Re: [PATCH 2/6] ARM: move vmalloc() lazy-page table population

[Sebastian Andrzej Siewior <bigeasy@linutronix.de>]

On 2026-02-27 15:19:13 [+0000], Russell King (Oracle) wrote:
> Split the vmalloc() lazy-page table population from
> do_translation_fault() into a new vmalloc_fault() function.
> 
> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>

> --- a/arch/arm/mm/fault.c
> +++ b/arch/arm/mm/fault.c
> @@ -261,6 +261,70 @@ static inline bool ttbr0_usermode_access_allowed(struct pt_regs *regs)
>  }
>  #endif
>  
> +/*
> + * Handle a vmalloc fault, copying the non-leaf page table entries from
> + * init_mm.pgd. Any kernel context can trigger this, so we must not sleep
> + * or enable interrupts. Having two CPUs execute this for the same page is

"unconditionally enable interrupts."? It wouldn't be wrong to enable
them if the calling context had them enabled, right?

> + * no problem, we'll just copy the same data twice.
> + *
> + * Returns false on failure.
> + */
> +static bool __kprobes __maybe_unused vmalloc_fault(unsigned long addr)

Maybe handle_vmalloc_fault().

> +{

Sebastian