revert "selftest: add simple test for soft-dirty bit"

Revert commit 58c7be84 ("selftest: add simple test for soft-dirty
bit").  This is the self test for Pavel's pagemap2 patches which didn't
actually get merged.
Reported-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/testing/selftests/Makefile

@@ -6,7 +6,6 @@ TARGETS += memory-hotplug
 TARGETS += mqueue
 TARGETS += net
 TARGETS += ptrace
-TARGETS += soft-dirty
 TARGETS += vm
 
 all:

tools/testing/selftests/soft-dirty/Makefile

-CFLAGS += -iquote../../../../include/uapi -Wall
-soft-dirty: soft-dirty.c
-
-all: soft-dirty
-
-clean:
-	rm -f soft-dirty
-
-run_tests: all
-	@./soft-dirty || echo "soft-dirty selftests: [FAIL]"

tools/testing/selftests/soft-dirty/soft-dirty.c

-#include <stdlib.h>
-#include <stdio.h>
-#include <sys/mman.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <sys/types.h>
-
-typedef unsigned long long u64;
-
-#define PME_PRESENT	(1ULL << 63)
-#define PME_SOFT_DIRTY	(1Ull << 55)
-
-#define PAGES_TO_TEST	3
-#ifndef PAGE_SIZE
-#define PAGE_SIZE	4096
-#endif
-
-static void get_pagemap2(char *mem, u64 *map)
-{
-	int fd;
-
-	fd = open("/proc/self/pagemap2", O_RDONLY);
-	if (fd < 0) {
-		perror("Can't open pagemap2");
-		exit(1);
-	}
-
-	lseek(fd, (unsigned long)mem / PAGE_SIZE * sizeof(u64), SEEK_SET);
-	read(fd, map, sizeof(u64) * PAGES_TO_TEST);
-	close(fd);
-}
-
-static inline char map_p(u64 map)
-{
-	return map & PME_PRESENT ? 'p' : '-';
-}
-
-static inline char map_sd(u64 map)
-{
-	return map & PME_SOFT_DIRTY ? 'd' : '-';
-}
-
-static int check_pte(int step, int page, u64 *map, u64 want)
-{
-	if ((map[page] & want) != want) {
-		printf("Step %d Page %d has %c%c, want %c%c\n",
-				step, page,
-				map_p(map[page]), map_sd(map[page]),
-				map_p(want), map_sd(want));
-		return 1;
-	}
-
-	return 0;
-}
-
-static void clear_refs(void)
-{
-	int fd;
-	char *v = "4";
-
-	fd = open("/proc/self/clear_refs", O_WRONLY);
-	if (write(fd, v, 3) < 3) {
-		perror("Can't clear soft-dirty bit");
-		exit(1);
-	}
-	close(fd);
-}
-
-int main(void)
-{
-	char *mem, x;
-	u64 map[PAGES_TO_TEST];
-
-	mem = mmap(NULL, PAGES_TO_TEST * PAGE_SIZE,
-			PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANON, 0, 0);
-
-	x = mem[0];
-	mem[2 * PAGE_SIZE] = 'c';
-	get_pagemap2(mem, map);
-
-	if (check_pte(1, 0, map, PME_PRESENT))
-		return 1;
-	if (check_pte(1, 1, map, 0))
-		return 1;
-	if (check_pte(1, 2, map, PME_PRESENT | PME_SOFT_DIRTY))
-		return 1;
-
-	clear_refs();
-	get_pagemap2(mem, map);
-
-	if (check_pte(2, 0, map, PME_PRESENT))
-		return 1;
-	if (check_pte(2, 1, map, 0))
-		return 1;
-	if (check_pte(2, 2, map, PME_PRESENT))
-		return 1;
-
-	mem[0] = 'a';
-	mem[PAGE_SIZE] = 'b';
-	x = mem[2 * PAGE_SIZE];
-	get_pagemap2(mem, map);
-
-	if (check_pte(3, 0, map, PME_PRESENT | PME_SOFT_DIRTY))
-		return 1;
-	if (check_pte(3, 1, map, PME_PRESENT | PME_SOFT_DIRTY))
-		return 1;
-	if (check_pte(3, 2, map, PME_PRESENT))
-		return 1;
-
-	(void)x; /* gcc warn */
-
-	printf("PASS\n");
-	return 0;
-}