Re: [PATCH] fs/proc/task_mmu: fix missed VMAs when reading /proc/PID/maps and friends

[Lorenzo Stoakes (ARM)]

On Mon, Oct 26, 2026 at 01:35:23PM +0000, Lorenzo Stoakes (ARM) wrote:
> /* Returns true if mmap write unlocked. */
> static bool reset_walk_if_mmap_lock_dropped(struct vma_iterator *vmi,
> 		struct mm_struct *mm, unsigned long from_addr,
> 		unsigned int *last_seq)
> {
> 	if (vma_tree_maybe_changed(mm, *last_seq)) {
> 		/* Reset walk and re-speculate. */
> 		vma_iter_set(vmi, from_addr);
> 		return mmap_lock_speculate_try_begin(mm, last_seq);
> 	}
>
> 	return true;
> }

Actually, nicer as:

/* Returns true if mmap write unlocked. */
static bool reset_walk_if_mmap_lock_dropped(struct vma_iterator *vmi,
		struct mm_struct *mm, unsigned long from_addr,
		unsigned int *last_seq)
{
	if (!vma_tree_maybe_changed(mm, *last_seq))
		return true;

	/* Reset walk and re-speculate. */
	vma_iter_set(vmi, from_addr);
	return mmap_lock_speculate_try_begin(mm, last_seq);
}

--
Cheers, Lorenzo