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Donenfeld" To: Christophe Leroy Cc: Michael Ellerman , Nicholas Piggin , Naveen N Rao , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Theodore Ts'o , Arnd Bergmann , Andrew Morton , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Vincenzo Frascino , Shuah Khan , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v2 05/17] vdso: Avoid call to memset() by getrandom Message-ID: References: <5deb67090b214f0e6eae96b7c406546d1a16f89b.1724309198.git.christophe.leroy@csgroup.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <5deb67090b214f0e6eae96b7c406546d1a16f89b.1724309198.git.christophe.leroy@csgroup.eu> X-Rspamd-Queue-Id: 659DA180006 X-Rspam-User: X-Rspamd-Server: rspam05 X-Stat-Signature: mjjxk478gs5szor3y8baczbdmqiigfs6 X-HE-Tag: 1724659654-646511 X-HE-Meta: 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 v9eRUZe2 mtquavjQnW6lYg41sxixzFwXmdT+c5KXmIbHCZX+TigZ5b/lnOSuSAar7hs4l5weIm+O95UNs1GLDgev+HkVF9dL70/HH0yxGBLLhPl8mLs57p5Elwx80sAnLrO0+6orBSZRhLfka9bmHcO+EOq6ywTe9S74AmjFIw0QhZZZxf1hNy26s7h2m3t9Q6VlXKKJMHUQo5tVAXZ5ca5A0ysvBK3CGV8dsNfwIPk7LbLayZev2Nz8LQzrrPaQ8bsEOsrErREhLnv+hKuWINjJp5sPBH0mrNNfq7MmoqjNJj0GCUYqWrm6/WS02qAOZ5XppQ8J2xvDXL4NfIXejcI55j/U0C39UULwd4vDGN6J66MWzQD+sSsnboal1Hvgema7wDZ3qv+4DZZ73swcYNYs2ess5caSbugv2vRm9nmGo4OcYl3DJkVdoeTOCO6KXCA== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Aug 22, 2024 at 09:13:13AM +0200, Christophe Leroy wrote: > With the current implementation, __cvdso_getrandom_data() calls > memset(), which is unexpected in the VDSO. > > Rewrite opaque data initialisation to avoid memset(). I think of the various ways I've seen of fixing this -- e.g. adding a memset() arch-by-arch -- this is the cleanest and simplest. I'll add this as a fix to random.git now. Jason