src/basic/process-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
   2 #pragma once
   3
   4 #include <errno.h>
   5 #include <sched.h>
   6 #include <signal.h>
   7 #include <stdbool.h>
   8 #include <stddef.h>
   9 #include <stdio.h>
  10 #include <string.h>
  11 #include <sys/resource.h>
  12 #include <sys/types.h>
  13
  14 #include "alloc-util.h"
  15 #include "format-util.h"
  16 #include "ioprio.h"
  17 #include "macro.h"
  18 #include "time-util.h"
  19
  20 #define procfs_file_alloca(pid, field)                                  \
  21         ({                                                              \
  22                 pid_t _pid_ = (pid);                                    \
  23                 const char *_field_ = (field);                          \
  24                 char *_r_;                                              \
  25                 if (_pid_ == 0) {                                       \
  26                         _r_ = newa(char, STRLEN("/proc/self/") + strlen(_field_) + 1); \
  27                         strcpy(stpcpy(_r_, "/proc/self/"), _field_);    \
  28                 } else {                                                \
  29                         _r_ = newa(char, STRLEN("/proc/") + DECIMAL_STR_MAX(pid_t) + 1 + strlen(_field_) + 1); \
  30                         sprintf(_r_, "/proc/" PID_FMT "/%s", _pid_, _field_); \
  31                 }                                                       \
  32                 (const char*) _r_;                                      \
  33         })
  34
  35 typedef enum ProcessCmdlineFlags {
  36         PROCESS_CMDLINE_COMM_FALLBACK = 1 << 0,
  37         PROCESS_CMDLINE_USE_LOCALE    = 1 << 1,
  38 } ProcessCmdlineFlags;
  39
  40 int get_process_comm(pid_t pid, char **name);
  41 int get_process_cmdline(pid_t pid, size_t max_columns, ProcessCmdlineFlags flags, char **line);
  42 int get_process_exe(pid_t pid, char **name);
  43 int get_process_uid(pid_t pid, uid_t *uid);
  44 int get_process_gid(pid_t pid, gid_t *gid);
  45 int get_process_capeff(pid_t pid, char **capeff);
  46 int get_process_cwd(pid_t pid, char **cwd);
  47 int get_process_root(pid_t pid, char **root);
  48 int get_process_environ(pid_t pid, char **environ);
  49 int get_process_ppid(pid_t pid, pid_t *ppid);
  50 int get_process_umask(pid_t pid, mode_t *umask);
  51
  52 int wait_for_terminate(pid_t pid, siginfo_t *status);
  53
  54 typedef enum WaitFlags {
  55         WAIT_LOG_ABNORMAL             = 1 << 0,
  56         WAIT_LOG_NON_ZERO_EXIT_STATUS = 1 << 1,
  57
  58         /* A shortcut for requesting the most complete logging */
  59         WAIT_LOG = WAIT_LOG_ABNORMAL|WAIT_LOG_NON_ZERO_EXIT_STATUS,
  60 } WaitFlags;
  61
  62 int wait_for_terminate_and_check(const char *name, pid_t pid, WaitFlags flags);
  63 int wait_for_terminate_with_timeout(pid_t pid, usec_t timeout);
  64
  65 void sigkill_wait(pid_t pid);
  66 void sigkill_waitp(pid_t *pid);
  67 void sigterm_wait(pid_t pid);
  68
  69 int kill_and_sigcont(pid_t pid, int sig);
  70
  71 int rename_process(const char name[]);
  72 int is_kernel_thread(pid_t pid);
  73
  74 int getenv_for_pid(pid_t pid, const char *field, char **_value);
  75
  76 bool pid_is_alive(pid_t pid);
  77 bool pid_is_unwaited(pid_t pid);
  78 int pid_is_my_child(pid_t pid);
  79 int pid_from_same_root_fs(pid_t pid);
  80
  81 bool is_main_thread(void);
  82
  83 _noreturn_ void freeze(void);
  84
  85 bool oom_score_adjust_is_valid(int oa);
  86
  87 #ifndef PERSONALITY_INVALID
  88 /* personality(7) documents that 0xffffffffUL is used for querying the
  89  * current personality, hence let's use that here as error
  90  * indicator. */
  91 #define PERSONALITY_INVALID 0xffffffffLU
  92 #endif
  93
  94 unsigned long personality_from_string(const char *p);
  95 const char *personality_to_string(unsigned long);
  96
  97 int safe_personality(unsigned long p);
  98 int opinionated_personality(unsigned long *ret);
  99
 100 int ioprio_class_to_string_alloc(int i, char **s);
 101 int ioprio_class_from_string(const char *s);
 102
 103 const char *sigchld_code_to_string(int i) _const_;
 104 int sigchld_code_from_string(const char *s) _pure_;
 105
 106 int sched_policy_to_string_alloc(int i, char **s);
 107 int sched_policy_from_string(const char *s);
 108
 109 static inline pid_t PTR_TO_PID(const void *p) {
 110         return (pid_t) ((uintptr_t) p);
 111 }
 112
 113 static inline void* PID_TO_PTR(pid_t pid) {
 114         return (void*) ((uintptr_t) pid);
 115 }
 116
 117 void valgrind_summary_hack(void);
 118
 119 int pid_compare_func(const pid_t *a, const pid_t *b);
 120
 121 static inline bool nice_is_valid(int n) {
 122         return n >= PRIO_MIN && n < PRIO_MAX;
 123 }
 124
 125 static inline bool sched_policy_is_valid(int i) {
 126         return IN_SET(i, SCHED_OTHER, SCHED_BATCH, SCHED_IDLE, SCHED_FIFO, SCHED_RR);
 127 }
 128
 129 static inline bool sched_priority_is_valid(int i) {
 130         return i >= 0 && i <= sched_get_priority_max(SCHED_RR);
 131 }
 132
 133 static inline bool ioprio_class_is_valid(int i) {
 134         return IN_SET(i, IOPRIO_CLASS_NONE, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE);
 135 }
 136
 137 static inline bool ioprio_priority_is_valid(int i) {
 138         return i >= 0 && i < IOPRIO_BE_NR;
 139 }
 140
 141 static inline bool pid_is_valid(pid_t p) {
 142         return p > 0;
 143 }
 144
 145 int ioprio_parse_priority(const char *s, int *ret);
 146
 147 pid_t getpid_cached(void);
 148 void reset_cached_pid(void);
 149
 150 int must_be_root(void);
 151
 152 typedef enum ForkFlags {
 153         FORK_RESET_SIGNALS      = 1 <<  0, /* Reset all signal handlers and signal mask */
 154         FORK_CLOSE_ALL_FDS      = 1 <<  1, /* Close all open file descriptors in the child, except for 0,1,2 */
 155         FORK_DEATHSIG           = 1 <<  2, /* Set PR_DEATHSIG in the child to SIGTERM */
 156         FORK_DEATHSIG_SIGINT    = 1 <<  3, /* Set PR_DEATHSIG in the child to SIGINT */
 157         FORK_NULL_STDIO         = 1 <<  4, /* Connect 0,1,2 to /dev/null */
 158         FORK_REOPEN_LOG         = 1 <<  5, /* Reopen log connection */
 159         FORK_LOG                = 1 <<  6, /* Log above LOG_DEBUG log level about failures */
 160         FORK_WAIT               = 1 <<  7, /* Wait until child exited */
 161         FORK_NEW_MOUNTNS        = 1 <<  8, /* Run child in its own mount namespace */
 162         FORK_MOUNTNS_SLAVE      = 1 <<  9, /* Make child's mount namespace MS_SLAVE */
 163         FORK_RLIMIT_NOFILE_SAFE = 1 << 10, /* Set RLIMIT_NOFILE soft limit to 1K for select() compat */
 164         FORK_STDOUT_TO_STDERR   = 1 << 11, /* Make stdout a copy of stderr */
 165         FORK_FLUSH_STDIO        = 1 << 12, /* fflush() stdout (and stderr) before forking */
 166 } ForkFlags;
 167
 168 int safe_fork_full(const char *name, const int except_fds[], size_t n_except_fds, ForkFlags flags, pid_t *ret_pid);
 169
 170 static inline int safe_fork(const char *name, ForkFlags flags, pid_t *ret_pid) {
 171         return safe_fork_full(name, NULL, 0, flags, ret_pid);
 172 }
 173
 174 int namespace_fork(const char *outer_name, const char *inner_name, const int except_fds[], size_t n_except_fds, ForkFlags flags, int pidns_fd, int mntns_fd, int netns_fd, int userns_fd, int root_fd, pid_t *ret_pid);
 175
 176 int fork_agent(const char *name, const int except[], size_t n_except, pid_t *pid, const char *path, ...) _sentinel_;
 177
 178 int set_oom_score_adjust(int value);
 179
 180 /* The highest possibly (theoretic) pid_t value on this architecture. */
 181 #define PID_T_MAX ((pid_t) INT32_MAX)
 182 /* The maximum number of concurrent processes Linux allows on this architecture, as well as the highest valid PID value
 183  * the kernel will potentially assign. This reflects a value compiled into the kernel (PID_MAX_LIMIT), and sets the
 184  * upper boundary on what may be written to the /proc/sys/kernel/pid_max sysctl (but do note that the sysctl is off by
 185  * 1, since PID 0 can never exist and there can hence only be one process less than the limit would suggest). Since
 186  * these values are documented in proc(5) we feel quite confident that they are stable enough for the near future at
 187  * least to define them here too. */
 188 #define TASKS_MAX 4194303U
 189
 190 assert_cc(TASKS_MAX <= (unsigned long) PID_T_MAX);
 191
 192 /* Like TAKE_PTR() but for child PIDs, resetting them to 0 */
 193 #define TAKE_PID(pid)                           \
 194         ({                                      \
 195                 pid_t _pid_ = (pid);            \
 196                 (pid) = 0;                      \
 197                 _pid_;                          \
 198         })
 199
 200 int pidfd_get_pid(int fd, pid_t *ret);
 201
 202 int setpriority_closest(int priority);
 203
 204 bool invoked_as(char *argv[], const char *token);