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From: Andy Lutomirski <luto@amacapital.net>
To: x86@kernel.org, Andrew Morton <akpm@linux-foundation.org>,
	Sasha Levin <sasha.levin@oracle.com>,
	"linux-mm@kvack.org" <linux-mm@kvack.org>,
	Dave Jones <davej@redhat.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
	Cyrill Gorcunov <gorcunov@gmail.com>,
	Pavel Emelyanov <xemul@parallels.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Stefani Seibold <stefani@seibold.net>
Subject: [PATCH 1/4] x86,vdso: Fix an OOPS accessing the hpet mapping w/o an hpet
Date: Mon, 19 May 2014 15:58:31 -0700
Message-ID: <c8b0a9a0b8d011a8b273cbb2de88d37190ed2751.1400538962.git.luto@amacapital.net> (raw)
In-Reply-To: <cover.1400538962.git.luto@amacapital.net>
In-Reply-To: <cover.1400538962.git.luto@amacapital.net>

The oops can be triggered in qemu using -no-hpet (but not nohpet) by
reading a couple of pages past the end of the vdso text.  This
should send SIGBUS instead of OOPSing.

The bug was introduced by:

commit 7a59ed415f5b57469e22e41fc4188d5399e0b194
Author: Stefani Seibold <stefani@seibold.net>
Date:   Mon Mar 17 23:22:09 2014 +0100

    x86, vdso: Add 32 bit VDSO time support for 32 bit kernel

which is new in 3.15.

This will be fixed separately in 3.15, but that patch will not apply
to tip/x86/vdso.  This is the equivalent fix for tip/x86/vdso and,
presumably, 3.16.

Cc: Stefani Seibold <stefani@seibold.net>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
---
 arch/x86/vdso/vma.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/vdso/vma.c b/arch/x86/vdso/vma.c
index e915eae..8ad0081 100644
--- a/arch/x86/vdso/vma.c
+++ b/arch/x86/vdso/vma.c
@@ -90,6 +90,7 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
 	struct vm_area_struct *vma;
 	unsigned long addr;
 	int ret = 0;
+	static struct page *no_pages[] = {NULL};
 
 	if (calculate_addr) {
 		addr = vdso_addr(current->mm->start_stack,
@@ -125,7 +126,7 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
 				       addr + image->size,
 				       image->sym_end_mapping - image->size,
 				       VM_READ,
-				       NULL);
+				       no_pages);
 
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
-- 
1.9.0

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Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-19 22:58 [PATCH 0/4] x86,mm: vdso fixes for an OOPS and /proc/PID/maps Andy Lutomirski
2014-05-19 22:58 ` Andy Lutomirski [this message]
2014-05-19 22:58 ` [PATCH 2/4] mm,fs: Add vm_ops->name as an alternative to arch_vma_name Andy Lutomirski
2014-05-19 22:58 ` [PATCH 3/4] x86,mm: Improve _install_special_mapping and fix x86 vdso naming Andy Lutomirski
2014-05-20 17:21   ` Cyrill Gorcunov
2014-05-20 17:24     ` Andy Lutomirski
2014-05-20 17:47       ` Cyrill Gorcunov
2014-05-20 17:52         ` Andy Lutomirski
2014-05-20 18:01           ` Cyrill Gorcunov
2014-05-20 18:18             ` H. Peter Anvin
2014-05-20 18:24               ` Andy Lutomirski
2014-05-20 18:27                 ` H. Peter Anvin
2014-05-20 18:38                   ` Andy Lutomirski
2014-05-20 18:39                 ` Cyrill Gorcunov
2014-05-20 18:37   ` H. Peter Anvin
2014-05-19 22:58 ` [PATCH 4/4] x86,mm: Replace arch_vma_name with vm_ops->name for vsyscalls Andy Lutomirski

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