1// SPDX-License-Identifier: GPL-2.0
2/*
3 * This test covers the anonymous VMA naming functionality through prctl calls
4 */
5
6#include <errno.h>
7#include <sys/prctl.h>
8#include <stdio.h>
9#include <stdlib.h>
10#include <sys/mman.h>
11#include <string.h>
12
13#include "../kselftest_harness.h"
14
15#define AREA_SIZE 1024
16
17#define GOOD_NAME "goodname"
18#define BAD_NAME "badname\1"
19
20#ifndef PR_SET_VMA
21#define PR_SET_VMA 0x53564d41
22#define PR_SET_VMA_ANON_NAME 0
23#endif
24
25
26int rename_vma(unsigned long addr, unsigned long size, char *name)
27{
28	int res;
29
30	res = prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, addr, size, name);
31	if (res < 0)
32		return -errno;
33	return res;
34}
35
36int was_renaming_successful(char *target_name, unsigned long ptr)
37{
38	FILE *maps_file;
39
40	char line_buf[512], name[128], mode[8];
41	unsigned long start_addr, end_addr, offset;
42	unsigned int major_id, minor_id, node_id;
43
44	char target_buf[128];
45	int res = 0, sscanf_res;
46
47	// The entry name in maps will be in format [anon:<target_name>]
48	sprintf(target_buf, "[anon:%s]", target_name);
49	maps_file = fopen("/proc/self/maps", "r");
50	if (!maps_file) {
51		printf("## /proc/self/maps file opening error\n");
52		return 0;
53	}
54
55	// Parse the maps file to find the entry we renamed
56	while (fgets(line_buf, sizeof(line_buf), maps_file)) {
57		sscanf_res = sscanf(line_buf, "%lx-%lx %7s %lx %u:%u %u %s", &start_addr,
58					&end_addr, mode, &offset, &major_id,
59					&minor_id, &node_id, name);
60		if (sscanf_res == EOF) {
61			res = 0;
62			printf("## EOF while parsing the maps file\n");
63			break;
64		}
65		if (!strcmp(name, target_buf) && start_addr == ptr) {
66			res = 1;
67			break;
68		}
69	}
70	fclose(maps_file);
71	return res;
72}
73
74FIXTURE(vma) {
75	void *ptr_anon, *ptr_not_anon;
76};
77
78FIXTURE_SETUP(vma) {
79	self->ptr_anon = mmap(NULL, AREA_SIZE, PROT_READ | PROT_WRITE,
80					MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
81	ASSERT_NE(self->ptr_anon, NULL);
82	self->ptr_not_anon = mmap(NULL, AREA_SIZE, PROT_READ | PROT_WRITE,
83					MAP_PRIVATE, 0, 0);
84	ASSERT_NE(self->ptr_not_anon, NULL);
85}
86
87FIXTURE_TEARDOWN(vma) {
88	munmap(self->ptr_anon, AREA_SIZE);
89	munmap(self->ptr_not_anon, AREA_SIZE);
90}
91
92TEST_F(vma, renaming) {
93	TH_LOG("Try to rename the VMA with correct parameters");
94	EXPECT_GE(rename_vma((unsigned long)self->ptr_anon, AREA_SIZE, GOOD_NAME), 0);
95	EXPECT_TRUE(was_renaming_successful(GOOD_NAME, (unsigned long)self->ptr_anon));
96
97	TH_LOG("Try to pass invalid name (with non-printable character \\1) to rename the VMA");
98	EXPECT_EQ(rename_vma((unsigned long)self->ptr_anon, AREA_SIZE, BAD_NAME), -EINVAL);
99
100	TH_LOG("Try to rename non-anonymous VMA");
101	EXPECT_EQ(rename_vma((unsigned long) self->ptr_not_anon, AREA_SIZE, GOOD_NAME), -EINVAL);
102}
103
104TEST_HARNESS_MAIN
105