[PATCH v4 47/55] selftests/mm: protection_keys: use library code for HugeTLB setup

[Mike Rapoport <rppt@kernel.org>]

From: "Mike Rapoport (Microsoft)" <rppt@kernel.org>

protection_keys open codes setup of HugeTLB pages.

Replace it with the library functions from hugepage_setup.

Replace exit() calls with _exit() to avoid restoring HugeTLB settings in
the middle of test.

Tested-by: Luiz Capitulino <luizcap@redhat.com>
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
---
 tools/testing/selftests/mm/protection_keys.c | 50 ++++++--------------
 1 file changed, 14 insertions(+), 36 deletions(-)

diff --git a/tools/testing/selftests/mm/protection_keys.c b/tools/testing/selftests/mm/protection_keys.c
index 4e4aa3b326c1..9a6d954ee371 100644
--- a/tools/testing/selftests/mm/protection_keys.c
+++ b/tools/testing/selftests/mm/protection_keys.c
@@ -62,6 +62,7 @@ noinline int read_ptr(int *ptr)
 	return *ptr;
 }
 
+#if CONTROL_TRACING > 0
 static void cat_into_file(char *str, char *file)
 {
 	int fd = open(file, O_RDWR);
@@ -87,7 +88,6 @@ static void cat_into_file(char *str, char *file)
 	close(fd);
 }
 
-#if CONTROL_TRACING > 0
 static int warned_tracing;
 static int tracing_root_ok(void)
 {
@@ -710,50 +710,28 @@ static void *malloc_pkey_anon_huge(long size, int prot, u16 pkey)
 }
 
 static int hugetlb_setup_ok;
-#define SYSFS_FMT_NR_HUGE_PAGES "/sys/kernel/mm/hugepages/hugepages-%ldkB/nr_hugepages"
 #define GET_NR_HUGE_PAGES 10
 static void setup_hugetlbfs(void)
 {
-	int err;
-	int fd;
-	char buf[256];
-	long hpagesz_kb;
-	long hpagesz_mb;
+	long hpagesz_mb = HPAGE_SIZE / 1024 / 1024;
+	unsigned long free_pages;
 
 	if (geteuid() != 0) {
 		ksft_print_msg("WARNING: not run as root, can not do hugetlb test\n");
 		return;
 	}
 
-	cat_into_file(__stringify(GET_NR_HUGE_PAGES), "/proc/sys/vm/nr_hugepages");
-
 	/*
-	 * Now go make sure that we got the pages and that they
+	 * Make sure that we got the pages and that they
 	 * are PMD-level pages. Someone might have made PUD-level
 	 * pages the default.
 	 */
-	hpagesz_kb = HPAGE_SIZE / 1024;
-	hpagesz_mb = hpagesz_kb / 1024;
-	sprintf(buf, SYSFS_FMT_NR_HUGE_PAGES, hpagesz_kb);
-	fd = open(buf, O_RDONLY);
-	if (fd < 0) {
-		fprintf(stderr, "opening sysfs %ldM hugetlb config: %s\n",
-			hpagesz_mb, strerror(errno));
-		return;
-	}
-
-	/* -1 to guarantee leaving the trailing \0 */
-	err = read(fd, buf, sizeof(buf)-1);
-	close(fd);
-	if (err <= 0) {
-		fprintf(stderr, "reading sysfs %ldM hugetlb config: %s\n",
-			hpagesz_mb, strerror(errno));
-		return;
-	}
-
-	if (atoi(buf) != GET_NR_HUGE_PAGES) {
-		fprintf(stderr, "could not confirm %ldM pages, got: '%s' expected %d\n",
-			hpagesz_mb, buf, GET_NR_HUGE_PAGES);
+	hugetlb_save_settings();
+	hugetlb_set_nr_pages(HPAGE_SIZE, GET_NR_HUGE_PAGES);
+	free_pages = hugetlb_free_pages(HPAGE_SIZE);
+	if (free_pages < GET_NR_HUGE_PAGES) {
+		ksft_print_msg("could not confirm %ldM pages, got: '%lu' expected %d\n",
+			       hpagesz_mb, free_pages, GET_NR_HUGE_PAGES);
 		return;
 	}
 
@@ -1130,7 +1108,7 @@ static void become_child(void)
 		/* in the child */
 		return;
 	}
-	exit(0);
+	_exit(0);
 }
 
 /* Assumes that all pkeys other than 'pkey' are unallocated */
@@ -1509,18 +1487,18 @@ static void test_ptrace_modifies_pkru(int *ptr, u16 pkey)
 		 * checking
 		 */
 		if (__read_pkey_reg() != new_pkru)
-			exit(1);
+			_exit(1);
 
 		/* Stop and allow the tracer to clear XSTATE_BV for PKRU */
 		raise(SIGSTOP);
 
 		if (__read_pkey_reg() != 0)
-			exit(1);
+			_exit(1);
 
 		/* Stop and allow the tracer to examine PKRU */
 		raise(SIGSTOP);
 
-		exit(0);
+		_exit(0);
 	}
 
 	pkey_assert(child == waitpid(child, &status, 0));
-- 
2.53.0