| /* SPDX-License-Identifier: LGPL-2.1+ */ |
| /*** |
| This file is part of systemd. |
| |
| Copyright 2010 Lennart Poettering |
| |
| systemd is free software; you can redistribute it and/or modify it |
| under the terms of the GNU Lesser General Public License as published by |
| the Free Software Foundation; either version 2.1 of the License, or |
| (at your option) any later version. |
| |
| systemd is distributed in the hope that it will be useful, but |
| WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with systemd; If not, see <http://www.gnu.org/licenses/>. |
| ***/ |
| |
| #include <ctype.h> |
| #include <errno.h> |
| #include <limits.h> |
| #include <linux/oom.h> |
| #include <sched.h> |
| #include <signal.h> |
| #include <stdbool.h> |
| #include <stdio.h> |
| #include <stdio_ext.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/mman.h> |
| #include <sys/personality.h> |
| #include <sys/prctl.h> |
| #include <sys/types.h> |
| #include <sys/wait.h> |
| #include <syslog.h> |
| #include <unistd.h> |
| #if HAVE_VALGRIND_VALGRIND_H |
| #include <valgrind/valgrind.h> |
| #endif |
| |
| #include "alloc-util.h" |
| #include "architecture.h" |
| #include "escape.h" |
| #include "fd-util.h" |
| #include "fileio.h" |
| #include "fs-util.h" |
| #include "ioprio.h" |
| #include "log.h" |
| #include "macro.h" |
| #include "missing.h" |
| #include "process-util.h" |
| #include "raw-clone.h" |
| #include "signal-util.h" |
| #include "stat-util.h" |
| #include "string-table.h" |
| #include "string-util.h" |
| #include "user-util.h" |
| #include "util.h" |
| |
| int get_process_state(pid_t pid) { |
| const char *p; |
| char state; |
| int r; |
| _cleanup_free_ char *line = NULL; |
| |
| assert(pid >= 0); |
| |
| p = procfs_file_alloca(pid, "stat"); |
| |
| r = read_one_line_file(p, &line); |
| if (r == -ENOENT) |
| return -ESRCH; |
| if (r < 0) |
| return r; |
| |
| p = strrchr(line, ')'); |
| if (!p) |
| return -EIO; |
| |
| p++; |
| |
| if (sscanf(p, " %c", &state) != 1) |
| return -EIO; |
| |
| return (unsigned char) state; |
| } |
| |
| int get_process_comm(pid_t pid, char **name) { |
| const char *p; |
| int r; |
| |
| assert(name); |
| assert(pid >= 0); |
| |
| p = procfs_file_alloca(pid, "comm"); |
| |
| r = read_one_line_file(p, name); |
| if (r == -ENOENT) |
| return -ESRCH; |
| |
| return r; |
| } |
| |
| int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char **line) { |
| _cleanup_fclose_ FILE *f = NULL; |
| bool space = false; |
| char *k, *ans = NULL; |
| const char *p; |
| int c; |
| |
| assert(line); |
| assert(pid >= 0); |
| |
| /* Retrieves a process' command line. Replaces unprintable characters while doing so by whitespace (coalescing |
| * multiple sequential ones into one). If max_length is != 0 will return a string of the specified size at most |
| * (the trailing NUL byte does count towards the length here!), abbreviated with a "..." ellipsis. If |
| * comm_fallback is true and the process has no command line set (the case for kernel threads), or has a |
| * command line that resolves to the empty string will return the "comm" name of the process instead. |
| * |
| * Returns -ESRCH if the process doesn't exist, and -ENOENT if the process has no command line (and |
| * comm_fallback is false). Returns 0 and sets *line otherwise. */ |
| |
| p = procfs_file_alloca(pid, "cmdline"); |
| |
| f = fopen(p, "re"); |
| if (!f) { |
| if (errno == ENOENT) |
| return -ESRCH; |
| return -errno; |
| } |
| |
| (void) __fsetlocking(f, FSETLOCKING_BYCALLER); |
| |
| if (max_length == 1) { |
| |
| /* If there's only room for one byte, return the empty string */ |
| ans = new0(char, 1); |
| if (!ans) |
| return -ENOMEM; |
| |
| *line = ans; |
| return 0; |
| |
| } else if (max_length == 0) { |
| size_t len = 0, allocated = 0; |
| |
| while ((c = getc(f)) != EOF) { |
| |
| if (!GREEDY_REALLOC(ans, allocated, len+3)) { |
| free(ans); |
| return -ENOMEM; |
| } |
| |
| if (isprint(c)) { |
| if (space) { |
| ans[len++] = ' '; |
| space = false; |
| } |
| |
| ans[len++] = c; |
| } else if (len > 0) |
| space = true; |
| } |
| |
| if (len > 0) |
| ans[len] = '\0'; |
| else |
| ans = mfree(ans); |
| |
| } else { |
| bool dotdotdot = false; |
| size_t left; |
| |
| ans = new(char, max_length); |
| if (!ans) |
| return -ENOMEM; |
| |
| k = ans; |
| left = max_length; |
| while ((c = getc(f)) != EOF) { |
| |
| if (isprint(c)) { |
| |
| if (space) { |
| if (left <= 2) { |
| dotdotdot = true; |
| break; |
| } |
| |
| *(k++) = ' '; |
| left--; |
| space = false; |
| } |
| |
| if (left <= 1) { |
| dotdotdot = true; |
| break; |
| } |
| |
| *(k++) = (char) c; |
| left--; |
| } else if (k > ans) |
| space = true; |
| } |
| |
| if (dotdotdot) { |
| if (max_length <= 4) { |
| k = ans; |
| left = max_length; |
| } else { |
| k = ans + max_length - 4; |
| left = 4; |
| |
| /* Eat up final spaces */ |
| while (k > ans && isspace(k[-1])) { |
| k--; |
| left++; |
| } |
| } |
| |
| strncpy(k, "...", left-1); |
| k[left-1] = 0; |
| } else |
| *k = 0; |
| } |
| |
| /* Kernel threads have no argv[] */ |
| if (isempty(ans)) { |
| _cleanup_free_ char *t = NULL; |
| int h; |
| |
| free(ans); |
| |
| if (!comm_fallback) |
| return -ENOENT; |
| |
| h = get_process_comm(pid, &t); |
| if (h < 0) |
| return h; |
| |
| if (max_length == 0) |
| ans = strjoin("[", t, "]"); |
| else { |
| size_t l; |
| |
| l = strlen(t); |
| |
| if (l + 3 <= max_length) |
| ans = strjoin("[", t, "]"); |
| else if (max_length <= 6) { |
| |
| ans = new(char, max_length); |
| if (!ans) |
| return -ENOMEM; |
| |
| memcpy(ans, "[...]", max_length-1); |
| ans[max_length-1] = 0; |
| } else { |
| char *e; |
| |
| t[max_length - 6] = 0; |
| |
| /* Chop off final spaces */ |
| e = strchr(t, 0); |
| while (e > t && isspace(e[-1])) |
| e--; |
| *e = 0; |
| |
| ans = strjoin("[", t, "...]"); |
| } |
| } |
| if (!ans) |
| return -ENOMEM; |
| } |
| |
| *line = ans; |
| return 0; |
| } |
| |
| int rename_process(const char name[]) { |
| static size_t mm_size = 0; |
| static char *mm = NULL; |
| bool truncated = false; |
| size_t l; |
| |
| /* This is a like a poor man's setproctitle(). It changes the comm field, argv[0], and also the glibc's |
| * internally used name of the process. For the first one a limit of 16 chars applies; to the second one in |
| * many cases one of 10 (i.e. length of "/sbin/init") — however if we have CAP_SYS_RESOURCES it is unbounded; |
| * to the third one 7 (i.e. the length of "systemd". If you pass a longer string it will likely be |
| * truncated. |
| * |
| * Returns 0 if a name was set but truncated, > 0 if it was set but not truncated. */ |
| |
| if (isempty(name)) |
| return -EINVAL; /* let's not confuse users unnecessarily with an empty name */ |
| |
| l = strlen(name); |
| |
| /* First step, change the comm field. */ |
| (void) prctl(PR_SET_NAME, name); |
| if (l > 15) /* Linux process names can be 15 chars at max */ |
| truncated = true; |
| |
| /* Second step, change glibc's ID of the process name. */ |
| if (program_invocation_name) { |
| size_t k; |
| |
| k = strlen(program_invocation_name); |
| strncpy(program_invocation_name, name, k); |
| if (l > k) |
| truncated = true; |
| } |
| |
| /* Third step, completely replace the argv[] array the kernel maintains for us. This requires privileges, but |
| * has the advantage that the argv[] array is exactly what we want it to be, and not filled up with zeros at |
| * the end. This is the best option for changing /proc/self/cmdline. */ |
| |
| /* Let's not bother with this if we don't have euid == 0. Strictly speaking we should check for the |
| * CAP_SYS_RESOURCE capability which is independent of the euid. In our own code the capability generally is |
| * present only for euid == 0, hence let's use this as quick bypass check, to avoid calling mmap() if |
| * PR_SET_MM_ARG_{START,END} fails with EPERM later on anyway. After all geteuid() is dead cheap to call, but |
| * mmap() is not. */ |
| if (geteuid() != 0) |
| log_debug("Skipping PR_SET_MM, as we don't have privileges."); |
| else if (mm_size < l+1) { |
| size_t nn_size; |
| char *nn; |
| |
| nn_size = PAGE_ALIGN(l+1); |
| nn = mmap(NULL, nn_size, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0); |
| if (nn == MAP_FAILED) { |
| log_debug_errno(errno, "mmap() failed: %m"); |
| goto use_saved_argv; |
| } |
| |
| strncpy(nn, name, nn_size); |
| |
| /* Now, let's tell the kernel about this new memory */ |
| if (prctl(PR_SET_MM, PR_SET_MM_ARG_START, (unsigned long) nn, 0, 0) < 0) { |
| log_debug_errno(errno, "PR_SET_MM_ARG_START failed, proceeding without: %m"); |
| (void) munmap(nn, nn_size); |
| goto use_saved_argv; |
| } |
| |
| /* And update the end pointer to the new end, too. If this fails, we don't really know what to do, it's |
| * pretty unlikely that we can rollback, hence we'll just accept the failure, and continue. */ |
| if (prctl(PR_SET_MM, PR_SET_MM_ARG_END, (unsigned long) nn + l + 1, 0, 0) < 0) |
| log_debug_errno(errno, "PR_SET_MM_ARG_END failed, proceeding without: %m"); |
| |
| if (mm) |
| (void) munmap(mm, mm_size); |
| |
| mm = nn; |
| mm_size = nn_size; |
| } else { |
| strncpy(mm, name, mm_size); |
| |
| /* Update the end pointer, continuing regardless of any failure. */ |
| if (prctl(PR_SET_MM, PR_SET_MM_ARG_END, (unsigned long) mm + l + 1, 0, 0) < 0) |
| log_debug_errno(errno, "PR_SET_MM_ARG_END failed, proceeding without: %m"); |
| } |
| |
| use_saved_argv: |
| /* Fourth step: in all cases we'll also update the original argv[], so that our own code gets it right too if |
| * it still looks here */ |
| |
| if (saved_argc > 0) { |
| int i; |
| |
| if (saved_argv[0]) { |
| size_t k; |
| |
| k = strlen(saved_argv[0]); |
| strncpy(saved_argv[0], name, k); |
| if (l > k) |
| truncated = true; |
| } |
| |
| for (i = 1; i < saved_argc; i++) { |
| if (!saved_argv[i]) |
| break; |
| |
| memzero(saved_argv[i], strlen(saved_argv[i])); |
| } |
| } |
| |
| return !truncated; |
| } |
| |
| int is_kernel_thread(pid_t pid) { |
| const char *p; |
| size_t count; |
| char c; |
| bool eof; |
| FILE *f; |
| |
| if (IN_SET(pid, 0, 1) || pid == getpid_cached()) /* pid 1, and we ourselves certainly aren't a kernel thread */ |
| return 0; |
| |
| assert(pid > 1); |
| |
| p = procfs_file_alloca(pid, "cmdline"); |
| f = fopen(p, "re"); |
| if (!f) { |
| if (errno == ENOENT) |
| return -ESRCH; |
| return -errno; |
| } |
| |
| (void) __fsetlocking(f, FSETLOCKING_BYCALLER); |
| |
| count = fread(&c, 1, 1, f); |
| eof = feof(f); |
| fclose(f); |
| |
| /* Kernel threads have an empty cmdline */ |
| |
| if (count <= 0) |
| return eof ? 1 : -errno; |
| |
| return 0; |
| } |
| |
| int get_process_capeff(pid_t pid, char **capeff) { |
| const char *p; |
| int r; |
| |
| assert(capeff); |
| assert(pid >= 0); |
| |
| p = procfs_file_alloca(pid, "status"); |
| |
| r = get_proc_field(p, "CapEff", WHITESPACE, capeff); |
| if (r == -ENOENT) |
| return -ESRCH; |
| |
| return r; |
| } |
| |
| static int get_process_link_contents(const char *proc_file, char **name) { |
| int r; |
| |
| assert(proc_file); |
| assert(name); |
| |
| r = readlink_malloc(proc_file, name); |
| if (r == -ENOENT) |
| return -ESRCH; |
| if (r < 0) |
| return r; |
| |
| return 0; |
| } |
| |
| int get_process_exe(pid_t pid, char **name) { |
| const char *p; |
| char *d; |
| int r; |
| |
| assert(pid >= 0); |
| |
| p = procfs_file_alloca(pid, "exe"); |
| r = get_process_link_contents(p, name); |
| if (r < 0) |
| return r; |
| |
| d = endswith(*name, " (deleted)"); |
| if (d) |
| *d = '\0'; |
| |
| return 0; |
| } |
| |
| static int get_process_id(pid_t pid, const char *field, uid_t *uid) { |
| _cleanup_fclose_ FILE *f = NULL; |
| char line[LINE_MAX]; |
| const char *p; |
| |
| assert(field); |
| assert(uid); |
| |
| if (pid < 0) |
| return -EINVAL; |
| |
| p = procfs_file_alloca(pid, "status"); |
| f = fopen(p, "re"); |
| if (!f) { |
| if (errno == ENOENT) |
| return -ESRCH; |
| return -errno; |
| } |
| |
| (void) __fsetlocking(f, FSETLOCKING_BYCALLER); |
| |
| FOREACH_LINE(line, f, return -errno) { |
| char *l; |
| |
| l = strstrip(line); |
| |
| if (startswith(l, field)) { |
| l += strlen(field); |
| l += strspn(l, WHITESPACE); |
| |
| l[strcspn(l, WHITESPACE)] = 0; |
| |
| return parse_uid(l, uid); |
| } |
| } |
| |
| return -EIO; |
| } |
| |
| int get_process_uid(pid_t pid, uid_t *uid) { |
| |
| if (pid == 0 || pid == getpid_cached()) { |
| *uid = getuid(); |
| return 0; |
| } |
| |
| return get_process_id(pid, "Uid:", uid); |
| } |
| |
| int get_process_gid(pid_t pid, gid_t *gid) { |
| |
| if (pid == 0 || pid == getpid_cached()) { |
| *gid = getgid(); |
| return 0; |
| } |
| |
| assert_cc(sizeof(uid_t) == sizeof(gid_t)); |
| return get_process_id(pid, "Gid:", gid); |
| } |
| |
| int get_process_cwd(pid_t pid, char **cwd) { |
| const char *p; |
| |
| assert(pid >= 0); |
| |
| p = procfs_file_alloca(pid, "cwd"); |
| |
| return get_process_link_contents(p, cwd); |
| } |
| |
| int get_process_root(pid_t pid, char **root) { |
| const char *p; |
| |
| assert(pid >= 0); |
| |
| p = procfs_file_alloca(pid, "root"); |
| |
| return get_process_link_contents(p, root); |
| } |
| |
| int get_process_environ(pid_t pid, char **env) { |
| _cleanup_fclose_ FILE *f = NULL; |
| _cleanup_free_ char *outcome = NULL; |
| int c; |
| const char *p; |
| size_t allocated = 0, sz = 0; |
| |
| assert(pid >= 0); |
| assert(env); |
| |
| p = procfs_file_alloca(pid, "environ"); |
| |
| f = fopen(p, "re"); |
| if (!f) { |
| if (errno == ENOENT) |
| return -ESRCH; |
| return -errno; |
| } |
| |
| (void) __fsetlocking(f, FSETLOCKING_BYCALLER); |
| |
| while ((c = fgetc(f)) != EOF) { |
| if (!GREEDY_REALLOC(outcome, allocated, sz + 5)) |
| return -ENOMEM; |
| |
| if (c == '\0') |
| outcome[sz++] = '\n'; |
| else |
| sz += cescape_char(c, outcome + sz); |
| } |
| |
| if (!outcome) { |
| outcome = strdup(""); |
| if (!outcome) |
| return -ENOMEM; |
| } else |
| outcome[sz] = '\0'; |
| |
| *env = outcome; |
| outcome = NULL; |
| |
| return 0; |
| } |
| |
| int get_process_ppid(pid_t pid, pid_t *_ppid) { |
| int r; |
| _cleanup_free_ char *line = NULL; |
| long unsigned ppid; |
| const char *p; |
| |
| assert(pid >= 0); |
| assert(_ppid); |
| |
| if (pid == 0 || pid == getpid_cached()) { |
| *_ppid = getppid(); |
| return 0; |
| } |
| |
| p = procfs_file_alloca(pid, "stat"); |
| r = read_one_line_file(p, &line); |
| if (r == -ENOENT) |
| return -ESRCH; |
| if (r < 0) |
| return r; |
| |
| /* Let's skip the pid and comm fields. The latter is enclosed |
| * in () but does not escape any () in its value, so let's |
| * skip over it manually */ |
| |
| p = strrchr(line, ')'); |
| if (!p) |
| return -EIO; |
| |
| p++; |
| |
| if (sscanf(p, " " |
| "%*c " /* state */ |
| "%lu ", /* ppid */ |
| &ppid) != 1) |
| return -EIO; |
| |
| if ((long unsigned) (pid_t) ppid != ppid) |
| return -ERANGE; |
| |
| *_ppid = (pid_t) ppid; |
| |
| return 0; |
| } |
| |
| int wait_for_terminate(pid_t pid, siginfo_t *status) { |
| siginfo_t dummy; |
| |
| assert(pid >= 1); |
| |
| if (!status) |
| status = &dummy; |
| |
| for (;;) { |
| zero(*status); |
| |
| if (waitid(P_PID, pid, status, WEXITED) < 0) { |
| |
| if (errno == EINTR) |
| continue; |
| |
| return negative_errno(); |
| } |
| |
| return 0; |
| } |
| } |
| |
| /* |
| * Return values: |
| * < 0 : wait_for_terminate() failed to get the state of the |
| * process, the process was terminated by a signal, or |
| * failed for an unknown reason. |
| * >=0 : The process terminated normally, and its exit code is |
| * returned. |
| * |
| * That is, success is indicated by a return value of zero, and an |
| * error is indicated by a non-zero value. |
| * |
| * A warning is emitted if the process terminates abnormally, |
| * and also if it returns non-zero unless check_exit_code is true. |
| */ |
| int wait_for_terminate_and_warn(const char *name, pid_t pid, bool check_exit_code) { |
| int r; |
| siginfo_t status; |
| |
| assert(name); |
| assert(pid > 1); |
| |
| r = wait_for_terminate(pid, &status); |
| if (r < 0) |
| return log_warning_errno(r, "Failed to wait for %s: %m", name); |
| |
| if (status.si_code == CLD_EXITED) { |
| if (status.si_status != 0) |
| log_full(check_exit_code ? LOG_WARNING : LOG_DEBUG, |
| "%s failed with error code %i.", name, status.si_status); |
| else |
| log_debug("%s succeeded.", name); |
| |
| return status.si_status; |
| } else if (IN_SET(status.si_code, CLD_KILLED, CLD_DUMPED)) { |
| |
| log_warning("%s terminated by signal %s.", name, signal_to_string(status.si_status)); |
| return -EPROTO; |
| } |
| |
| log_warning("%s failed due to unknown reason.", name); |
| return -EPROTO; |
| } |
| |
| /* |
| * Return values: |
| * < 0 : wait_for_terminate_with_timeout() failed to get the state of the |
| * process, the process timed out, the process was terminated by a |
| * signal, or failed for an unknown reason. |
| * >=0 : The process terminated normally with no failures. |
| * |
| * Success is indicated by a return value of zero, a timeout is indicated |
| * by ETIMEDOUT, and all other child failure states are indicated by error |
| * is indicated by a non-zero value. |
| */ |
| int wait_for_terminate_with_timeout(pid_t pid, usec_t timeout) { |
| sigset_t mask; |
| int r; |
| usec_t until; |
| |
| assert_se(sigemptyset(&mask) == 0); |
| assert_se(sigaddset(&mask, SIGCHLD) == 0); |
| |
| /* Drop into a sigtimewait-based timeout. Waiting for the |
| * pid to exit. */ |
| until = now(CLOCK_MONOTONIC) + timeout; |
| for (;;) { |
| usec_t n; |
| siginfo_t status = {}; |
| struct timespec ts; |
| |
| n = now(CLOCK_MONOTONIC); |
| if (n >= until) |
| break; |
| |
| r = sigtimedwait(&mask, NULL, timespec_store(&ts, until - n)) < 0 ? -errno : 0; |
| /* Assuming we woke due to the child exiting. */ |
| if (waitid(P_PID, pid, &status, WEXITED|WNOHANG) == 0) { |
| if (status.si_pid == pid) { |
| /* This is the correct child.*/ |
| if (status.si_code == CLD_EXITED) |
| return (status.si_status == 0) ? 0 : -EPROTO; |
| else |
| return -EPROTO; |
| } |
| } |
| /* Not the child, check for errors and proceed appropriately */ |
| if (r < 0) { |
| switch (r) { |
| case -EAGAIN: |
| /* Timed out, child is likely hung. */ |
| return -ETIMEDOUT; |
| case -EINTR: |
| /* Received a different signal and should retry */ |
| continue; |
| default: |
| /* Return any unexpected errors */ |
| return r; |
| } |
| } |
| } |
| |
| return -EPROTO; |
| } |
| |
| void sigkill_wait(pid_t pid) { |
| assert(pid > 1); |
| |
| if (kill(pid, SIGKILL) > 0) |
| (void) wait_for_terminate(pid, NULL); |
| } |
| |
| void sigkill_waitp(pid_t *pid) { |
| PROTECT_ERRNO; |
| |
| if (!pid) |
| return; |
| if (*pid <= 1) |
| return; |
| |
| sigkill_wait(*pid); |
| } |
| |
| int kill_and_sigcont(pid_t pid, int sig) { |
| int r; |
| |
| r = kill(pid, sig) < 0 ? -errno : 0; |
| |
| /* If this worked, also send SIGCONT, unless we already just sent a SIGCONT, or SIGKILL was sent which isn't |
| * affected by a process being suspended anyway. */ |
| if (r >= 0 && !IN_SET(sig, SIGCONT, SIGKILL)) |
| (void) kill(pid, SIGCONT); |
| |
| return r; |
| } |
| |
| int getenv_for_pid(pid_t pid, const char *field, char **_value) { |
| _cleanup_fclose_ FILE *f = NULL; |
| char *value = NULL; |
| int r; |
| bool done = false; |
| size_t l; |
| const char *path; |
| |
| assert(pid >= 0); |
| assert(field); |
| assert(_value); |
| |
| path = procfs_file_alloca(pid, "environ"); |
| |
| f = fopen(path, "re"); |
| if (!f) { |
| if (errno == ENOENT) |
| return -ESRCH; |
| return -errno; |
| } |
| |
| (void) __fsetlocking(f, FSETLOCKING_BYCALLER); |
| |
| l = strlen(field); |
| r = 0; |
| |
| do { |
| char line[LINE_MAX]; |
| unsigned i; |
| |
| for (i = 0; i < sizeof(line)-1; i++) { |
| int c; |
| |
| c = getc(f); |
| if (_unlikely_(c == EOF)) { |
| done = true; |
| break; |
| } else if (c == 0) |
| break; |
| |
| line[i] = c; |
| } |
| line[i] = 0; |
| |
| if (strneq(line, field, l) && line[l] == '=') { |
| value = strdup(line + l + 1); |
| if (!value) |
| return -ENOMEM; |
| |
| r = 1; |
| break; |
| } |
| |
| } while (!done); |
| |
| *_value = value; |
| return r; |
| } |
| |
| bool pid_is_unwaited(pid_t pid) { |
| /* Checks whether a PID is still valid at all, including a zombie */ |
| |
| if (pid < 0) |
| return false; |
| |
| if (pid <= 1) /* If we or PID 1 would be dead and have been waited for, this code would not be running */ |
| return true; |
| |
| if (pid == getpid_cached()) |
| return true; |
| |
| if (kill(pid, 0) >= 0) |
| return true; |
| |
| return errno != ESRCH; |
| } |
| |
| bool pid_is_alive(pid_t pid) { |
| int r; |
| |
| /* Checks whether a PID is still valid and not a zombie */ |
| |
| if (pid < 0) |
| return false; |
| |
| if (pid <= 1) /* If we or PID 1 would be a zombie, this code would not be running */ |
| return true; |
| |
| if (pid == getpid_cached()) |
| return true; |
| |
| r = get_process_state(pid); |
| if (IN_SET(r, -ESRCH, 'Z')) |
| return false; |
| |
| return true; |
| } |
| |
| int pid_from_same_root_fs(pid_t pid) { |
| const char *root; |
| |
| if (pid < 0) |
| return false; |
| |
| if (pid == 0 || pid == getpid_cached()) |
| return true; |
| |
| root = procfs_file_alloca(pid, "root"); |
| |
| return files_same(root, "/proc/1/root", 0); |
| } |
| |
| bool is_main_thread(void) { |
| static thread_local int cached = 0; |
| |
| if (_unlikely_(cached == 0)) |
| cached = getpid_cached() == gettid() ? 1 : -1; |
| |
| return cached > 0; |
| } |
| |
| _noreturn_ void freeze(void) { |
| |
| log_close(); |
| |
| /* Make sure nobody waits for us on a socket anymore */ |
| close_all_fds(NULL, 0); |
| |
| sync(); |
| |
| for (;;) |
| pause(); |
| } |
| |
| bool oom_score_adjust_is_valid(int oa) { |
| return oa >= OOM_SCORE_ADJ_MIN && oa <= OOM_SCORE_ADJ_MAX; |
| } |
| |
| unsigned long personality_from_string(const char *p) { |
| int architecture; |
| |
| if (!p) |
| return PERSONALITY_INVALID; |
| |
| /* Parse a personality specifier. We use our own identifiers that indicate specific ABIs, rather than just |
| * hints regarding the register size, since we want to keep things open for multiple locally supported ABIs for |
| * the same register size. */ |
| |
| architecture = architecture_from_string(p); |
| if (architecture < 0) |
| return PERSONALITY_INVALID; |
| |
| if (architecture == native_architecture()) |
| return PER_LINUX; |
| #ifdef SECONDARY_ARCHITECTURE |
| if (architecture == SECONDARY_ARCHITECTURE) |
| return PER_LINUX32; |
| #endif |
| |
| return PERSONALITY_INVALID; |
| } |
| |
| const char* personality_to_string(unsigned long p) { |
| int architecture = _ARCHITECTURE_INVALID; |
| |
| if (p == PER_LINUX) |
| architecture = native_architecture(); |
| #ifdef SECONDARY_ARCHITECTURE |
| else if (p == PER_LINUX32) |
| architecture = SECONDARY_ARCHITECTURE; |
| #endif |
| |
| if (architecture < 0) |
| return NULL; |
| |
| return architecture_to_string(architecture); |
| } |
| |
| int safe_personality(unsigned long p) { |
| int ret; |
| |
| /* So here's the deal, personality() is weirdly defined by glibc. In some cases it returns a failure via errno, |
| * and in others as negative return value containing an errno-like value. Let's work around this: this is a |
| * wrapper that uses errno if it is set, and uses the return value otherwise. And then it sets both errno and |
| * the return value indicating the same issue, so that we are definitely on the safe side. |
| * |
| * See https://github.com/systemd/systemd/issues/6737 */ |
| |
| errno = 0; |
| ret = personality(p); |
| if (ret < 0) { |
| if (errno != 0) |
| return -errno; |
| |
| errno = -ret; |
| } |
| |
| return ret; |
| } |
| |
| int opinionated_personality(unsigned long *ret) { |
| int current; |
| |
| /* Returns the current personality, or PERSONALITY_INVALID if we can't determine it. This function is a bit |
| * opinionated though, and ignores all the finer-grained bits and exotic personalities, only distinguishing the |
| * two most relevant personalities: PER_LINUX and PER_LINUX32. */ |
| |
| current = safe_personality(PERSONALITY_INVALID); |
| if (current < 0) |
| return current; |
| |
| if (((unsigned long) current & 0xffff) == PER_LINUX32) |
| *ret = PER_LINUX32; |
| else |
| *ret = PER_LINUX; |
| |
| return 0; |
| } |
| |
| void valgrind_summary_hack(void) { |
| #if HAVE_VALGRIND_VALGRIND_H |
| if (getpid_cached() == 1 && RUNNING_ON_VALGRIND) { |
| pid_t pid; |
| pid = raw_clone(SIGCHLD); |
| if (pid < 0) |
| log_emergency_errno(errno, "Failed to fork off valgrind helper: %m"); |
| else if (pid == 0) |
| exit(EXIT_SUCCESS); |
| else { |
| log_info("Spawned valgrind helper as PID "PID_FMT".", pid); |
| (void) wait_for_terminate(pid, NULL); |
| } |
| } |
| #endif |
| } |
| |
| int pid_compare_func(const void *a, const void *b) { |
| const pid_t *p = a, *q = b; |
| |
| /* Suitable for usage in qsort() */ |
| |
| if (*p < *q) |
| return -1; |
| if (*p > *q) |
| return 1; |
| return 0; |
| } |
| |
| int ioprio_parse_priority(const char *s, int *ret) { |
| int i, r; |
| |
| assert(s); |
| assert(ret); |
| |
| r = safe_atoi(s, &i); |
| if (r < 0) |
| return r; |
| |
| if (!ioprio_priority_is_valid(i)) |
| return -EINVAL; |
| |
| *ret = i; |
| return 0; |
| } |
| |
| /* The cached PID, possible values: |
| * |
| * == UNSET [0] → cache not initialized yet |
| * == BUSY [-1] → some thread is initializing it at the moment |
| * any other → the cached PID |
| */ |
| |
| #define CACHED_PID_UNSET ((pid_t) 0) |
| #define CACHED_PID_BUSY ((pid_t) -1) |
| |
| static pid_t cached_pid = CACHED_PID_UNSET; |
| |
| static void reset_cached_pid(void) { |
| /* Invoked in the child after a fork(), i.e. at the first moment the PID changed */ |
| cached_pid = CACHED_PID_UNSET; |
| } |
| |
| /* We use glibc __register_atfork() + __dso_handle directly here, as they are not included in the glibc |
| * headers. __register_atfork() is mostly equivalent to pthread_atfork(), but doesn't require us to link against |
| * libpthread, as it is part of glibc anyway. */ |
| extern int __register_atfork(void (*prepare) (void), void (*parent) (void), void (*child) (void), void * __dso_handle); |
| extern void* __dso_handle __attribute__ ((__weak__)); |
| |
| pid_t getpid_cached(void) { |
| pid_t current_value; |
| |
| /* getpid_cached() is much like getpid(), but caches the value in local memory, to avoid having to invoke a |
| * system call each time. This restores glibc behaviour from before 2.24, when getpid() was unconditionally |
| * cached. Starting with 2.24 getpid() started to become prohibitively expensive when used for detecting when |
| * objects were used across fork()s. With this caching the old behaviour is somewhat restored. |
| * |
| * https://bugzilla.redhat.com/show_bug.cgi?id=1443976 |
| * https://sourceware.org/git/gitweb.cgi?p=glibc.git;h=c579f48edba88380635ab98cb612030e3ed8691e |
| */ |
| |
| current_value = __sync_val_compare_and_swap(&cached_pid, CACHED_PID_UNSET, CACHED_PID_BUSY); |
| |
| switch (current_value) { |
| |
| case CACHED_PID_UNSET: { /* Not initialized yet, then do so now */ |
| pid_t new_pid; |
| |
| new_pid = getpid(); |
| |
| if (__register_atfork(NULL, NULL, reset_cached_pid, __dso_handle) != 0) { |
| /* OOM? Let's try again later */ |
| cached_pid = CACHED_PID_UNSET; |
| return new_pid; |
| } |
| |
| cached_pid = new_pid; |
| return new_pid; |
| } |
| |
| case CACHED_PID_BUSY: /* Somebody else is currently initializing */ |
| return getpid(); |
| |
| default: /* Properly initialized */ |
| return current_value; |
| } |
| } |
| |
| int must_be_root(void) { |
| |
| if (geteuid() == 0) |
| return 0; |
| |
| log_error("Need to be root."); |
| return -EPERM; |
| } |
| |
| static const char *const ioprio_class_table[] = { |
| [IOPRIO_CLASS_NONE] = "none", |
| [IOPRIO_CLASS_RT] = "realtime", |
| [IOPRIO_CLASS_BE] = "best-effort", |
| [IOPRIO_CLASS_IDLE] = "idle" |
| }; |
| |
| DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ioprio_class, int, INT_MAX); |
| |
| static const char *const sigchld_code_table[] = { |
| [CLD_EXITED] = "exited", |
| [CLD_KILLED] = "killed", |
| [CLD_DUMPED] = "dumped", |
| [CLD_TRAPPED] = "trapped", |
| [CLD_STOPPED] = "stopped", |
| [CLD_CONTINUED] = "continued", |
| }; |
| |
| DEFINE_STRING_TABLE_LOOKUP(sigchld_code, int); |
| |
| static const char* const sched_policy_table[] = { |
| [SCHED_OTHER] = "other", |
| [SCHED_BATCH] = "batch", |
| [SCHED_IDLE] = "idle", |
| [SCHED_FIFO] = "fifo", |
| [SCHED_RR] = "rr" |
| }; |
| |
| DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(sched_policy, int, INT_MAX); |