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From: bauerman at linux.ibm.com (Thiago Jung Bauermann)
Subject: [PATCH v2 1/4] userfaultfd: selftest: Fix checking of userfaultfd_open() result
Date: Fri,  3 Aug 2018 19:00:43 -0300	[thread overview]
Message-ID: <20180803220046.4019-2-bauerman@linux.ibm.com> (raw)
In-Reply-To: <20180803220046.4019-1-bauerman@linux.ibm.com>

If the userfaultfd test is run on a kernel with CONFIG_USERFAULTFD=n, it
will report that the system call is not available yet go ahead and continue
anyway:

  # ./userfaultfd anon 30 1
  nr_pages: 480, nr_pages_per_cpu: 120
  userfaultfd syscall not available in this kernel
  bounces: 0, mode:, register failure

This is because userfaultfd_open() returns 0 on success and 1 on error but
all callers assume that it returns < 0 on error.

Since the convention of the test as a whole is the one used by
userfault_open(), fix its callers instead. Now the test behaves correctly:

  # ./userfaultfd anon 30 1
  nr_pages: 480, nr_pages_per_cpu: 120
  userfaultfd syscall not available in this kernel

Signed-off-by: Thiago Jung Bauermann <bauerman at linux.ibm.com>
---
 tools/testing/selftests/vm/userfaultfd.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 7b8171e3128a..e4099afe7557 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -859,7 +859,7 @@ static int userfaultfd_zeropage_test(void)
 	if (uffd_test_ops->release_pages(area_dst))
 		return 1;
 
-	if (userfaultfd_open(0) < 0)
+	if (userfaultfd_open(0))
 		return 1;
 	uffdio_register.range.start = (unsigned long) area_dst;
 	uffdio_register.range.len = nr_pages * page_size;
@@ -902,7 +902,7 @@ static int userfaultfd_events_test(void)
 
 	features = UFFD_FEATURE_EVENT_FORK | UFFD_FEATURE_EVENT_REMAP |
 		UFFD_FEATURE_EVENT_REMOVE;
-	if (userfaultfd_open(features) < 0)
+	if (userfaultfd_open(features))
 		return 1;
 	fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK);
 
@@ -961,7 +961,7 @@ static int userfaultfd_sig_test(void)
 		return 1;
 
 	features = UFFD_FEATURE_EVENT_FORK|UFFD_FEATURE_SIGBUS;
-	if (userfaultfd_open(features) < 0)
+	if (userfaultfd_open(features))
 		return 1;
 	fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK);
 
@@ -1027,7 +1027,7 @@ static int userfaultfd_stress(void)
 	if (!area_dst)
 		return 1;
 
-	if (userfaultfd_open(0) < 0)
+	if (userfaultfd_open(0))
 		return 1;
 
 	count_verify = malloc(nr_pages * sizeof(unsigned long long));

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WARNING: multiple messages have this Message-ID (diff)
From: bauerman@linux.ibm.com (Thiago Jung Bauermann)
Subject: [PATCH v2 1/4] userfaultfd: selftest: Fix checking of userfaultfd_open() result
Date: Fri,  3 Aug 2018 19:00:43 -0300	[thread overview]
Message-ID: <20180803220046.4019-2-bauerman@linux.ibm.com> (raw)
Message-ID: <20180803220043.m_bGgRWSdaObxaylZ7hHEbKdL_jINJF81EkQNeVTHx8@z> (raw)
In-Reply-To: <20180803220046.4019-1-bauerman@linux.ibm.com>

If the userfaultfd test is run on a kernel with CONFIG_USERFAULTFD=n, it
will report that the system call is not available yet go ahead and continue
anyway:

  # ./userfaultfd anon 30 1
  nr_pages: 480, nr_pages_per_cpu: 120
  userfaultfd syscall not available in this kernel
  bounces: 0, mode:, register failure

This is because userfaultfd_open() returns 0 on success and 1 on error but
all callers assume that it returns < 0 on error.

Since the convention of the test as a whole is the one used by
userfault_open(), fix its callers instead. Now the test behaves correctly:

  # ./userfaultfd anon 30 1
  nr_pages: 480, nr_pages_per_cpu: 120
  userfaultfd syscall not available in this kernel

Signed-off-by: Thiago Jung Bauermann <bauerman at linux.ibm.com>
---
 tools/testing/selftests/vm/userfaultfd.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 7b8171e3128a..e4099afe7557 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -859,7 +859,7 @@ static int userfaultfd_zeropage_test(void)
 	if (uffd_test_ops->release_pages(area_dst))
 		return 1;
 
-	if (userfaultfd_open(0) < 0)
+	if (userfaultfd_open(0))
 		return 1;
 	uffdio_register.range.start = (unsigned long) area_dst;
 	uffdio_register.range.len = nr_pages * page_size;
@@ -902,7 +902,7 @@ static int userfaultfd_events_test(void)
 
 	features = UFFD_FEATURE_EVENT_FORK | UFFD_FEATURE_EVENT_REMAP |
 		UFFD_FEATURE_EVENT_REMOVE;
-	if (userfaultfd_open(features) < 0)
+	if (userfaultfd_open(features))
 		return 1;
 	fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK);
 
@@ -961,7 +961,7 @@ static int userfaultfd_sig_test(void)
 		return 1;
 
 	features = UFFD_FEATURE_EVENT_FORK|UFFD_FEATURE_SIGBUS;
-	if (userfaultfd_open(features) < 0)
+	if (userfaultfd_open(features))
 		return 1;
 	fcntl(uffd, F_SETFL, uffd_flags | O_NONBLOCK);
 
@@ -1027,7 +1027,7 @@ static int userfaultfd_stress(void)
 	if (!area_dst)
 		return 1;
 
-	if (userfaultfd_open(0) < 0)
+	if (userfaultfd_open(0))
 		return 1;
 
 	count_verify = malloc(nr_pages * sizeof(unsigned long long));

--
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  parent reply	other threads:[~2018-08-03 22:00 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-03 22:00 [PATCH v2 0/4] userfaultfd: selftest: Improve behavior with older kernels bauerman
2018-08-03 22:00 ` Thiago Jung Bauermann
2018-08-03 22:00 ` bauerman [this message]
2018-08-03 22:00   ` [PATCH v2 1/4] userfaultfd: selftest: Fix checking of userfaultfd_open() result Thiago Jung Bauermann
2018-08-07  6:50   ` rppt
2018-08-07  6:50     ` Mike Rapoport
2018-08-03 22:00 ` [PATCH v2 2/4] userfaultfd: selftest: Skip test if userfaultfd() syscall not supported bauerman
2018-08-03 22:00   ` Thiago Jung Bauermann
2018-08-07  6:50   ` rppt
2018-08-07  6:50     ` Mike Rapoport
2018-08-03 22:00 ` [PATCH v2 3/4] userfaultfd: selftest: Skip test if a feature isn't supported bauerman
2018-08-03 22:00   ` Thiago Jung Bauermann
2018-08-07  6:51   ` rppt
2018-08-07  6:51     ` Mike Rapoport
2018-08-03 22:00 ` [PATCH v2 4/4] userfaultfd: selftest: Cope if shmem doesn't support zeropage bauerman
2018-08-03 22:00   ` Thiago Jung Bauermann
2018-08-07  6:56   ` rppt
2018-08-07  6:56     ` Mike Rapoport
2018-08-28  2:46     ` bauerman
2018-08-28  2:46       ` Thiago Jung Bauermann
2018-08-28  6:15       ` rppt
2018-08-28  6:15         ` Mike Rapoport

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