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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 3/3] xen, pvh: fix unbootable VMs by inlining memset() in xen_prepare_pvh()
Date: Fri,  2 Aug 2024 18:42:53 +0300	[thread overview]
Message-ID: <20240802154253.482658-3-adobriyan@gmail.com> (raw)
In-Reply-To: <20240802154253.482658-1-adobriyan@gmail.com>

If this memset() is not inlined than PVH early boot code can call
into KASAN-instrumented memset() which results in unbootable VMs.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
---
 arch/x86/platform/pvh/enlighten.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/x86/platform/pvh/enlighten.c b/arch/x86/platform/pvh/enlighten.c
index 944e0290f2c0..2263885d16ba 100644
--- a/arch/x86/platform/pvh/enlighten.c
+++ b/arch/x86/platform/pvh/enlighten.c
@@ -130,7 +130,11 @@ void __init xen_prepare_pvh(void)
 		BUG();
 	}
 
-	memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
+	/*
+	 * This must not compile to "call memset" because memset() may be
+	 * instrumented.
+	 */
+	__builtin_memset(&pvh_bootparams, 0, sizeof(pvh_bootparams));
 
 	hypervisor_specific_init(xen_guest);
 
-- 
2.45.0


  parent 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 [PATCH 1/3] xen, pvh: fix unbootable VMs (PVH + KASAN - AMD_MEM_ENCRYPT) Alexey Dobriyan
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 ` Alexey Dobriyan [this message]
2024-08-15 13:33   ` [PATCH 3/3] xen, pvh: fix unbootable VMs by inlining memset() in xen_prepare_pvh() Jürgen Groß

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