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charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <7f392b4e-9970-42d4-8204-2aa967a5375d@sirena.org.uk> X-Rspam-User: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 328EA1402A4 X-Stat-Signature: pi6xmftt5xc17qpp7dafnc3t7n8qh784 X-HE-Tag: 1731627018-410274 X-HE-Meta: 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 zIFOxAwM QtDS2CZkNIgXAFZo0Scqn43j+hBgGj6ufH/lVaNusuA/5vuhPEW4bv6o9cLtBlGdHfXmnskEWOgS6gI0Yke4KzA3Pg5I2ypDzkpQIYDf47GxHQ+69u1zAisAtDqzgmVqnHXSmUq5Qq3fjp/dn98KBpYgHkmJHf4lXOPWeY/m1zemCmULmaMrGWNU+Jm5oKqv7+IaWCeViz6V8hFbJyklJ6oZDcPcscFPWtPLfF0HOXoPIb1okofyVaej2owT13WFjBNXYlIRI0vJFNXxpQhbp8xH4QBTlTqSAKFMSB/r+zqcPWL7+odEE9CiOCx3XOgvmvx2zvXLx77k/Ay+Xcejsb8eeDqLjE287lmPlWXk9fPj2NPEEa3o/bTBTIvxuBIrLSd+mtjZsV8lMdHbVrzrRZfxXbA== 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 Fri, Nov 01, 2024 at 10:39:15PM +0000, Mark Brown wrote: >On Fri, Nov 01, 2024 at 09:50:27PM +0000, Edgecombe, Rick P wrote: >> On Wed, 2024-10-16 at 14:57 -0700, Deepak Gupta wrote: > >> > - * The maximum distance INCSSP can move the SSP is 2040 bytes, before >> > - * it would read the memory. Therefore a single page gap will be enough >> > - * to prevent any operation from shifting the SSP to an adjacent stack, >> > - * since it would have to land in the gap at least once, causing a >> > - * fault. > >> I want to take a deeper look at this series once I can apply and test it, but >> can we maybe make this comment more generic and keep it? I think it is similar >> reasoning for arm (?), is there anything situation like this for risc-v? Or >> rather, why does risc-v have the guard gaps? > >Yes, for arm64 you can only move the pointer in single frames so a >single page is enough. Yeah on risc-v as well guard gap is expected and single page is enough. I removed this comment from here because of x86 specifics. I can make it generic, do you think it belongs here or the place where we define VM_SHADOW_STACK?