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 <fcntl.h> 8 #include <sys/prctl.h> 9 #include <stdio.h> 10 #include <stdlib.h> 11 #include <sys/mman.h> 12 #include <string.h> 13 #include <unistd.h> 14 15 #include "kselftest_harness.h" 16 17 #define AREA_SIZE 1024 18 19 #define GOOD_NAME "goodname" 20 #define BAD_NAME "badname\1" 21 22 #ifndef PR_SET_VMA 23 #define PR_SET_VMA 0x53564d41 24 #define PR_SET_VMA_ANON_NAME 0 25 #endif 26 27 28 int rename_vma(unsigned long addr, unsigned long size, char *name) 29 { 30 int res; 31 32 res = prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, addr, size, name); 33 if (res < 0) 34 return -errno; 35 return res; 36 } 37 38 int was_renaming_successful(char *target_name, unsigned long ptr) 39 { 40 FILE *maps_file; 41 42 char line_buf[512], name[128], mode[8]; 43 unsigned long start_addr, end_addr, offset; 44 unsigned int major_id, minor_id, node_id; 45 46 char target_buf[128]; 47 int res = 0, sscanf_res; 48 49 // The entry name in maps will be in format [anon:<target_name>] 50 sprintf(target_buf, "[anon:%s]", target_name); 51 maps_file = fopen("/proc/self/maps", "r"); 52 if (!maps_file) { 53 printf("## /proc/self/maps file opening error\n"); 54 return 0; 55 } 56 57 // Parse the maps file to find the entry we renamed 58 while (fgets(line_buf, sizeof(line_buf), maps_file)) { 59 sscanf_res = sscanf(line_buf, "%lx-%lx %7s %lx %u:%u %u %s", &start_addr, 60 &end_addr, mode, &offset, &major_id, 61 &minor_id, &node_id, name); 62 if (sscanf_res == EOF) { 63 res = 0; 64 printf("## EOF while parsing the maps file\n"); 65 break; 66 } 67 if (!strcmp(name, target_buf) && start_addr == ptr) { 68 res = 1; 69 break; 70 } 71 } 72 fclose(maps_file); 73 return res; 74 } 75 76 FIXTURE(vma) { 77 void *ptr_anon, *ptr_not_anon; 78 int fd_not_anon; 79 }; 80 81 FIXTURE_SETUP(vma) { 82 char template[] = "./set-anon-vma-test-XXXXXX"; 83 84 self->ptr_anon = mmap(NULL, AREA_SIZE, PROT_READ | PROT_WRITE, 85 MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); 86 ASSERT_NE(self->ptr_anon, MAP_FAILED); 87 88 self->fd_not_anon = mkstemp(template); 89 ASSERT_NE(self->fd_not_anon, -1); 90 unlink(template); 91 ASSERT_EQ(ftruncate(self->fd_not_anon, AREA_SIZE), 0); 92 self->ptr_not_anon = mmap(NULL, AREA_SIZE, PROT_READ | PROT_WRITE, 93 MAP_PRIVATE, self->fd_not_anon, 0); 94 ASSERT_NE(self->ptr_not_anon, MAP_FAILED); 95 close(self->fd_not_anon); 96 } 97 98 FIXTURE_TEARDOWN(vma) { 99 munmap(self->ptr_anon, AREA_SIZE); 100 munmap(self->ptr_not_anon, AREA_SIZE); 101 } 102 103 TEST_F(vma, renaming) { 104 TH_LOG("Try to rename the VMA with correct parameters"); 105 EXPECT_GE(rename_vma((unsigned long)self->ptr_anon, AREA_SIZE, GOOD_NAME), 0); 106 EXPECT_TRUE(was_renaming_successful(GOOD_NAME, (unsigned long)self->ptr_anon)); 107 108 TH_LOG("Try to pass invalid name (with non-printable character \\1) to rename the VMA"); 109 EXPECT_EQ(rename_vma((unsigned long)self->ptr_anon, AREA_SIZE, BAD_NAME), -EINVAL); 110 111 TH_LOG("Try to rename non-anonymous VMA"); 112 EXPECT_EQ(rename_vma((unsigned long) self->ptr_not_anon, AREA_SIZE, GOOD_NAME), -EBADF); 113 } 114 115 TEST_HARNESS_MAIN 116