linux-kernel - Re: [PATCH 26/26] x86/mm: allow to have userspace mappings above 47-bits

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: <8760j4sfcz.fsf@skywalker.in.ibm.com>
Date:   Mon, 20 Mar 2017 10:40:20 +0530
From:   "Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
To:     "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        Andrew Morton <akpm@...ux-foundation.org>, x86@...nel.org,
        Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Arnd Bergmann <arnd@...db.de>,
        "H. Peter Anvin" <hpa@...or.com>
Cc:     Andi Kleen <ak@...ux.intel.com>,
        Dave Hansen <dave.hansen@...el.com>,
        Andy Lutomirski <luto@...capital.net>,
        Michal Hocko <mhocko@...e.com>, linux-arch@...r.kernel.org,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: Re: [PATCH 26/26] x86/mm: allow to have userspace mappings above 47-bits

"Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com> writes:
 @@ -168,6 +182,10 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
>  	unsigned long addr = addr0;
>  	struct vm_unmapped_area_info info;
>  
> +	addr = mpx_unmapped_area_check(addr, len, flags);
> +	if (IS_ERR_VALUE(addr))
> +		return addr;
> +
>  	/* requested length too big for entire address space */
>  	if (len > TASK_SIZE)
>  		return -ENOMEM;
> @@ -192,6 +210,14 @@ arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
>  	info.length = len;
>  	info.low_limit = PAGE_SIZE;
>  	info.high_limit = mm->mmap_base;
> +
> +	/*
> +	 * If hint address is above DEFAULT_MAP_WINDOW, look for unmapped area
> +	 * in the full address space.
> +	 */
> +	if (addr > DEFAULT_MAP_WINDOW)
> +		info.high_limit += TASK_SIZE - DEFAULT_MAP_WINDOW;
> +

Is this ok for 32 bit application ?


>  	info.align_mask = 0;
>  	info.align_offset = pgoff << PAGE_SHIFT;
>  	if (filp) {


-aneesh