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[198.0.35.241]) by smtp.gmail.com with ESMTPSA id u139-20020a627991000000b00561cf757749sm1677934pfc.183.2022.11.17.14.58.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 17 Nov 2022 14:58:20 -0800 (PST) Date: Thu, 17 Nov 2022 14:58:19 -0800 From: Kees Cook To: Linus Torvalds Cc: David Hildenbrand , linux-kernel@vger.kernel.org, x86@kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, Andrew Morton , Jason Gunthorpe , John Hubbard , Peter Xu , Greg Kroah-Hartman , Andrea Arcangeli , Hugh Dickins , Nadav Amit , Vlastimil Babka , Matthew Wilcox , Mike Kravetz , Muchun Song , Shuah Khan , Lucas Stach , David Airlie , Oded Gabbay , Arnd Bergmann , Christoph Hellwig , Alex Williamson , Oleg Nesterov , Richard Henderson , Ivan Kokshaysky , Matt Turner , Catalin Marinas , Will Deacon , Thomas Bogendoerfer , Michael Ellerman , Nicholas Piggin , Christophe Leroy , "David S. 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Hallyn" Subject: Re: [PATCH mm-unstable v1 20/20] mm: rename FOLL_FORCE to FOLL_PTRACE Message-ID: <202211171439.CDE720EAD@keescook> References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-21-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1668725902; a=rsa-sha256; cv=none; b=yI2Yz9577aqpjHlca39PtAnW+3OVzmnfzWDgL9CsGsbU+0aR1qAKqOznCRcMj3/vqG47nI zGbauUrbybxG12kxsRbw3DMmRBfzj3rKoTLh+zSqU0M8yxcS4FkUuXyzz5FCUTCx6qxWyH 4EoR+qkcm9M6gwMa93cx8ZjQx+JsXPE= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=Fy4BdUGW; dmarc=pass (policy=none) header.from=chromium.org; spf=pass (imf02.hostedemail.com: domain of keescook@chromium.org designates 209.85.210.172 as permitted sender) smtp.mailfrom=keescook@chromium.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1668725902; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=gB4fu8WxG++brcac1xEx09Jo8IsSv6jaRuNq5hahL+I=; b=Rbyk+VALiTRKCgS1Xr//2w0ozQZXkgYf6nKvg1ZDmQ/BYv2aYGFk7ZPQU7nYkTyJTnr8Kp +Q/+KCI++aniJgmiXi51lTEBRJbTVYtYCad4e+XIZum0JkTAEqyhvJUu4w1YBxixH78k/c 7pRxkdpMbFhfADMQFZJmgQXd3WZMmxo= Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=chromium.org header.s=google header.b=Fy4BdUGW; dmarc=pass (policy=none) header.from=chromium.org; spf=pass (imf02.hostedemail.com: domain of keescook@chromium.org designates 209.85.210.172 as permitted sender) smtp.mailfrom=keescook@chromium.org X-Rspam-User: X-Stat-Signature: 6s1mtmbpxxox89eirbxhofr743445co9 X-Rspamd-Queue-Id: 1FADA80010 X-Rspamd-Server: rspam11 X-HE-Tag: 1668725901-988165 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: On Wed, Nov 16, 2022 at 10:16:34AM -0800, Linus Torvalds wrote: > There _are_ also small random cases too, like get_cmdline(). Maybe > that counts as ptrace, but the execve() case most definitely does not. Oh, er, why does get_arg_page() even need FOLL_FORCE? This is writing the new stack contents to the nascent brpm->vma, which was newly allocated with VM_STACK_FLAGS, which an arch can override, but they all appear to include VM_WRITE | VM_MAYWRITE. -- Kees Cook