[PATCH v2 0/5] x86/cpu: Refactor identify_cpu()

From: Ihor Solodrai

Date: Fri Aug 14 2026 - 19:56:05 EST


This series refactors identify_cpu() machinery on x86 and then
implements 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.

Suggested-by: Borislav Petkov <bp@xxxxxxxxx>
Signed-off-by: Ihor Solodrai <ihor.solodrai@xxxxxxxxx>

[1] https://lore.kernel.org/bpf/20260610175651.647515-1-ihor.solodrai@xxxxxxxxx/

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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@xxxxxxxxx/

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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: db2ddb87143519e20a95aa36c60b36107b736a58
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2.55.0