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From: Roberto Sassu <roberto.sassu@huaweicloud.com>
To: richard@nod.at,
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	Roberto Sassu <roberto.sassu@huawei.com>
Subject: [PATCH v2] x86: um: vdso: Disable UBSAN instrumentation
Date: Mon, 13 May 2024 15:10:24 +0200
Message-Id: <20240513131024.1309073-1-roberto.sassu@huaweicloud.com>
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From: Roberto Sassu <roberto.sassu@huawei.com>

The UBSAN instrumentation cannot work in the vDSO since it is executing in
userspace, so disable it in the Makefile. Fixes the build failures such as:

  CALL    scripts/checksyscalls.sh
  VDSO    arch/x86/um/vdso/vdso.so.dbg
arch/x86/um/vdso/vdso.so.dbg: undefined symbols found

Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
---
 arch/x86/um/vdso/Makefile | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/x86/um/vdso/Makefile b/arch/x86/um/vdso/Makefile
index b86d634730b2..ca79c0de582e 100644
--- a/arch/x86/um/vdso/Makefile
+++ b/arch/x86/um/vdso/Makefile
@@ -3,8 +3,10 @@
 # Building vDSO images for x86.
 #
 
-# do not instrument on vdso because KASAN is not compatible with user mode
+# do not instrument on vdso because KASAN/UBSAN are not compatible with user
+# mode
 KASAN_SANITIZE			:= n
+UBSAN_SANITIZE			:= n
 
 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
 KCOV_INSTRUMENT                := n
-- 
2.34.1