When building with clang via:
make LLVM=1 -C tools/testing/selftests
two distinct failures occur:
1) gcc requires -static-libasan in order to ensure that Address
Sanitizer's library is the first one loaded. However, this leads to
build failures on clang, when building via:
make LLVM=1 -C tools/testing/selftests
However, clang already does the right thing by default: it statically
links the Address Sanitizer if -fsanitize is specified. Therefore, fix
this by simply omitting -static-libasan for clang builds. And leave
behind a comment, because the whole reason for static linking might not
be obvious.
2) clang won't accept invocations of this form, but gcc will:
$(CC) file1.c header2.h
Fix this by using selftests/lib.mk facilities for tracking local header
file dependencies: add them to LOCAL_HDRS, leaving only the .c files to
be passed to the compiler.
Reviewed-by: Ryan Roberts <[email protected]>
Signed-off-by: John Hubbard <[email protected]>
---
tools/testing/selftests/openat2/Makefile | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/openat2/Makefile b/tools/testing/selftests/openat2/Makefile
index 254d676a2689..185dc76ebb5f 100644
--- a/tools/testing/selftests/openat2/Makefile
+++ b/tools/testing/selftests/openat2/Makefile
@@ -1,8 +1,18 @@
# SPDX-License-Identifier: GPL-2.0-or-later
-CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined -static-libasan
+CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined
TEST_GEN_PROGS := openat2_test resolve_test rename_attack_test
+# gcc requires -static-libasan in order to ensure that Address Sanitizer's
+# library is the first one loaded. However, clang already statically links the
+# Address Sanitizer if -fsanitize is specified. Therefore, simply omit
+# -static-libasan for clang builds.
+ifeq ($(LLVM),)
+ CFLAGS += -static-libasan
+endif
+
+LOCAL_HDRS += helpers.h
+
include ../lib.mk
-$(TEST_GEN_PROGS): helpers.c helpers.h
+$(TEST_GEN_PROGS): helpers.c
--
2.45.1
On Fri, May 31, 2024 at 06:45:33PM -0700, John Hubbard wrote:
> When building with clang via:
>
> make LLVM=1 -C tools/testing/selftests
>
> two distinct failures occur:
>
> 1) gcc requires -static-libasan in order to ensure that Address
> Sanitizer's library is the first one loaded. However, this leads to
> build failures on clang, when building via:
>
> make LLVM=1 -C tools/testing/selftests
>
> However, clang already does the right thing by default: it statically
> links the Address Sanitizer if -fsanitize is specified. Therefore, fix
> this by simply omitting -static-libasan for clang builds. And leave
> behind a comment, because the whole reason for static linking might not
> be obvious.
>
> 2) clang won't accept invocations of this form, but gcc will:
>
> $(CC) file1.c header2.h
>
> Fix this by using selftests/lib.mk facilities for tracking local header
> file dependencies: add them to LOCAL_HDRS, leaving only the .c files to
> be passed to the compiler.
>
> Reviewed-by: Ryan Roberts <[email protected]>
> Signed-off-by: John Hubbard <[email protected]>
Assuming that $(LLVM) is the correct conditional to test for:
Reviewed-by: Nathan Chancellor <[email protected]>
> ---
> tools/testing/selftests/openat2/Makefile | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/openat2/Makefile b/tools/testing/selftests/openat2/Makefile
> index 254d676a2689..185dc76ebb5f 100644
> --- a/tools/testing/selftests/openat2/Makefile
> +++ b/tools/testing/selftests/openat2/Makefile
> @@ -1,8 +1,18 @@
> # SPDX-License-Identifier: GPL-2.0-or-later
>
> -CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined -static-libasan
> +CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined
> TEST_GEN_PROGS := openat2_test resolve_test rename_attack_test
>
> +# gcc requires -static-libasan in order to ensure that Address Sanitizer's
> +# library is the first one loaded. However, clang already statically links the
> +# Address Sanitizer if -fsanitize is specified. Therefore, simply omit
> +# -static-libasan for clang builds.
> +ifeq ($(LLVM),)
> + CFLAGS += -static-libasan
> +endif
> +
> +LOCAL_HDRS += helpers.h
> +
> include ../lib.mk
>
> -$(TEST_GEN_PROGS): helpers.c helpers.h
> +$(TEST_GEN_PROGS): helpers.c
> --
> 2.45.1
>
>
On Fri, May 31, 2024 at 06:45:33PM -0700, John Hubbard wrote:
> When building with clang via:
>
> make LLVM=1 -C tools/testing/selftests
>
> two distinct failures occur:
>
> 1) gcc requires -static-libasan in order to ensure that Address
> Sanitizer's library is the first one loaded. However, this leads to
> build failures on clang, when building via:
>
> make LLVM=1 -C tools/testing/selftests
>
> However, clang already does the right thing by default: it statically
> links the Address Sanitizer if -fsanitize is specified. Therefore, fix
> this by simply omitting -static-libasan for clang builds. And leave
> behind a comment, because the whole reason for static linking might not
> be obvious.
>
> 2) clang won't accept invocations of this form, but gcc will:
>
> $(CC) file1.c header2.h
>
> Fix this by using selftests/lib.mk facilities for tracking local header
> file dependencies: add them to LOCAL_HDRS, leaving only the .c files to
> be passed to the compiler.
>
> Reviewed-by: Ryan Roberts <[email protected]>
> Signed-off-by: John Hubbard <[email protected]>
Assuming that $(LLVM) is the correct conditional to test for:
Reviewed-by: Nathan Chancellor <[email protected]>
> ---
> tools/testing/selftests/openat2/Makefile | 14 ++++++++++++--
> 1 file changed, 12 insertions(+), 2 deletions(-)
>
> diff --git a/tools/testing/selftests/openat2/Makefile b/tools/testing/selftests/openat2/Makefile
> index 254d676a2689..185dc76ebb5f 100644
> --- a/tools/testing/selftests/openat2/Makefile
> +++ b/tools/testing/selftests/openat2/Makefile
> @@ -1,8 +1,18 @@
> # SPDX-License-Identifier: GPL-2.0-or-later
>
> -CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined -static-libasan
> +CFLAGS += -Wall -O2 -g -fsanitize=address -fsanitize=undefined
> TEST_GEN_PROGS := openat2_test resolve_test rename_attack_test
>
> +# gcc requires -static-libasan in order to ensure that Address Sanitizer's
> +# library is the first one loaded. However, clang already statically links the
> +# Address Sanitizer if -fsanitize is specified. Therefore, simply omit
> +# -static-libasan for clang builds.
> +ifeq ($(LLVM),)
> + CFLAGS += -static-libasan
> +endif
> +
> +LOCAL_HDRS += helpers.h
> +
> include ../lib.mk
>
> -$(TEST_GEN_PROGS): helpers.c helpers.h
> +$(TEST_GEN_PROGS): helpers.c
> --
> 2.45.1
>
>