On Wed, Jan 24, 2024 at 07:09:20PM +0100, Uladzislau Rezki (Sony) wrote:
> This patch tends to simplify the function in question,
> by removing an extra stack "objp" variable, returning
> back to an early exit approach if spin_trylock() fails
> or VA was not found.
>
> Signed-off-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx>
> ---
> mm/vmalloc.c | 33 +++++++++++++++++----------------
> 1 file changed, 17 insertions(+), 16 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index b8be601b056d..449f45b0e474 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -4696,34 +4696,35 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
> #ifdef CONFIG_PRINTK
> bool vmalloc_dump_obj(void *object)
> {
> - void *objp = (void *)PAGE_ALIGN((unsigned long)object);
> const void *caller;
> + struct vm_struct *vm;
> struct vmap_area *va;
> struct vmap_node *vn;
> unsigned long addr;
> unsigned int nr_pages;
> - bool success = false;
> -
> - vn = addr_to_node((unsigned long)objp);
>
> - if (spin_trylock(&vn->busy.lock)) {
> - va = __find_vmap_area((unsigned long)objp, &vn->busy.root);
> + addr = PAGE_ALIGN((unsigned long) object);
> + vn = addr_to_node(addr);
>
> - if (va && va->vm) {
> - addr = (unsigned long)va->vm->addr;
> - caller = va->vm->caller;
> - nr_pages = va->vm->nr_pages;
> - success = true;
> - }
> + if (!spin_trylock(&vn->busy.lock))
> + return false;
>
> + va = __find_vmap_area(addr, &vn->busy.root);
> + if (!va || !va->vm) {
> spin_unlock(&vn->busy.lock);
> + return false;
> }
>
> - if (success)
> - pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
> - nr_pages, addr, caller);
> + vm = va->vm;
> + addr = (unsigned long) vm->addr;
Hmm not so nice to reuse addr here for something different, might be nice
to have separate obj_addr and vm_addr or something. But it's not critical!
> + caller = vm->caller;
> + nr_pages = vm->nr_pages;
> + spin_unlock(&vn->busy.lock);
>
> - return success;
> + pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
> + nr_pages, addr, caller);
> +
> + return true;
> }
> #endif
>
> --
> 2.39.2
>
Other than the nit, which I don't insist on, this is a big improvement so,
Reviewed-by: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
