[RESEND v2 0/2] arm64: spectre: Fix hard lockup and cleanup mitigation messages

shechenglong shechenglong at xfusion.com
Tue Oct 28 20:45:52 PDT 2025


On Wed, Sep 24, 2025 at 08:32:47PM +0800, shechenglong wrote:
> relocate the printk() calls from spectre_v4_mitigations_off() and
> spectre_v2_mitigations_off() into setup_system_capabilities() 
> function, preventing hard lockups that occur when printk() is invoked from scheduler context.
> 
> Link: 
> https://patchwork.kernel.org/project/linux-arm-kernel/patch/2025091806
> 4907.1832-1-shechenglong at xfusion.com/
> Suggested-by: Mark Rutland <mark.rutland at arm.com>
> Suggested-by: Catalin Marinas <catalin.marinas at arm.com>
> Signed-off-by: shechenglong <shechenglong at xfusion.com>

Thanks for the review and suggestions, Will!

This v2 series addresses your comments:
- Fixed the message to use "command-line" consistently
- Created spectre_print_disabled_mitigations() function to handle all spectre mitigation messages
- Added a separate patch to remove the CONFIG_MITIGATE_SPECTRE_BHB option

The series includes two patches:

Patch 1: "fix hard lockup triggered by printk calls within scheduling context"
- Moves printk calls from scheduler context to setup_system_capabilities()
- Prevents hard lockups by avoiding printk in unsafe contexts
- Consolidates spectre mitigation status reporting

Patch 2: "Remove the print when the CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY Kconfig option is disabled"
- Removes the obsolete CONFIG_MITIGATE_SPECTRE_BHB Kconfig option
- Cleans up the spectre mitigation code as suggested

shechenglong (2):
  arm64: spectre: fix hard lockup triggered by printk calls within scheduling context
  arm64: spectre: Remove the print when the CONFIG_MITIGATE_SPECTRE_BRANCH_HISTORY Kconfig option is disabled

 arch/arm64/include/asm/spectre.h |  2 ++
 arch/arm64/kernel/cpufeature.c   |  7 ++++++-
 arch/arm64/kernel/proton-pack.c  | 28 ++++++++++++++--------------
 3 files changed, 22 insertions(+), 17 deletions(-)

-- 
2.25.1


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