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R. Silva" , Nathan Chancellor , Nick Desaulniers , Justin Stitt , Miguel Ojeda , Heiko Carstens , Marc Herbert , Uros Bizjak , Tejun Heo , Jeff Xu , Michal =?iso-8859-1?Q?Koutn=FD?= , Shakeel Butt , Thomas =?iso-8859-1?Q?Wei=DFschuh?= , John Stultz , Christian Brauner , Randy Dunlap , Brian Gerst , Masahiro Yamada , Mike Rapoport , linux-mm@kvack.org, linux-hardening@vger.kernel.org, llvm@lists.linux.dev Subject: Re: [PATCH 2/2] memblock: annotate struct memblock_type with __counted_by_ptr Message-ID: <20260116084259.GK830755@noisy.programming.kicks-ass.net> References: <20251121193957.1655580-1-morbo@google.com> <20251121193957.1655580-3-morbo@google.com> <202511211525.05CB7E1AEC@keescook> <20251122141614.80f1a845cd694b1b470107ca@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251122141614.80f1a845cd694b1b470107ca@linux-foundation.org> X-Stat-Signature: uqhh3q3jbdx3a3owbnaw1bua7xdqc3zj X-Rspam-User: X-Rspamd-Queue-Id: 06E9840009 X-Rspamd-Server: rspam08 X-HE-Tag: 1768552983-187375 X-HE-Meta: U2FsdGVkX192T9q+2kFpbCICyh7Mn3Ygjed9eenXJSqqsPh3gzhrAqGyy0F6z1rOBLTwa20SSZeqMnzFMVO2y/yB8FCqEcGslhtBJ9MRepQ0eeLExbEJEwmkIJ+RWpq7XomWNXfYoWPUCC2r9XIMIBuGLMkveIhodGiEPtpqbwiSGKedvjoImIEoyo3cpnY2V2BcXOb1RXQmhSCNXWnwawYvLPB9Iy9tLlL3+wfBto2Gl/lOpX1CJnazUz0Kpp3FDBaG14gKysVhcgcuppskE0QWCV89MZdJ4hX3QbVX9mSXuVPpWpvVXAbVIjuS/Q66S8Oo2NLTAUNM3qmyYhxwoDSWmuo/I+XMum6Ye80X4oe6yzc942RFW4gGy0fBlJogo4jp8S8y0q/vRCy/MP0ylyRq1EzJf3Qv533WCKPUrIDMzs8WTjZZFf3+YaBgp23kcEslv+Zz4sm2XyeXArR/YhZJaReiiL4ZIZs0VVYGHZ3QREH8wDS2COSzDMN7r8k20jcoakUNXpHNjAAS2SmeIumUUJ/5kgMq6U97XsxGhKRzYFDBEqAumvIt4REsdYqEOQlAq5HOo5AlrG3ZJv+NQeHs2RFtso+hk78xP6mZLzMliw3cXeBVW4iyLmvH1vkrdkJfIsSjrSo0XFf4x025XA2CNgxGgJ9v4uLkZNbirWflKyAOPSsMdD4/QLsDmRd9esPVaMyBhxAyqpxa/2DkATD8VorS0RHNzuR/LLl/esf66wIDlPjHMUeDXWcP2SXnezc5OfMMNfLgMNW3fc7xJZj5fm62lURoVJlZr+2N0FmjYxC2/O/3IIvQJ5kDDTLVYCa6CgXRRWFGK8ck8kBl5qfVMeMdIxeNIeEye+3D8Hhhq6m7FLG2aD02nNjZMYwDxdi9Z+s2qUv7rPoh2GJ3jsPlBSUkgmpvk7f2mD0UCZk1dVCoFaqC5p7EFDUYqbsjBnjEj7O3SBwOBI9dSBy 2/jS35/b xkktmuYGGJONkFt6JxmQHC2bpdJKiXeWERFIjPa4omMtrbALHMQYnhEH2GvX6SL24cSLTfuhBf+WTqmpWQFirWzio08a21T0BGjDdhFLNyKd7GsR2uClyTxs+4yxg8w3c6nVeyS731bpYGy4iaifWzuWcNWdgSdyt3LkTXGZo88HKYD74zjDDI+4l3llNZMEQwuiNrrmhY7KeoS/kCOGrO1bD+DYtVt6Oh6yKay5PxAJjMQEoRe5sIty/APab5Zw3vAuRF0+ICSkapxop4AWPR0QCaIZJoFVl6/rjUZAL2W2XpOczpdDkrGNC2OZQeHqoN9BcmL03ZHvNTPXXuPwQCYBt6dMKa67YBbu1VGT2AcU4IdJxLL5E6c/+rNtXduSkuQdr2gNN9t93rghuB+8Rioz8QNOV6ingkSnchi0FwMVFhlaif4tWtmUFYATMk/FRfsfy1jtHwsSMGE5P50WE9/5OGQ== 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 Sat, Nov 22, 2025 at 02:16:14PM -0800, Andrew Morton wrote: > On Fri, 21 Nov 2025 16:30:43 -0800 Kees Cook wrote: > > > On Fri, Nov 21, 2025 at 07:39:44PM +0000, Bill Wendling wrote: > > > Add the '__counted_by_ptr' attribute to the 'regions' field of 'struct > > > memblock_type'. The 'regions' field is an array of 'struct > > > memblock_region' and its size is tracked by the 'max' field, which > > > represents the total number of allocated regions. > > > > As part of any counted_by annotation patch, there needs to be discussion > > in the commit log about how it's been shown to be a safe annotation > > to make. e.g. in this case, if all allocations of "regions" have a > > corresponding "max" assignment, etc. If just "git grep" can't find them > > all, using something like Coccinelle or CodeQL to search for struct > > memblock_type::regions assignments can work. > > How is anyone to know these things? I can't find anything about this > in include/ or Documentation/ or in the relevant commits. > > There should be a comment at the __counted_by() definition site, please. > > And possibly write a Documentation/ file then change checkpatch to > direct people to that file if they add a counted_by? There is: https://clang.llvm.org/docs/BoundsSafety.html