From: tip-bot for Kees Cook <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: dvlasenk@redhat.com, yinghai@kernel.org,
akpm@linux-foundation.org, tglx@linutronix.de,
peterz@infradead.org, bp@suse.de, keescook@chromium.org,
torvalds@linux-foundation.org, dyoung@redhat.com,
vgoyal@redhat.com, bp@alien8.de, hpa@zytor.com, luto@kernel.org,
mingo@kernel.org, bhe@redhat.com, luto@amacapital.net,
brgerst@gmail.com, linux-kernel@vger.kernel.org
Subject: [tip:x86/boot] x86/KASLR: Clarify purpose of each get_random_long()
Date: Tue, 10 May 2016 01:42:48 -0700 [thread overview]
Message-ID: <tip-d2d3462f9f08da364c8fbd41e8e32229d610d49d@git.kernel.org> (raw)
In-Reply-To: <1462825332-10505-7-git-send-email-keescook@chromium.org>
Commit-ID: d2d3462f9f08da364c8fbd41e8e32229d610d49d
Gitweb: http://git.kernel.org/tip/d2d3462f9f08da364c8fbd41e8e32229d610d49d
Author: Kees Cook <keescook@chromium.org>
AuthorDate: Mon, 9 May 2016 13:22:09 -0700
Committer: Ingo Molnar <mingo@kernel.org>
CommitDate: Tue, 10 May 2016 10:12:08 +0200
x86/KASLR: Clarify purpose of each get_random_long()
KASLR will be calling get_random_long() twice, but the debug output
won't distinguishing between them. This patch adds a report on when it
is fetching the physical vs virtual address. With this, once the virtual
offset is separate, the report changes from:
KASLR using RDTSC...
KASLR using RDTSC...
into:
Physical KASLR using RDTSC...
Virtual KASLR using RDTSC...
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bp@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: kernel-hardening@lists.openwall.com
Cc: lasse.collin@tukaani.org
Link: http://lkml.kernel.org/r/1462825332-10505-7-git-send-email-keescook@chromium.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
---
arch/x86/boot/compressed/kaslr.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
index 016a4f4..cfeb025 100644
--- a/arch/x86/boot/compressed/kaslr.c
+++ b/arch/x86/boot/compressed/kaslr.c
@@ -72,7 +72,7 @@ static unsigned long get_random_boot(void)
return hash;
}
-static unsigned long get_random_long(void)
+static unsigned long get_random_long(const char *purpose)
{
#ifdef CONFIG_X86_64
const unsigned long mix_const = 0x5d6008cbf3848dd3UL;
@@ -82,7 +82,8 @@ static unsigned long get_random_long(void)
unsigned long raw, random = get_random_boot();
bool use_i8254 = true;
- debug_putstr("KASLR using");
+ debug_putstr(purpose);
+ debug_putstr(" KASLR using");
if (has_cpuflag(X86_FEATURE_RDRAND)) {
debug_putstr(" RDRAND");
@@ -365,7 +366,7 @@ static unsigned long slots_fetch_random(void)
if (slot_max == 0)
return 0;
- return slots[get_random_long() % slot_max];
+ return slots[get_random_long("Physical") % slot_max];
}
static void process_e820_entry(struct e820entry *entry,
@@ -453,7 +454,7 @@ static unsigned long find_random_virt_addr(unsigned long minimum,
slots = (KERNEL_IMAGE_SIZE - minimum - image_size) /
CONFIG_PHYSICAL_ALIGN + 1;
- random_addr = get_random_long() % slots;
+ random_addr = get_random_long("Virtual") % slots;
return random_addr * CONFIG_PHYSICAL_ALIGN + minimum;
}
next prev parent reply other threads:[~2016-05-10 8:43 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-09 20:22 [PATCH v7 0/9] x86/KASLR: Randomize virtual address separately Kees Cook
2016-05-09 20:22 ` [PATCH v7 1/9] x86/KASLR: Initialize mapping_info every time Kees Cook
2016-05-09 22:01 ` Yinghai Lu
2016-05-09 22:23 ` Yinghai Lu
2016-05-09 22:27 ` Yinghai Lu
2016-05-09 22:23 ` Kees Cook
2016-05-09 22:28 ` Yinghai Lu
2016-05-10 5:58 ` Ingo Molnar
2016-05-10 11:21 ` Borislav Petkov
2016-05-10 8:40 ` [tip:x86/boot] " tip-bot for Kees Cook
2016-05-09 20:22 ` [PATCH v7 2/9] x86/boot: Add missing file header comments Kees Cook
2016-05-10 8:41 ` [tip:x86/boot] " tip-bot for Kees Cook
2016-05-09 20:22 ` [PATCH v7 3/9] x86/KASLR: Add slot_area to manage random_addr slots Kees Cook
2016-05-10 8:41 ` [tip:x86/boot] x86/KASLR: Add 'struct slot_area' " tip-bot for Baoquan He
2016-05-09 20:22 ` [PATCH v7 4/9] x86/KASLR: Return earliest overlap when avoiding regions Kees Cook
2016-05-10 8:42 ` [tip:x86/boot] " tip-bot for Kees Cook
2016-05-09 20:22 ` [PATCH v7 5/9] x86/KASLR: Add virtual address choosing function Kees Cook
2016-05-10 8:42 ` [tip:x86/boot] " tip-bot for Baoquan He
2016-05-09 20:22 ` [PATCH v7 6/9] x86/KASLR: Clarify purpose of each get_random_long() Kees Cook
2016-05-10 8:42 ` tip-bot for Kees Cook [this message]
2016-05-09 20:22 ` [PATCH v7 7/9] x86/KASLR: Randomize virtual address separately Kees Cook
2016-05-09 20:22 ` [PATCH v7 8/9] x86/KASLR: Add physical address randomization >4G Kees Cook
2016-05-09 20:22 ` [PATCH v7 9/9] x86/KASLR: Allow randomization below load address Kees Cook
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=tip-d2d3462f9f08da364c8fbd41e8e32229d610d49d@git.kernel.org \
--to=tipbot@zytor.com \
--cc=akpm@linux-foundation.org \
--cc=bhe@redhat.com \
--cc=bp@alien8.de \
--cc=bp@suse.de \
--cc=brgerst@gmail.com \
--cc=dvlasenk@redhat.com \
--cc=dyoung@redhat.com \
--cc=hpa@zytor.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-tip-commits@vger.kernel.org \
--cc=luto@amacapital.net \
--cc=luto@kernel.org \
--cc=mingo@kernel.org \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=vgoyal@redhat.com \
--cc=yinghai@kernel.org \
/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).