linux-kernel - [PATCH 15/29] selftests/mm: uffd_open

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Thu, 30 Mar 2023 12:07:49 -0400
From:   Peter Xu <peterx@...hat.com>
To:     linux-mm@...ck.org, linux-kernel@...r.kernel.org
Cc:     Andrea Arcangeli <aarcange@...hat.com>, peterx@...hat.com,
        David Hildenbrand <david@...hat.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Nadav Amit <nadav.amit@...il.com>,
        Mike Kravetz <mike.kravetz@...cle.com>,
        Axel Rasmussen <axelrasmussen@...gle.com>,
        Leonardo Bras Soares Passos <lsoaresp@...hat.com>,
        Mike Rapoport <rppt@...ux.vnet.ibm.com>
Subject: [PATCH 15/29] selftests/mm: uffd_open_{dev|sys}()

Provide two helpers to open an uffd handle.  Drop the error checks around
SKIPs because it's inside an errexit() anyway, which IMHO doesn't really
help much if the test will not continue.

Signed-off-by: Peter Xu <peterx@...hat.com>
---
 tools/testing/selftests/mm/uffd-common.c | 28 +++++-------------------
 tools/testing/selftests/mm/vm_util.c     | 24 ++++++++++++++++++++
 2 files changed, 29 insertions(+), 23 deletions(-)

diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
index 17f2bb82c3db..3a9b5c1aca9d 100644
--- a/tools/testing/selftests/mm/uffd-common.c
+++ b/tools/testing/selftests/mm/uffd-common.c
@@ -192,34 +192,16 @@ void uffd_stats_report(struct uffd_stats *stats, int n_cpus)
 	printf("\n");
 }
 
-static int __userfaultfd_open_dev(void)
-{
-	int fd, _uffd;
-
-	fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC);
-	if (fd < 0)
-		errexit(KSFT_SKIP, "opening /dev/userfaultfd failed");
-
-	_uffd = ioctl(fd, USERFAULTFD_IOC_NEW, UFFD_FLAGS);
-	if (_uffd < 0)
-		errexit(errno == ENOTTY ? KSFT_SKIP : 1,
-			"creating userfaultfd failed");
-	close(fd);
-	return _uffd;
-}
-
 void userfaultfd_open(uint64_t *features)
 {
 	struct uffdio_api uffdio_api;
 
 	if (test_dev_userfaultfd)
-		uffd = __userfaultfd_open_dev();
-	else {
-		uffd = syscall(__NR_userfaultfd, UFFD_FLAGS);
-		if (uffd < 0)
-			errexit(errno == ENOSYS ? KSFT_SKIP : 1,
-				"creating userfaultfd failed");
-	}
+		uffd = uffd_open_dev(UFFD_FLAGS);
+	else
+		uffd = uffd_open_sys(UFFD_FLAGS);
+	if (uffd < 0)
+		err("uffd open failed (dev=%d)", test_dev_userfaultfd);
 	uffd_flags = fcntl(uffd, F_GETFD, NULL);
 
 	uffdio_api.api = UFFD_API;
diff --git a/tools/testing/selftests/mm/vm_util.c b/tools/testing/selftests/mm/vm_util.c
index 10e76400ed70..7c2bf88d6393 100644
--- a/tools/testing/selftests/mm/vm_util.c
+++ b/tools/testing/selftests/mm/vm_util.c
@@ -3,6 +3,8 @@
 #include <fcntl.h>
 #include <sys/ioctl.h>
 #include <linux/userfaultfd.h>
+#include <sys/syscall.h>
+#include <unistd.h>
 #include "../kselftest.h"
 #include "vm_util.h"
 
@@ -230,3 +232,25 @@ int uffd_unregister(int uffd, void *addr, uint64_t len)
 
 	return ret;
 }
+
+int uffd_open_dev(unsigned int flags)
+{
+	int fd, uffd;
+
+	fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC);
+	if (fd < 0)
+		return fd;
+	uffd = ioctl(fd, USERFAULTFD_IOC_NEW, flags);
+	close(fd);
+
+	return uffd;
+}
+
+int uffd_open_sys(unsigned int flags)
+{
+#ifdef __NR_userfaultfd
+	return syscall(__NR_userfaultfd, flags);
+#else
+	return -1;
+#endif
+}
-- 
2.39.1