[PATCH v2 1/3] selftests/powerpc: Allocate base registers

Subsystems: kernel selftest framework, the rest

STALE2842d REVIEWED: 1 (0M)

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6 messages, 3 authors, 2018-11-27 · open the first message on its own page

[PATCH v2 1/3] selftests/powerpc: Allocate base registers

From: Breno Leitao <leitao@debian.org>
Date: 2018-10-31 14:40:28

Some ptrace selftests are passing input operands using a constraint that
can allocate any register for the operand, and using these registers on
load/store operations.

If the register allocated by the compiler happens to be zero (r0), it might
cause an invalid memory address access, since load and store operations
consider the content of 0x0 address if the base register is r0, instead of
the content of the r0 register. For example:

	r1 := 0xdeadbeef
	r0 := 0xdeadbeef

	ld r2, 0(1) /* will load into r2 the content of r1 address */
	ld r2, 0(0) /* will load into r2 the content of 0x0 */

In order to avoid this possible problem, the inline assembly constraint
should be aware that these registers will be used as a base register, thus,
r0 should not be allocated.

Other than that, this patch removes inline assembly operands that are not
used by the tests.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Segher Boessenkool <redacted>
---
 tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c        | 2 +-
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-gpr.c     | 4 ++--
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c | 2 +-
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c | 3 +--
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c     | 2 +-
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar.c     | 2 +-
 tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c     | 3 +--
 7 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c b/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c
index 0b4ebcc2f485..ca29fafeed5d 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-gpr.c

@@ -31,7 +31,7 @@ void gpr(void)
 		ASM_LOAD_GPR_IMMED(gpr_1)
 		ASM_LOAD_FPR_SINGLE_PRECISION(flt_1)
 		:
-		: [gpr_1]"i"(GPR_1), [flt_1] "r" (&a)
+		: [gpr_1]"i"(GPR_1), [flt_1] "b" (&a)
 		: "memory", "r6", "r7", "r8", "r9", "r10",
 		"r11", "r12", "r13", "r14", "r15", "r16", "r17",
 		"r18", "r19", "r20", "r21", "r22", "r23", "r24",

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-gpr.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-gpr.c
index 59206b96e98a..a08a91594dbe 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-gpr.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-gpr.c

@@ -59,8 +59,8 @@ void tm_gpr(void)
 		"3: ;"
 		: [res] "=r" (result), [texasr] "=r" (texasr)
 		: [gpr_1]"i"(GPR_1), [gpr_2]"i"(GPR_2),
-		[sprn_texasr] "i" (SPRN_TEXASR), [flt_1] "r" (&a),
-		[flt_2] "r" (&b), [cptr1] "r" (&cptr[1])
+		[sprn_texasr] "i" (SPRN_TEXASR), [flt_1] "b" (&a),
+		[flt_2] "b" (&b), [cptr1] "b" (&cptr[1])
 		: "memory", "r7", "r8", "r9", "r10",
 		"r11", "r12", "r13", "r14", "r15", "r16",
 		"r17", "r18", "r19", "r20", "r21", "r22",

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c
index b3c061dc9512..f47174746231 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-tar.c

@@ -72,7 +72,7 @@ void tm_spd_tar(void)
 		"3: ;"
 
 		: [res] "=r" (result), [texasr] "=r" (texasr)
-		: [val] "r" (cptr[1]), [sprn_dscr]"i"(SPRN_DSCR),
+		: [sprn_dscr]"i"(SPRN_DSCR),
 		[sprn_tar]"i"(SPRN_TAR), [sprn_ppr]"i"(SPRN_PPR),
 		[sprn_texasr]"i"(SPRN_TEXASR), [tar_1]"i"(TAR_1),
 		[dscr_1]"i"(DSCR_1), [tar_2]"i"(TAR_2), [dscr_2]"i"(DSCR_2),

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c
index 277dade1b382..18a685bf6a09 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spd-vsx.c

@@ -77,8 +77,7 @@ void tm_spd_vsx(void)
 
 		"3: ;"
 		: [res] "=r" (result), [texasr] "=r" (texasr)
-		: [fp_load] "r" (fp_load), [fp_load_ckpt] "r" (fp_load_ckpt),
-		[sprn_texasr] "i"  (SPRN_TEXASR)
+		: [sprn_texasr] "i"  (SPRN_TEXASR)
 		: "memory", "r0", "r1", "r3", "r4",
 		"r7", "r8", "r9", "r10", "r11"
 		);

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
index 51427a2465f6..ba04999254e3 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-spr.c

@@ -74,7 +74,7 @@ void tm_spr(void)
 
 		"3: ;"
 		: [tfhar] "=r" (tfhar), [res] "=r" (result),
-		[texasr] "=r" (texasr), [cptr1] "=r" (cptr1)
+		[texasr] "=r" (texasr), [cptr1] "=b" (cptr1)
 		: [sprn_texasr] "i"  (SPRN_TEXASR)
 		: "memory", "r0", "r8", "r31"
 		);

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar.c
index 48b462f75023..f70023b25e6e 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-tar.c

@@ -65,7 +65,7 @@ void tm_tar(void)
 		: [sprn_dscr]"i"(SPRN_DSCR), [sprn_tar]"i"(SPRN_TAR),
 		[sprn_ppr]"i"(SPRN_PPR), [sprn_texasr]"i"(SPRN_TEXASR),
 		[tar_1]"i"(TAR_1), [dscr_1]"i"(DSCR_1), [tar_2]"i"(TAR_2),
-		[dscr_2]"i"(DSCR_2), [cptr1] "r" (&cptr[1])
+		[dscr_2]"i"(DSCR_2), [cptr1] "b" (&cptr[1])
 		: "memory", "r0", "r1", "r3", "r4", "r5", "r6"
 		);

diff --git a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c
index 17c23cabac3e..dfba80058977 100644
--- a/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c
+++ b/tools/testing/selftests/powerpc/ptrace/ptrace-tm-vsx.c

@@ -65,8 +65,7 @@ void tm_vsx(void)
 
 		"3: ;"
 		: [res] "=r" (result), [texasr] "=r" (texasr)
-		: [fp_load] "r" (fp_load), [fp_load_ckpt] "r" (fp_load_ckpt),
-		[sprn_texasr] "i"  (SPRN_TEXASR), [cptr1] "r" (&cptr[1])
+		: [sprn_texasr] "i"  (SPRN_TEXASR), [cptr1] "b" (&cptr[1])
 		: "memory", "r0", "r1", "r3", "r4",
 		"r7", "r8", "r9", "r10", "r11"
 		);

-- 
2.13.2

[PATCH v2 2/3] selftests/powerpc: Create a new SKIP_IF macro

From: Breno Leitao <leitao@debian.org>
Date: 2018-10-31 14:42:19

This patch creates a new macro that skips a test and prints a message to
stderr. This is useful to give an idea why the tests is being skipped,
other than just skipping the test blindly.

Signed-off-by: Breno Leitao <leitao@debian.org>
---
 tools/testing/selftests/powerpc/include/utils.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h
index da1b963cdb32..486c1782c23e 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h

@@ -72,6 +72,16 @@ do {								\
 	}							\
 } while (0)
 
+#define SKIP_IF_MSG(x, msg)					\
+do {								\
+	if ((x)) {						\
+		fprintf(stderr,					\
+		"[SKIP] Test skipped on line %d: %s\n",		\
+		 __LINE__, msg);				\
+		return MAGIC_SKIP_RETURN_VALUE;			\
+	}							\
+} while (0)
+
 #define _str(s) #s
 #define str(s) _str(s)

-- 
2.13.2

[PATCH v2 3/3] selftests/powerpc: Skip test instead of failing

From: Breno Leitao <leitao@debian.org>
Date: 2018-10-31 14:44:35

Current core-pkey selftest fails if the test runs without privileges to
write into the core pattern file (/proc/sys/kernel/core_pattern). This
causes the test to fail and give the impression that the subsystem being
tested is broken, when, in fact, the test is being executed without the
proper privileges. This is the current error:

	test: core_pkey
	tags: git_version:v4.19-3-g9e3363be9bce-dirty
	Error writing to core_pattern file: Permission denied
	failure: core_pkey

This patch simply skips this test if it runs without the proper privileges,
avoiding this undesired failure.

CC: Tyrel Datwyler <redacted>
CC: Thiago Jung Bauermann <redacted>
Signed-off-by: Breno Leitao <leitao@debian.org>
---
 tools/testing/selftests/powerpc/ptrace/core-pkey.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tools/testing/selftests/powerpc/ptrace/core-pkey.c b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
index e23e2e199eb4..d5c64fee032d 100644
--- a/tools/testing/selftests/powerpc/ptrace/core-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/core-pkey.c

@@ -352,10 +352,7 @@ static int write_core_pattern(const char *core_pattern)
 	FILE *f;
 
 	f = fopen(core_pattern_file, "w");
-	if (!f) {
-		perror("Error writing to core_pattern file");
-		return TEST_FAIL;
-	}
+	SKIP_IF_MSG(!f, "Try with root privileges");
 
 	ret = fwrite(core_pattern, 1, len, f);
 	fclose(f);

-- 
2.13.2

Re: [PATCH v2 2/3] selftests/powerpc: Create a new SKIP_IF macro

From: Thiago Jung Bauermann <hidden>
Date: 2018-10-31 15:46:31

Breno Leitao [off-list ref] writes:

This patch creates a new macro that skips a test and prints a message to
stderr. This is useful to give an idea why the tests is being skipped,
other than just skipping the test blindly.

Signed-off-by: Breno Leitao <leitao@debian.org>

Reviewed-by: Thiago Jung Bauermann <redacted>

quoted hunk

---
 tools/testing/selftests/powerpc/include/utils.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tools/testing/selftests/powerpc/include/utils.h b/tools/testing/selftests/powerpc/include/utils.h
index da1b963cdb32..486c1782c23e 100644
--- a/tools/testing/selftests/powerpc/include/utils.h
+++ b/tools/testing/selftests/powerpc/include/utils.h

@@ -72,6 +72,16 @@ do {								\
 	}							\
 } while (0)
 
+#define SKIP_IF_MSG(x, msg)					\
+do {								\
+	if ((x)) {						\
+		fprintf(stderr,					\
+		"[SKIP] Test skipped on line %d: %s\n",		\
+		 __LINE__, msg);				\
+		return MAGIC_SKIP_RETURN_VALUE;			\
+	}							\
+} while (0)
+
 #define _str(s) #s
 #define str(s) _str(s)


-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [PATCH v2 3/3] selftests/powerpc: Skip test instead of failing

From: Thiago Jung Bauermann <hidden>
Date: 2018-10-31 15:48:27

Breno Leitao [off-list ref] writes:

Current core-pkey selftest fails if the test runs without privileges to
write into the core pattern file (/proc/sys/kernel/core_pattern). This
causes the test to fail and give the impression that the subsystem being
tested is broken, when, in fact, the test is being executed without the
proper privileges. This is the current error:

	test: core_pkey
	tags: git_version:v4.19-3-g9e3363be9bce-dirty
	Error writing to core_pattern file: Permission denied
	failure: core_pkey

This patch simply skips this test if it runs without the proper privileges,
avoiding this undesired failure.

CC: Tyrel Datwyler <redacted>
CC: Thiago Jung Bauermann <redacted>
Signed-off-by: Breno Leitao <leitao@debian.org>

Reviewed-by: Thiago Jung Bauermann <redacted>

quoted hunk

---
 tools/testing/selftests/powerpc/ptrace/core-pkey.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tools/testing/selftests/powerpc/ptrace/core-pkey.c b/tools/testing/selftests/powerpc/ptrace/core-pkey.c
index e23e2e199eb4..d5c64fee032d 100644
--- a/tools/testing/selftests/powerpc/ptrace/core-pkey.c
+++ b/tools/testing/selftests/powerpc/ptrace/core-pkey.c

@@ -352,10 +352,7 @@ static int write_core_pattern(const char *core_pattern)
 	FILE *f;
 
 	f = fopen(core_pattern_file, "w");
-	if (!f) {
-		perror("Error writing to core_pattern file");
-		return TEST_FAIL;
-	}
+	SKIP_IF_MSG(!f, "Try with root privileges");
 
 	ret = fwrite(core_pattern, 1, len, f);
 	fclose(f);


-- 
Thiago Jung Bauermann
IBM Linux Technology Center

Re: [v2,1/3] selftests/powerpc: Allocate base registers

From: Michael Ellerman <hidden>
Date: 2018-11-27 09:35:45

On Wed, 2018-10-31 at 14:38:20 UTC, Breno Leitao wrote:

Some ptrace selftests are passing input operands using a constraint that
can allocate any register for the operand, and using these registers on
load/store operations.

If the register allocated by the compiler happens to be zero (r0), it might
cause an invalid memory address access, since load and store operations
consider the content of 0x0 address if the base register is r0, instead of
the content of the r0 register. For example:

	r1 := 0xdeadbeef
	r0 := 0xdeadbeef

	ld r2, 0(1) /* will load into r2 the content of r1 address */
	ld r2, 0(0) /* will load into r2 the content of 0x0 */

In order to avoid this possible problem, the inline assembly constraint
should be aware that these registers will be used as a base register, thus,
r0 should not be allocated.

Other than that, this patch removes inline assembly operands that are not
used by the tests.

Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Segher Boessenkool <redacted>

Series applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/5249497a7bb6334fcc128588d6a7e1

cheers

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