From: Alexey Dobriyan <adobriyan@gmail.com>
To: jgross@suse.com, boris.ostrovsky@oracle.com, tglx@linutronix.de,
mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com
Cc: adobriyan@gmail.com, linux-kernel@vger.kernel.org,
x86@kernel.org, hpa@zytor.com
Subject: [PATCH 1/3] xen, pvh: fix unbootable VMs (PVH + KASAN - AMD_MEM_ENCRYPT)
Date: Fri, 2 Aug 2024 18:42:51 +0300 [thread overview]
Message-ID: <20240802154253.482658-1-adobriyan@gmail.com> (raw)
Uninstrument arch/x86/platform/pvh/enlighten.c: KASAN has not been setup
_this_ early in the boot process.
Steps to reproduce:
make allnoconfig
make sure CONFIG_AMD_MEM_ENCRYPT is disabled
AMD_MEM_ENCRYPT independently uninstruments lib/string.o
so PVH boot code calls into uninstrumented memset() and
memcmp() which can make the bug disappear depending on
the compiler.
enable CONFIG_PVH
enable CONFIG_KASAN
enable serial console
this is fun exercise if you never done it from nothing :^)
make
qemu-system-x86_64 \
-enable-kvm \
-cpu host \
-smp cpus=1 \
-m 4096 \
-serial stdio \
-kernel vmlinux \
-append 'console=ttyS0 ignore_loglevel'
Messages on serial console will easily tell OK kernel from unbootable
kernel. In bad case qemu hangs in an infinite loop stroboscoping
"SeaBIOS" message.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Juergen Gross <jgross@suse.com>
---
arch/x86/platform/pvh/Makefile | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/x86/platform/pvh/Makefile b/arch/x86/platform/pvh/Makefile
index 5dec5067c9fb..c43fb7964dc4 100644
--- a/arch/x86/platform/pvh/Makefile
+++ b/arch/x86/platform/pvh/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
OBJECT_FILES_NON_STANDARD_head.o := y
+KASAN_SANITIZE := n
obj-$(CONFIG_PVH) += enlighten.o
obj-$(CONFIG_PVH) += head.o
--
2.45.0
next reply other threads:[~2024-08-02 15:43 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-08-02 15:42 Alexey Dobriyan [this message]
2024-08-02 15:42 ` [PATCH 2/3] x86/cpu: fix unbootable VMs by inlining memcmp() in hypervisor_cpuid_base() Alexey Dobriyan
2024-08-15 13:32 ` Jürgen Groß
2024-08-02 15:42 ` [PATCH 3/3] xen, pvh: fix unbootable VMs by inlining memset() in xen_prepare_pvh() Alexey Dobriyan
2024-08-15 13:33 ` Jürgen Groß
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=20240802154253.482658-1-adobriyan@gmail.com \
--to=adobriyan@gmail.com \
--cc=boris.ostrovsky@oracle.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=jgross@suse.com \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=tglx@linutronix.de \
--cc=x86@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