From 7cf2e7373ab145bf972c3cbcb495fd1a9770c3b0 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 13 Dec 2022 00:16:48 +0000 Subject: [PATCH] KVM: selftests: Explicitly disable builtins for mem*() overrides Explicitly disable the compiler's builtin memcmp(), memcpy(), and memset(). Because only lib/string_override.c is built with -ffreestanding, the compiler reserves the right to do what it wants and can try to link the non-freestanding code to its own crud. /usr/bin/x86_64-linux-gnu-ld: /lib/x86_64-linux-gnu/libc.a(memcmp.o): in function `memcmp_ifunc': (.text+0x0): multiple definition of `memcmp'; tools/testing/selftests/kvm/lib/string_override.o: tools/testing/selftests/kvm/lib/string_override.c:15: first defined here clang: error: linker command failed with exit code 1 (use -v to see invocation) Fixes: 6b6f71484bf4 ("KVM: selftests: Implement memcmp(), memcpy(), and memset() for guest use") Reported-by: Aaron Lewis Reported-by: Raghavendra Rao Ananta Signed-off-by: Sean Christopherson Message-Id: <20221213001653.3852042-10-seanjc@google.com> Signed-off-by: Paolo Bonzini --- tools/testing/selftests/kvm/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 2ffd87247279..ecd3c8126c3d 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -189,6 +189,7 @@ else LINUX_TOOL_ARCH_INCLUDE = $(top_srcdir)/tools/arch/$(ARCH)/include endif CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \ + -fno-builtin-memcmp -fno-builtin-memcpy -fno-builtin-memset \ -fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \ -I$(LINUX_TOOL_ARCH_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude \ -I$(