1 files changed, 246 insertions, 0 deletions
diff --git a/tools/testing/selftests/mm/virtual_address_range.c b/tools/testing/selftests/mm/virtual_address_range.c
new file mode 100644
index 000000000000..b380e102b22f
--- /dev/null
+++ b/tools/testing/selftests/mm/virtual_address_range.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2017, Anshuman Khandual, IBM Corp.
+ *
+ * Works on architectures which support 128TB virtual
+ * address range and beyond.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <sys/prctl.h>
+#include <sys/mman.h>
+#include <sys/time.h>
+#include <fcntl.h>
+
+#include "vm_util.h"
+#include "../kselftest.h"
+
+/*
+ * Maximum address range mapped with a single mmap()
+ * call is little bit more than 1GB. Hence 1GB is
+ * chosen as the single chunk size for address space
+ * mapping.
+ */
+
+#define SZ_1GB	(1024 * 1024 * 1024UL)
+#define SZ_1TB	(1024 * 1024 * 1024 * 1024UL)
+
+#define MAP_CHUNK_SIZE	SZ_1GB
+
+/*
+ * Address space till 128TB is mapped without any hint
+ * and is enabled by default. Address space beyond 128TB
+ * till 512TB is obtained by passing hint address as the
+ * first argument into mmap() system call.
+ *
+ * The process heap address space is divided into two
+ * different areas one below 128TB and one above 128TB
+ * till it reaches 512TB. One with size 128TB and the
+ * other being 384TB.
+ *
+ * On Arm64 the address space is 256TB and support for
+ * high mappings up to 4PB virtual address space has
+ * been added.
+ */
+
+#define NR_CHUNKS_128TB   ((128 * SZ_1TB) / MAP_CHUNK_SIZE) /* Number of chunks for 128TB */
+#define NR_CHUNKS_256TB   (NR_CHUNKS_128TB * 2UL)
+#define NR_CHUNKS_384TB   (NR_CHUNKS_128TB * 3UL)
+#define NR_CHUNKS_3840TB  (NR_CHUNKS_128TB * 30UL)
+
+#define ADDR_MARK_128TB  (1UL << 47) /* First address beyond 128TB */
+#define ADDR_MARK_256TB  (1UL << 48) /* First address beyond 256TB */
+
+#ifdef __aarch64__
+#define HIGH_ADDR_MARK  ADDR_MARK_256TB
+#define HIGH_ADDR_SHIFT 49
+#define NR_CHUNKS_LOW   NR_CHUNKS_256TB
+#define NR_CHUNKS_HIGH  NR_CHUNKS_3840TB
+#else
+#define HIGH_ADDR_MARK  ADDR_MARK_128TB
+#define HIGH_ADDR_SHIFT 48
+#define NR_CHUNKS_LOW   NR_CHUNKS_128TB
+#define NR_CHUNKS_HIGH  NR_CHUNKS_384TB
+#endif
+
+static char *hint_addr(void)
+{
+	int bits = HIGH_ADDR_SHIFT + rand() % (63 - HIGH_ADDR_SHIFT);
+
+	return (char *) (1UL << bits);
+}
+
+static void validate_addr(char *ptr, int high_addr)
+{
+	unsigned long addr = (unsigned long) ptr;
+
+	if (high_addr && addr < HIGH_ADDR_MARK)
+		ksft_exit_fail_msg("Bad address %lx\n", addr);
+
+	if (addr > HIGH_ADDR_MARK)
+		ksft_exit_fail_msg("Bad address %lx\n", addr);
+}
+
+static void mark_range(char *ptr, size_t size)
+{
+	if (prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, ptr, size, "virtual_address_range") == -1) {
+		if (errno == EINVAL) {
+			/* Depends on CONFIG_ANON_VMA_NAME */
+			ksft_test_result_skip("prctl(PR_SET_VMA_ANON_NAME) not supported\n");
+			ksft_finished();
+		} else {
+			ksft_exit_fail_perror("prctl(PR_SET_VMA_ANON_NAME) failed\n");
+		}
+	}
+}
+
+static int is_marked_vma(const char *vma_name)
+{
+	return vma_name && !strcmp(vma_name, "[anon:virtual_address_range]\n");
+}
+
+static int validate_lower_address_hint(void)
+{
+	char *ptr;
+
+	ptr = mmap((void *) (1UL << 45), MAP_CHUNK_SIZE, PROT_READ |
+		   PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+	if (ptr == MAP_FAILED)
+		return 0;
+
+	return 1;
+}
+
+static int validate_complete_va_space(void)
+{
+	unsigned long start_addr, end_addr, prev_end_addr;
+	char line[400];
+	char prot[6];
+	FILE *file;
+	int fd;
+
+	fd = open("va_dump", O_CREAT | O_WRONLY, 0600);
+	unlink("va_dump");
+	if (fd < 0) {
+		ksft_test_result_skip("cannot create or open dump file\n");
+		ksft_finished();
+	}
+
+	file = fopen("/proc/self/maps", "r");
+	if (file == NULL)
+		ksft_exit_fail_msg("cannot open /proc/self/maps\n");
+
+	prev_end_addr = 0;
+	while (fgets(line, sizeof(line), file)) {
+		const char *vma_name = NULL;
+		int vma_name_start = 0;
+		unsigned long hop;
+
+		if (sscanf(line, "%lx-%lx %4s %*s %*s %*s %n",
+			   &start_addr, &end_addr, prot, &vma_name_start) != 3)
+			ksft_exit_fail_msg("cannot parse /proc/self/maps\n");
+
+		if (vma_name_start)
+			vma_name = line + vma_name_start;
+
+		/* end of userspace mappings; ignore vsyscall mapping */
+		if (start_addr & (1UL << 63))
+			return 0;
+
+		/* /proc/self/maps must have gaps less than MAP_CHUNK_SIZE */
+		if (start_addr - prev_end_addr >= MAP_CHUNK_SIZE)
+			return 1;
+
+		prev_end_addr = end_addr;
+
+		if (prot[0] != 'r')
+			continue;
+
+		if (check_vmflag_io((void *)start_addr))
+			continue;
+
+		/*
+		 * Confirm whether MAP_CHUNK_SIZE chunk can be found or not.
+		 * If write succeeds, no need to check MAP_CHUNK_SIZE - 1
+		 * addresses after that. If the address was not held by this
+		 * process, write would fail with errno set to EFAULT.
+		 * Anyways, if write returns anything apart from 1, exit the
+		 * program since that would mean a bug in /proc/self/maps.
+		 */
+		hop = 0;
+		while (start_addr + hop < end_addr) {
+			if (write(fd, (void *)(start_addr + hop), 1) != 1)
+				return 1;
+			lseek(fd, 0, SEEK_SET);
+
+			if (is_marked_vma(vma_name))
+				munmap((char *)(start_addr + hop), MAP_CHUNK_SIZE);
+
+			hop += MAP_CHUNK_SIZE;
+		}
+	}
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	char *ptr[NR_CHUNKS_LOW];
+	char **hptr;
+	char *hint;
+	unsigned long i, lchunks, hchunks;
+
+	ksft_print_header();
+	ksft_set_plan(1);
+
+	for (i = 0; i < NR_CHUNKS_LOW; i++) {
+		ptr[i] = mmap(NULL, MAP_CHUNK_SIZE, PROT_READ,
+			      MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+		if (ptr[i] == MAP_FAILED) {
+			if (validate_lower_address_hint())
+				ksft_exit_fail_msg("mmap unexpectedly succeeded with hint\n");
+			break;
+		}
+
+		mark_range(ptr[i], MAP_CHUNK_SIZE);
+		validate_addr(ptr[i], 0);
+	}
+	lchunks = i;
+	hptr = (char **) calloc(NR_CHUNKS_HIGH, sizeof(char *));
+	if (hptr == NULL) {
+		ksft_test_result_skip("Memory constraint not fulfilled\n");
+		ksft_finished();
+	}
+
+	for (i = 0; i < NR_CHUNKS_HIGH; i++) {
+		hint = hint_addr();
+		hptr[i] = mmap(hint, MAP_CHUNK_SIZE, PROT_READ,
+			       MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
+
+		if (hptr[i] == MAP_FAILED)
+			break;
+
+		mark_range(ptr[i], MAP_CHUNK_SIZE);
+		validate_addr(hptr[i], 1);
+	}
+	hchunks = i;
+	if (validate_complete_va_space()) {
+		ksft_test_result_fail("BUG in mmap() or /proc/self/maps\n");
+		ksft_finished();
+	}
+
+	for (i = 0; i < lchunks; i++)
+		munmap(ptr[i], MAP_CHUNK_SIZE);
+
+	for (i = 0; i < hchunks; i++)
+		munmap(hptr[i], MAP_CHUNK_SIZE);
+
+	free(hptr);
+
+	ksft_test_result_pass("Test\n");
+	ksft_finished();
+}