15bc73bb3SAlexey Dobriyan /* 25bc73bb3SAlexey Dobriyan * Copyright (c) 2022 Alexey Dobriyan <adobriyan@gmail.com> 35bc73bb3SAlexey Dobriyan * 45bc73bb3SAlexey Dobriyan * Permission to use, copy, modify, and distribute this software for any 55bc73bb3SAlexey Dobriyan * purpose with or without fee is hereby granted, provided that the above 65bc73bb3SAlexey Dobriyan * copyright notice and this permission notice appear in all copies. 75bc73bb3SAlexey Dobriyan * 85bc73bb3SAlexey Dobriyan * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES 95bc73bb3SAlexey Dobriyan * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF 105bc73bb3SAlexey Dobriyan * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR 115bc73bb3SAlexey Dobriyan * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES 125bc73bb3SAlexey Dobriyan * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN 135bc73bb3SAlexey Dobriyan * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF 145bc73bb3SAlexey Dobriyan * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 155bc73bb3SAlexey Dobriyan */ 165bc73bb3SAlexey Dobriyan /* 175bc73bb3SAlexey Dobriyan * Create a process without mappings by unmapping everything at once and 185bc73bb3SAlexey Dobriyan * holding it with ptrace(2). See what happens to 195bc73bb3SAlexey Dobriyan * 205bc73bb3SAlexey Dobriyan * /proc/${pid}/maps 215bc73bb3SAlexey Dobriyan * /proc/${pid}/numa_maps 225bc73bb3SAlexey Dobriyan * /proc/${pid}/smaps 235bc73bb3SAlexey Dobriyan * /proc/${pid}/smaps_rollup 245bc73bb3SAlexey Dobriyan */ 255bc73bb3SAlexey Dobriyan #undef NDEBUG 265bc73bb3SAlexey Dobriyan #include <assert.h> 275bc73bb3SAlexey Dobriyan #include <errno.h> 28*5316a017SAlexey Dobriyan #include <stdint.h> 295bc73bb3SAlexey Dobriyan #include <stdio.h> 305bc73bb3SAlexey Dobriyan #include <stdlib.h> 315bc73bb3SAlexey Dobriyan #include <string.h> 325bc73bb3SAlexey Dobriyan #include <fcntl.h> 335bc73bb3SAlexey Dobriyan #include <sys/mman.h> 345bc73bb3SAlexey Dobriyan #include <sys/ptrace.h> 355bc73bb3SAlexey Dobriyan #include <sys/resource.h> 365bc73bb3SAlexey Dobriyan #include <sys/types.h> 375bc73bb3SAlexey Dobriyan #include <sys/wait.h> 385bc73bb3SAlexey Dobriyan #include <unistd.h> 395bc73bb3SAlexey Dobriyan 405bc73bb3SAlexey Dobriyan /* 415bc73bb3SAlexey Dobriyan * 0: vsyscall VMA doesn't exist vsyscall=none 425bc73bb3SAlexey Dobriyan * 1: vsyscall VMA is --xp vsyscall=xonly 435bc73bb3SAlexey Dobriyan * 2: vsyscall VMA is r-xp vsyscall=emulate 445bc73bb3SAlexey Dobriyan */ 45*5316a017SAlexey Dobriyan static volatile int g_vsyscall; 465bc73bb3SAlexey Dobriyan static const char *g_proc_pid_maps_vsyscall; 475bc73bb3SAlexey Dobriyan static const char *g_proc_pid_smaps_vsyscall; 485bc73bb3SAlexey Dobriyan 495bc73bb3SAlexey Dobriyan static const char proc_pid_maps_vsyscall_0[] = ""; 505bc73bb3SAlexey Dobriyan static const char proc_pid_maps_vsyscall_1[] = 515bc73bb3SAlexey Dobriyan "ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall]\n"; 525bc73bb3SAlexey Dobriyan static const char proc_pid_maps_vsyscall_2[] = 535bc73bb3SAlexey Dobriyan "ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]\n"; 545bc73bb3SAlexey Dobriyan 555bc73bb3SAlexey Dobriyan static const char proc_pid_smaps_vsyscall_0[] = ""; 565bc73bb3SAlexey Dobriyan 575bc73bb3SAlexey Dobriyan static const char proc_pid_smaps_vsyscall_1[] = 585bc73bb3SAlexey Dobriyan "ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]\n" 595bc73bb3SAlexey Dobriyan "Size: 4 kB\n" 605bc73bb3SAlexey Dobriyan "KernelPageSize: 4 kB\n" 615bc73bb3SAlexey Dobriyan "MMUPageSize: 4 kB\n" 625bc73bb3SAlexey Dobriyan "Rss: 0 kB\n" 635bc73bb3SAlexey Dobriyan "Pss: 0 kB\n" 645bc73bb3SAlexey Dobriyan "Pss_Dirty: 0 kB\n" 655bc73bb3SAlexey Dobriyan "Shared_Clean: 0 kB\n" 665bc73bb3SAlexey Dobriyan "Shared_Dirty: 0 kB\n" 675bc73bb3SAlexey Dobriyan "Private_Clean: 0 kB\n" 685bc73bb3SAlexey Dobriyan "Private_Dirty: 0 kB\n" 695bc73bb3SAlexey Dobriyan "Referenced: 0 kB\n" 705bc73bb3SAlexey Dobriyan "Anonymous: 0 kB\n" 715bc73bb3SAlexey Dobriyan "LazyFree: 0 kB\n" 725bc73bb3SAlexey Dobriyan "AnonHugePages: 0 kB\n" 735bc73bb3SAlexey Dobriyan "ShmemPmdMapped: 0 kB\n" 745bc73bb3SAlexey Dobriyan "FilePmdMapped: 0 kB\n" 755bc73bb3SAlexey Dobriyan "Shared_Hugetlb: 0 kB\n" 765bc73bb3SAlexey Dobriyan "Private_Hugetlb: 0 kB\n" 775bc73bb3SAlexey Dobriyan "Swap: 0 kB\n" 785bc73bb3SAlexey Dobriyan "SwapPss: 0 kB\n" 795bc73bb3SAlexey Dobriyan "Locked: 0 kB\n" 805bc73bb3SAlexey Dobriyan "THPeligible: 0\n" 815bc73bb3SAlexey Dobriyan /* 825bc73bb3SAlexey Dobriyan * "ProtectionKey:" field is conditional. It is possible to check it as well, 835bc73bb3SAlexey Dobriyan * but I don't have such machine. 845bc73bb3SAlexey Dobriyan */ 855bc73bb3SAlexey Dobriyan ; 865bc73bb3SAlexey Dobriyan 875bc73bb3SAlexey Dobriyan static const char proc_pid_smaps_vsyscall_2[] = 885bc73bb3SAlexey Dobriyan "ffffffffff600000-ffffffffff601000 --xp 00000000 00:00 0 [vsyscall]\n" 895bc73bb3SAlexey Dobriyan "Size: 4 kB\n" 905bc73bb3SAlexey Dobriyan "KernelPageSize: 4 kB\n" 915bc73bb3SAlexey Dobriyan "MMUPageSize: 4 kB\n" 925bc73bb3SAlexey Dobriyan "Rss: 0 kB\n" 935bc73bb3SAlexey Dobriyan "Pss: 0 kB\n" 945bc73bb3SAlexey Dobriyan "Pss_Dirty: 0 kB\n" 955bc73bb3SAlexey Dobriyan "Shared_Clean: 0 kB\n" 965bc73bb3SAlexey Dobriyan "Shared_Dirty: 0 kB\n" 975bc73bb3SAlexey Dobriyan "Private_Clean: 0 kB\n" 985bc73bb3SAlexey Dobriyan "Private_Dirty: 0 kB\n" 995bc73bb3SAlexey Dobriyan "Referenced: 0 kB\n" 1005bc73bb3SAlexey Dobriyan "Anonymous: 0 kB\n" 1015bc73bb3SAlexey Dobriyan "LazyFree: 0 kB\n" 1025bc73bb3SAlexey Dobriyan "AnonHugePages: 0 kB\n" 1035bc73bb3SAlexey Dobriyan "ShmemPmdMapped: 0 kB\n" 1045bc73bb3SAlexey Dobriyan "FilePmdMapped: 0 kB\n" 1055bc73bb3SAlexey Dobriyan "Shared_Hugetlb: 0 kB\n" 1065bc73bb3SAlexey Dobriyan "Private_Hugetlb: 0 kB\n" 1075bc73bb3SAlexey Dobriyan "Swap: 0 kB\n" 1085bc73bb3SAlexey Dobriyan "SwapPss: 0 kB\n" 1095bc73bb3SAlexey Dobriyan "Locked: 0 kB\n" 1105bc73bb3SAlexey Dobriyan "THPeligible: 0\n" 1115bc73bb3SAlexey Dobriyan /* 1125bc73bb3SAlexey Dobriyan * "ProtectionKey:" field is conditional. It is possible to check it as well, 1135bc73bb3SAlexey Dobriyan * but I'm too tired. 1145bc73bb3SAlexey Dobriyan */ 1155bc73bb3SAlexey Dobriyan ; 1165bc73bb3SAlexey Dobriyan 1175bc73bb3SAlexey Dobriyan static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___) 1185bc73bb3SAlexey Dobriyan { 1195bc73bb3SAlexey Dobriyan _exit(EXIT_FAILURE); 1205bc73bb3SAlexey Dobriyan } 1215bc73bb3SAlexey Dobriyan 1225bc73bb3SAlexey Dobriyan static void sigaction_SIGSEGV_vsyscall(int _, siginfo_t *__, void *___) 1235bc73bb3SAlexey Dobriyan { 1245bc73bb3SAlexey Dobriyan _exit(g_vsyscall); 1255bc73bb3SAlexey Dobriyan } 1265bc73bb3SAlexey Dobriyan 1275bc73bb3SAlexey Dobriyan /* 1285bc73bb3SAlexey Dobriyan * vsyscall page can't be unmapped, probe it directly. 1295bc73bb3SAlexey Dobriyan */ 1305bc73bb3SAlexey Dobriyan static void vsyscall(void) 1315bc73bb3SAlexey Dobriyan { 1325bc73bb3SAlexey Dobriyan pid_t pid; 1335bc73bb3SAlexey Dobriyan int wstatus; 1345bc73bb3SAlexey Dobriyan 1355bc73bb3SAlexey Dobriyan pid = fork(); 1365bc73bb3SAlexey Dobriyan if (pid < 0) { 1375bc73bb3SAlexey Dobriyan fprintf(stderr, "fork, errno %d\n", errno); 1385bc73bb3SAlexey Dobriyan exit(1); 1395bc73bb3SAlexey Dobriyan } 1405bc73bb3SAlexey Dobriyan if (pid == 0) { 1415bc73bb3SAlexey Dobriyan setrlimit(RLIMIT_CORE, &(struct rlimit){}); 1425bc73bb3SAlexey Dobriyan 1435bc73bb3SAlexey Dobriyan /* Hide "segfault at ffffffffff600000" messages. */ 1445bc73bb3SAlexey Dobriyan struct sigaction act = {}; 1455bc73bb3SAlexey Dobriyan act.sa_flags = SA_SIGINFO; 1465bc73bb3SAlexey Dobriyan act.sa_sigaction = sigaction_SIGSEGV_vsyscall; 1475bc73bb3SAlexey Dobriyan sigaction(SIGSEGV, &act, NULL); 1485bc73bb3SAlexey Dobriyan 1495bc73bb3SAlexey Dobriyan g_vsyscall = 0; 1505bc73bb3SAlexey Dobriyan /* gettimeofday(NULL, NULL); */ 151*5316a017SAlexey Dobriyan uint64_t rax = 0xffffffffff600000; 1525bc73bb3SAlexey Dobriyan asm volatile ( 153*5316a017SAlexey Dobriyan "call *%[rax]" 154*5316a017SAlexey Dobriyan : [rax] "+a" (rax) 155*5316a017SAlexey Dobriyan : "D" (NULL), "S" (NULL) 156*5316a017SAlexey Dobriyan : "rcx", "r11" 1575bc73bb3SAlexey Dobriyan ); 1585bc73bb3SAlexey Dobriyan 1595bc73bb3SAlexey Dobriyan g_vsyscall = 1; 1605bc73bb3SAlexey Dobriyan *(volatile int *)0xffffffffff600000UL; 1615bc73bb3SAlexey Dobriyan 1625bc73bb3SAlexey Dobriyan g_vsyscall = 2; 1635bc73bb3SAlexey Dobriyan exit(g_vsyscall); 1645bc73bb3SAlexey Dobriyan } 1655bc73bb3SAlexey Dobriyan waitpid(pid, &wstatus, 0); 1665bc73bb3SAlexey Dobriyan if (WIFEXITED(wstatus)) { 1675bc73bb3SAlexey Dobriyan g_vsyscall = WEXITSTATUS(wstatus); 1685bc73bb3SAlexey Dobriyan } else { 1695bc73bb3SAlexey Dobriyan fprintf(stderr, "error: vsyscall wstatus %08x\n", wstatus); 1705bc73bb3SAlexey Dobriyan exit(1); 1715bc73bb3SAlexey Dobriyan } 1725bc73bb3SAlexey Dobriyan } 1735bc73bb3SAlexey Dobriyan 1745bc73bb3SAlexey Dobriyan static int test_proc_pid_maps(pid_t pid) 1755bc73bb3SAlexey Dobriyan { 1765bc73bb3SAlexey Dobriyan char buf[4096]; 1775bc73bb3SAlexey Dobriyan snprintf(buf, sizeof(buf), "/proc/%u/maps", pid); 1785bc73bb3SAlexey Dobriyan int fd = open(buf, O_RDONLY); 1795bc73bb3SAlexey Dobriyan if (fd == -1) { 1805bc73bb3SAlexey Dobriyan perror("open /proc/${pid}/maps"); 1815bc73bb3SAlexey Dobriyan return EXIT_FAILURE; 1825bc73bb3SAlexey Dobriyan } else { 1835bc73bb3SAlexey Dobriyan ssize_t rv = read(fd, buf, sizeof(buf)); 1845bc73bb3SAlexey Dobriyan close(fd); 1855bc73bb3SAlexey Dobriyan if (g_vsyscall == 0) { 1865bc73bb3SAlexey Dobriyan assert(rv == 0); 1875bc73bb3SAlexey Dobriyan } else { 1885bc73bb3SAlexey Dobriyan size_t len = strlen(g_proc_pid_maps_vsyscall); 1895bc73bb3SAlexey Dobriyan assert(rv == len); 1905bc73bb3SAlexey Dobriyan assert(memcmp(buf, g_proc_pid_maps_vsyscall, len) == 0); 1915bc73bb3SAlexey Dobriyan } 1925bc73bb3SAlexey Dobriyan return EXIT_SUCCESS; 1935bc73bb3SAlexey Dobriyan } 1945bc73bb3SAlexey Dobriyan } 1955bc73bb3SAlexey Dobriyan 1965bc73bb3SAlexey Dobriyan static int test_proc_pid_numa_maps(pid_t pid) 1975bc73bb3SAlexey Dobriyan { 1985bc73bb3SAlexey Dobriyan char buf[4096]; 1995bc73bb3SAlexey Dobriyan snprintf(buf, sizeof(buf), "/proc/%u/numa_maps", pid); 2005bc73bb3SAlexey Dobriyan int fd = open(buf, O_RDONLY); 2015bc73bb3SAlexey Dobriyan if (fd == -1) { 2025bc73bb3SAlexey Dobriyan if (errno == ENOENT) { 2035bc73bb3SAlexey Dobriyan /* 2045bc73bb3SAlexey Dobriyan * /proc/${pid}/numa_maps is under CONFIG_NUMA, 2055bc73bb3SAlexey Dobriyan * it doesn't necessarily exist. 2065bc73bb3SAlexey Dobriyan */ 2075bc73bb3SAlexey Dobriyan return EXIT_SUCCESS; 2085bc73bb3SAlexey Dobriyan } 2095bc73bb3SAlexey Dobriyan perror("open /proc/${pid}/numa_maps"); 2105bc73bb3SAlexey Dobriyan return EXIT_FAILURE; 2115bc73bb3SAlexey Dobriyan } else { 2125bc73bb3SAlexey Dobriyan ssize_t rv = read(fd, buf, sizeof(buf)); 2135bc73bb3SAlexey Dobriyan close(fd); 2145bc73bb3SAlexey Dobriyan assert(rv == 0); 2155bc73bb3SAlexey Dobriyan return EXIT_SUCCESS; 2165bc73bb3SAlexey Dobriyan } 2175bc73bb3SAlexey Dobriyan } 2185bc73bb3SAlexey Dobriyan 2195bc73bb3SAlexey Dobriyan static int test_proc_pid_smaps(pid_t pid) 2205bc73bb3SAlexey Dobriyan { 2215bc73bb3SAlexey Dobriyan char buf[4096]; 2225bc73bb3SAlexey Dobriyan snprintf(buf, sizeof(buf), "/proc/%u/smaps", pid); 2235bc73bb3SAlexey Dobriyan int fd = open(buf, O_RDONLY); 2245bc73bb3SAlexey Dobriyan if (fd == -1) { 2255bc73bb3SAlexey Dobriyan if (errno == ENOENT) { 2265bc73bb3SAlexey Dobriyan /* 2275bc73bb3SAlexey Dobriyan * /proc/${pid}/smaps is under CONFIG_PROC_PAGE_MONITOR, 2285bc73bb3SAlexey Dobriyan * it doesn't necessarily exist. 2295bc73bb3SAlexey Dobriyan */ 2305bc73bb3SAlexey Dobriyan return EXIT_SUCCESS; 2315bc73bb3SAlexey Dobriyan } 2325bc73bb3SAlexey Dobriyan perror("open /proc/${pid}/smaps"); 2335bc73bb3SAlexey Dobriyan return EXIT_FAILURE; 2345bc73bb3SAlexey Dobriyan } else { 2355bc73bb3SAlexey Dobriyan ssize_t rv = read(fd, buf, sizeof(buf)); 2365bc73bb3SAlexey Dobriyan close(fd); 2375bc73bb3SAlexey Dobriyan if (g_vsyscall == 0) { 2385bc73bb3SAlexey Dobriyan assert(rv == 0); 2395bc73bb3SAlexey Dobriyan } else { 2405bc73bb3SAlexey Dobriyan size_t len = strlen(g_proc_pid_maps_vsyscall); 2415bc73bb3SAlexey Dobriyan /* TODO "ProtectionKey:" */ 2425bc73bb3SAlexey Dobriyan assert(rv > len); 2435bc73bb3SAlexey Dobriyan assert(memcmp(buf, g_proc_pid_maps_vsyscall, len) == 0); 2445bc73bb3SAlexey Dobriyan } 2455bc73bb3SAlexey Dobriyan return EXIT_SUCCESS; 2465bc73bb3SAlexey Dobriyan } 2475bc73bb3SAlexey Dobriyan } 2485bc73bb3SAlexey Dobriyan 2495bc73bb3SAlexey Dobriyan static const char g_smaps_rollup[] = 2505bc73bb3SAlexey Dobriyan "00000000-00000000 ---p 00000000 00:00 0 [rollup]\n" 2515bc73bb3SAlexey Dobriyan "Rss: 0 kB\n" 2525bc73bb3SAlexey Dobriyan "Pss: 0 kB\n" 2535bc73bb3SAlexey Dobriyan "Pss_Dirty: 0 kB\n" 2545bc73bb3SAlexey Dobriyan "Pss_Anon: 0 kB\n" 2555bc73bb3SAlexey Dobriyan "Pss_File: 0 kB\n" 2565bc73bb3SAlexey Dobriyan "Pss_Shmem: 0 kB\n" 2575bc73bb3SAlexey Dobriyan "Shared_Clean: 0 kB\n" 2585bc73bb3SAlexey Dobriyan "Shared_Dirty: 0 kB\n" 2595bc73bb3SAlexey Dobriyan "Private_Clean: 0 kB\n" 2605bc73bb3SAlexey Dobriyan "Private_Dirty: 0 kB\n" 2615bc73bb3SAlexey Dobriyan "Referenced: 0 kB\n" 2625bc73bb3SAlexey Dobriyan "Anonymous: 0 kB\n" 2635bc73bb3SAlexey Dobriyan "LazyFree: 0 kB\n" 2645bc73bb3SAlexey Dobriyan "AnonHugePages: 0 kB\n" 2655bc73bb3SAlexey Dobriyan "ShmemPmdMapped: 0 kB\n" 2665bc73bb3SAlexey Dobriyan "FilePmdMapped: 0 kB\n" 2675bc73bb3SAlexey Dobriyan "Shared_Hugetlb: 0 kB\n" 2685bc73bb3SAlexey Dobriyan "Private_Hugetlb: 0 kB\n" 2695bc73bb3SAlexey Dobriyan "Swap: 0 kB\n" 2705bc73bb3SAlexey Dobriyan "SwapPss: 0 kB\n" 2715bc73bb3SAlexey Dobriyan "Locked: 0 kB\n" 2725bc73bb3SAlexey Dobriyan ; 2735bc73bb3SAlexey Dobriyan 2745bc73bb3SAlexey Dobriyan static int test_proc_pid_smaps_rollup(pid_t pid) 2755bc73bb3SAlexey Dobriyan { 2765bc73bb3SAlexey Dobriyan char buf[4096]; 2775bc73bb3SAlexey Dobriyan snprintf(buf, sizeof(buf), "/proc/%u/smaps_rollup", pid); 2785bc73bb3SAlexey Dobriyan int fd = open(buf, O_RDONLY); 2795bc73bb3SAlexey Dobriyan if (fd == -1) { 2805bc73bb3SAlexey Dobriyan if (errno == ENOENT) { 2815bc73bb3SAlexey Dobriyan /* 2825bc73bb3SAlexey Dobriyan * /proc/${pid}/smaps_rollup is under CONFIG_PROC_PAGE_MONITOR, 2835bc73bb3SAlexey Dobriyan * it doesn't necessarily exist. 2845bc73bb3SAlexey Dobriyan */ 2855bc73bb3SAlexey Dobriyan return EXIT_SUCCESS; 2865bc73bb3SAlexey Dobriyan } 2875bc73bb3SAlexey Dobriyan perror("open /proc/${pid}/smaps_rollup"); 2885bc73bb3SAlexey Dobriyan return EXIT_FAILURE; 2895bc73bb3SAlexey Dobriyan } else { 2905bc73bb3SAlexey Dobriyan ssize_t rv = read(fd, buf, sizeof(buf)); 2915bc73bb3SAlexey Dobriyan close(fd); 2925bc73bb3SAlexey Dobriyan assert(rv == sizeof(g_smaps_rollup) - 1); 2935bc73bb3SAlexey Dobriyan assert(memcmp(buf, g_smaps_rollup, sizeof(g_smaps_rollup) - 1) == 0); 2945bc73bb3SAlexey Dobriyan return EXIT_SUCCESS; 2955bc73bb3SAlexey Dobriyan } 2965bc73bb3SAlexey Dobriyan } 2975bc73bb3SAlexey Dobriyan 2985bc73bb3SAlexey Dobriyan int main(void) 2995bc73bb3SAlexey Dobriyan { 3005bc73bb3SAlexey Dobriyan int rv = EXIT_SUCCESS; 3015bc73bb3SAlexey Dobriyan 3025bc73bb3SAlexey Dobriyan vsyscall(); 3035bc73bb3SAlexey Dobriyan 3045bc73bb3SAlexey Dobriyan switch (g_vsyscall) { 3055bc73bb3SAlexey Dobriyan case 0: 3065bc73bb3SAlexey Dobriyan g_proc_pid_maps_vsyscall = proc_pid_maps_vsyscall_0; 3075bc73bb3SAlexey Dobriyan g_proc_pid_smaps_vsyscall = proc_pid_smaps_vsyscall_0; 3085bc73bb3SAlexey Dobriyan break; 3095bc73bb3SAlexey Dobriyan case 1: 3105bc73bb3SAlexey Dobriyan g_proc_pid_maps_vsyscall = proc_pid_maps_vsyscall_1; 3115bc73bb3SAlexey Dobriyan g_proc_pid_smaps_vsyscall = proc_pid_smaps_vsyscall_1; 3125bc73bb3SAlexey Dobriyan break; 3135bc73bb3SAlexey Dobriyan case 2: 3145bc73bb3SAlexey Dobriyan g_proc_pid_maps_vsyscall = proc_pid_maps_vsyscall_2; 3155bc73bb3SAlexey Dobriyan g_proc_pid_smaps_vsyscall = proc_pid_smaps_vsyscall_2; 3165bc73bb3SAlexey Dobriyan break; 3175bc73bb3SAlexey Dobriyan default: 3185bc73bb3SAlexey Dobriyan abort(); 3195bc73bb3SAlexey Dobriyan } 3205bc73bb3SAlexey Dobriyan 3215bc73bb3SAlexey Dobriyan pid_t pid = fork(); 3225bc73bb3SAlexey Dobriyan if (pid == -1) { 3235bc73bb3SAlexey Dobriyan perror("fork"); 3245bc73bb3SAlexey Dobriyan return EXIT_FAILURE; 3255bc73bb3SAlexey Dobriyan } else if (pid == 0) { 3265bc73bb3SAlexey Dobriyan rv = ptrace(PTRACE_TRACEME, 0, NULL, NULL); 3275bc73bb3SAlexey Dobriyan if (rv != 0) { 3285bc73bb3SAlexey Dobriyan if (errno == EPERM) { 3295bc73bb3SAlexey Dobriyan fprintf(stderr, 3305bc73bb3SAlexey Dobriyan "Did you know? ptrace(PTRACE_TRACEME) doesn't work under strace.\n" 3315bc73bb3SAlexey Dobriyan ); 3325bc73bb3SAlexey Dobriyan kill(getppid(), SIGTERM); 3335bc73bb3SAlexey Dobriyan return EXIT_FAILURE; 3345bc73bb3SAlexey Dobriyan } 3355bc73bb3SAlexey Dobriyan perror("ptrace PTRACE_TRACEME"); 3365bc73bb3SAlexey Dobriyan return EXIT_FAILURE; 3375bc73bb3SAlexey Dobriyan } 3385bc73bb3SAlexey Dobriyan 3395bc73bb3SAlexey Dobriyan /* 3405bc73bb3SAlexey Dobriyan * Hide "segfault at ..." messages. Signal handler won't run. 3415bc73bb3SAlexey Dobriyan */ 3425bc73bb3SAlexey Dobriyan struct sigaction act = {}; 3435bc73bb3SAlexey Dobriyan act.sa_flags = SA_SIGINFO; 3445bc73bb3SAlexey Dobriyan act.sa_sigaction = sigaction_SIGSEGV; 3455bc73bb3SAlexey Dobriyan sigaction(SIGSEGV, &act, NULL); 3465bc73bb3SAlexey Dobriyan 3475bc73bb3SAlexey Dobriyan #ifdef __amd64__ 3485bc73bb3SAlexey Dobriyan munmap(NULL, ((size_t)1 << 47) - 4096); 3495bc73bb3SAlexey Dobriyan #else 3505bc73bb3SAlexey Dobriyan #error "implement 'unmap everything'" 3515bc73bb3SAlexey Dobriyan #endif 3525bc73bb3SAlexey Dobriyan return EXIT_FAILURE; 3535bc73bb3SAlexey Dobriyan } else { 3545bc73bb3SAlexey Dobriyan /* 3555bc73bb3SAlexey Dobriyan * TODO find reliable way to signal parent that munmap(2) completed. 3565bc73bb3SAlexey Dobriyan * Child can't do it directly because it effectively doesn't exist 3575bc73bb3SAlexey Dobriyan * anymore. Looking at child's VM files isn't 100% reliable either: 3585bc73bb3SAlexey Dobriyan * due to a bug they may not become empty or empty-like. 3595bc73bb3SAlexey Dobriyan */ 3605bc73bb3SAlexey Dobriyan sleep(1); 3615bc73bb3SAlexey Dobriyan 3625bc73bb3SAlexey Dobriyan if (rv == EXIT_SUCCESS) { 3635bc73bb3SAlexey Dobriyan rv = test_proc_pid_maps(pid); 3645bc73bb3SAlexey Dobriyan } 3655bc73bb3SAlexey Dobriyan if (rv == EXIT_SUCCESS) { 3665bc73bb3SAlexey Dobriyan rv = test_proc_pid_numa_maps(pid); 3675bc73bb3SAlexey Dobriyan } 3685bc73bb3SAlexey Dobriyan if (rv == EXIT_SUCCESS) { 3695bc73bb3SAlexey Dobriyan rv = test_proc_pid_smaps(pid); 3705bc73bb3SAlexey Dobriyan } 3715bc73bb3SAlexey Dobriyan if (rv == EXIT_SUCCESS) { 3725bc73bb3SAlexey Dobriyan rv = test_proc_pid_smaps_rollup(pid); 3735bc73bb3SAlexey Dobriyan } 3745bc73bb3SAlexey Dobriyan /* 3755bc73bb3SAlexey Dobriyan * TODO test /proc/${pid}/statm, task_statm() 3765bc73bb3SAlexey Dobriyan * ->start_code, ->end_code aren't updated by munmap(). 3775bc73bb3SAlexey Dobriyan * Output can be "0 0 0 2 0 0 0\n" where "2" can be anything. 3785bc73bb3SAlexey Dobriyan */ 3795bc73bb3SAlexey Dobriyan 3805bc73bb3SAlexey Dobriyan /* Cut the rope. */ 3815bc73bb3SAlexey Dobriyan int wstatus; 3825bc73bb3SAlexey Dobriyan waitpid(pid, &wstatus, 0); 3835bc73bb3SAlexey Dobriyan assert(WIFSTOPPED(wstatus)); 3845bc73bb3SAlexey Dobriyan assert(WSTOPSIG(wstatus) == SIGSEGV); 3855bc73bb3SAlexey Dobriyan } 3865bc73bb3SAlexey Dobriyan 3875bc73bb3SAlexey Dobriyan return rv; 3885bc73bb3SAlexey Dobriyan } 389