[PATCH v2 0/6] selftests/x86: fix build errors and warnings found via clang

[PATCH v2 0/6] selftests/x86: fix build errors and warnings found via clang

[John Hubbard]

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.

Changes since the first version:

1) Rebased onto Linux 6.10-rc1

Enjoy!

thanks,
John Hubbard

John Hubbard (6):
  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 warnings reported by clang

 tools/testing/selftests/x86/Makefile          | 10 +++++++
 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, 72 insertions(+), 58 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: 2bfcfd584ff5ccc8bb7acde19b42570414bf880b
prerequisite-patch-id: 39d606b9b165077aa1a3a3b0a3b396dba0c20070
-- 
2.45.1

[PATCH v2 1/6] selftests/x86: build test_FISTTP.c with clang

[John Hubbard]

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

...the build fails because clang inline asm requires size suffixes for
instructions, including the fisttp instruction. In this case, the 16-bit
suffix 's' is missing.

Fix by adding an 's' (short) suffix in each place that it is missing.

[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 tools/testing/selftests/x86/test_FISTTP.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/x86/test_FISTTP.c b/tools/testing/selftests/x86/test_FISTTP.c
index 09789c0ce3e9..b9ae9d8cebcb 100644
--- a/tools/testing/selftests/x86/test_FISTTP.c
+++ b/tools/testing/selftests/x86/test_FISTTP.c
@@ -25,7 +25,7 @@ int test(void)
 	feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);
 	asm volatile ("\n"
 	"	fld1""\n"
-	"	fisttp	res16""\n"
+	"	fisttps	res16""\n"
 	"	fld1""\n"
 	"	fisttpl	res32""\n"
 	"	fld1""\n"
@@ -45,7 +45,7 @@ int test(void)
 	feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);
 	asm volatile ("\n"
 	"	fldpi""\n"
-	"	fisttp	res16""\n"
+	"	fisttps	res16""\n"
 	"	fldpi""\n"
 	"	fisttpl	res32""\n"
 	"	fldpi""\n"
@@ -66,7 +66,7 @@ int test(void)
 	asm volatile ("\n"
 	"	fldpi""\n"
 	"	fchs""\n"
-	"	fisttp	res16""\n"
+	"	fisttps	res16""\n"
 	"	fldpi""\n"
 	"	fchs""\n"
 	"	fisttpl	res32""\n"
@@ -88,7 +88,7 @@ int test(void)
 	feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);
 	asm volatile ("\n"
 	"	fldln2""\n"
-	"	fisttp	res16""\n"
+	"	fisttps	res16""\n"
 	"	fldln2""\n"
 	"	fisttpl	res32""\n"
 	"	fldln2""\n"
-- 
2.45.1

[PATCH v2 2/6] selftests/x86: build fsgsbase_restore.c with clang

[John Hubbard]

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 <jhubbard@nvidia.com>
---
 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)
 {
-- 
2.45.1

[PATCH v2 3/6] selftests/x86: build sysret_rip.c with clang

[John Hubbard]

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

...the build fails because clang's inline asm doesn't support all of the
features that are used in the asm() snippet in sysret_rip.c.

Fix this by moving the asm code into the clang_helpers_64.S file, where
it can be built with the assembler's full set of features.

[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 tools/testing/selftests/x86/Makefile          |  1 +
 .../testing/selftests/x86/clang_helpers_64.S  | 16 +++++++++++++++
 tools/testing/selftests/x86/sysret_rip.c      | 20 ++++++-------------
 3 files changed, 23 insertions(+), 14 deletions(-)

diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index 99bc2ef84f5a..d0bb32bd5538 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -115,6 +115,7 @@ $(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 $(call extra-files,fsgsbase_restore_32,clang_helpers_32.S))
+$(eval $(call extra-files,sysret_rip_64,clang_helpers_64.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_64.S b/tools/testing/selftests/x86/clang_helpers_64.S
index 0d81c71cad97..185a69dbf39c 100644
--- a/tools/testing/selftests/x86/clang_helpers_64.S
+++ b/tools/testing/selftests/x86/clang_helpers_64.S
@@ -9,4 +9,20 @@ dereference_seg_base:
 	mov %gs:(0), %rax
 	ret
 
+.global test_page
+.global test_syscall_insn
+
+.pushsection ".text", "ax"
+.balign 4096
+test_page: .globl test_page
+	.fill 4094,1,0xcc
+
+test_syscall_insn:
+	syscall
+
+.ifne . - test_page - 4096
+	.error "test page is not one page long"
+.endif
+.popsection
+
 .section .note.GNU-stack,"",%progbits
diff --git a/tools/testing/selftests/x86/sysret_rip.c b/tools/testing/selftests/x86/sysret_rip.c
index 84d74be1d902..b30de9aaa6d4 100644
--- a/tools/testing/selftests/x86/sysret_rip.c
+++ b/tools/testing/selftests/x86/sysret_rip.c
@@ -22,21 +22,13 @@
 #include <sys/mman.h>
 #include <assert.h>
 
-
-asm (
-	".pushsection \".text\", \"ax\"\n\t"
-	".balign 4096\n\t"
-	"test_page: .globl test_page\n\t"
-	".fill 4094,1,0xcc\n\t"
-	"test_syscall_insn:\n\t"
-	"syscall\n\t"
-	".ifne . - test_page - 4096\n\t"
-	".error \"test page is not one page long\"\n\t"
-	".endif\n\t"
-	".popsection"
-    );
-
+/*
+ * These items are in clang_helpers_64.S, in order to avoid clang inline asm
+ * limitations:
+ */
+void test_syscall_ins(void);
 extern const char test_page[];
+
 static void const *current_test_page_addr = test_page;
 
 static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
-- 
2.45.1

[PATCH v2 4/6] selftests/x86: avoid -no-pie warnings from clang during compilation

[John Hubbard]

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

...clang warns that -no-pie is "unused during compilation".

This occurs because clang only wants to see -no-pie during linking.
Here, we don't have a separate linking stage, so a compiler warning is
unavoidable without (wastefully) restructuring the Makefile.

Avoid the warning by simply disabling that warning, for clang builds.

[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 tools/testing/selftests/x86/Makefile | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile
index d0bb32bd5538..5c8757a25998 100644
--- a/tools/testing/selftests/x86/Makefile
+++ b/tools/testing/selftests/x86/Makefile
@@ -40,6 +40,13 @@ CFLAGS := -O2 -g -std=gnu99 -pthread -Wall $(KHDR_INCLUDES)
 # call32_from_64 in thunks.S uses absolute addresses.
 ifeq ($(CAN_BUILD_WITH_NOPIE),1)
 CFLAGS += -no-pie
+
+ifneq ($(LLVM),)
+# clang only wants to see -no-pie during linking. Here, we don't have a separate
+# linking stage, so a compiler warning is unavoidable without (wastefully)
+# restructuring the Makefile. Avoid this by simply disabling that warning.
+CFLAGS += -Wno-unused-command-line-argument
+endif
 endif
 
 define gen-target-rule-32
-- 
2.45.1

[PATCH v2 5/6] selftests/x86: remove (or use) unused variables and functions

[John Hubbard]

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

...quite a few functions are variables are generating "unused" warnings.
Fix the warnings by deleting the unused items.

One item, the "nerrs" variable in vsdo_restorer.c's main(), is unused
but probably wants to be returned from main(), as a non-zero result.
That result is also unused right now, so another option would be to
delete it entirely, but this way, main() also gets fixed. It was missing
a return value.

[1] https://lore.kernel.org/all/20240329-selftests-libmk-llvm-rfc-v1-1-2f9ed7d1c49f@valentinobst.de/

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 tools/testing/selftests/x86/amx.c               | 16 ----------------
 tools/testing/selftests/x86/fsgsbase.c          |  6 ------
 tools/testing/selftests/x86/syscall_arg_fault.c |  1 -
 tools/testing/selftests/x86/test_vsyscall.c     |  5 -----
 tools/testing/selftests/x86/vdso_restorer.c     |  2 ++
 5 files changed, 2 insertions(+), 28 deletions(-)

diff --git a/tools/testing/selftests/x86/amx.c b/tools/testing/selftests/x86/amx.c
index 95aad6d8849b..1fdf35a4d7f6 100644
--- a/tools/testing/selftests/x86/amx.c
+++ b/tools/testing/selftests/x86/amx.c
@@ -39,16 +39,6 @@ struct xsave_buffer {
 	};
 };
 
-static inline uint64_t xgetbv(uint32_t index)
-{
-	uint32_t eax, edx;
-
-	asm volatile("xgetbv;"
-		     : "=a" (eax), "=d" (edx)
-		     : "c" (index));
-	return eax + ((uint64_t)edx << 32);
-}
-
 static inline void xsave(struct xsave_buffer *xbuf, uint64_t rfbm)
 {
 	uint32_t rfbm_lo = rfbm;
@@ -164,12 +154,6 @@ static inline void clear_xstate_header(struct xsave_buffer *buffer)
 	memset(&buffer->header, 0, sizeof(buffer->header));
 }
 
-static inline uint64_t get_xstatebv(struct xsave_buffer *buffer)
-{
-	/* XSTATE_BV is at the beginning of the header: */
-	return *(uint64_t *)&buffer->header;
-}
-
 static inline void set_xstatebv(struct xsave_buffer *buffer, uint64_t bv)
 {
 	/* XSTATE_BV is at the beginning of the header: */
diff --git a/tools/testing/selftests/x86/fsgsbase.c b/tools/testing/selftests/x86/fsgsbase.c
index 8c780cce941d..50cf32de6313 100644
--- a/tools/testing/selftests/x86/fsgsbase.c
+++ b/tools/testing/selftests/x86/fsgsbase.c
@@ -109,11 +109,6 @@ static inline void wrgsbase(unsigned long gsbase)
 	asm volatile("wrgsbase %0" :: "r" (gsbase) : "memory");
 }
 
-static inline void wrfsbase(unsigned long fsbase)
-{
-	asm volatile("wrfsbase %0" :: "r" (fsbase) : "memory");
-}
-
 enum which_base { FS, GS };
 
 static unsigned long read_base(enum which_base which)
@@ -212,7 +207,6 @@ static void mov_0_gs(unsigned long initial_base, bool schedule)
 }
 
 static volatile unsigned long remote_base;
-static volatile bool remote_hard_zero;
 static volatile unsigned int ftx;
 
 /*
diff --git a/tools/testing/selftests/x86/syscall_arg_fault.c b/tools/testing/selftests/x86/syscall_arg_fault.c
index 461fa41a4d02..48ab065a76f9 100644
--- a/tools/testing/selftests/x86/syscall_arg_fault.c
+++ b/tools/testing/selftests/x86/syscall_arg_fault.c
@@ -29,7 +29,6 @@ static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *),
 		err(1, "sigaction");
 }
 
-static volatile sig_atomic_t sig_traps;
 static sigjmp_buf jmpbuf;
 
 static volatile sig_atomic_t n_errs;
diff --git a/tools/testing/selftests/x86/test_vsyscall.c b/tools/testing/selftests/x86/test_vsyscall.c
index d4c8e8d79d38..1c9895cfc660 100644
--- a/tools/testing/selftests/x86/test_vsyscall.c
+++ b/tools/testing/selftests/x86/test_vsyscall.c
@@ -97,11 +97,6 @@ static inline long sys_gtod(struct timeval *tv, struct timezone *tz)
 	return syscall(SYS_gettimeofday, tv, tz);
 }
 
-static inline int sys_clock_gettime(clockid_t id, struct timespec *ts)
-{
-	return syscall(SYS_clock_gettime, id, ts);
-}
-
 static inline long sys_time(time_t *t)
 {
 	return syscall(SYS_time, t);
diff --git a/tools/testing/selftests/x86/vdso_restorer.c b/tools/testing/selftests/x86/vdso_restorer.c
index fe99f2434155..ac8d8e1e9805 100644
--- a/tools/testing/selftests/x86/vdso_restorer.c
+++ b/tools/testing/selftests/x86/vdso_restorer.c
@@ -92,4 +92,6 @@ int main()
 		printf("[FAIL]\t!SA_SIGINFO handler was not called\n");
 		nerrs++;
 	}
+
+	return nerrs;
 }
-- 
2.45.1

[PATCH v2 6/6] selftests/x86: fix printk warnings reported by clang

[John Hubbard]

These warnings are all of the form, "the format specified a short
(signed or unsigned) int, but the value is a full length int".

Signed-off-by: John Hubbard <jhubbard@nvidia.com>
---
 tools/testing/selftests/x86/sigreturn.c     |  2 +-
 tools/testing/selftests/x86/test_vsyscall.c | 10 +++++-----
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/testing/selftests/x86/sigreturn.c b/tools/testing/selftests/x86/sigreturn.c
index 5d7961a5f7f6..0b75b29f794b 100644
--- a/tools/testing/selftests/x86/sigreturn.c
+++ b/tools/testing/selftests/x86/sigreturn.c
@@ -487,7 +487,7 @@ static void sigtrap(int sig, siginfo_t *info, void *ctx_void)
 	greg_t asm_ss = ctx->uc_mcontext.gregs[REG_CX];
 	if (asm_ss != sig_ss && sig == SIGTRAP) {
 		/* Sanity check failure. */
-		printf("[FAIL]\tSIGTRAP: ss = %hx, frame ss = %hx, ax = %llx\n",
+		printf("[FAIL]\tSIGTRAP: ss = %hx, frame ss = %x, ax = %llx\n",
 		       ss, *ssptr(ctx), (unsigned long long)asm_ss);
 		nerrs++;
 	}
diff --git a/tools/testing/selftests/x86/test_vsyscall.c b/tools/testing/selftests/x86/test_vsyscall.c
index 1c9895cfc660..6de11b4df458 100644
--- a/tools/testing/selftests/x86/test_vsyscall.c
+++ b/tools/testing/selftests/x86/test_vsyscall.c
@@ -247,7 +247,7 @@ static void test_getcpu(int cpu)
 
 	if (ret_sys == 0) {
 		if (cpu_sys != cpu)
-			ksft_print_msg("syscall reported CPU %hu but should be %d\n",
+			ksft_print_msg("syscall reported CPU %u but should be %d\n",
 				       cpu_sys, cpu);
 
 		have_node = true;
@@ -265,10 +265,10 @@ static void test_getcpu(int cpu)
 
 			if (cpu_vdso != cpu || node_vdso != node) {
 				if (cpu_vdso != cpu)
-					ksft_print_msg("vDSO reported CPU %hu but should be %d\n",
+					ksft_print_msg("vDSO reported CPU %u but should be %d\n",
 						       cpu_vdso, cpu);
 				if (node_vdso != node)
-					ksft_print_msg("vDSO reported node %hu but should be %hu\n",
+					ksft_print_msg("vDSO reported node %u but should be %u\n",
 						       node_vdso, node);
 				ksft_test_result_fail("Wrong values\n");
 			} else {
@@ -290,10 +290,10 @@ static void test_getcpu(int cpu)
 
 			if (cpu_vsys != cpu || node_vsys != node) {
 				if (cpu_vsys != cpu)
-					ksft_print_msg("vsyscall reported CPU %hu but should be %d\n",
+					ksft_print_msg("vsyscall reported CPU %u but should be %d\n",
 						       cpu_vsys, cpu);
 				if (node_vsys != node)
-					ksft_print_msg("vsyscall reported node %hu but should be %hu\n",
+					ksft_print_msg("vsyscall reported node %u but should be %u\n",
 						       node_vsys, node);
 				ksft_test_result_fail("Wrong values\n");
 			} else {
-- 
2.45.1

Re: [PATCH v2 0/6] selftests/x86: fix build errors and warnings found via clang

[Shuah Khan]

On 5/27/24 15:00, John Hubbard wrote:
> 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.
> 
> Changes since the first version:
> 
> 1) Rebased onto Linux 6.10-rc1

x86 test patches usually go through x86 tree.

This series requires x86 maintainer review and ack for me
to take this through kselftest tree.


> 
> Enjoy!
> 
> thanks,
> John Hubbard
> 
> John Hubbard (6):
>    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 warnings reported by clang
> 
>   tools/testing/selftests/x86/Makefile          | 10 +++++++
>   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, 72 insertions(+), 58 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: 2bfcfd584ff5ccc8bb7acde19b42570414bf880b
> prerequisite-patch-id: 39d606b9b165077aa1a3a3b0a3b396dba0c20070

thanks,
-- Shuah

Re: [PATCH v2 0/6] selftests/x86: fix build errors and warnings found via clang

[John Hubbard]

On 5/30/24 7:58 AM, Shuah Khan wrote:
> On 5/27/24 15:00, John Hubbard wrote:
>> 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.
>>
>> Changes since the first version:
>>
>> 1) Rebased onto Linux 6.10-rc1
> 
> x86 test patches usually go through x86 tree.
> 
> This series requires x86 maintainer review and ack for me
> to take this through kselftest tree.

Hi Shuah,

Yes. I'm having some difficulty getting anyone from x86 to respond to
these. Let me add a few more x86 maintainers to this thread in hopes
of hearing something.

thanks,
-- 
John Hubbard
NVIDIA

...
>> John Hubbard (6):
>>    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 warnings reported by clang
>>
>>   tools/testing/selftests/x86/Makefile          | 10 +++++++
>>   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, 72 insertions(+), 58 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: 2bfcfd584ff5ccc8bb7acde19b42570414bf880b
>> prerequisite-patch-id: 39d606b9b165077aa1a3a3b0a3b396dba0c20070
> 
> thanks,
> -- Shuah
> 

Re: [PATCH v2 0/6] selftests/x86: fix build errors and warnings found via clang

[Dave Hansen]

On 5/27/24 14:00, John Hubbard wrote:
> John Hubbard (6):
>   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 warnings reported by clang

John, could you and Muhammad have a chat and perhaps settle on a series
series that gets acks from both of you?

> https://lore.kernel.org/all/20240501122918.3831734-1-usama.anjum@collabora.com/

I had Muhammad's in my queue and didn't realize we had two overlapping
series' bouncing around until now.

Re: [PATCH v2 0/6] selftests/x86: fix build errors and warnings found via clang

[John Hubbard]

On 5/30/24 12:46 PM, Dave Hansen wrote:
> On 5/27/24 14:00, John Hubbard wrote:
>> John Hubbard (6):
>>    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 warnings reported by clang
> 
> John, could you and Muhammad have a chat and perhaps settle on a series
> series that gets acks from both of you?
> 
>> https://lore.kernel.org/all/20240501122918.3831734-1-usama.anjum@collabora.com/
> 
> I had Muhammad's in my queue and didn't realize we had two overlapping
> series' bouncing around until now.

Aha OK. Muhummad, after looking through this, I see that our
test_FISTTP.c fix is identical, and that's about it. My series goes
a bit deeper IMHO and completely fixes all the errors; the tradeoff
is that it is more intrusive. Which I think is appropriate.

Would you be OK with my posting v3 that uses your patch for
test_FISTTP.c [1], and the rest of my patches for the rest?


[1] 
https://lore.kernel.org/all/20240501122918.3831734-7-usama.anjum@collabora.com/

thanks,
-- 
John Hubbard
NVIDIA

Re: [PATCH v2 0/6] selftests/x86: fix build errors and warnings found via clang

[Muhammad Usama Anjum]

On 5/31/24 1:00 AM, John Hubbard wrote:
> On 5/30/24 12:46 PM, Dave Hansen wrote:
>> On 5/27/24 14:00, John Hubbard wrote:
>>> John Hubbard (6):
>>>    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 warnings reported by clang
>>
>> John, could you and Muhammad have a chat and perhaps settle on a series
>> series that gets acks from both of you?
>>
>>> https://lore.kernel.org/all/20240501122918.3831734-1-usama.anjum@collabora.com/
>>
>> I had Muhammad's in my queue and didn't realize we had two overlapping
>> series' bouncing around until now.
> 
> Aha OK. Muhummad, after looking through this, I see that our
> test_FISTTP.c fix is identical, and that's about it. My series goes
> a bit deeper IMHO and completely fixes all the errors; the tradeoff
> is that it is more intrusive. Which I think is appropriate.
> 
> Would you be OK with my posting v3 that uses your patch for
> test_FISTTP.c [1], and the rest of my patches for the rest?
Yeah, sure go ahead. I'll test/review the v3 series.

> 
> 
> [1]
> https://lore.kernel.org/all/20240501122918.3831734-7-usama.anjum@collabora.com/
> 
> thanks,

-- 
BR,
Muhammad Usama Anjum