1 files changed, 6 insertions, 8 deletions

diff --git a/Documentation/arch/arm64/sve.rst b/Documentation/arch/arm64/sve.rst
index 0d9a426e9f85..28152492c29c 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
@@ -407,6 +402,10 @@ The regset data starts with struct user_sve_header, containing:
   streaming mode and any SETREGSET of NT_ARM_SSVE will enter streaming mode
   if the target was not in streaming mode.
 
+* If any register data is provided along with SVE_PT_VL_ONEXEC then the
+  registers data will be interpreted with the current vector length, not
+  the vector length configured for use on exec.
+
 * The effect of writing a partial, incomplete payload is unspecified.
 
 
@@ -428,9 +427,8 @@ 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.