mm/selftests: hugepage-mremap: conform test to TAP format output

Conform the layout, informational and status messages to TAP.  No
functional change is intended other than the layout of output messages.

Link: https://lkml.kernel.org/r/20240102081919.2325570-1-usama.anjum@collabora.com
Signed-off-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: Muhammad Usama Anjum

tools/testing/selftests/mm/hugepage-mremap.c

@@ -24,6 +24,7 @@
 #include <sys/ioctl.h>
 #include <string.h>
 #include <stdbool.h>
+#include "../kselftest.h"
 #include "vm_util.h"
 
 #define DEFAULT_LENGTH_MB 10UL
@@ -34,7 +35,7 @@
 
 static void check_bytes(char *addr)
 {
-	printf("First hex is %x\n", *((unsigned int *)addr));
+	ksft_print_msg("First hex is %x\n", *((unsigned int *)addr));
 }
 
 static void write_bytes(char *addr, size_t len)
@@ -52,7 +53,7 @@ static int read_bytes(char *addr, size_t len)
 	check_bytes(addr);
 	for (i = 0; i < len; i++)
 		if (*(addr + i) != (char)i) {
-			printf("Mismatch at %lu\n", i);
+			ksft_print_msg("Mismatch at %lu\n", i);
 			return 1;
 		}
 	return 0;
@@ -66,17 +67,13 @@ static void register_region_with_uffd(char *addr, size_t len)
 	/* Create and enable userfaultfd object. */
 
 	uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK);
-	if (uffd == -1) {
-		perror("userfaultfd");
-		exit(1);
-	}
+	if (uffd == -1)
+		ksft_exit_fail_msg("userfaultfd: %s\n", strerror(errno));
 
 	uffdio_api.api = UFFD_API;
 	uffdio_api.features = 0;
-	if (ioctl(uffd, UFFDIO_API, &uffdio_api) == -1) {
-		perror("ioctl-UFFDIO_API");
-		exit(1);
-	}
+	if (ioctl(uffd, UFFDIO_API, &uffdio_api) == -1)
+		ksft_exit_fail_msg("ioctl-UFFDIO_API: %s\n", strerror(errno));
 
 	/* Create a private anonymous mapping. The memory will be
 	 * demand-zero paged--that is, not yet allocated. When we
@@ -86,32 +83,29 @@ static void register_region_with_uffd(char *addr, size_t len)
 
 	addr = mmap(NULL, len, PROT_READ | PROT_WRITE,
 		    MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
-	if (addr == MAP_FAILED) {
-		perror("mmap");
-		exit(1);
-	}
+	if (addr == MAP_FAILED)
+		ksft_exit_fail_msg("mmap: %s\n", strerror(errno));
 
-	printf("Address returned by mmap() = %p\n", addr);
+	ksft_print_msg("Address returned by mmap() = %p\n", addr);
 
 	/* Register the memory range of the mapping we just created for
 	 * handling by the userfaultfd object. In mode, we request to track
 	 * missing pages (i.e., pages that have not yet been faulted in).
 	 */
-	if (uffd_register(uffd, addr, len, true, false, false)) {
-		perror("ioctl-UFFDIO_REGISTER");
-		exit(1);
-	}
+	if (uffd_register(uffd, addr, len, true, false, false))
+		ksft_exit_fail_msg("ioctl-UFFDIO_REGISTER: %s\n", strerror(errno));
 }
 
 int main(int argc, char *argv[])
 {
 	size_t length = 0;
 	int ret = 0, fd;
 
-	if (argc >= 2 && !strcmp(argv[1], "-h")) {
-		printf("Usage: %s [length_in_MB]\n", argv[0]);
-		exit(1);
-	}
+	ksft_print_header();
+	ksft_set_plan(1);
+
+	if (argc >= 2 && !strcmp(argv[1], "-h"))
+		ksft_exit_fail_msg("Usage: %s [length_in_MB]\n", argv[0]);
 
 	/* Read memory length as the first arg if valid, otherwise fallback to
 	 * the default length.
@@ -123,63 +117,52 @@ int main(int argc, char *argv[])
 
 	length = MB_TO_BYTES(length);
 	fd = memfd_create(argv[0], MFD_HUGETLB);
-	if (fd < 0) {
-		perror("Open failed");
-		exit(1);
-	}
+	if (fd < 0)
+		ksft_exit_fail_msg("Open failed: %s\n", strerror(errno));
 
 	/* mmap to a PUD aligned address to hopefully trigger pmd sharing. */
 	unsigned long suggested_addr = 0x7eaa40000000;
 	void *haddr = mmap((void *)suggested_addr, length, PROTECTION,
 			   MAP_HUGETLB | MAP_SHARED | MAP_POPULATE, fd, 0);
-	printf("Map haddr: Returned address is %p\n", haddr);
-	if (haddr == MAP_FAILED) {
-		perror("mmap1");
-		exit(1);
-	}
+	ksft_print_msg("Map haddr: Returned address is %p\n", haddr);
+	if (haddr == MAP_FAILED)
+		ksft_exit_fail_msg("mmap1: %s\n", strerror(errno));
 
 	/* mmap again to a dummy address to hopefully trigger pmd sharing. */
 	suggested_addr = 0x7daa40000000;
 	void *daddr = mmap((void *)suggested_addr, length, PROTECTION,
 			   MAP_HUGETLB | MAP_SHARED | MAP_POPULATE, fd, 0);
-	printf("Map daddr: Returned address is %p\n", daddr);
-	if (daddr == MAP_FAILED) {
-		perror("mmap3");
-		exit(1);
-	}
+	ksft_print_msg("Map daddr: Returned address is %p\n", daddr);
+	if (daddr == MAP_FAILED)
+		ksft_exit_fail_msg("mmap3: %s\n", strerror(errno));
 
 	suggested_addr = 0x7faa40000000;
 	void *vaddr =
 		mmap((void *)suggested_addr, length, PROTECTION, FLAGS, -1, 0);
-	printf("Map vaddr: Returned address is %p\n", vaddr);
-	if (vaddr == MAP_FAILED) {
-		perror("mmap2");
-		exit(1);
-	}
+	ksft_print_msg("Map vaddr: Returned address is %p\n", vaddr);
+	if (vaddr == MAP_FAILED)
+		ksft_exit_fail_msg("mmap2: %s\n", strerror(errno));
 
 	register_region_with_uffd(haddr, length);
 
 	void *addr = mremap(haddr, length, length,
 			    MREMAP_MAYMOVE | MREMAP_FIXED, vaddr);
-	if (addr == MAP_FAILED) {
-		perror("mremap");
-		exit(1);
-	}
+	if (addr == MAP_FAILED)
+		ksft_exit_fail_msg("mremap: %s\n", strerror(errno));
 
-	printf("Mremap: Returned address is %p\n", addr);
+	ksft_print_msg("Mremap: Returned address is %p\n", addr);
 	check_bytes(addr);
 	write_bytes(addr, length);
 	ret = read_bytes(addr, length);
 
 	munmap(addr, length);
 
 	addr = mremap(addr, length, length, 0);
-	if (addr != MAP_FAILED) {
-		printf("mremap: Expected failure, but call succeeded\n");
-		exit(1);
-	}
+	if (addr != MAP_FAILED)
+		ksft_exit_fail_msg("mremap: Expected failure, but call succeeded\n");
 
 	close(fd);
 
-	return ret;
+	ksft_test_result(!ret, "Read same data\n");
+	ksft_exit(!ret);
 }