Hi,
Just a bunch of build and warnings fixes that show up when
building with clang. Some of these depend on each other, so
I'm sending them as a series.
Enjoy!
thanks,
John Hubbard
John Hubbard (7):
selftests/x86: fix Makefile dependencies to work with clang
selftests/x86: build test_FISTTP.c with clang
selftests/x86: build fsgsbase_restore.c with clang
selftests/x86: build sysret_rip.c with clang
selftests/x86: avoid -no-pie warnings from clang during compilation
selftests/x86: remove (or use) unused variables and functions
selftests/x86: fix printk() format warnings
tools/testing/selftests/x86/Makefile | 31 +++++++++++++++----
tools/testing/selftests/x86/amx.c | 16 ----------
.../testing/selftests/x86/clang_helpers_32.S | 11 +++++++
.../testing/selftests/x86/clang_helpers_64.S | 28 +++++++++++++++++
tools/testing/selftests/x86/fsgsbase.c | 6 ----
.../testing/selftests/x86/fsgsbase_restore.c | 11 +++----
tools/testing/selftests/x86/sigreturn.c | 2 +-
.../testing/selftests/x86/syscall_arg_fault.c | 1 -
tools/testing/selftests/x86/sysret_rip.c | 20 ++++--------
tools/testing/selftests/x86/test_FISTTP.c | 8 ++---
tools/testing/selftests/x86/test_vsyscall.c | 15 +++------
tools/testing/selftests/x86/vdso_restorer.c | 2 ++
12 files changed, 87 insertions(+), 64 deletions(-)
create mode 100644 tools/testing/selftests/x86/clang_helpers_32.S
create mode 100644 tools/testing/selftests/x86/clang_helpers_64.S
base-commit: f03359bca01bf4372cf2c118cd9a987a5951b1c8
prerequisite-patch-id: b901ece2a5b78503e2fb5480f20e304d36a0ea27
--
2.45.0
First of all, in order to build with clang at all, one must first apply
Valentin Obst's build fix for LLVM [1]. Once that is done, then when
building with clang, via:
make LLVM=1 -C tools/testing/selftests
Fix this by moving the inline asm to "pure" assembly, in two new files:
clang_helpers_32.S, clang_helpers_64.S.
As a bonus, the pure asm avoids the need for ifdefs, and is now very
simple and easy on the eyes.
[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/
Signed-off-by: John Hubbard <[email protected]>
---
tools/testing/selftests/x86/Makefile | 2 ++
tools/testing/selftests/x86/clang_helpers_32.S | 11 +++++++++++
tools/testing/selftests/x86/clang_helpers_64.S | 12 ++++++++++++
tools/testing/selftests/x86/fsgsbase_restore.c | 11 +++++------
4 files changed, 30 insertions(+), 6 deletions(-)
create mode 100644 tools/testing/selftests/x86/clang_helpers_32.S
create mode 100644 tools/testing/selftests/x86/clang_helpers_64.S
diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index c1269466e0f8..99bc2ef84f5a 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -113,6 +113,8 @@ endef
$(eval $(call extra-files,sysret_ss_attrs_64,thunks.S))
$(eval $(call extra-files,ptrace_syscall_32,raw_syscall_helper_32.S))
$(eval $(call extra-files,test_syscall_vdso_32,thunks_32.S))
+$(eval $(call extra-files,fsgsbase_restore_64,clang_helpers_64.S))
+$(eval $(call extra-files,fsgsbase_restore_32,clang_helpers_32.S))
# check_initial_reg_state is special: it needs a custom entry, and it
# needs to be static so that its interpreter doesn't destroy its initial
diff --git a/tools/testing/selftests/x86/clang_helpers_32.S b/tools/testing/selftests/x86/clang_helpers_32.S
new file mode 100644
index 000000000000..dc16271bac70
--- /dev/null
+++ b/tools/testing/selftests/x86/clang_helpers_32.S
@@ -0,0 +1,11 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * 32-bit assembly helpers for asm operations that lack support in both gcc and
+ * clang. For example, clang asm does not support segment prefixes.
+ */
+.global dereference_seg_base
+dereference_seg_base:
+ mov %fs:(0), %eax
+ ret
+
+.section .note.GNU-stack,"",%progbits
diff --git a/tools/testing/selftests/x86/clang_helpers_64.S b/tools/testing/selftests/x86/clang_helpers_64.S
new file mode 100644
index 000000000000..0d81c71cad97
--- /dev/null
+++ b/tools/testing/selftests/x86/clang_helpers_64.S
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * 64-bit assembly helpers for asm operations that lack support in both gcc and
+ * clang. For example, clang asm does not support segment prefixes.
+ */
+.global dereference_seg_base
+
+dereference_seg_base:
+ mov %gs:(0), %rax
+ ret
+
+.section .note.GNU-stack,"",%progbits
diff --git a/tools/testing/selftests/x86/fsgsbase_restore.c b/tools/testing/selftests/x86/fsgsbase_restore.c
index 6fffadc51579..224058c1e4b2 100644
--- a/tools/testing/selftests/x86/fsgsbase_restore.c
+++ b/tools/testing/selftests/x86/fsgsbase_restore.c
@@ -39,12 +39,11 @@
# define SEG "%fs"
#endif
-static unsigned int dereference_seg_base(void)
-{
- int ret;
- asm volatile ("mov %" SEG ":(0), %0" : "=rm" (ret));
- return ret;
-}
+/*
+ * Defined in clang_helpers_[32|64].S, because unlike gcc, clang inline asm does
+ * not support segmentation prefixes.
+ */
+unsigned int dereference_seg_base(void);
static void init_seg(void)
{
--
2.45.0