src/basic/process-util.h

   1 /* SPDX-License-Identifier: LGPL-2.1+ */
   2 #pragma once
   3
   4 #include <alloca.h>
   5 #include <errno.h>
   6 #include <sched.h>
   7 #include <signal.h>
   8 #include <stdbool.h>
   9 #include <stddef.h>
  10 #include <stdio.h>
  11 #include <string.h>
  12 #include <sys/resource.h>
  13 #include <sys/types.h>
  14
  15 #include "alloc-util.h"
  16 #include "format-util.h"
  17 #include "ioprio.h"
  18 #include "macro.h"
  19 #include "time-util.h"
  20
  21 #define procfs_file_alloca(pid, field)                                  \
  22         ({                                                              \
  23                 pid_t _pid_ = (pid);                                    \
  24                 const char *_r_;                                        \
  25                 if (_pid_ == 0) {                                       \
  26                         _r_ = ("/proc/self/" field);                    \
  27                 } else {                                                \
  28                         _r_ = newa(char, STRLEN("/proc/") + DECIMAL_STR_MAX(pid_t) + 1 + sizeof(field)); \
  29                         sprintf((char*) _r_, "/proc/"PID_FMT"/" field, _pid_); \
  30                 }                                                       \
  31                 _r_;                                                    \
  32         })
  33
  34 int get_process_comm(pid_t pid, char **name);
  35 int get_process_cmdline(pid_t pid, size_t max_columns, bool comm_fallback, char **line);
  36 int get_process_exe(pid_t pid, char **name);
  37 int get_process_uid(pid_t pid, uid_t *uid);
  38 int get_process_gid(pid_t pid, gid_t *gid);
  39 int get_process_capeff(pid_t pid, char **capeff);
  40 int get_process_cwd(pid_t pid, char **cwd);
  41 int get_process_root(pid_t pid, char **root);
  42 int get_process_environ(pid_t pid, char **environ);
  43 int get_process_ppid(pid_t pid, pid_t *ppid);
  44
  45 int wait_for_terminate(pid_t pid, siginfo_t *status);
  46
  47 typedef enum WaitFlags {
  48         WAIT_LOG_ABNORMAL             = 1 << 0,
  49         WAIT_LOG_NON_ZERO_EXIT_STATUS = 1 << 1,
  50
  51         /* A shortcut for requesting the most complete logging */
  52         WAIT_LOG = WAIT_LOG_ABNORMAL|WAIT_LOG_NON_ZERO_EXIT_STATUS,
  53 } WaitFlags;
  54
  55 int wait_for_terminate_and_check(const char *name, pid_t pid, WaitFlags flags);
  56 int wait_for_terminate_with_timeout(pid_t pid, usec_t timeout);
  57
  58 void sigkill_wait(pid_t pid);
  59 void sigkill_waitp(pid_t *pid);
  60 void sigterm_wait(pid_t pid);
  61
  62 int kill_and_sigcont(pid_t pid, int sig);
  63
  64 int rename_process(const char name[]);
  65 int is_kernel_thread(pid_t pid);
  66
  67 int getenv_for_pid(pid_t pid, const char *field, char **_value);
  68
  69 bool pid_is_alive(pid_t pid);
  70 bool pid_is_unwaited(pid_t pid);
  71 int pid_is_my_child(pid_t pid);
  72 int pid_from_same_root_fs(pid_t pid);
  73
  74 bool is_main_thread(void);
  75
  76 _noreturn_ void freeze(void);
  77
  78 bool oom_score_adjust_is_valid(int oa);
  79
  80 #ifndef PERSONALITY_INVALID
  81 /* personality(7) documents that 0xffffffffUL is used for querying the
  82  * current personality, hence let's use that here as error
  83  * indicator. */
  84 #define PERSONALITY_INVALID 0xffffffffLU
  85 #endif
  86
  87 unsigned long personality_from_string(const char *p);
  88 const char *personality_to_string(unsigned long);
  89
  90 int safe_personality(unsigned long p);
  91 int opinionated_personality(unsigned long *ret);
  92
  93 int ioprio_class_to_string_alloc(int i, char **s);
  94 int ioprio_class_from_string(const char *s);
  95
  96 const char *sigchld_code_to_string(int i) _const_;
  97 int sigchld_code_from_string(const char *s) _pure_;
  98
  99 int sched_policy_to_string_alloc(int i, char **s);
 100 int sched_policy_from_string(const char *s);
 101
 102 static inline pid_t PTR_TO_PID(const void *p) {
 103         return (pid_t) ((uintptr_t) p);
 104 }
 105
 106 static inline void* PID_TO_PTR(pid_t pid) {
 107         return (void*) ((uintptr_t) pid);
 108 }
 109
 110 void valgrind_summary_hack(void);
 111
 112 int pid_compare_func(const pid_t *a, const pid_t *b);
 113
 114 static inline bool nice_is_valid(int n) {
 115         return n >= PRIO_MIN && n < PRIO_MAX;
 116 }
 117
 118 static inline bool sched_policy_is_valid(int i) {
 119         return IN_SET(i, SCHED_OTHER, SCHED_BATCH, SCHED_IDLE, SCHED_FIFO, SCHED_RR);
 120 }
 121
 122 static inline bool sched_priority_is_valid(int i) {
 123         return i >= 0 && i <= sched_get_priority_max(SCHED_RR);
 124 }
 125
 126 static inline bool ioprio_class_is_valid(int i) {
 127         return IN_SET(i, IOPRIO_CLASS_NONE, IOPRIO_CLASS_RT, IOPRIO_CLASS_BE, IOPRIO_CLASS_IDLE);
 128 }
 129
 130 static inline bool ioprio_priority_is_valid(int i) {
 131         return i >= 0 && i < IOPRIO_BE_NR;
 132 }
 133
 134 static inline bool pid_is_valid(pid_t p) {
 135         return p > 0;
 136 }
 137
 138 int ioprio_parse_priority(const char *s, int *ret);
 139
 140 pid_t getpid_cached(void);
 141 void reset_cached_pid(void);
 142
 143 int must_be_root(void);
 144
 145 typedef enum ForkFlags {
 146         FORK_RESET_SIGNALS      = 1 << 0, /* Reset all signal handlers and signal mask */
 147         FORK_CLOSE_ALL_FDS      = 1 << 1, /* Close all open file descriptors in the child, except for 0,1,2 */
 148         FORK_DEATHSIG           = 1 << 2, /* Set PR_DEATHSIG in the child */
 149         FORK_NULL_STDIO         = 1 << 3, /* Connect 0,1,2 to /dev/null */
 150         FORK_REOPEN_LOG         = 1 << 4, /* Reopen log connection */
 151         FORK_LOG                = 1 << 5, /* Log above LOG_DEBUG log level about failures */
 152         FORK_WAIT               = 1 << 6, /* Wait until child exited */
 153         FORK_NEW_MOUNTNS        = 1 << 7, /* Run child in its own mount namespace */
 154         FORK_MOUNTNS_SLAVE      = 1 << 8, /* Make child's mount namespace MS_SLAVE */
 155         FORK_RLIMIT_NOFILE_SAFE = 1 << 9, /* Set RLIMIT_NOFILE soft limit to 1K for select() compat */
 156 } ForkFlags;
 157
 158 int safe_fork_full(const char *name, const int except_fds[], size_t n_except_fds, ForkFlags flags, pid_t *ret_pid);
 159
 160 static inline int safe_fork(const char *name, ForkFlags flags, pid_t *ret_pid) {
 161         return safe_fork_full(name, NULL, 0, flags, ret_pid);
 162 }
 163
 164 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);
 165
 166 int fork_agent(const char *name, const int except[], size_t n_except, pid_t *pid, const char *path, ...) _sentinel_;
 167
 168 int set_oom_score_adjust(int value);
 169
 170 #if SIZEOF_PID_T == 4
 171 /* The highest possibly (theoretic) pid_t value on this architecture. */
 172 #define PID_T_MAX ((pid_t) INT32_MAX)
 173 /* The maximum number of concurrent processes Linux allows on this architecture, as well as the highest valid PID value
 174  * the kernel will potentially assign. This reflects a value compiled into the kernel (PID_MAX_LIMIT), and sets the
 175  * upper boundary on what may be written to the /proc/sys/kernel/pid_max sysctl (but do note that the sysctl is off by
 176  * 1, since PID 0 can never exist and there can hence only be one process less than the limit would suggest). Since
 177  * these values are documented in proc(5) we feel quite confident that they are stable enough for the near future at
 178  * least to define them here too. */
 179 #define TASKS_MAX 4194303U
 180 #elif SIZEOF_PID_T == 2
 181 #define PID_T_MAX ((pid_t) INT16_MAX)
 182 #define TASKS_MAX 32767U
 183 #else
 184 #error "Unknown pid_t size"
 185 #endif
 186
 187 assert_cc(TASKS_MAX <= (unsigned long) PID_T_MAX)
 188
 189 /* Like TAKE_PTR() but for child PIDs, resetting them to 0 */
 190 #define TAKE_PID(pid)                           \
 191         ({                                      \
 192                 pid_t _pid_ = (pid);            \
 193                 (pid) = 0;                      \
 194                 _pid_;                          \
 195         })
 196
 197 int cpus_in_affinity_mask(void);