From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ramana.Radhakrishnan@arm.com (Ramana Radhakrishnan) Date: Fri, 2 Nov 2018 09:46:47 +0000 Subject: [PATCH v5 11/17] arm64: docs: document pointer authentication In-Reply-To: References: <20181005084754.20950-1-kristina.martsenko@arm.com> <20181005084754.20950-12-kristina.martsenko@arm.com> Message-ID: <7f9c1bc4-2e82-e930-7d00-c26791ab9eef@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org >> + >> +When CONFIG_ARM64_PTR_AUTH is selected, and relevant HW support is >> +present, the kernel will assign a random APIAKey value to each process >> +at exec*() time. This key is shared by all threads within the process, >> +and the key is preserved across fork(). Presence of functionality using >> +APIAKey is advertised via HWCAP_APIA. > > It might be useful to include documentation here on how many bits of > the address are being used for the PAC bits (I'm assuming it's 7?) the number of bits available depends on the VA size, so you can't really document a number. Ramana > > -Kees >