2020-02-23 22:00 ` [PATCH] x86/boot/compressed: Fix compressed kernel linking with lld Kees Cook
2020-02-24 6:06 ` Fangrui Song
2020-02-22 17:29 ` [PATCH 2/2] x86/boot/compressed: Remove unnecessary sections from bzImage Borislav Petkov
2020-02-22 17:53 ` Arvind Sankar
2020-02-22 7:42 ` Borislav Petkov
2020-02-22 16:22 ` Arvind Sankar
2020-02-22 23:20 ` Nick Desaulniers
2020-02-24 13:28 ` Michael Matz
2020-02-24 20:51 ` Nick Desaulniers
2020-02-24 21:28 ` Fangrui Song
2020-02-24 21:48 ` Arvind Sankar
2020-02-24 22:17 ` Fangrui Song
2020-02-24 22:43 ` Arvind Sankar
2020-02-24 22:50 ` Fangrui Song
2020-02-24 23:08 ` Arvind Sankar
2020-02-25 5:35 ` --orphan-handling=warn (was Re: [PATCH 2/2] x86/boot/compressed: Remove unnecessary sections) " Kees Cook
2020-02-25 16:42 ` --orphan-handling=warn Arvind Sankar
2020-02-25 18:29 ` --orphan-handling=warn Arvind Sankar
2020-02-25 19:42 ` --orphan-handling=warn Kees Cook
2020-02-25 20:37 ` --orphan-handling=warn Nick Desaulniers
2020-02-25 22:02 ` --orphan-handling=warn Kees Cook
2020-02-26 1:56 ` --orphan-handling=warn Fangrui Song
2020-02-26 5:35 ` --orphan-handling=warn Kees Cook
2020-02-26 19:11 ` --orphan-handling=warn Kristen Carlson Accardi
2020-02-26 19:26 ` --orphan-handling=warn Nick Desaulniers
2020-02-24 11:37 ` [tip: x86/boot] x86/boot/compressed: Remove .eh_frame section from bzImage tip-bot2 for Arvind Sankar
2020-02-24 16:41 ` Arvind Sankar
2020-02-24 17:16 ` Borislav Petkov
2020-02-24 17:28 ` Arvind Sankar
2020-02-05 16:29 ` [PATCH 1/2] x86/boot/compressed/64: Remove .bss/.pgtable " Arvind Sankar
2020-02-18 18:03 ` Arvind Sankar
2020-02-19 12:09 ` Borislav Petkov
2020-02-19 17:57 ` Arvind Sankar
2020-02-19 18:22 ` Borislav Petkov
2020-02-19 19:06 ` Arvind Sankar
2020-02-06 11:18 ` Kees Cook
2020-02-19 16:55 ` [tip: x86/boot] " tip-bot2 for Arvind Sankar
2020-04-05 15:42 ` [PATCH 1/2] " Sergey Shatunov
2020-04-05 23:18 ` Arvind Sankar
2020-04-06 0:00 ` Sergey Shatunov
2020-04-06 3:51 ` Arvind Sankar
2020-04-06 3:51 ` Arvind Sankar
2020-04-06 7:32 ` Ard Biesheuvel
2020-04-06 8:47 ` Borislav Petkov [this message]
2020-04-06 9:11 ` Ard Biesheuvel
2020-04-06 9:11 ` Ard Biesheuvel
2020-04-06 11:20 ` Borislav Petkov
2020-04-06 11:20 ` Borislav Petkov
2020-04-06 13:22 ` Arvind Sankar
2020-04-06 13:29 ` Ard Biesheuvel
2020-04-06 13:29 ` Ard Biesheuvel
2020-04-06 16:01 ` Arvind Sankar
2020-04-06 16:01 ` Arvind Sankar
2020-04-06 16:22 ` Ard Biesheuvel
2020-04-06 16:22 ` Ard Biesheuvel
2020-04-06 16:52 ` Arvind Sankar
2020-04-06 16:52 ` Arvind Sankar
2020-04-06 16:59 ` Ard Biesheuvel
2020-04-06 18:06 ` [PATCH 1/2] efi/x86: Move efi stub globals from .bss to .data Arvind Sankar
2020-04-06 18:06 ` Arvind Sankar
2020-04-06 18:06 ` [PATCH 2/2] efi/x86: Always relocate the kernel for EFI handover entry Arvind Sankar
2020-04-14 8:20 ` [tip: efi/urgent] " tip-bot2 for Arvind Sankar
2020-04-06 18:29 ` [PATCH 1/2] efi/x86: Move efi stub globals from .bss to .data Ard Biesheuvel
2020-04-06 18:29 ` Ard Biesheuvel
2020-04-08 7:43 ` Dave Young
2020-04-08 7:43 ` Dave Young
2020-04-08 7:49 ` Ard Biesheuvel
2020-04-08 7:49 ` Ard Biesheuvel
2020-04-09 14:39 ` Arvind Sankar
2020-04-09 14:47 ` Ard Biesheuvel
2020-04-09 16:35 ` Arvind Sankar
2020-04-09 16:35 ` Arvind Sankar
2020-04-10 14:47 ` Arvind Sankar
2020-04-10 14:47 ` Arvind Sankar
2020-04-10 15:26 ` Ard Biesheuvel
2020-04-14 14:57 ` Daniel Kiper
2020-04-14 14:57 ` Daniel Kiper
2020-04-10 11:26 ` Thomas Meyer
2020-04-10 14:38 ` Arvind Sankar
2020-04-11 8:50 ` Thomas Meyer
2020-04-14 8:20 ` [tip: efi/urgent] " tip-bot2 for Arvind Sankar
2020-04-06 17:21 ` [PATCH 1/2] x86/boot/compressed/64: Remove .bss/.pgtable from bzImage Borislav Petkov
2020-04-06 17:21 ` Borislav Petkov
2020-04-06 8:44 ` Ard Biesheuvel
2020-04-06 12:36 ` Sergey Shatunov
2020-04-06 13:20 ` Ard Biesheuvel
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