[PATCH 3/14] uml: physical memory shouldn't include initial stack

[PATCH 3/14] uml: physical memory shouldn't include initial stack

[Jeff Dike]

>From 57c582f7eb25314e650f143c2c5141a0cc4172eb Mon Sep 17 00:00:00 2001

The top of physical memory should be below the initial process stack, not the
top of the address space, at least for as long as the stack isn't known to the
kernel VM system and appropriately reserved.

Cc: "Christopher S. Aker" <caker@theshore.net>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/um/kernel/um_arch.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index a6c1dd1..9cecb42 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -259,6 +259,7 @@ int __init linux_main(int argc, char **argv)
 	unsigned long avail, diff;
 	unsigned long virtmem_size, max_physmem;
 	unsigned int i, add;
+	unsigned long stack;
 	char * mode;
 
 	for (i = 1; i < argc; i++) {
@@ -347,7 +348,9 @@ int __init linux_main(int argc, char **argv)
 	}
 
 	virtmem_size = physmem_size;
-	avail = TASK_SIZE - start_vm;
+	stack = (unsigned long) argv;
+	stack &= ~(1024 * 1024 - 1);
+	avail = stack - start_vm;
 	if (physmem_size > avail)
 		virtmem_size = avail;
 	end_vm = start_vm + virtmem_size;
-- 
1.5.5.1

[PATCH 3/14] uml: physical memory shouldn't include initial stack

[Jeff Dike]

>From 60a2988aea701a6424809a5432bf068667aac177

The top of physical memory should be below the initial process stack, not the
top of the address space, at least for as long as the stack isn't known to the
kernel VM system and appropriately reserved.

Cc: "Christopher S. Aker" <caker@theshore.net>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
 arch/um/kernel/um_arch.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/arch/um/kernel/um_arch.c b/arch/um/kernel/um_arch.c
index a6c1dd1..9cecb42 100644
--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -259,6 +259,7 @@ int __init linux_main(int argc, char **argv)
 	unsigned long avail, diff;
 	unsigned long virtmem_size, max_physmem;
 	unsigned int i, add;
+	unsigned long stack;
 	char * mode;
 
 	for (i = 1; i < argc; i++) {
@@ -347,7 +348,9 @@ int __init linux_main(int argc, char **argv)
 	}
 
 	virtmem_size = physmem_size;
-	avail = TASK_SIZE - start_vm;
+	stack = (unsigned long) argv;
+	stack &= ~(1024 * 1024 - 1);
+	avail = stack - start_vm;
 	if (physmem_size > avail)
 		virtmem_size = avail;
 	end_vm = start_vm + virtmem_size;
-- 
1.5.5.1

patch uml-physical-memory-shouldn-t-include-initial-stack.patch added to 2.6.25-stable tree

[gregkh]

This is a note to let you know that we have just queued up the patch titled

    Subject: uml: physical memory shouldn't include initial stack

to the 2.6.25-stable tree.  Its filename is

    uml-physical-memory-shouldn-t-include-initial-stack.patch

A git repo of this tree can be found at 
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary


>From stable-bounces@linux.kernel.org Tue Aug  5 13:14:54 2008
From: Jeff Dike <jdike@addtoit.com>
Date: Tue, 5 Aug 2008 16:14:04 -0400
Subject: uml: physical memory shouldn't include initial stack
To: stable@kernel.org
Cc: LKML <linux-kernel@vger.kernel.org>, uml-devel <user-mode-linux-devel@lists.sourceforge.net>
Message-ID: <20080805201404.GA11782@c2.user-mode-linux.org>
Content-Disposition: inline

From: Jeff Dike <jdike@addtoit.com>

commit 60a2988aea701a6424809a5432bf068667aac177 upstream

The top of physical memory should be below the initial process stack, not the
top of the address space, at least for as long as the stack isn't known to the
kernel VM system and appropriately reserved.

Cc: "Christopher S. Aker" <caker@theshore.net>
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 arch/um/kernel/um_arch.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/arch/um/kernel/um_arch.c
+++ b/arch/um/kernel/um_arch.c
@@ -259,6 +259,7 @@ int __init linux_main(int argc, char **a
 	unsigned long avail, diff;
 	unsigned long virtmem_size, max_physmem;
 	unsigned int i, add;
+	unsigned long stack;
 	char * mode;
 
 	for (i = 1; i < argc; i++) {
@@ -347,7 +348,9 @@ int __init linux_main(int argc, char **a
 	}
 
 	virtmem_size = physmem_size;
-	avail = TASK_SIZE - start_vm;
+	stack = (unsigned long) argv;
+	stack &= ~(1024 * 1024 - 1);
+	avail = stack - start_vm;
 	if (physmem_size > avail)
 		virtmem_size = avail;
 	end_vm = start_vm + virtmem_size;


Patches currently in stable-queue which might be from jdike@addtoit.com are

queue-2.6.25/uml-fix-build-when-slob-is-enabled.patch
queue-2.6.25/uml-fix-bad-ntp-interaction-with-clock.patch
queue-2.6.25/uml-physical-memory-shouldn-t-include-initial-stack.patch
queue-2.6.25/uml-track-and-make-up-lost-ticks.patch
queue-2.6.25/uml-missed-kmalloc-in-pcap_user.c.patch
queue-2.6.25/uml-deal-with-host-time-going-backwards.patch
queue-2.6.25/uml-deal-with-inaccessible-address-space-start.patch
queue-2.6.25/uml-missing-export-of-csum_partial-on-uml-amd64.patch
queue-2.6.25/uml-memcpy-export-needs-to-follow-host-declaration.patch
queue-2.6.25/uml-stub-needs-to-tolerate-sigwinch.patch
queue-2.6.25/uml-work-around-broken-host-ptrace_sysemu.patch
queue-2.6.25/uml-fix-gcc-ices-and-unresolved-externs.patch
queue-2.6.25/uml-fix-boot-crash.patch