[PATCH v3 0/5] x86/cpu: Refactor identify_cpu()
From: Ihor Solodrai
Date: Wed Sep 16 2026 - 15:57:54 EST
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 <bp@xxxxxxxxx>
Signed-off-by: Ihor Solodrai <ihor.solodrai@xxxxxxxxx>
[1] https://lore.kernel.org/bpf/20260610175651.647515-1-ihor.solodrai@xxxxxxxxx/
---
v2->v3:
* Commit message edits on patches #1, #2, #5
v2: https://lore.kernel.org/bpf/20260814235134.3461435-1-ihor.solodrai@xxxxxxxxx/
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/
---
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