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Tue, 3 Mar 2026 13:36:57 -0800 DKIM-Filter: OpenDKIM Filter v2.11.0 mail.zytor.com 623LavOS3436858 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zytor.com; s=2026022301; t=1772573825; bh=D1r1C1nkJC8myDUqBbWlJuno+S+Hsv+z3MI/a3FcqHc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=RLwZ/rk8vaq6V4tFXUGKShs9EBYHpeXArYtAO8GRTPF0Qb9ckRJAy3tcD5EWeuBHX vr0OB9eU7N3DVYjRVanoVDfqhq4F+AkTzExopgowDGEFypgJWOgNXBkU6FNdThL97f Lw7JtD6O+ENFjRKkORJY5LGdYpcgeiUuBzkeJbD5nNV5qeKq9oq8xMw9GJMwXTJY58 GQjC3/XyTBNrpt/UhJOXTqWbTWEJKRY1JmqsyxsLflRD6J85F4d6toUWrWmiKQly38 ciLSIrOtlh968Kr67YxA/mjWIPI5I11u1R6hN8+kq3t5kAbHjJDAA+e6EhT7AmEGux lOCVXVCJis+ZQ== Message-ID: <0d2d834d-0f3c-43bb-9530-da6c2492763a@zytor.com> Date: Tue, 3 Mar 2026 13:36:52 -0800 X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/7] x86/vdso: Respect COMPAT_32BIT_TIME To: Arnd Bergmann , =?UTF-8?Q?Thomas_Wei=C3=9Fschuh?= Cc: Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, Russell King , Catalin Marinas , Will Deacon , Madhavan Srinivasan , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Thomas Bogendoerfer , Vincenzo Frascino , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-mips@vger.kernel.org References: <20260227-vdso-compat_32bit_time-v1-0-3f0286a7bac3@linutronix.de> <20260227-vdso-compat_32bit_time-v1-1-3f0286a7bac3@linutronix.de> <03cd1e21-a2f2-46a1-a674-cbaef9712016@app.fastmail.com> <20260227103226-cc3bb32c-0107-4c09-b81a-ca33ea03ad5c@linutronix.de> <49b7c9f9-198a-49f7-880b-6ae74d7bd985@zytor.com> <2b1ac7b9-fcc8-4aa3-a0ad-eb37e4bce030@app.fastmail.com> <56591FD5-0DD0-4117-BC7B-4565E3F6512E@zytor.com> Content-Language: en-US, sv-SE From: "H. Peter Anvin" In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2026-03-03 13:27, Arnd Bergmann wrote: > > I see. I would argue here that a link failure is actually the best > case then: the entire point of CONFIG_COMPAT_32BIT_TIME=n is to > enforce the fail-early case, as opposed to silent data corruption > after (now) 12 years of operation. > > I don't think there is an actual link failure here, as dl_vdso_vsym() > resolves it at runtime by glibc (when using time32), while musl > doesn't use __vdso_gettimeofday at all. > Well, the former is a link failure -- just one handled reasonably gracefully. A library that really wants a fallback can presumably also avoid the problem by provide a weak reference for the fallback. -hpa