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[94.254.104.176]) by smtp.gmail.com with ESMTPSA id 38308e7fff4ca-389a78d2326sm29347181fa.15.2026.02.25.03.06.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Feb 2026 03:06:10 -0800 (PST) From: Magnus Lindholm To: richard.henderson@linaro.org, mattst88@gmail.com, linux-kernel@vger.kernel.org, linux-alpha@vger.kernel.org, skhan@linuxfoundation.org, chenmiao.ku@gmail.com, shorne@gmail.com, corbet@lwn.net Cc: glaubitz@physik.fu-berlin.de, macro@orcam.me.uk, macro@redhat.com, mcree@orcon.net.nz, ink@unseen.parts, Magnus Lindholm Subject: [PATCH v2 0/1] alpha: Add support for HAVE_ARCH_JUMP_LABEL Date: Wed, 25 Feb 2026 12:02:45 +0100 Message-ID: <20260225110548.31431-1-linmag7@gmail.com> X-Mailer: git-send-email 2.52.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This patch adds jump label (static key) support for Alpha. Testing and verification were performed on an UP2000+ system. Verification steps: - Confirmed __jump_table section is present at runtime via /proc/kallsyms and contains a non-zero number of entries. - Instrumented arch_jump_label_transform() to log patch operations and verified instruction sites toggle between: NOP (bis $31,$31,$31, 0x47ff041f) BR (br $31,target) - Added temporary instrumentation in arch_jump_label_transform() to log old/new instruction values at each patch site, and used a Python script to validate correct NOP/BR transitions and branch encoding, confirming functional runtime patching. Instruction stream synchronization uses imb()/smp_imb() via flush_icache_range(), and runtime behavior confirms correct I-cache coherency. The system remained stable throughout all testing. --- Changes since v1: - Update features documentation for features/core/jump-labels link: https://lore.kernel.org/linux-alpha/20260219170013.15884-1-linmag7@gmail.com/T/#t Magnus Lindholm (1): alpha: Add support for HAVE_ARCH_JUMP_LABEL .../core/jump-labels/arch-support.txt | 2 +- arch/alpha/Kconfig | 1 + arch/alpha/include/asm/jump_label.h | 66 +++++++++++++++ arch/alpha/kernel/Makefile | 1 + arch/alpha/kernel/jump_label.c | 81 +++++++++++++++++++ 5 files changed, 150 insertions(+), 1 deletion(-) create mode 100644 arch/alpha/include/asm/jump_label.h create mode 100644 arch/alpha/kernel/jump_label.c -- 2.52.0