From: "Hou Wenlong" <houwenlong.hwl@antgroup.com>
To: linux-kernel@vger.kernel.org
Cc: "Hou Wenlong" <houwenlong.hwl@antgroup.com>,
"Juergen Gross" <jgross@suse.com>,
"Boris Ostrovsky" <boris.ostrovsky@oracle.com>,
"Darren Hart" <dvhart@infradead.org>,
"Andy Shevchenko" <andy@infradead.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
"maintainer:X86 ARCHITECTURE 32-BIT AND 64-BIT" <x86@kernel.org>,
"H. Peter Anvin" <hpa@zytor.com>,
"moderated list:XEN HYPERVISOR X86"
<xen-devel@lists.xenproject.org>,
"open list:X86 PLATFORM DRIVERS - ARCH"
<platform-driver-x86@vger.kernel.org>
Subject: [PATCH 1/2] x86/xen/pvh: Set up percpu for stack canary in 32-bit kernel entry
Date: Mon, 23 Oct 2023 17:09:38 +0800 [thread overview]
Message-ID: <90df6cf5674241a85ac7dfe0a1558f1fd025cc17.1698051454.git.houwenlong.hwl@antgroup.com> (raw)
In-Reply-To: <cover.1698051454.git.houwenlong.hwl@antgroup.com>
In a 32-bit SMP kernel, the stack canary is a percpu variable accessed
as %fs:__stack_chk_guard. However, the ABI for PVH entry does not
specify the %fs register state. It currently works because the initial
%fs register is 0x10 for QEMU, which is the same as $PVH_DS_SEL.
%However, for added safety, the percpu should be set up explicitly
%before calling xen_prepare_pvh(), which accesses the stack canary.
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
---
arch/x86/platform/pvh/head.S | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/x86/platform/pvh/head.S b/arch/x86/platform/pvh/head.S
index c4365a05ab83..cee4dadf5344 100644
--- a/arch/x86/platform/pvh/head.S
+++ b/arch/x86/platform/pvh/head.S
@@ -121,6 +121,10 @@ SYM_CODE_START_LOCAL(pvh_start_xen)
ljmp $PVH_CS_SEL, $1f
1:
+ /* Set percpu for stack canary. */
+ mov $PVH_DS_SEL,%eax
+ mov %eax, %fs
+
call xen_prepare_pvh
mov $_pa(pvh_bootparams), %esi
--
2.31.1
next prev parent reply other threads:[~2023-10-23 9:10 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-23 9:09 [PATCH 0/2] x86/xen/pvh: Clean up stack canary setup in PVH entry Hou Wenlong
2023-10-23 9:09 ` Hou Wenlong [this message]
2023-10-23 12:02 ` [PATCH 1/2] x86/xen/pvh: Set up percpu for stack canary in 32-bit kernel entry Andy Shevchenko
2023-10-24 2:33 ` Hou Wenlong
2023-10-23 9:09 ` [PATCH 2/2] x86/xen/pvh: Use fixed_percpu_data to set up GS base Hou Wenlong
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=90df6cf5674241a85ac7dfe0a1558f1fd025cc17.1698051454.git.houwenlong.hwl@antgroup.com \
--to=houwenlong.hwl@antgroup.com \
--cc=andy@infradead.org \
--cc=boris.ostrovsky@oracle.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=dvhart@infradead.org \
--cc=hpa@zytor.com \
--cc=jgross@suse.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=platform-driver-x86@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=x86@kernel.org \
--cc=xen-devel@lists.xenproject.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.