From: Tim Abbott <tabbott@MIT.EDU>
To: Sam Ravnborg <sam@ravnborg.org>
Cc: Linux kernel mailing list <linux-kernel@vger.kernel.org>,
Anders Kaseorg <andersk@MIT.EDU>, Waseem Daher <wdaher@MIT.EDU>,
Denys Vlasenko <vda.linux@googlemail.com>,
Jeff Arnold <jbarnold@MIT.EDU>, Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Anders Kaseorg <andersk@MIT.EDU>
Subject: [PATCH 09/11] x86: fix fragile computation of vsyscall address
Date: Thu, 30 Apr 2009 20:01:36 -0400 [thread overview]
Message-ID: <1241136098-10376-10-git-send-email-tabbott@mit.edu> (raw)
In-Reply-To: <1241136098-10376-9-git-send-email-tabbott@mit.edu>
From: Anders Kaseorg <andersk@mit.edu>
Previously, the address of the vsyscall page (VSYSCALL_PHYS_ADDR,
VSYSCALL_VIRT_ADDR) was computed by arithmetic on the address of the
last section. This leads to bugs when new sections are inserted, such
as the one fixed by commit d312ceda567ab91acd756cde95ac5fbc6b40ed40.
Let's compute it from the current address instead.
Signed-off-by: Anders Kaseorg <andersk@mit.edu>
---
arch/x86/kernel/vmlinux.lds.S | 19 +++++++------------
1 files changed, 7 insertions(+), 12 deletions(-)
diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S
index 6b8a633..296b49c 100644
--- a/arch/x86/kernel/vmlinux.lds.S
+++ b/arch/x86/kernel/vmlinux.lds.S
@@ -137,24 +137,21 @@ SECTIONS
#ifdef CONFIG_X86_64
#define VSYSCALL_ADDR (-10*1024*1024)
-#define VSYSCALL_PHYS_ADDR ((LOADADDR(.data.read_mostly) + \
- SIZEOF(.data.read_mostly) + 4095) & ~(4095))
-#define VSYSCALL_VIRT_ADDR ((ADDR(.data.read_mostly) + \
- SIZEOF(.data.read_mostly) + 4095) & ~(4095))
-#define VLOAD_OFFSET (VSYSCALL_ADDR - VSYSCALL_PHYS_ADDR)
+#define VLOAD_OFFSET (VSYSCALL_ADDR - __vsyscall_0 + LOAD_OFFSET)
#define VLOAD(x) (ADDR(x) - VLOAD_OFFSET)
-#define VVIRT_OFFSET (VSYSCALL_ADDR - VSYSCALL_VIRT_ADDR)
+#define VVIRT_OFFSET (VSYSCALL_ADDR - __vsyscall_0)
#define VVIRT(x) (ADDR(x) - VVIRT_OFFSET)
+ . = ALIGN(4096);
+ __vsyscall_0 = .;
+
. = VSYSCALL_ADDR;
- .vsyscall_0 : AT(VSYSCALL_PHYS_ADDR) {
+ .vsyscall_0 : AT(VLOAD(.vsyscall_0)) {
*(.vsyscall_0)
} :user
- __vsyscall_0 = VSYSCALL_VIRT_ADDR;
-
. = ALIGN(CONFIG_X86_L1_CACHE_BYTES);
.vsyscall_fn : AT(VLOAD(.vsyscall_fn)) {
*(.vsyscall_fn)
@@ -194,11 +191,9 @@ SECTIONS
*(.vsyscall_3)
}
- . = VSYSCALL_VIRT_ADDR + PAGE_SIZE;
+ . = __vsyscall_0 + PAGE_SIZE;
#undef VSYSCALL_ADDR
-#undef VSYSCALL_PHYS_ADDR
-#undef VSYSCALL_VIRT_ADDR
#undef VLOAD_OFFSET
#undef VLOAD
#undef VVIRT_OFFSET
--
1.6.2.1
next prev parent reply other threads:[~2009-05-01 0:32 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-05-01 0:01 [PATCH 00/11] section name cleanup for x86 Tim Abbott
2009-05-01 0:01 ` [PATCH 01/11] x86: Use macros for .bss.page_aligned section Tim Abbott
2009-05-01 0:01 ` [PATCH 02/11] x86: Use section .data.page_aligned for the idt_table Tim Abbott
2009-05-01 0:01 ` [PATCH 03/11] x86: Use macros for .data.page_aligned Tim Abbott
2009-05-01 0:01 ` [PATCH 04/11] x86: convert compressed loader to use __HEAD and HEAD_TEXT macros Tim Abbott
2009-05-01 0:01 ` [PATCH 05/11] x86: convert " Tim Abbott
2009-05-01 0:01 ` [PATCH 06/11] x86: use NOSAVE_DATA macro for .data.nosave section Tim Abbott
2009-05-01 0:01 ` [PATCH 07/11] x86: use new macro for .data.cacheline_aligned section Tim Abbott
2009-05-01 0:01 ` [PATCH 08/11] x86: use new macros for .data.init_task Tim Abbott
2009-05-01 0:01 ` Tim Abbott [this message]
2009-05-01 0:01 ` [PATCH 10/11] x86: use new macro for .data.read_mostly section Tim Abbott
2009-05-01 0:01 ` [PATCH 11/11] x86: convert to new generic read_mostly support Tim Abbott
2009-05-06 16:19 ` [PATCH 03/11] x86: Use macros for .data.page_aligned H. Peter Anvin
2009-05-01 11:58 ` [PATCH 00/11] section name cleanup for x86 Ingo Molnar
2009-05-01 12:07 ` Sam Ravnborg
2009-05-01 15:34 ` Ingo Molnar
2009-05-01 16:31 ` H. Peter Anvin
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=1241136098-10376-10-git-send-email-tabbott@mit.edu \
--to=tabbott@mit.edu \
--cc=andersk@MIT.EDU \
--cc=hpa@zytor.com \
--cc=jbarnold@MIT.EDU \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=sam@ravnborg.org \
--cc=tglx@linutronix.de \
--cc=vda.linux@googlemail.com \
--cc=wdaher@MIT.EDU \
/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
all inboxes | Powered by JetHome®