diff options
Diffstat (limited to 'tools/testing/selftests/proc/proc-pid-vm.c')
| -rw-r--r-- | tools/testing/selftests/proc/proc-pid-vm.c | 462 |
1 files changed, 462 insertions, 0 deletions
diff --git a/tools/testing/selftests/proc/proc-pid-vm.c b/tools/testing/selftests/proc/proc-pid-vm.c new file mode 100644 index 000000000..18a3bde8b --- /dev/null +++ b/tools/testing/selftests/proc/proc-pid-vm.c @@ -0,0 +1,462 @@ +/* + * Copyright (c) 2019 Alexey Dobriyan <adobriyan@gmail.com> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +/* + * Fork and exec tiny 1 page executable which precisely controls its VM. + * Test /proc/$PID/maps + * Test /proc/$PID/smaps + * Test /proc/$PID/smaps_rollup + * Test /proc/$PID/statm + * + * FIXME require CONFIG_TMPFS which can be disabled + * FIXME test other values from "smaps" + * FIXME support other archs + */ +#undef NDEBUG +#include <assert.h> +#include <errno.h> +#include <sched.h> +#include <signal.h> +#include <stdbool.h> +#include <stdint.h> +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <sys/mount.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <sys/wait.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/syscall.h> +#include <sys/uio.h> +#include <linux/kdev_t.h> +#include <sys/time.h> +#include <sys/resource.h> + +static inline long sys_execveat(int dirfd, const char *pathname, char **argv, char **envp, int flags) +{ + return syscall(SYS_execveat, dirfd, pathname, argv, envp, flags); +} + +static void make_private_tmp(void) +{ + if (unshare(CLONE_NEWNS) == -1) { + if (errno == ENOSYS || errno == EPERM) { + exit(4); + } + exit(1); + } + if (mount(NULL, "/", NULL, MS_PRIVATE|MS_REC, NULL) == -1) { + exit(1); + } + if (mount(NULL, "/tmp", "tmpfs", 0, NULL) == -1) { + exit(1); + } +} + +static pid_t pid = -1; +static void ate(void) +{ + if (pid > 0) { + kill(pid, SIGTERM); + } +} + +struct elf64_hdr { + uint8_t e_ident[16]; + uint16_t e_type; + uint16_t e_machine; + uint32_t e_version; + uint64_t e_entry; + uint64_t e_phoff; + uint64_t e_shoff; + uint32_t e_flags; + uint16_t e_ehsize; + uint16_t e_phentsize; + uint16_t e_phnum; + uint16_t e_shentsize; + uint16_t e_shnum; + uint16_t e_shstrndx; +}; + +struct elf64_phdr { + uint32_t p_type; + uint32_t p_flags; + uint64_t p_offset; + uint64_t p_vaddr; + uint64_t p_paddr; + uint64_t p_filesz; + uint64_t p_memsz; + uint64_t p_align; +}; + +#ifdef __x86_64__ +#define PAGE_SIZE 4096 +#define VADDR (1UL << 32) +#define MAPS_OFFSET 73 + +#define syscall 0x0f, 0x05 +#define mov_rdi(x) \ + 0x48, 0xbf, \ + (x)&0xff, ((x)>>8)&0xff, ((x)>>16)&0xff, ((x)>>24)&0xff, \ + ((x)>>32)&0xff, ((x)>>40)&0xff, ((x)>>48)&0xff, ((x)>>56)&0xff + +#define mov_rsi(x) \ + 0x48, 0xbe, \ + (x)&0xff, ((x)>>8)&0xff, ((x)>>16)&0xff, ((x)>>24)&0xff, \ + ((x)>>32)&0xff, ((x)>>40)&0xff, ((x)>>48)&0xff, ((x)>>56)&0xff + +#define mov_eax(x) \ + 0xb8, (x)&0xff, ((x)>>8)&0xff, ((x)>>16)&0xff, ((x)>>24)&0xff + +static const uint8_t payload[] = { + /* Casually unmap stack, vDSO and everything else. */ + /* munmap */ + mov_rdi(VADDR + 4096), + mov_rsi((1ULL << 47) - 4096 - VADDR - 4096), + mov_eax(11), + syscall, + + /* Ping parent. */ + /* write(0, &c, 1); */ + 0x31, 0xff, /* xor edi, edi */ + 0x48, 0x8d, 0x35, 0x00, 0x00, 0x00, 0x00, /* lea rsi, [rip] */ + 0xba, 0x01, 0x00, 0x00, 0x00, /* mov edx, 1 */ + mov_eax(1), + syscall, + + /* 1: pause(); */ + mov_eax(34), + syscall, + + 0xeb, 0xf7, /* jmp 1b */ +}; + +static int make_exe(const uint8_t *payload, size_t len) +{ + struct elf64_hdr h; + struct elf64_phdr ph; + + struct iovec iov[3] = { + {&h, sizeof(struct elf64_hdr)}, + {&ph, sizeof(struct elf64_phdr)}, + {(void *)payload, len}, + }; + int fd, fd1; + char buf[64]; + + memset(&h, 0, sizeof(h)); + h.e_ident[0] = 0x7f; + h.e_ident[1] = 'E'; + h.e_ident[2] = 'L'; + h.e_ident[3] = 'F'; + h.e_ident[4] = 2; + h.e_ident[5] = 1; + h.e_ident[6] = 1; + h.e_ident[7] = 0; + h.e_type = 2; + h.e_machine = 0x3e; + h.e_version = 1; + h.e_entry = VADDR + sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr); + h.e_phoff = sizeof(struct elf64_hdr); + h.e_shoff = 0; + h.e_flags = 0; + h.e_ehsize = sizeof(struct elf64_hdr); + h.e_phentsize = sizeof(struct elf64_phdr); + h.e_phnum = 1; + h.e_shentsize = 0; + h.e_shnum = 0; + h.e_shstrndx = 0; + + memset(&ph, 0, sizeof(ph)); + ph.p_type = 1; + ph.p_flags = (1<<2)|1; + ph.p_offset = 0; + ph.p_vaddr = VADDR; + ph.p_paddr = 0; + ph.p_filesz = sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr) + len; + ph.p_memsz = sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr) + len; + ph.p_align = 4096; + + fd = openat(AT_FDCWD, "/tmp", O_WRONLY|O_EXCL|O_TMPFILE, 0700); + if (fd == -1) { + exit(1); + } + + if (writev(fd, iov, 3) != sizeof(struct elf64_hdr) + sizeof(struct elf64_phdr) + len) { + exit(1); + } + + /* Avoid ETXTBSY on exec. */ + snprintf(buf, sizeof(buf), "/proc/self/fd/%u", fd); + fd1 = open(buf, O_RDONLY|O_CLOEXEC); + close(fd); + + return fd1; +} +#endif + +static bool g_vsyscall = false; + +static const char str_vsyscall[] = +"ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]\n"; + +#ifdef __x86_64__ +static void sigaction_SIGSEGV(int _, siginfo_t *__, void *___) +{ + _exit(1); +} + +/* + * vsyscall page can't be unmapped, probe it with memory load. + */ +static void vsyscall(void) +{ + pid_t pid; + int wstatus; + + pid = fork(); + if (pid < 0) { + fprintf(stderr, "fork, errno %d\n", errno); + exit(1); + } + if (pid == 0) { + struct rlimit rlim = {0, 0}; + (void)setrlimit(RLIMIT_CORE, &rlim); + + /* Hide "segfault at ffffffffff600000" messages. */ + struct sigaction act; + memset(&act, 0, sizeof(struct sigaction)); + act.sa_flags = SA_SIGINFO; + act.sa_sigaction = sigaction_SIGSEGV; + (void)sigaction(SIGSEGV, &act, NULL); + + *(volatile int *)0xffffffffff600000UL; + exit(0); + } + waitpid(pid, &wstatus, 0); + if (WIFEXITED(wstatus) && WEXITSTATUS(wstatus) == 0) { + g_vsyscall = true; + } +} + +int main(void) +{ + int pipefd[2]; + int exec_fd; + + vsyscall(); + + atexit(ate); + + make_private_tmp(); + + /* Reserve fd 0 for 1-byte pipe ping from child. */ + close(0); + if (open("/", O_RDONLY|O_DIRECTORY|O_PATH) != 0) { + return 1; + } + + exec_fd = make_exe(payload, sizeof(payload)); + + if (pipe(pipefd) == -1) { + return 1; + } + if (dup2(pipefd[1], 0) != 0) { + return 1; + } + + pid = fork(); + if (pid == -1) { + return 1; + } + if (pid == 0) { + sys_execveat(exec_fd, "", NULL, NULL, AT_EMPTY_PATH); + return 1; + } + + char _; + if (read(pipefd[0], &_, 1) != 1) { + return 1; + } + + struct stat st; + if (fstat(exec_fd, &st) == -1) { + return 1; + } + + /* Generate "head -n1 /proc/$PID/maps" */ + char buf0[256]; + memset(buf0, ' ', sizeof(buf0)); + int len = snprintf(buf0, sizeof(buf0), + "%08lx-%08lx r-xp 00000000 %02lx:%02lx %llu", + VADDR, VADDR + PAGE_SIZE, + MAJOR(st.st_dev), MINOR(st.st_dev), + (unsigned long long)st.st_ino); + buf0[len] = ' '; + snprintf(buf0 + MAPS_OFFSET, sizeof(buf0) - MAPS_OFFSET, + "/tmp/#%llu (deleted)\n", (unsigned long long)st.st_ino); + + /* Test /proc/$PID/maps */ + { + const size_t len = strlen(buf0) + (g_vsyscall ? strlen(str_vsyscall) : 0); + char buf[256]; + ssize_t rv; + int fd; + + snprintf(buf, sizeof(buf), "/proc/%u/maps", pid); + fd = open(buf, O_RDONLY); + if (fd == -1) { + return 1; + } + rv = read(fd, buf, sizeof(buf)); + assert(rv == len); + assert(memcmp(buf, buf0, strlen(buf0)) == 0); + if (g_vsyscall) { + assert(memcmp(buf + strlen(buf0), str_vsyscall, strlen(str_vsyscall)) == 0); + } + } + + /* Test /proc/$PID/smaps */ + { + char buf[4096]; + ssize_t rv; + int fd; + + snprintf(buf, sizeof(buf), "/proc/%u/smaps", pid); + fd = open(buf, O_RDONLY); + if (fd == -1) { + return 1; + } + rv = read(fd, buf, sizeof(buf)); + assert(0 <= rv && rv <= sizeof(buf)); + + assert(rv >= strlen(buf0)); + assert(memcmp(buf, buf0, strlen(buf0)) == 0); + +#define RSS1 "Rss: 4 kB\n" +#define RSS2 "Rss: 0 kB\n" +#define PSS1 "Pss: 4 kB\n" +#define PSS2 "Pss: 0 kB\n" + assert(memmem(buf, rv, RSS1, strlen(RSS1)) || + memmem(buf, rv, RSS2, strlen(RSS2))); + assert(memmem(buf, rv, PSS1, strlen(PSS1)) || + memmem(buf, rv, PSS2, strlen(PSS2))); + + static const char *S[] = { + "Size: 4 kB\n", + "KernelPageSize: 4 kB\n", + "MMUPageSize: 4 kB\n", + "Anonymous: 0 kB\n", + "AnonHugePages: 0 kB\n", + "Shared_Hugetlb: 0 kB\n", + "Private_Hugetlb: 0 kB\n", + "Locked: 0 kB\n", + }; + int i; + + for (i = 0; i < sizeof(S)/sizeof(S[0]); i++) { + assert(memmem(buf, rv, S[i], strlen(S[i]))); + } + + if (g_vsyscall) { + assert(memmem(buf, rv, str_vsyscall, strlen(str_vsyscall))); + } + } + + /* Test /proc/$PID/smaps_rollup */ + { + char bufr[256]; + memset(bufr, ' ', sizeof(bufr)); + len = snprintf(bufr, sizeof(bufr), + "%08lx-%08lx ---p 00000000 00:00 0", + VADDR, VADDR + PAGE_SIZE); + bufr[len] = ' '; + snprintf(bufr + MAPS_OFFSET, sizeof(bufr) - MAPS_OFFSET, + "[rollup]\n"); + + char buf[1024]; + ssize_t rv; + int fd; + + snprintf(buf, sizeof(buf), "/proc/%u/smaps_rollup", pid); + fd = open(buf, O_RDONLY); + if (fd == -1) { + return 1; + } + rv = read(fd, buf, sizeof(buf)); + assert(0 <= rv && rv <= sizeof(buf)); + + assert(rv >= strlen(bufr)); + assert(memcmp(buf, bufr, strlen(bufr)) == 0); + + assert(memmem(buf, rv, RSS1, strlen(RSS1)) || + memmem(buf, rv, RSS2, strlen(RSS2))); + assert(memmem(buf, rv, PSS1, strlen(PSS1)) || + memmem(buf, rv, PSS2, strlen(PSS2))); + + static const char *S[] = { + "Anonymous: 0 kB\n", + "AnonHugePages: 0 kB\n", + "Shared_Hugetlb: 0 kB\n", + "Private_Hugetlb: 0 kB\n", + "Locked: 0 kB\n", + }; + int i; + + for (i = 0; i < sizeof(S)/sizeof(S[0]); i++) { + assert(memmem(buf, rv, S[i], strlen(S[i]))); + } + } + + /* Test /proc/$PID/statm */ + { + char buf[64]; + ssize_t rv; + int fd; + + snprintf(buf, sizeof(buf), "/proc/%u/statm", pid); + fd = open(buf, O_RDONLY); + if (fd == -1) { + return 1; + } + rv = read(fd, buf, sizeof(buf)); + assert(rv == 7 * 2); + + assert(buf[0] == '1'); /* ->total_vm */ + assert(buf[1] == ' '); + assert(buf[2] == '0' || buf[2] == '1'); /* rss */ + assert(buf[3] == ' '); + assert(buf[4] == '0' || buf[2] == '1'); /* file rss */ + assert(buf[5] == ' '); + assert(buf[6] == '1'); /* ELF executable segments */ + assert(buf[7] == ' '); + assert(buf[8] == '0'); + assert(buf[9] == ' '); + assert(buf[10] == '0'); /* ->data_vm + ->stack_vm */ + assert(buf[11] == ' '); + assert(buf[12] == '0'); + assert(buf[13] == '\n'); + } + + return 0; +} +#else +int main(void) +{ + return 4; +} +#endif |