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-rw-r--r--Documentation/arch/arm64/sve.rst10
1 files changed, 2 insertions, 8 deletions
diff --git a/Documentation/arch/arm64/sve.rst b/Documentation/arch/arm64/sve.rst
index 0d9a426e9f..8d8837fc39 100644
--- a/Documentation/arch/arm64/sve.rst
+++ b/Documentation/arch/arm64/sve.rst
@@ -117,11 +117,6 @@ the SVE instruction set architecture.
* The SVE registers are not used to pass arguments to or receive results from
any syscall.
-* In practice the affected registers/bits will be preserved or will be replaced
- with zeros on return from a syscall, but userspace should not make
- assumptions about this. The kernel behaviour may vary on a case-by-case
- basis.
-
* All other SVE state of a thread, including the currently configured vector
length, the state of the PR_SVE_VL_INHERIT flag, and the deferred vector
length (if any), is preserved across all syscalls, subject to the specific
@@ -428,9 +423,8 @@ The regset data starts with struct user_sve_header, containing:
/proc/sys/abi/sve_default_vector_length
Writing the text representation of an integer to this file sets the system
- default vector length to the specified value, unless the value is greater
- than the maximum vector length supported by the system in which case the
- default vector length is set to that maximum.
+ default vector length to the specified value rounded to a supported value
+ using the same rules as for setting vector length via PR_SVE_SET_VL.
The result can be determined by reopening the file and reading its
contents.