From f285da05c62a429f1978c5520cf069d483a7d9af Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Mon, 29 Aug 2022 16:49:19 +0100 Subject: [PATCH] arm64/ptrace: Document extension of NT_ARM_TLS to cover TPIDR2_EL0 In order to allow debuggers to discover lazily saved SME state we need to provide access to TPIDR2_EL0, we will extend the existing NT_ARM_TLS used for TPIDR to also include TPIDR2_EL0 as the second register in the regset. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20220829154921.837871-3-broonie@kernel.org Signed-off-by: Catalin Marinas --- Documentation/arm64/sme.rst | 3 +++ 1 file changed, 3 insertions(+) diff --git a/Documentation/arm64/sme.rst b/Documentation/arm64/sme.rst index 937147f..16d2db4 100644 --- a/Documentation/arm64/sme.rst +++ b/Documentation/arm64/sme.rst @@ -331,6 +331,9 @@ The regset data starts with struct user_za_header, containing: been read if a PTRACE_GETREGSET of NT_ARM_ZA were executed for each thread when the coredump was generated. +* The NT_ARM_TLS note will be extended to two registers, the second register + will contain TPIDR2_EL0 on systems that support SME and will be read as + zero with writes ignored otherwise. 9. System runtime configuration -------------------------------- -- 2.7.4