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Peter Anvin" To: Peter Zijlstra , =?ISO-8859-1?Q?Thomas_Wei=DFschuh?= CC: Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Nathan Chancellor , Nick Desaulniers , Bill Wendling , Justin Stitt , Andy Lutomirski , Vincenzo Frascino , Kees Cook , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Richard Weinberger , Anton Ivanov , Johannes Berg , Russell King , Catalin Marinas , Will Deacon , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Huacai Chen , WANG Xuerui , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Thomas Bogendoerfer , Miguel Ojeda , Alex Gaynor , Gary Guo , =?ISO-8859-1?Q?Bj=F6rn_Roy_Baron?= , Benno Lossin , Andreas Hindborg , Alice Ryhl , Trevor Gross , Danilo Krummrich , Thomas Gleixner , Christophe Leroy , Boqun Feng , Nicolas Schier , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, llvm@lists.linux.dev, linux-mm@kvack.org, linux-um@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, loongarch@lists.linux.dev, linux-s390@vger.kernel.org, linux-mips@vger.kernel.org, rust-for-linux@vger.kernel.org, linux-kbuild@vger.kernel.org, Jan Stancek , Arnaldo Carvalho de Melo , Alexandre Ghiti Subject: Re: [PATCH v5 12/24] vdso: Add the vdsocheck tool User-Agent: K-9 Mail for Android In-Reply-To: <20260908071911.GU4120091@noisy.programming.kicks-ass.net> References: <20260908-vdso-absolute-reloc-v5-0-3a93791af1cf@linutronix.de> <20260908-vdso-absolute-reloc-v5-12-3a93791af1cf@linutronix.de> <20260908071911.GU4120091@noisy.programming.kicks-ass.net> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: 3F424180002 X-Stat-Signature: 4fr6fccc7jgxsqxhc1mz5xkpmw6twhz8 X-Rspam-User: X-HE-Tag: 1788982388-274742 X-HE-Meta: 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 1SuGrtXE 1vrj7lSLjXXsjiZSv7wGtHdlAgtewsgc5Gu9h5fEDxK0uLpUAiaHqtsY8N2QFSczwLJ1QKqnnhX6ruBlpzHXnB0IY10bKO6mpemTBImjxVCte50d5KuWV62a/bBMiOwHPYugrNHZqC3/Jz3JV1y2ikYhp+TRRHwv4CMBDb8kZmvvbUBxeNYdJK+g+Njm+Im7GA20kRu88IS7sFaUpUvAUhAJ9cvWX6+ZPrFsUcgq+YoC/WQ1Gv1KzED9vyO9mnQdb6mjs2yw1DztGmQ7Gom0cORG0TIaWWRG8H5CfXz7A2z7nTNMshK5+cEPq1XESLTZfCvX7esevJb2+kMEiP5zm5oXCXMUYZAPx94PG8FvTk1uEDeZIAuioqO6fZhPO4MNbOJLzHfyTe1RNMYb9xmB9NgJYNAdoo7EAwqXJ Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On September 8, 2026 12:19:11 AM PDT, Peter Zijlstra wrote: >On Tue, Sep 08, 2026 at 08:33:46AM +0200, Thomas Wei=C3=9Fschuh wrote: >> All vDSO code needs to be completely position independent=2E Symbol >> references are marked as hidden so the compiler emits PC-relative >> relocations=2E However there are cases where the compiler may still >> emit absolute relocations, as they are valid in regular PIC DSO code=2E >> These would be resolved by the linker and will break at runtime=2E >> This has been observed on arm64, see commit 0c314cda9325 ("arm64: vdso: >> Work around invalid absolute relocations from GCC") >>=20 >> Introduce a tool to check for absolute relocations during the build, >> as the current inline-shell logic is not expressive enough=2E >> The check is done on the object files as the relocations will not exist >> anymore in the final DSO=2E As there is no extension point for the >> compilation of each object file, perform the validation in vdso_check= =2E >>=20 >> Signed-off-by: Thomas Wei=C3=9Fschuh >> --- >> Makefile | 19 ++ >> lib/vdso/Kconfig | 5 + >> lib/vdso/Makefile | 2 + >> lib/vdso/Makefile=2Einclude | 14 ++ >> lib/vdso/check/=2Egitignore | 3 + >> lib/vdso/check/Makefile | 34 +++ >> lib/vdso/check/elf=2Ers | 498 ++++++++++++++++++++++++++++++++++= ++++++++++ >> lib/vdso/check/vdsocheck=2Ers | 154 ++++++++++++++ >> 8 files changed, 729 insertions(+) > >Urgh, does this mean I have to have rust installed just to build a >kernel now? It was going to happen, and now we'll have to suffer the instability of ru= st=2E=2E=2E