Files
systemd/src/basic/process-util.h
Daan De Meyer f102bc3e5f tree-wide: Introduce sd-forward.h and shared-forward.h headers
Let's not leak details from src/shared and src/libsystemd into
src/basic, even though you can't actually do anything useful with
just forward declarations from src/shared.

The sd-forward.h header is put in src/libsystemd/sd-common as we
don't have a directory for shared internal headers for libsystemd
yet.

Let's also rename forward.h to basic-forward.h to keep things
self-explanatory.
2025-10-16 17:00:29 +02:00

270 lines
12 KiB
C

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once
#include <signal.h>
#include "fileio.h"
#include "format-util.h"
#include "basic-forward.h"
#include "string-util.h"
#define procfs_file_alloca(pid, field) \
({ \
pid_t _pid_ = (pid); \
const char *_field_ = (field); \
char *_r_; \
if (_pid_ == 0) \
_r_ = strjoina("/proc/self/", _field_); \
else { \
assert(_pid_ > 0); \
_r_ = newa(char, STRLEN("/proc/") + DECIMAL_STR_MAX(pid_t) + 1 + strlen(_field_) + 1); \
sprintf(_r_, "/proc/" PID_FMT "/%s", _pid_, _field_); \
} \
(const char*) _r_; \
})
static inline int procfs_file_get_field(pid_t pid, const char *name, const char *key, char **ret) {
return get_proc_field(procfs_file_alloca(pid, name), key, ret);
}
typedef enum ProcessCmdlineFlags {
PROCESS_CMDLINE_COMM_FALLBACK = 1 << 0,
PROCESS_CMDLINE_USE_LOCALE = 1 << 1,
PROCESS_CMDLINE_QUOTE = 1 << 2,
PROCESS_CMDLINE_QUOTE_POSIX = 1 << 3,
} ProcessCmdlineFlags;
int pid_get_comm(pid_t pid, char **ret);
int pidref_get_comm(const PidRef *pid, char **ret);
int pid_get_cmdline(pid_t pid, size_t max_columns, ProcessCmdlineFlags flags, char **ret);
int pidref_get_cmdline(const PidRef *pid, size_t max_columns, ProcessCmdlineFlags flags, char **ret);
int pid_get_cmdline_strv(pid_t pid, ProcessCmdlineFlags flags, char ***ret);
int pidref_get_cmdline_strv(const PidRef *pid, ProcessCmdlineFlags flags, char ***ret);
int get_process_exe(pid_t pid, char **ret);
int pid_get_uid(pid_t pid, uid_t *ret);
int pidref_get_uid(const PidRef *pid, uid_t *ret);
int get_process_gid(pid_t pid, gid_t *ret);
int get_process_cwd(pid_t pid, char **ret);
int get_process_root(pid_t pid, char **ret);
int get_process_environ(pid_t pid, char **ret);
int pid_get_ppid(pid_t pid, pid_t *ret);
int pidref_get_ppid(const PidRef *pidref, pid_t *ret);
int pidref_get_ppid_as_pidref(const PidRef *pidref, PidRef *ret);
int pid_get_start_time(pid_t pid, usec_t *ret);
int pidref_get_start_time(const PidRef *pid, usec_t *ret);
int get_process_umask(pid_t pid, mode_t *ret);
int container_get_leader(const char *machine, pid_t *pid);
static inline bool SIGINFO_CODE_IS_DEAD(int code) {
return IN_SET(code, CLD_EXITED, CLD_KILLED, CLD_DUMPED);
}
int wait_for_terminate(pid_t pid, siginfo_t *ret);
typedef enum WaitFlags {
WAIT_LOG_ABNORMAL = 1 << 0,
WAIT_LOG_NON_ZERO_EXIT_STATUS = 1 << 1,
/* A shortcut for requesting the most complete logging */
WAIT_LOG = WAIT_LOG_ABNORMAL|WAIT_LOG_NON_ZERO_EXIT_STATUS,
} WaitFlags;
int pidref_wait_for_terminate_and_check(const char *name, PidRef *pidref, WaitFlags flags);
int wait_for_terminate_and_check(const char *name, pid_t pid, WaitFlags flags);
int wait_for_terminate_with_timeout(pid_t pid, usec_t timeout);
void sigkill_wait(pid_t pid);
void sigkill_waitp(pid_t *pid);
void sigterm_wait(pid_t pid);
void sigkill_nowait(pid_t pid);
void sigkill_nowaitp(pid_t *pid);
int kill_and_sigcont(pid_t pid, int sig);
int pid_is_kernel_thread(pid_t pid);
int pidref_is_kernel_thread(const PidRef *pid);
int getenv_for_pid(pid_t pid, const char *field, char **_value);
int pid_is_alive(pid_t pid);
int pidref_is_alive(const PidRef *pidref);
int pid_is_unwaited(pid_t pid);
int pidref_is_unwaited(PidRef *pidref);
int pid_is_my_child(pid_t pid);
int pidref_is_my_child(PidRef *pidref);
int pidref_from_same_root_fs(PidRef *a, PidRef *b);
bool is_main_thread(void);
bool oom_score_adjust_is_valid(int oa);
#ifndef PERSONALITY_INVALID
/* personality(2) documents that 0xFFFFFFFFUL is used for querying the
* current personality, hence let's use that here as error
* indicator. */
#define PERSONALITY_INVALID 0xFFFFFFFFUL
#endif
/* The personality() syscall returns a 32-bit value where the top three bytes are reserved for flags that
* emulate historical or architectural quirks, and only the least significant byte reflects the actual
* personality we're interested in. */
#define OPINIONATED_PERSONALITY_MASK 0xFFUL
unsigned long personality_from_string(const char *p);
const char* personality_to_string(unsigned long);
int safe_personality(unsigned long p);
int opinionated_personality(unsigned long *ret);
const char* sigchld_code_to_string(int i) _const_;
int sigchld_code_from_string(const char *s) _pure_;
int sched_policy_to_string_alloc(int i, char **s);
int sched_policy_from_string(const char *s);
static inline pid_t PTR_TO_PID(const void *p) {
return (pid_t) ((uintptr_t) p);
}
static inline void* PID_TO_PTR(pid_t pid) {
return (void*) ((uintptr_t) pid);
}
void valgrind_summary_hack(void);
int pid_compare_func(const pid_t *a, const pid_t *b);
bool nice_is_valid(int n) _const_;
bool sched_policy_is_valid(int i) _const_;
bool sched_priority_is_valid(int i) _const_;
#define PID_AUTOMATIC ((pid_t) INT_MIN) /* special value indicating "acquire pid from connection peer" */
static inline bool pid_is_valid(pid_t p) {
return p > 0;
}
static inline bool pid_is_automatic(pid_t p) {
return p == PID_AUTOMATIC;
}
pid_t getpid_cached(void);
void reset_cached_pid(void);
int must_be_root(void);
pid_t clone_with_nested_stack(int (*fn)(void *), int flags, void *userdata);
/* 💣 Note that FORK_NEW_USERNS, FORK_NEW_MOUNTNS, FORK_NEW_NETNS or FORK_NEW_PIDNS should not be called in threaded
* programs, because they cause us to use raw_clone() which does not synchronize the glibc malloc() locks,
* and thus will cause deadlocks if the parent uses threads and the child does memory allocations. Hence: if
* the parent is threaded these flags may not be used. These flags cannot be used if the parent uses threads
* or the child uses malloc(). 💣 */
typedef enum ForkFlags {
FORK_RESET_SIGNALS = 1 << 0, /* Reset all signal handlers and signal mask */
FORK_CLOSE_ALL_FDS = 1 << 1, /* Close all open file descriptors in the child, except for 0,1,2 */
FORK_DEATHSIG_SIGTERM = 1 << 2, /* Set PR_DEATHSIG in the child to SIGTERM */
FORK_DEATHSIG_SIGINT = 1 << 3, /* Set PR_DEATHSIG in the child to SIGINT */
FORK_DEATHSIG_SIGKILL = 1 << 4, /* Set PR_DEATHSIG in the child to SIGKILL */
FORK_REARRANGE_STDIO = 1 << 5, /* Connect 0,1,2 to specified fds or /dev/null */
FORK_REOPEN_LOG = 1 << 6, /* Reopen log connection */
FORK_LOG = 1 << 7, /* Log above LOG_DEBUG log level about failures */
FORK_WAIT = 1 << 8, /* Wait until child exited */
FORK_MOUNTNS_SLAVE = 1 << 9, /* Make child's mount namespace MS_SLAVE */
FORK_PRIVATE_TMP = 1 << 10, /* Mount new /tmp/ in the child (combine with FORK_NEW_MOUNTNS!) */
FORK_RLIMIT_NOFILE_SAFE = 1 << 11, /* Set RLIMIT_NOFILE soft limit to 1K for select() compat */
FORK_STDOUT_TO_STDERR = 1 << 12, /* Make stdout a copy of stderr */
FORK_FLUSH_STDIO = 1 << 13, /* fflush() stdout (and stderr) before forking */
FORK_CLOEXEC_OFF = 1 << 14, /* In the child: turn off O_CLOEXEC on all fds in except_fds[] */
FORK_KEEP_NOTIFY_SOCKET = 1 << 15, /* Unless this specified, $NOTIFY_SOCKET will be unset. */
FORK_DETACH = 1 << 16, /* Double fork if needed to ensure PID1/subreaper is parent */
FORK_PACK_FDS = 1 << 17, /* Rearrange the passed FDs to be FD 3,4,5,etc. Updates the array in place (combine with FORK_CLOSE_ALL_FDS!) */
FORK_NEW_MOUNTNS = 1 << 18, /* Run child in its own mount namespace 💣 DO NOT USE IN THREADED PROGRAMS! 💣 */
FORK_NEW_USERNS = 1 << 19, /* Run child in its own user namespace 💣 DO NOT USE IN THREADED PROGRAMS! 💣 */
FORK_NEW_NETNS = 1 << 20, /* Run child in its own network namespace 💣 DO NOT USE IN THREADED PROGRAMS! 💣 */
FORK_NEW_PIDNS = 1 << 21, /* Run child in its own PID namespace 💣 DO NOT USE IN THREADED PROGRAMS! 💣 */
FORK_FREEZE = 1 << 22, /* Don't return in child, just call freeze() instead */
FORK_PID_ONLY = 1 << 23, /* Don't open a pidfd referencing the child process */
} ForkFlags;
int pidref_safe_fork_full(
const char *name,
const int stdio_fds[3],
int except_fds[],
size_t n_except_fds,
ForkFlags flags,
PidRef *ret_pid);
static inline int pidref_safe_fork(const char *name, ForkFlags flags, PidRef *ret_pid) {
return pidref_safe_fork_full(name, NULL, NULL, 0, flags, ret_pid);
}
int safe_fork_full(
const char *name,
const int stdio_fds[3],
int except_fds[],
size_t n_except_fds,
ForkFlags flags,
pid_t *ret_pid);
static inline int safe_fork(const char *name, ForkFlags flags, pid_t *ret_pid) {
return safe_fork_full(name, NULL, NULL, 0, flags, ret_pid);
}
int namespace_fork(
const char *outer_name,
const char *inner_name,
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);
int set_oom_score_adjust(int value);
int get_oom_score_adjust(int *ret);
/* The highest possibly (theoretic) pid_t value on this architecture. */
#define PID_T_MAX ((pid_t) INT32_MAX)
/* The maximum number of concurrent processes Linux allows on this architecture, as well as the highest valid PID value
* the kernel will potentially assign. This reflects a value compiled into the kernel (PID_MAX_LIMIT), and sets the
* upper boundary on what may be written to the /proc/sys/kernel/pid_max sysctl (but do note that the sysctl is off by
* 1, since PID 0 can never exist and there can hence only be one process less than the limit would suggest). Since
* these values are documented in proc(5) we feel quite confident that they are stable enough for the near future at
* least to define them here too. */
#define TASKS_MAX 4194303U
assert_cc(TASKS_MAX <= (unsigned long) PID_T_MAX);
/* Like TAKE_PTR() but for pid_t, resetting them to 0 */
#define TAKE_PID(pid) TAKE_GENERIC(pid, pid_t, 0)
int setpriority_closest(int priority);
_noreturn_ void freeze(void);
int get_process_threads(pid_t pid);
int is_reaper_process(void);
int make_reaper_process(bool b);
int posix_spawn_wrapper(
const char *path,
char * const *argv,
char * const *envp,
const char *cgroup,
PidRef *ret_pidref);
int proc_dir_open(DIR **ret);
int proc_dir_read(DIR *d, pid_t *ret);
int proc_dir_read_pidref(DIR *d, PidRef *ret);
_noreturn_ void report_errno_and_exit(int errno_fd, int error);
int read_errno(int errno_fd);