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-rw-r--r--src/libsystemd-basic/src/process-util.c861
1 files changed, 861 insertions, 0 deletions
diff --git a/src/libsystemd-basic/src/process-util.c b/src/libsystemd-basic/src/process-util.c
new file mode 100644
index 0000000000..aa1c31a089
--- /dev/null
+++ b/src/libsystemd-basic/src/process-util.c
@@ -0,0 +1,861 @@
+/***
+ 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 <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>
+
+#include <linux/oom.h>
+#ifdef HAVE_VALGRIND_VALGRIND_H
+#include <valgrind/valgrind.h>
+#endif
+
+#include "systemd-basic/alloc-util.h"
+#include "systemd-basic/architecture.h"
+#include "systemd-basic/escape.h"
+#include "systemd-basic/fd-util.h"
+#include "systemd-basic/fileio.h"
+#include "systemd-basic/fs-util.h"
+#include "systemd-basic/ioprio.h"
+#include "systemd-basic/log.h"
+#include "systemd-basic/macro.h"
+#include "systemd-basic/missing.h"
+#include "systemd-basic/process-util.h"
+#include "systemd-basic/raw-clone.h"
+#include "systemd-basic/signal-util.h"
+#include "systemd-basic/stat-util.h"
+#include "systemd-basic/string-table.h"
+#include "systemd-basic/string-util.h"
+#include "systemd-basic/user-util.h"
+#include "systemd-basic/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 *r = NULL, *k;
+ 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). */
+
+ p = procfs_file_alloca(pid, "cmdline");
+
+ f = fopen(p, "re");
+ if (!f) {
+ if (errno == ENOENT)
+ return -ESRCH;
+ return -errno;
+ }
+
+ if (max_length == 1) {
+
+ /* If there's only room for one byte, return the empty string */
+ r = new0(char, 1);
+ if (!r)
+ return -ENOMEM;
+
+ *line = r;
+ return 0;
+
+ } else if (max_length == 0) {
+ size_t len = 0, allocated = 0;
+
+ while ((c = getc(f)) != EOF) {
+
+ if (!GREEDY_REALLOC(r, allocated, len+3)) {
+ free(r);
+ return -ENOMEM;
+ }
+
+ if (isprint(c)) {
+ if (space) {
+ r[len++] = ' ';
+ space = false;
+ }
+
+ r[len++] = c;
+ } else if (len > 0)
+ space = true;
+ }
+
+ if (len > 0)
+ r[len] = 0;
+ else
+ r = mfree(r);
+
+ } else {
+ bool dotdotdot = 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 <= 2) {
+ dotdotdot = true;
+ break;
+ }
+
+ *(k++) = ' ';
+ left--;
+ space = false;
+ }
+
+ if (left <= 1) {
+ dotdotdot = true;
+ break;
+ }
+
+ *(k++) = (char) c;
+ left--;
+ } else if (k > r)
+ space = true;
+ }
+
+ if (dotdotdot) {
+ if (max_length <= 4) {
+ k = r;
+ left = max_length;
+ } else {
+ k = r + max_length - 4;
+ left = 4;
+
+ /* Eat up final spaces */
+ while (k > r && isspace(k[-1])) {
+ k--;
+ left++;
+ }
+ }
+
+ strncpy(k, "...", left-1);
+ k[left-1] = 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;
+
+ if (max_length == 0)
+ r = strjoin("[", t, "]", NULL);
+ else {
+ size_t l;
+
+ l = strlen(t);
+
+ if (l + 3 <= max_length)
+ r = strjoin("[", t, "]", NULL);
+ else if (max_length <= 6) {
+
+ r = new(char, max_length);
+ if (!r)
+ return -ENOMEM;
+
+ memcpy(r, "[...]", max_length-1);
+ r[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;
+
+ 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 */
+
+ (void) 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);
+
+ 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 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 (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) {
+ assert(pid > 1);
+
+ if (kill(pid, SIGKILL) > 0)
+ (void) wait_for_terminate(pid, NULL);
+}
+
+void sigkill_waitp(pid_t *pid) {
+ 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(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;
+ }
+
+ 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) {
+
+ 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);
+}
+
+void valgrind_summary_hack(void) {
+#ifdef HAVE_VALGRIND_VALGRIND_H
+ if (getpid() == 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;
+}
+
+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);
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 12:19:20 +0000