Re: [PATCH 3/5] arm64/sme: Support disabling streaming mode via ptrace on SME only systems
From: Randy Dunlap <hidden>
Date: 2025-08-20 18:39:20
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linux-doc, linux-kselftest, lkml
On 8/20/25 11:29 AM, Mark Brown wrote:
quoted hunk ↗ jump to hunk
diff --git a/Documentation/arch/arm64/sve.rst b/Documentation/arch/arm64/sve.rst index 28152492c29c..a61c9d0efe4d 100644 --- a/Documentation/arch/arm64/sve.rst +++ b/Documentation/arch/arm64/sve.rst@@ -402,6 +402,11 @@ 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. +* On systems that do not support SVE it is permitted to use SETREGSET to + write SVE_PT_REGS_FPSIMD formatted data via NT_ARM_SVE, in this case the
s/,/;/
or
NT_ARM_SVE. In this case
+ vector length should be specified as 0. This allows streaming mode to be + disabled on systems with SME but not SVE. + * 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.
-- ~Randy