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Peter Anvin" To: =?ISO-8859-1?Q?Thomas_Wei=DFschuh?= CC: Arnd Bergmann , 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 Subject: Re: [PATCH 1/7] x86/vdso: Respect COMPAT_32BIT_TIME User-Agent: K-9 Mail for Android In-Reply-To: <20260306103113-ae63c668-2921-4ac1-84f6-35fbc8a6397d@linutronix.de> 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> <20260304081505-a2a3a376-20c9-46cb-8dc9-2c4deec1a55e@linutronix.de> <6909A81E-AE50-459C-9604-3EEAEFE3838E@zytor.com> <20260305080950-ff43457b-0551-480f-916e-6c252e6a64af@linutronix.de> <2e609a1b-62de-4688-b363-58025ab9e703@zytor.com> <20260306103113-ae63c668-2921-4ac1-84f6-35fbc8a6397d@linutronix.de> Message-ID: 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 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On March 6, 2026 1:42:25 AM PST, "Thomas Wei=C3=9Fschuh" wrote: >On Thu, Mar 05, 2026 at 03:57:59PM -0800, H=2E Peter Anvin wrote: >> On 2026-03-05 01:24, Thomas Wei=C3=9Fschuh wrote: >> >=20 >> >> Weak references would be a way to work around the link failures=2E= =20 >> >=20 >> > I am still not sure where "the link failures" should be coming from= =2E >> > The only sense I can make out of it, is if somebody manually and dire= ctly links >> > to vdso=2Eso=2E Like in the following example: > >(=2E=2E=2E) > >> > This actually works on glibc (not on musl)=2E But it is highly non-st= andard and >> > relies on multiple implementation details=2E Furthermore it can fail = to run on >> > systems without a vDSO, as mentioned before=2E >> >=20 >> > Is this the usage pattern you have in mind? >> > Do you know of anybody doing things this way? >> >=20 >>=20 >> Yes, and yes, I do=2E > >Thanks=2E > >Do you know why it is done this way? Are these applications public and >if so, could you point me to them? >In case we stub out the vDSO functions with ENOSYS, would these >applications be able to handle that error gracefully? > >Personally I am still in favor of removing these functions completely >when !COMPAT_32BIT_TIME=2E > > >Thomas I think I agree with you (and sadly, no, I can't point at them directly=2E= )