/*** 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 <stdlib.h> #include <string.h> #include <sys/personality.h> #include <sys/prctl.h> #include <sys/types.h> #include <sys/wait.h> #include <syslog.h> #include <unistd.h> #ifdef HAVE_VALGRIND_VALGRIND_H #include <valgrind/valgrind.h> #endif #include "alloc-util.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 "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; char *r = NULL, *k; const char *p; int c; assert(line); assert(pid >= 0); p = procfs_file_alloca(pid, "cmdline"); f = fopen(p, "re"); if (!f) { if (errno == ENOENT) return -ESRCH; return -errno; } if (max_length == 0) { size_t len = 0, allocated = 0; while ((c = getc(f)) != EOF) { if (!GREEDY_REALLOC(r, allocated, len+2)) { free(r); return -ENOMEM; } r[len++] = isprint(c) ? c : ' '; } if (len > 0) r[len-1] = 0; } else { bool space = false; size_t left; r = new(char, max_length); if (!r) return -ENOMEM; k = r; left = max_length; while ((c = getc(f)) != EOF) { if (isprint(c)) { if (space) { if (left <= 4) break; *(k++) = ' '; left--; space = false; } if (left <= 4) break; *(k++) = (char) c; left--; } else space = true; } if (left <= 4) { size_t n = MIN(left-1, 3U); memcpy(k, "...", n); k[n] = 0; } else *k = 0; } /* Kernel threads have no argv[] */ if (isempty(r)) { _cleanup_free_ char *t = NULL; int h; free(r); if (!comm_fallback) return -ENOENT; h = get_process_comm(pid, &t); if (h < 0) return h; r = strjoin("[", t, "]", NULL); if (!r) return -ENOMEM; } *line = r; return 0; } void rename_process(const char name[8]) { assert(name); /* 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 usually one of 10 (i.e. length * of "/sbin/init"), to the third one one of 7 (i.e. length of * "systemd"). If you pass a longer string it will be * truncated */ prctl(PR_SET_NAME, name); if (program_invocation_name) strncpy(program_invocation_name, name, strlen(program_invocation_name)); if (saved_argc > 0) { int i; if (saved_argv[0]) strncpy(saved_argv[0], name, strlen(saved_argv[0])); for (i = 1; i < saved_argc; i++) { if (!saved_argv[i]) break; memzero(saved_argv[i], strlen(saved_argv[i])); } } } int is_kernel_thread(pid_t pid) { const char *p; size_t count; char c; bool eof; FILE *f; if (pid == 0 || pid == 1) /* 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; } 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 getuid(); p = procfs_file_alloca(pid, "status"); f = fopen(p, "re"); if (!f) { if (errno == ENOENT) return -ESRCH; return -errno; } 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) { return get_process_id(pid, "Uid:", uid); } int get_process_gid(pid_t pid, gid_t *gid) { 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; } 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) { *_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 -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 (status.si_code == CLD_KILLED || status.si_code == 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; } void sigkill_wait(pid_t *pid) { if (!pid) return; if (*pid <= 1) return; if (kill(*pid, SIGKILL) > 0) (void) wait_for_terminate(*pid, NULL); } int kill_and_sigcont(pid_t pid, int sig) { int r; r = kill(pid, sig) < 0 ? -errno : 0; if (r >= 0) 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; } 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 (memcmp(line, field, l) == 0 && 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 (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; r = get_process_state(pid); if (r == -ESRCH || r == 'Z') return false; return true; } int pid_from_same_root_fs(pid_t pid) { const char *root; if (pid < 0) return 0; root = procfs_file_alloca(pid, "root"); return files_same(root, "/proc/1/root"); } bool is_main_thread(void) { static thread_local int cached = 0; if (_unlikely_(cached == 0)) cached = getpid() == gettid() ? 1 : -1; return cached > 0; } noreturn void freeze(void) { /* 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) { /* Parse a personality specifier. We introduce 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. We try to reuse the ABI identifiers * used by libseccomp. */ #if defined(__x86_64__) if (streq(p, "x86")) return PER_LINUX32; if (streq(p, "x86-64")) return PER_LINUX; #elif defined(__i386__) if (streq(p, "x86")) return PER_LINUX; #elif defined(__s390x__) if (streq(p, "s390")) return PER_LINUX32; if (streq(p, "s390x")) return PER_LINUX; #elif defined(__s390__) if (streq(p, "s390")) return PER_LINUX; #endif return PERSONALITY_INVALID; } const char* personality_to_string(unsigned long p) { #if defined(__x86_64__) if (p == PER_LINUX32) return "x86"; if (p == PER_LINUX) return "x86-64"; #elif defined(__i386__) if (p == PER_LINUX) return "x86"; #elif defined(__s390x__) if (p == PER_LINUX) return "s390x"; if (p == PER_LINUX32) return "s390"; #elif defined(__s390__) if (p == PER_LINUX) return "s390"; #endif return NULL; } void valgrind_summary_hack(void) { #ifdef HAVE_VALGRIND_VALGRIND_H if (getpid() == 1 && RUNNING_ON_VALGRIND) { pid_t pid; pid = raw_clone(SIGCHLD, NULL); 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 } 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);