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[209.85.218.42]) by smtp.gmail.com with ESMTPSA id s20-20020a50d494000000b0054cc2e952f0sm5290453edi.81.2023.12.12.16.39.48 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 12 Dec 2023 16:39:48 -0800 (PST) Received: by mail-ej1-f42.google.com with SMTP id a640c23a62f3a-a1f0616a15bso710709866b.2 for ; Tue, 12 Dec 2023 16:39:48 -0800 (PST) X-Received: by 2002:a17:906:d8cd:b0:a19:a19b:78bb with SMTP id re13-20020a170906d8cd00b00a19a19b78bbmr3094683ejb.126.1702427988541; Tue, 12 Dec 2023 16:39:48 -0800 (PST) MIME-Version: 1.0 References: <20231212231706.2680890-1-jeffxu@chromium.org> <20231212231706.2680890-12-jeffxu@chromium.org> In-Reply-To: <20231212231706.2680890-12-jeffxu@chromium.org> From: Linus Torvalds Date: Tue, 12 Dec 2023 16:39:31 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [RFC PATCH v3 11/11] mseal:add documentation To: jeffxu@chromium.org Cc: akpm@linux-foundation.org, keescook@chromium.org, jannh@google.com, sroettger@google.com, willy@infradead.org, gregkh@linuxfoundation.org, jeffxu@google.com, jorgelo@chromium.org, groeck@chromium.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, pedro.falcato@gmail.com, dave.hansen@intel.com, linux-hardening@vger.kernel.org, deraadt@openbsd.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 57C6180008 X-Rspam-User: X-Stat-Signature: sdqh71nit1uxg7j8tqphcfc1ui886uyf X-Rspamd-Server: rspam03 X-HE-Tag: 1702427992-451262 X-HE-Meta: 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 UgLw1wyH 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000002, 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 Tue, 12 Dec 2023 at 15:17, wrote: > + > +**types**: bit mask to specify the sealing types, they are: I really want a real-life use-case for more than one bit of "don't modify". IOW, when would you *ever* say "seal this area, but MADV_DONTNEED is ok"? Or when would you *ever* say "seal this area, but mprotect()" is ok. IOW, I want to know why we don't just do the BSD immutable thing, and why we need this multi-level sealing thing. Linus