linux kernel - Disabling all interrupts to protect CPU register state on multi processor systems -

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i need ensure in code portion (in kernel mode) no 1 else can modify/check cr0 register. on one-processor system think disabling interrupts best. on multi-processor systems :

  • is there way disable interrupts processors during code section (with spinlock mechanism example)?

  • is necessary? when modifying cr0 register on multi-processor system, guess register modified current cpu? --> disabling interrupts current cpu sufficient? --> there way check/modify other cpus (on same system) register cpu?

many in forward answers (and sorry approximative english)

jérôme.

jérôme,

have looked using spin_lock_irqsave() , spin_unlock_irqrestore()? disables local interrupts.

i believe more all-encompassing version spin_lock_irq() , spin_unlock_irq() stops interrupts unconditionally (like cli()/sti()).

there many conditions take account when using these locking mechanisms. 1 of primary examples losing ability call kernel functions may sleep while inside spin_lock. may need bit of research before can determine best in particular case. brief explanation provided seems 1 of 2 schemes above should work you.

good luck!


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