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Peter Anvin" , Andrey Konovalov , linux-kernel@vger.kernel.org, x86@kernel.org, bpf@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, kernel-team@meta.com Subject: [PATCH v3 0/5] x86/cpu: Refactor identify_cpu() Date: Wed, 16 Sep 2026 12:51:58 -0700 Message-ID: <20260916195203.1099646-1-ihor.solodrai@linux.dev> X-Mailer: git-send-email 2.55.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 429EF40007 X-Stat-Signature: cfefppweykoxhgqm5x8abhypqr8zozds X-HE-Tag: 1789588339-495154 X-HE-Meta: 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 I+Y5XVIk SpHEH/a3X/1qS+tpncQzcwHtKC1SdLYpfIIuT3nJkopa/p2SdzopzphhMQbziamFxUpAKpXquzEsj8BQjOq4bDqZx3bLair+D6Pz0sv3HKaR3jsrF3fY+hveSE3gWDXk1g8jWeNF7J372w3Z7LK7IBUwtJ3ofO/QXQZSffGoSYzMsngRy0CTRPWM0U8ZZTtcFbd8k/9MdzTBn0gSfmmxeV3HZG9P+OgRsH36vrWJD4Ly3EvbSlXhP4/m1XHpLDO1J3SX8sa01YGeVVGnkqZgOi0nG8caID88TBSVpLrPNKi8KDbaLpUCA3tkwSxpfWxaP7q3xMsVkpYkrU9FBk7VCjlfJmvpD0bwOuCajzYJ2JYHOa1duk4Fxd/ZsKw== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Refactor identify_cpu() machinery on x86 and then implement a fix for a bug when cpu capabilities are temporarily cleared within an interruptable window. For more details and discussion see the relevant bug report [1] and patch #5 ("x86/cpu: Don't transiently clear the boot CPU's capabilities"). Suggested-by: Borislav Petkov Signed-off-by: Ihor Solodrai [1] https://lore.kernel.org/bpf/20260610175651.647515-1-ihor.solodrai@linux.dev/ --- v2->v3: * Commit message edits on patches #1, #2, #5 v2: https://lore.kernel.org/bpf/20260814235134.3461435-1-ihor.solodrai@linux.dev/ v1->v2: * Rewrite commit messages to fit more conventional structure (Boris) * Drop identify_cpu_32() helper, it's unnecessary (Boris) * New patch (#2): now early_identify_cpu() resets boot_cpu_data through init_cpu_info() as well * The boot CPU reset is now skipped on 32-bit too (sashiko) v1: https://lore.kernel.org/bpf/20260704002046.3859585-1-ihor.solodrai@linux.dev/ --- Ihor Solodrai (5): x86/cpu: Factor init_cpu_info() out of identify_cpu() x86/cpu: Initialize boot CPU cpuinfo defaults early x86/cpu: Inline generic_identify() into identify_cpu() x86/cpu: Move 32-bit SEP setup into identify_cpu() x86/cpu: Don't transiently clear the boot CPU's capabilities arch/x86/kernel/cpu/common.c | 92 +++++++++++++++++------------------- 1 file changed, 44 insertions(+), 48 deletions(-) base-commit: fd73f4a6659897191fa0d40695fe370925dd3780 -- 2.55.0