From: Michal Hocko <mhocko@kernel.org>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Kees Cook <keescook@chromium.org>, Ingo Molnar <mingo@elte.hu>,
"H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Nicholas Piggin <npiggin@gmail.com>
Subject: Re: [PATCH] x86/mm: Fix ELF_ET_DYN_BASE for 5-level paging
Date: Thu, 9 Nov 2017 16:38:51 +0100 [thread overview]
Message-ID: <20171109153851.xvgmfnbkoxj64jm6@dhcp22.suse.cz> (raw)
In-Reply-To: <20171107103804.47341-1-kirill.shutemov@linux.intel.com>
On Tue 07-11-17 13:38:04, Kirill A. Shutemov wrote:
> On machines with 5-level paging we don't want to allocate mapping above
> 47-bit unless user explicitly asked for it. See b569bab78d8d ("x86/mm:
> Prepare to expose larger address space to userspace") for details.
>
> c715b72c1ba4 ("mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base
> changes") broke the behaviour. After the commit elf binary and heap got
> mapped above 47-bits.
>
> Let's fix this.
>
> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
> Fixes: c715b72c1ba4 ("mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base changes")
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Nicholas Piggin <npiggin@gmail.com>
FWIW
Acked-by: Michal Hocko <mhocko@suse.com>
> ---
> arch/x86/include/asm/elf.h | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/x86/include/asm/elf.h b/arch/x86/include/asm/elf.h
> index c1a125e47ff3..3a091cea36c5 100644
> --- a/arch/x86/include/asm/elf.h
> +++ b/arch/x86/include/asm/elf.h
> @@ -253,7 +253,7 @@ extern int force_personality32;
> * space open for things that want to use the area for 32-bit pointers.
> */
> #define ELF_ET_DYN_BASE (mmap_is_ia32() ? 0x000400000UL : \
> - (TASK_SIZE / 3 * 2))
> + (DEFAULT_MAP_WINDOW / 3 * 2))
>
> /* This yields a mask that user programs can use to figure out what
> instruction set this CPU supports. This could be done in user space,
> --
> 2.14.2
--
Michal Hocko
SUSE Labs
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2017-11-09 15:38 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-07 10:38 [PATCH] x86/mm: Fix ELF_ET_DYN_BASE for 5-level paging Kirill A. Shutemov
2017-11-09 10:38 ` Kirill A. Shutemov
2017-11-09 15:38 ` Michal Hocko [this message]
2017-11-09 17:12 ` Thomas Gleixner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20171109153851.xvgmfnbkoxj64jm6@dhcp22.suse.cz \
--to=mhocko@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=hpa@zytor.com \
--cc=keescook@chromium.org \
--cc=kirill.shutemov@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mingo@elte.hu \
--cc=mingo@redhat.com \
--cc=npiggin@gmail.com \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).