linux-kernel - Re: [PATCH 5/9] mm: vmalloc: Insert busy-VA per-cpu zone

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 22 May 2023 23:12:08 -0700
From:   Christoph Hellwig <hch@...radead.org>
To:     "Uladzislau Rezki (Sony)" <urezki@...il.com>
Cc:     linux-mm@...ck.org, Andrew Morton <akpm@...ux-foundation.org>,
        LKML <linux-kernel@...r.kernel.org>, Baoquan He <bhe@...hat.com>,
        Lorenzo Stoakes <lstoakes@...il.com>,
        Christoph Hellwig <hch@...radead.org>,
        Matthew Wilcox <willy@...radead.org>,
        "Liam R . Howlett" <Liam.Howlett@...cle.com>,
        Dave Chinner <david@...morbit.com>,
        "Paul E . McKenney" <paulmck@...nel.org>,
        Joel Fernandes <joel@...lfernandes.org>,
        Oleksiy Avramchenko <oleksiy.avramchenko@...y.com>
Subject: Re: [PATCH 5/9] mm: vmalloc: Insert busy-VA per-cpu zone

>  /* Look up the first VA which satisfies addr < va_end, NULL if none. */
> -static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr)
> +static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr, struct rb_root *root)

Please avoid the overly long line.

> +	struct cpu_vmap_zone *z = addr_to_cvz(va->va_start);
> +
>  	/*
>  	 * Remove from the busy tree/list.
>  	 */
> -	spin_lock(&vmap_area_lock);
> -	unlink_va(va, &vmap_area_root);
> -	spin_unlock(&vmap_area_lock);
> +	fbl_lock(z, BUSY);
> +	unlink_va(va, &fbl_root(z, BUSY));
> +	fbl_unlock(z, BUSY);

I find the BUSY magic here very confusing, and would prefer to
just spell the actual lock reference out.