Commit 260cf5c5 authored Nov 28, 2023 by Mark Brown Committed by yanhaitao Nov 29, 2023

arm64/sve: Minor clarification of ABI documentation

mainline inclusion
from mainline-v5.17-rc1
commit aed34d9e
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I8E73O
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=aed34d9e52b80b4e7485119272c77c5553a21499



-------------------------------------------------

As suggested by Luis for the SME version of this explicitly say that the
vector length should be extracted from the return value of a set vector
length prctl() with a bitwise and rather than just any old and.

Suggested-by: Luis Machado <Luis.Machado@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20211210184133.320748-4-broonie@kernel.org


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Wang ShaoBo <bobo.shaobowang@huawei.com>

parent cc36b4a8

Documentation/arm64/sve.rst

+1 −1

Original line number	Diff line number	Diff line
		@@ -255,7 +255,7 @@ prctl(PR_SVE_GET_VL)
		vector length change (which would only normally be the case between a
		fork() or vfork() and the corresponding execve() in typical use).

		To extract the vector length from the result, and it with
		To extract the vector length from the result, bitwise and it with
		PR_SVE_VL_LEN_MASK.

		Return value: a nonnegative value on success, or a negative value on error: