proc: fixup map_files test on arm

PATCH Superseded Alexey Dobriyan 3 participants 7 messages Nov 10, 2018 – Nov 13, 2018

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Alexey Dobriyan

author

2018-11-10 18:49 UTC #0 lore raw

PATCH 1/1 proc: fixup map_files test on arm

https://bugs.linaro.org/show_bug.cgi?id=3782

Turns out arm doesn't allow to map address 0, so try minimum virtual address instead.

Reported-by Rafael David Tinoco <[email protected]>

Signed-off-by Alexey Dobriyan <[email protected]>

---

 tools/testing/selftests/proc/proc-self-map-files-002.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

tools/testing/selftests/proc/proc-self-map-files-002.c +7 -2

@@ -13,7 +13,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
-/* Test readlink /proc/self/map_files/... with address 0. */
+/* Test readlink /proc/self/map_files/... with minimum address. */
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>

@@ -47,6 +47,11 @@ static void fail(const char *fmt, unsigned long a, unsigned long b)
 int main(void)
 {
 	const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+#ifdef __arm__
+	unsigned long va = 2 * PAGE_SIZE;
+#else
+	unsigned long va = 0;
+#endif
 	void *p;
 	int fd;
 	unsigned long a, b;

@@ -55,7 +60,7 @@ int main(void)
 	if (fd == -1)
 		return 1;
 
-	p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
+	p = mmap(va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
 	if (p == MAP_FAILED) {
 		if (errno == EPERM)
 			return 2;

Rafael David Tinoco

2018-11-11 02:48 UTC #1 lore raw

Including Shuah and kselftest list...

Quoted 38 lines · Alexey Dobriyan

https://bugs.linaro.org/show_bug.cgi?id=3782
Turns out arm doesn't allow to map address 0, so try minimum virtual address instead.
Reported-by Rafael David Tinoco <rafael.tinoco at linaro.org>
Signed-off-by Alexey Dobriyan <adobriyan at gmail.com>
---
 tools/testing/selftests/proc/proc-self-map-files-002.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)
tools/testing/selftests/proc/proc-self-map-files-002.c +0 -0
@@ -13,7 +13,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 
OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
tools/testing/selftests/proc/proc-self-map-files-002.c +6 -1
-/* Test readlink /proc/self/map_files/... with address 0. */
+/* Test readlink /proc/self/map_files/... with minimum address. */
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -47,6 +47,11 @@ static void fail(const char *fmt, unsigned long a, 
 unsigned long b)
 int main(void)
 {
 	const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+#ifdef __arm__
+	unsigned long va = 2 * PAGE_SIZE;
+#else
+	unsigned long va = 0;
+#endif
 	void *p;
 	int fd;
tools/testing/selftests/proc/proc-self-map-files-002.c +0 -0
 	unsigned long a, b;

tools/testing/selftests/proc/proc-self-map-files-002.c int main(void) · line 66

Quoted 8 lines

tools/testing/selftests/proc/proc-self-map-files-002.c +1 -1

@@ -55,7 +60,7 @@ int main(void)
 	if (fd == -1)
 		return 1;
 
-	p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
+	p = mmap(va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
 	if (p == MAP_FAILED) {
 		if (errno == EPERM)
 			return 2;

I have sent a patch removing proc-self-map-files-002 AND making 001 to use as a HINT for mmap (MAP_FIXED) *at least* *(2 * PAGE_SIZE), which would, likely, attend all architectures, avoiding trying to make the test specific to one, and, still, test the symlinks for issues (like bad chars, spaces, so on).

Both tests (001 and 002) have pretty much the same code, while they could have 2 tests in a single code, using kselftest framework. Is NULL hint + MAP_FIXED something imperative for this test ? Why not to have all in a single test ? Are you keeping the NULL hint just to test mmap, apart" from the core of this test ?

Sorry to insist.. If you want to keep it like this, I can create a similar test in LTP - for the symlinks only, which seem important - and blacklist this one in our function tests kselftest list (https://lkft.linaro.org/), then no change is needed on your side.

Thanks

Alexey Dobriyan

author

2018-11-12 14:14 UTC #2 lore raw

Quoted 44 lines · Rafael David Tinoco

Including Shuah and kselftest list...
Quoted 41 lines · Alexey Dobriyan
https://bugs.linaro.org/show_bug.cgi?id=3782
Turns out arm doesn't allow to map address 0, so try minimum virtual address instead.
Reported-by Rafael David Tinoco <rafael.tinoco at linaro.org>
Signed-off-by Alexey Dobriyan <adobriyan at gmail.com>
---
 tools/testing/selftests/proc/proc-self-map-files-002.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)
tools/testing/selftests/proc/proc-self-map-files-002.c +0 -0
@@ -13,7 +13,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT 
OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
tools/testing/selftests/proc/proc-self-map-files-002.c +6 -1
-/* Test readlink /proc/self/map_files/... with address 0. */
+/* Test readlink /proc/self/map_files/... with minimum address. */
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>
@@ -47,6 +47,11 @@ static void fail(const char *fmt, unsigned long a, 
 unsigned long b)
 int main(void)
 {
 	const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+#ifdef __arm__
+	unsigned long va = 2 * PAGE_SIZE;
+#else
+	unsigned long va = 0;
+#endif
 	void *p;
 	int fd;
tools/testing/selftests/proc/proc-self-map-files-002.c +0 -0
 	unsigned long a, b;
@@ -55,7 +60,7 @@ int main(void)
 	if (fd == -1)
 		return 1;
 

Quoted 10 lines

tools/testing/selftests/proc/proc-self-map-files-002.c int main(void) · line 66
Quoted 5 lines
tools/testing/selftests/proc/proc-self-map-files-002.c +1 -1
-	p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
+	p = mmap(va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
 	if (p == MAP_FAILED) {
 		if (errno == EPERM)
 			return 2;
I have sent a patch removing proc-self-map-files-002 AND making 001 to use as a HINT for mmap (MAP_FIXED) *at least* *(2 * PAGE_SIZE), which would, likely, attend all architectures, avoiding trying to make the test specific to one, and, still, test the symlinks for issues (like bad chars, spaces, so on).

If the goal is to test the lowest address then going for 2*PAGE_SIZE is a mistake.

Which BTW hints to add a test for the highest address.

Quoted 3 lines

Both tests (001 and 002) have pretty much the same code, while they could have 2 tests in a single code, using kselftest framework. Is NULL hint + MAP_FIXED something imperative for this test ? Why not to have all in a single test ?

I dislike tests which lump everything together into one process.

Quoted 2 lines

Are you keeping the NULL hint just to test mmap, apart" from the core of this test ?

Cyrill Gorcunov

2018-11-12 15:55 UTC #3 lore raw

On Mon, Nov 12, 2018 at 05:14:57PM +0300, Alexey Dobriyan wrote:
...

Quoted 8 lines

Quoted 8 lines
Quoted 8 lines
int main(void)
{
tools/testing/selftests/proc/proc-self-map-files-002.c +5 -0
 	const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+#ifdef __arm__
+	unsigned long va = 2 * PAGE_SIZE;
+#else
+	unsigned long va = 0;
+#endif

...

Quoted 9 lines

Quoted 5 lines
I have sent a patch removing proc-self-map-files-002 AND making 001 to use as a HINT for mmap (MAP_FIXED) *at least* *(2 * PAGE_SIZE), which would, likely, attend all architectures, avoiding trying to make the test specific to one, and, still, test the symlinks for issues (like bad chars, spaces, so on).
If the goal is to test the lowest address then going for 2*PAGE_SIZE is a mistake.

Quoted 10 lines

Which BTW hints to add a test for the highest address.
Quoted 3 lines
Both tests (001 and 002) have pretty much the same code, while they could have 2 tests in a single code, using kselftest framework. Is NULL hint + MAP_FIXED something imperative for this test ? Why not to have all in a single test ?
I dislike tests which lump everything together into one process.
Quoted 2 lines
Are you keeping the NULL hint just to test mmap, apart" from the core of this test ?

Guys, lets simply stick with Alexey's patch. I personnally think that testing mappings should be a separate test in vm/, but seriously this took too long already :) If Alexey's patch fixes the problem with arm I think we're fine.

Rafael David Tinoco

Tested-by

2018-11-12 16:35 UTC #4 lore raw

Quoted 28 lines · Cyrill Gorcunov

On Mon, Nov 12, 2018 at 05:14:57PM +0300, Alexey Dobriyan wrote:
...
Quoted 8 lines
Quoted 8 lines
Quoted 8 lines
  int main(void)
  {
  	const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
tools/testing/selftests/proc/proc-self-map-files-002.c +5 -0
+#ifdef __arm__
+	unsigned long va = 2 * PAGE_SIZE;
+#else
+	unsigned long va = 0;
+#endif
...
Quoted 17 lines
Quoted 5 lines
I have sent a patch removing proc-self-map-files-002 AND making 001 to use as a HINT for mmap (MAP_FIXED) *at least* *(2 * PAGE_SIZE), which would, likely, attend all architectures, avoiding trying to make the test specific to one, and, still, test the symlinks for issues (like bad chars, spaces, so on).
If the goal is to test the lowest address then going for 2*PAGE_SIZE is a mistake.
Which BTW hints to add a test for the highest address.
Quoted 3 lines
Both tests (001 and 002) have pretty much the same code, while they could have 2 tests in a single code, using kselftest framework. Is NULL hint + MAP_FIXED something imperative for this test ? Why not to have all in a single test ?
I dislike tests which lump everything together into one process.

Quoted 8 lines

Quoted 2 lines
Quoted 2 lines
Are you keeping the NULL hint just to test mmap, apart" from the core of this test ?
Guys, lets simply stick with Alexey's patch. I personnally think that testing mappings should be a separate test in vm/, but seriously this took too long already :) If Alexey's patch fixes the problem with arm I think we're fine.

Fine for me. It works in armhf.

Tested-by Rafael David Tinoco <rafael.tinoco at linaro.org>

Note: Maybe you should amend the patch and cast "va" in mmap() to avoid:

In file included from proc-self-map-files-002.c:7:
/usr/include/arm-linux-gnueabihf/sys/mman.h:57:14: note: expected ‘void *’ but argument is of type ‘long unsigned int’
extern void *mmap (void *__addr, size_t __len, int __prot,

--
Rafael D. Tinoco
Linaro Kernel Validation

Alexey Dobriyan

author

2018-11-13 16:54 UTC #5 lore raw

PATCH v2 1/1 proc: fixup map_files test on arm

https://bugs.linaro.org/show_bug.cgi?id=3782

Turns out arm doesn't allow to map address 0, so try minimum virtual address instead.

Reported-by Rafael David Tinoco <rafael.tinoco at linaro.org>

Tested-by Rafael David Tinoco <rafael.tinoco at linaro.org>

Signed-off-by Alexey Dobriyan <adobriyan at gmail.com>

---

 tools/testing/selftests/proc/proc-self-map-files-002.c |    9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

tools/testing/selftests/proc/proc-self-map-files-002.c +7 -2

@@ -13,7 +13,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
-/* Test readlink /proc/self/map_files/... with address 0. */
+/* Test readlink /proc/self/map_files/... with minimum address. */
 #include <errno.h>
 #include <sys/types.h>
 #include <sys/stat.h>

@@ -47,6 +47,11 @@ static void fail(const char *fmt, unsigned long a, unsigned long b)
 int main(void)
 {
 	const unsigned int PAGE_SIZE = sysconf(_SC_PAGESIZE);
+#ifdef __arm__
+	unsigned long va = 2 * PAGE_SIZE;
+#else
+	unsigned long va = 0;
+#endif
 	void *p;
 	int fd;
 	unsigned long a, b;

@@ -55,7 +60,7 @@ int main(void)
 	if (fd == -1)
 		return 1;
 
-	p = mmap(NULL, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
+	p = mmap((void *)va, PAGE_SIZE, PROT_NONE, MAP_PRIVATE|MAP_FILE|MAP_FIXED, fd, 0);
 	if (p == MAP_FAILED) {
 		if (errno == EPERM)
 			return 2;

Cyrill Gorcunov

Acked-by on v2 1/1

2018-11-13 17:01 UTC #6 lore raw

Quoted 8 lines · Alexey Dobriyan

https://bugs.linaro.org/show_bug.cgi?id=3782
Turns out arm doesn't allow to map address 0, so try minimum virtual address instead.
Reported-by Rafael David Tinoco <rafael.tinoco at linaro.org>
Tested-by Rafael David Tinoco <rafael.tinoco at linaro.org>
Signed-off-by Alexey Dobriyan <adobriyan at gmail.com>

Acked-by Cyrill Gorcunov <gorcunov at gmail.com>

Thank you!