[PATCH v15 11/23] selftests: vm: pkeys: Use the correct huge page size

[Sandipan Das <sandipan@xxxxxxxxxxxxx>]

The huge page size can vary across architectures. This will
ensure that the correct huge page size is used when accessing
the hugetlb controls under sysfs. Instead of using a hardcoded
page size (i.e. 2MB), this now uses the HPAGE_SIZE macro which
is arch-specific.

Cc: Dave Hansen <dave.hansen@xxxxxxxxx>
Cc: Florian Weimer <fweimer@xxxxxxxxxx>
Cc: Ram Pai <linuxram@xxxxxxxxxx>
Signed-off-by: Sandipan Das <sandipan@xxxxxxxxxxxxx>
---
 tools/testing/selftests/vm/protection_keys.c | 23 ++++++++++++++------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c
index d3c13283bbd0..2327cfa0b836 100644
--- a/tools/testing/selftests/vm/protection_keys.c
+++ b/tools/testing/selftests/vm/protection_keys.c
@@ -738,12 +738,15 @@ void *malloc_pkey_anon_huge(long size, int prot, u16 pkey)
 }
 
 int hugetlb_setup_ok;
+#define SYSFS_FMT_NR_HUGE_PAGES "/sys/kernel/mm/hugepages/hugepages-%ldkB/nr_hugepages"
 #define GET_NR_HUGE_PAGES 10
 void setup_hugetlbfs(void)
 {
 	int err;
 	int fd;
-	char buf[] = "123";
+	char buf[256];
+	long hpagesz_kb;
+	long hpagesz_mb;
 
 	if (geteuid() != 0) {
 		fprintf(stderr, "WARNING: not run as root, can not do hugetlb test\n");
@@ -754,11 +757,16 @@ void setup_hugetlbfs(void)
 
 	/*
 	 * Now go make sure that we got the pages and that they
-	 * are 2M pages.  Someone might have made 1G the default.
+	 * are PMD-level pages. Someone might have made PUD-level
+	 * pages the default.
 	 */
-	fd = open("/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages", O_RDONLY);
+	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) {
-		perror("opening sysfs 2M hugetlb config");
+		fprintf(stderr, "opening sysfs %ldM hugetlb config: %s\n",
+			hpagesz_mb, strerror(errno));
 		return;
 	}
 
@@ -766,13 +774,14 @@ void setup_hugetlbfs(void)
 	err = read(fd, buf, sizeof(buf)-1);
 	close(fd);
 	if (err <= 0) {
-		perror("reading sysfs 2M hugetlb config");
+		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 2M pages, got: '%s' expected %d\n",
-			buf, GET_NR_HUGE_PAGES);
+		fprintf(stderr, "could not confirm %ldM pages, got: '%s' expected %d\n",
+			hpagesz_mb, buf, GET_NR_HUGE_PAGES);
 		return;
 	}
 
-- 
2.17.1