diff options
Diffstat (limited to 'src/basic/process-util.c')
-rw-r--r-- | src/basic/process-util.c | 410 |
1 files changed, 364 insertions, 46 deletions
diff --git a/src/basic/process-util.c b/src/basic/process-util.c index 2c05f2fee4..54b644ad56 100644 --- a/src/basic/process-util.c +++ b/src/basic/process-util.c @@ -17,22 +17,44 @@ 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 <sys/types.h> -#include <string.h> #include <stdio.h> -#include <assert.h> -#include <errno.h> -#include <unistd.h> +#include <stdlib.h> +#include <string.h> +#include <sys/personality.h> +#include <sys/prctl.h> +#include <sys/types.h> #include <sys/wait.h> -#include <signal.h> -#include <ctype.h> - +#include <syslog.h> +#include <unistd.h> +#ifdef 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 "util.h" +#include "fs-util.h" +#include "ioprio.h" #include "log.h" -#include "signal-util.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; @@ -43,7 +65,10 @@ int get_process_state(pid_t pid) { 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; @@ -77,6 +102,7 @@ int get_process_comm(pid_t pid, char **name) { 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; @@ -84,30 +110,62 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * 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 (!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; - if (max_length == 0) { + } else if (max_length == 0) { size_t len = 0, allocated = 0; while ((c = getc(f)) != EOF) { - if (!GREEDY_REALLOC(r, allocated, len+2)) { + if (!GREEDY_REALLOC(r, allocated, len+3)) { free(r); return -ENOMEM; } - r[len++] = isprint(c) ? c : ' '; - } + if (isprint(c)) { + if (space) { + r[len++] = ' '; + space = false; + } + + r[len++] = c; + } else if (len > 0) + space = true; + } if (len > 0) - r[len-1] = 0; + r[len] = 0; + else + r = mfree(r); } else { - bool space = false; + bool dotdotdot = false; size_t left; r = new(char, max_length); @@ -119,28 +177,46 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * while ((c = getc(f)) != EOF) { if (isprint(c)) { + if (space) { - if (left <= 4) + if (left <= 2) { + dotdotdot = true; break; + } *(k++) = ' '; left--; space = false; } - if (left <= 4) + if (left <= 1) { + dotdotdot = true; break; + } *(k++) = (char) c; left--; - } else + } else if (k > r) space = true; } - if (left <= 4) { - size_t n = MIN(left-1, 3U); - memcpy(k, "...", n); - k[n] = 0; + 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; } @@ -159,7 +235,37 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * if (h < 0) return h; - r = strjoin("[", t, "]", NULL); + 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; } @@ -168,6 +274,37 @@ int get_process_cmdline(pid_t pid, size_t max_length, bool comm_fallback, char * 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; @@ -175,15 +312,18 @@ int is_kernel_thread(pid_t pid) { bool eof; FILE *f; - if (pid == 0) + if (pid == 0 || pid == 1) /* pid 1, and we ourselves certainly aren't a kernel thread */ return 0; - assert(pid > 0); + assert(pid > 1); p = procfs_file_alloca(pid, "cmdline"); f = fopen(p, "re"); - if (!f) + if (!f) { + if (errno == ENOENT) + return -ESRCH; return -errno; + } count = fread(&c, 1, 1, f); eof = feof(f); @@ -199,13 +339,18 @@ int is_kernel_thread(pid_t pid) { 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"); - return get_status_field(p, "\nCapEff:", capeff); + 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) { @@ -215,8 +360,10 @@ static int get_process_link_contents(const char *proc_file, char **name) { assert(name); r = readlink_malloc(proc_file, name); + if (r == -ENOENT) + return -ESRCH; if (r < 0) - return r == -ENOENT ? -ESRCH : r; + return r; return 0; } @@ -248,13 +395,13 @@ static int get_process_id(pid_t pid, const char *field, uid_t *uid) { assert(field); assert(uid); - if (pid == 0) - return getuid(); - p = procfs_file_alloca(pid, "status"); f = fopen(p, "re"); - if (!f) + if (!f) { + if (errno == ENOENT) + return -ESRCH; return -errno; + } FOREACH_LINE(line, f, return -errno) { char *l; @@ -316,8 +463,11 @@ int get_process_environ(pid_t pid, char **env) { p = procfs_file_alloca(pid, "environ"); f = fopen(p, "re"); - if (!f) + if (!f) { + if (errno == ENOENT) + return -ESRCH; return -errno; + } while ((c = fgetc(f)) != EOF) { if (!GREEDY_REALLOC(outcome, allocated, sz + 5)) @@ -329,17 +479,20 @@ int get_process_environ(pid_t pid, char **env) { sz += cescape_char(c, outcome + sz); } - if (sz == 0) - return -ENOENT; + if (!outcome) { + outcome = strdup(""); + if (!outcome) + return -ENOMEM; + } else + outcome[sz] = '\0'; - outcome[sz] = '\0'; *env = outcome; outcome = NULL; return 0; } -int get_parent_of_pid(pid_t pid, pid_t *_ppid) { +int get_process_ppid(pid_t pid, pid_t *_ppid) { int r; _cleanup_free_ char *line = NULL; long unsigned ppid; @@ -355,6 +508,8 @@ int get_parent_of_pid(pid_t pid, pid_t *_ppid) { p = procfs_file_alloca(pid, "stat"); r = read_one_line_file(p, &line); + if (r == -ENOENT) + return -ESRCH; if (r < 0) return r; @@ -398,7 +553,7 @@ int wait_for_terminate(pid_t pid, siginfo_t *status) { if (errno == EINTR) continue; - return -errno; + return negative_errno(); } return 0; @@ -449,13 +604,31 @@ int wait_for_terminate_and_warn(const char *name, pid_t pid, bool check_exit_cod 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 (r >= 0) - kill(pid, SIGCONT); + /* 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; } @@ -475,8 +648,11 @@ int getenv_for_pid(pid_t pid, const char *field, char **_value) { path = procfs_file_alloca(pid, "environ"); f = fopen(path, "re"); - if (!f) + if (!f) { + if (errno == ENOENT) + return -ESRCH; return -errno; + } l = strlen(field); r = 0; @@ -517,9 +693,12 @@ int getenv_for_pid(pid_t pid, const char *field, char **_value) { bool pid_is_unwaited(pid_t pid) { /* Checks whether a PID is still valid at all, including a zombie */ - if (pid <= 0) + 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; @@ -531,12 +710,151 @@ bool pid_is_alive(pid_t pid) { /* Checks whether a PID is still valid and not a zombie */ - if (pid <= 0) + 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 == -ENOENT || r == 'Z') + 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); |