From: Kees Cook <kees@kernel.org>
To: "Thomas Weißschuh" <thomas.weissschuh@linutronix.de>
Cc: Eric Biederman <ebiederm@xmission.com>,
Shuah Khan <shuah@kernel.org>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Bill Wendling <morbo@google.com>,
Justin Stitt <justinstitt@google.com>,
Andy Lutomirski <luto@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
linux-kselftest@vger.kernel.org, llvm@lists.linux.dev
Subject: Re: [PATCH 04/16] elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK
Date: Tue, 4 Feb 2025 07:32:14 -0800 [thread overview]
Message-ID: <202502040731.4EE9CCBB@keescook> (raw)
In-Reply-To: <20250204161210-b788ff6b-9c77-4a9c-8ab8-8b727b0b2003@linutronix.de>
On Tue, Feb 04, 2025 at 04:17:03PM +0100, Thomas Weißschuh wrote:
> On Tue, Feb 04, 2025 at 07:10:00AM -0800, Kees Cook wrote:
> > On Mon, Feb 03, 2025 at 10:05:05AM +0100, Thomas Weißschuh wrote:
> > > The definitions are used by tools/testing/selftests/vDSO/parse_vdso.c.
> > > To be able to build the vDSO selftests without a libc dependency,
> > > add the definitions to the kernels own UAPI headers.
> >
> > For all the UAPI changes, where are the defines "normally" found? i.e.
> > how does adding these to UAPI not break something that already has them?
> > Or have these never been defined before? I'm confused about how removing
> > the libc dependency exposes the lack of these defines. Are they defined
> > in a non-exported libc header somewhere?
>
> They are normally defined directly in libc <elf.h>, which does not use
> UAPI headers. Libc elf.h and Linux UAPI elf.h can not be used at the
> same time because they define the same symbols.
> In theory some user of UAPI elf.h could have defined these new symbols
> on their own without ifdef guards. However UAPI elf.h is regularly
> updated with new symbols.
Okay, great. As long as the collision risk is low, I'm fine with all the
UAPI additions. Thanks for doing this!
--
Kees Cook
next prev parent reply other threads:[~2025-02-04 15:32 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-03 9:05 [PATCH 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 01/16] MAINTAINERS: Add vDSO selftests Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 02/16] elf, uapi: Add definition for STN_UNDEF Thomas Weißschuh
2025-02-04 15:32 ` Kees Cook
2025-02-03 9:05 ` [PATCH 03/16] elf, uapi: Add definition for DT_GNU_HASH Thomas Weißschuh
2025-02-04 15:32 ` Kees Cook
2025-02-03 9:05 ` [PATCH 04/16] elf, uapi: Add definitions for VER_FLG_BASE and VER_FLG_WEAK Thomas Weißschuh
2025-02-04 15:10 ` Kees Cook
2025-02-04 15:17 ` Thomas Weißschuh
2025-02-04 15:32 ` Kees Cook [this message]
2025-02-04 15:33 ` Kees Cook
2025-02-03 9:05 ` [PATCH 05/16] elf, uapi: Add type ElfXX_Versym Thomas Weißschuh
2025-02-04 15:32 ` Kees Cook
2025-02-03 9:05 ` [PATCH 06/16] elf, uapi: Add types ElfXX_Verdef and ElfXX_Veraux Thomas Weißschuh
2025-02-04 15:33 ` Kees Cook
2025-02-03 9:05 ` [PATCH 07/16] tools/include: Add uapi/linux/elf.h Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 08/16] selftests: Add headers target Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 09/16] selftests: vDSO: vdso_standalone_test_x86: Use vdso_init_form_sysinfo_ehdr Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 10/16] selftests: vDSO: parse_vdso: Drop vdso_init_from_auxv() Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 11/16] selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 12/16] selftests: vDSO: parse_vdso: Test __SIZEOF_LONG__ instead of ULONG_MAX Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 13/16] selftests: vDSO: parse_vdso: Make compatible with nolibc Thomas Weißschuh
2025-02-22 10:24 ` Willy Tarreau
2025-02-24 14:41 ` Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 14/16] selftests: vDSO: vdso_test_gettimeofday: Clean up includes Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 15/16] selftests: vDSO: vdso_test_gettimeofday: Make compatible with nolibc Thomas Weißschuh
2025-02-03 9:05 ` [PATCH 16/16] selftests: vDSO: vdso_standalone_test_x86: Switch to nolibc Thomas Weißschuh
2025-02-03 11:23 ` [PATCH 00/16] selftests: vDSO: parse_vdso: Make compatible with nolibc Christophe Leroy
2025-02-03 13:50 ` Thomas Weißschuh
2025-02-03 15:43 ` Christophe Leroy
2025-02-03 16:14 ` Thomas Weißschuh
2025-02-22 10:26 ` Willy Tarreau
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