On Fri, May 03, 2024 at 02:01:33PM +0100, Joey Gouly wrote:
> @@ -529,6 +547,8 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
> unsigned int mm_flags = FAULT_FLAG_DEFAULT;
> unsigned long addr = untagged_addr(far);
> struct vm_area_struct *vma;
> + bool pkey_fault = false;
> + int pkey = -1;
>
> if (kprobe_page_fault(regs, esr))
> return 0;
> @@ -590,6 +610,12 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
> vma_end_read(vma);
> goto lock_mmap;
> }
> +
> + if (fault_from_pkey(esr, vma, mm_flags)) {
> + vma_end_read(vma);
> + goto lock_mmap;
> + }
> +
> fault = handle_mm_fault(vma, addr, mm_flags | FAULT_FLAG_VMA_LOCK, regs);
> if (!(fault & (VM_FAULT_RETRY | VM_FAULT_COMPLETED)))
> vma_end_read(vma);
> @@ -617,6 +643,11 @@ static int __kprobes do_page_fault(unsigned long far, unsigned long esr,
> goto done;
> }
>
> + if (fault_from_pkey(esr, vma, mm_flags)) {
> + pkey_fault = true;
> + pkey = vma_pkey(vma);
> + }
I was wondering if we actually need to test this again. We know the
fault was from a pkey already above but I guess it matches what we do
with the vma->vm_flags check in case it races with some mprotect() call.
> +
> fault = __do_page_fault(mm, vma, addr, mm_flags, vm_flags, regs);
You'll need to rebase this on 6.10-rcX since this function disappeared.
Otherwise the patch looks fine.
Reviewed-by: Catalin Marinas <catalin.marinas@xxxxxxx>
