linux-kernel - Re: [PATCH 1/9] mm: vmalloc: Add va

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]

Message-ID: <96a75e2d-3108-4f9d-a90f-ad636f0401f1@lucifer.local>
Date:   Sat, 27 May 2023 20:55:43 +0100
From:   Lorenzo Stoakes <lstoakes@...il.com>
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>,
        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 1/9] mm: vmalloc: Add va_alloc() helper

On Mon, May 22, 2023 at 01:08:41PM +0200, Uladzislau Rezki (Sony) wrote:
> Currently __alloc_vmap_area() function contains an open codded
> logic that finds and adjusts a VA based on allocation request.
>
> Introduce a va_alloc() helper that adjusts found VA only. It
> will be used later at least in two places.
>
> There is no a functional change as a result of this patch.
>
> Signed-off-by: Uladzislau Rezki (Sony) <urezki@...il.com>
> ---
>  mm/vmalloc.c | 41 ++++++++++++++++++++++++++++-------------
>  1 file changed, 28 insertions(+), 13 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 31ff782d368b..409285b68a67 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -1482,6 +1482,32 @@ adjust_va_to_fit_type(struct rb_root *root, struct list_head *head,
>  	return 0;
>  }
>
> +static unsigned long
> +va_alloc(struct vmap_area *va,
> +	struct rb_root *root, struct list_head *head,
> +	unsigned long size, unsigned long align,
> +	unsigned long vstart, unsigned long vend)
> +{
> +	unsigned long nva_start_addr;
> +	int ret;
> +
> +	if (va->va_start > vstart)
> +		nva_start_addr = ALIGN(va->va_start, align);
> +	else
> +		nva_start_addr = ALIGN(vstart, align);
> +
> +	/* Check the "vend" restriction. */
> +	if (nva_start_addr + size > vend)
> +		return vend;
> +
> +	/* Update the free vmap_area. */
> +	ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
> +	if (WARN_ON_ONCE(ret))
> +		return vend;
> +
> +	return nva_start_addr;
> +}
> +
>  /*
>   * Returns a start address of the newly allocated area, if success.
>   * Otherwise a vend is returned that indicates failure.
> @@ -1494,7 +1520,6 @@ __alloc_vmap_area(struct rb_root *root, struct list_head *head,
>  	bool adjust_search_size = true;
>  	unsigned long nva_start_addr;
>  	struct vmap_area *va;
> -	int ret;
>
>  	/*
>  	 * Do not adjust when:
> @@ -1512,18 +1537,8 @@ __alloc_vmap_area(struct rb_root *root, struct list_head *head,
>  	if (unlikely(!va))
>  		return vend;
>
> -	if (va->va_start > vstart)
> -		nva_start_addr = ALIGN(va->va_start, align);
> -	else
> -		nva_start_addr = ALIGN(vstart, align);
> -
> -	/* Check the "vend" restriction. */
> -	if (nva_start_addr + size > vend)
> -		return vend;
> -
> -	/* Update the free vmap_area. */
> -	ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
> -	if (WARN_ON_ONCE(ret))
> +	nva_start_addr = va_alloc(va, root, head, size, align, vstart, vend);
> +	if (nva_start_addr == vend)
>  		return vend;
>
>  #if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
> --
> 2.30.2
>

LGTM,

Reviewed-by: Lorenzo Stoakes <lstoakes@...il.com>