linux-kernel - Re: [PATCH 2/5] uprobes: Change __copy_insn() to use copy_from

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: <20130325103105.GC8163@bandura.brq.redhat.com>
Date:	Mon, 25 Mar 2013 11:31:05 +0100
From:	Anton Arapov <anton@...hat.com>
To:	Oleg Nesterov <oleg@...hat.com>
Cc:	Srikar Dronamraju <srikar@...ux.vnet.ibm.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Josh Stone <jistone@...hat.com>,
	Frank Eigler <fche@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...e.hu>,
	Ananth N Mavinakayanahalli <ananth@...ibm.com>,
	adrian.m.negreanu@...el.com, Torsten.Polle@....de
Subject: Re: [PATCH 2/5] uprobes: Change __copy_insn() to use copy_from_page()

On Sun, Mar 24, 2013 at 07:21:15PM +0100, Oleg Nesterov wrote:
> Change __copy_insn() to use copy_from_page() and simplify the code.
> 
> Signed-off-by: Oleg Nesterov <oleg@...hat.com>
> ---
>  kernel/events/uprobes.c |   13 ++-----------
>  1 files changed, 2 insertions(+), 11 deletions(-)
> 
> diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
> index d6891cb..0a759c6 100644
> --- a/kernel/events/uprobes.c
> +++ b/kernel/events/uprobes.c
> @@ -477,30 +477,21 @@ __copy_insn(struct address_space *mapping, struct file *filp, char *insn,
>  			unsigned long nbytes, loff_t offset)
>  {
>  	struct page *page;
> -	void *vaddr;
> -	unsigned long off;
> -	pgoff_t idx;
>  
>  	if (!filp)
>  		return -EINVAL;
>  
>  	if (!mapping->a_ops->readpage)
>  		return -EIO;
> -
> -	idx = offset >> PAGE_CACHE_SHIFT;
> -	off = offset & ~PAGE_MASK;
> -
>  	/*
>  	 * Ensure that the page that has the original instruction is
>  	 * populated and in page-cache.
>  	 */
> -	page = read_mapping_page(mapping, idx, filp);
> +	page = read_mapping_page(mapping, offset >> PAGE_CACHE_SHIFT, filp);
>  	if (IS_ERR(page))
>  		return PTR_ERR(page);
>  
> -	vaddr = kmap_atomic(page);
> -	memcpy(insn, vaddr + off, nbytes);
> -	kunmap_atomic(vaddr);
> +	copy_from_page(page, offset, insn, nbytes);
>  	page_cache_release(page);
>  
>  	return 0;
> -- 
> 1.5.5.1
> 
Acked-by: Anton Arapov <anton@...hat.com>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/