Something went wrong. Try again.
(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
Something went wrong. Try again.
123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359// SPDX-License-Identifier: GPL-2.0#include <unistd.h>#include <sys/types.h>#include <sys/stat.h>#include <ctype.h>#include <fcntl.h>#include <string.h>#include <linux/compiler.h>#include <linux/string.h>#include <errno.h>#include <sys/wait.h>#include "subcmd-util.h"#include "run-command.h"#include "exec-cmd.h"
#define STRERR_BUFSIZE 128
static inline void close_pair(int fd[2]){ close(fd[0]); close(fd[1]);}
static inline void dup_devnull(int to){ int fd = open("/dev/null", O_RDWR); dup2(fd, to); close(fd);}
int start_command(struct child_process *cmd){ int need_in, need_out, need_err; int fdin[2], fdout[2], fderr[2]; char sbuf[STRERR_BUFSIZE];
/* * In case of errors we must keep the promise to close FDs * that have been passed in via ->in and ->out. */
need_in = !cmd->no_stdin && cmd->in < 0; if (need_in) { if (pipe(fdin) < 0) { if (cmd->out > 0) close(cmd->out); return -ERR_RUN_COMMAND_PIPE; } cmd->in = fdin[1]; }
need_out = !cmd->no_stdout && !cmd->stdout_to_stderr && cmd->out < 0; if (need_out) { if (pipe(fdout) < 0) { if (need_in) close_pair(fdin); else if (cmd->in) close(cmd->in); return -ERR_RUN_COMMAND_PIPE; } cmd->out = fdout[0]; }
need_err = !cmd->no_stderr && cmd->err < 0; if (need_err) { if (pipe(fderr) < 0) { if (need_in) close_pair(fdin); else if (cmd->in) close(cmd->in); if (need_out) close_pair(fdout); else if (cmd->out) close(cmd->out); return -ERR_RUN_COMMAND_PIPE; } cmd->err = fderr[0]; }
fflush(NULL); cmd->pid = fork(); if (!cmd->pid) { if (cmd->no_stdin) dup_devnull(0); else if (need_in) { dup2(fdin[0], 0); close_pair(fdin); } else if (cmd->in) { dup2(cmd->in, 0); close(cmd->in); }
if (cmd->no_stderr) dup_devnull(2); else if (need_err) { dup2(fderr[1], 2); close_pair(fderr); }
if (cmd->no_stdout) dup_devnull(1); else if (cmd->stdout_to_stderr) dup2(2, 1); else if (need_out) { dup2(fdout[1], 1); close_pair(fdout); } else if (cmd->out > 1) { dup2(cmd->out, 1); close(cmd->out); }
if (cmd->dir && chdir(cmd->dir)) die("exec %s: cd to %s failed (%s)", cmd->argv[0], cmd->dir, str_error_r(errno, sbuf, sizeof(sbuf))); if (cmd->env) { for (; *cmd->env; cmd->env++) { if (strchr(*cmd->env, '=')) putenv((char*)*cmd->env); else unsetenv(*cmd->env); } } if (cmd->preexec_cb) cmd->preexec_cb(); if (cmd->no_exec_cmd) exit(cmd->no_exec_cmd(cmd)); if (cmd->exec_cmd) { execv_cmd(cmd->argv); } else { execvp(cmd->argv[0], (char *const*) cmd->argv); } exit(127); }
if (cmd->pid < 0) { int err = errno; if (need_in) close_pair(fdin); else if (cmd->in) close(cmd->in); if (need_out) close_pair(fdout); else if (cmd->out) close(cmd->out); if (need_err) close_pair(fderr); return err == ENOENT ? -ERR_RUN_COMMAND_EXEC : -ERR_RUN_COMMAND_FORK; }
if (need_in) close(fdin[0]); else if (cmd->in) close(cmd->in);
if (need_out) close(fdout[1]); else if (cmd->out) close(cmd->out);
if (need_err) close(fderr[1]);
return 0;}
static int wait_or_whine(struct child_process *cmd, bool block){ bool finished; int result;
if (cmd->pid <= 0) { cmd->finished = 1; if (cmd->pid < 0 && cmd->finish_result == 0) cmd->finish_result = -ERR_RUN_COMMAND_FORK; return cmd->finish_result; }
finished = cmd->finished; result = cmd->finish_result;
while (!finished) { int status, code; pid_t waiting = waitpid(cmd->pid, &status, block ? 0 : WNOHANG);
if (!block && waiting == 0) break;
if (waiting < 0 && errno == EINTR) continue;
finished = true; if (waiting < 0) { char sbuf[STRERR_BUFSIZE];
fprintf(stderr, " Error: waitpid failed (%s)", str_error_r(errno, sbuf, sizeof(sbuf))); result = -ERR_RUN_COMMAND_WAITPID; } else if (waiting != cmd->pid) { result = -ERR_RUN_COMMAND_WAITPID_WRONG_PID; } else if (WIFSIGNALED(status)) { result = -ERR_RUN_COMMAND_WAITPID_SIGNAL; } else if (!WIFEXITED(status)) { result = -ERR_RUN_COMMAND_WAITPID_NOEXIT; } else { code = WEXITSTATUS(status); switch (code) { case 127: result = -ERR_RUN_COMMAND_EXEC; break; case 0: result = 0; break; default: result = -code; break; } } } if (finished) { cmd->finished = 1; cmd->finish_result = result; } return result;}
/* * Conservative estimate of number of characaters needed to hold an a decoded * integer, assume each 3 bits needs a character byte and plus a possible sign * character. */#ifndef is_signed_type#define is_signed_type(type) (((type)(-1)) < (type)1)#endif#define MAX_STRLEN_TYPE(type) (sizeof(type) * 8 / 3 + (is_signed_type(type) ? 1 : 0))
int check_if_command_finished(struct child_process *cmd){#ifdef __linux__ char filename[6 + MAX_STRLEN_TYPE(typeof(cmd->pid)) + 7 + 1]; char status_line[256]; FILE *status_file;#endif
if (cmd->finished) return 1; if (cmd->pid <= 0) { cmd->finished = 1; if (cmd->pid < 0 && cmd->finish_result == 0) cmd->finish_result = -ERR_RUN_COMMAND_FORK; return 1; }
#ifdef __linux__ /* * Check by reading /proc/<pid>/status as calling waitpid causes * stdout/stderr to be closed and data lost. */ sprintf(filename, "/proc/%u/status", cmd->pid); status_file = fopen(filename, "r"); if (status_file == NULL) { int status; pid_t waiting;
/* * fopen() can fail with ENOENT if the process has been reaped. * It can also fail with EMFILE/ENFILE if RLIMIT_NOFILE is reached. * In those cases, use waitpid(..., WNOHANG) to robustly check * and reap the process if it has exited. */ if (errno == ENOENT) return 1;
waiting = waitpid(cmd->pid, &status, WNOHANG); if (waiting == cmd->pid) { int result; int code;
cmd->finished = 1; if (WIFSIGNALED(status)) { result = -ERR_RUN_COMMAND_WAITPID_SIGNAL; } else if (!WIFEXITED(status)) { result = -ERR_RUN_COMMAND_WAITPID_NOEXIT; } else { code = WEXITSTATUS(status); switch (code) { case 127: result = -ERR_RUN_COMMAND_EXEC; break; case 0: result = 0; break; default: result = -code; break; } } cmd->finish_result = result; return 1; } if (waiting < 0 && (errno == ECHILD || errno == ESRCH)) return 1; return 0; } while (fgets(status_line, sizeof(status_line), status_file) != NULL) { char *p;
if (strncmp(status_line, "State:", 6)) continue;
fclose(status_file); p = status_line + 6; while (isspace(*p)) p++; return *p == 'Z' ? 1 : 0; } /* Read failed assume finish_command was called. */ fclose(status_file); return 1;#else wait_or_whine(cmd, /*block=*/false); return cmd->finished;#endif}
int finish_command(struct child_process *cmd){ return wait_or_whine(cmd, /*block=*/true);}
int run_command(struct child_process *cmd){ int code = start_command(cmd); if (code) return code; return finish_command(cmd);}
static void prepare_run_command_v_opt(struct child_process *cmd, const char **argv, int opt){ memset(cmd, 0, sizeof(*cmd)); cmd->argv = argv; cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0; cmd->exec_cmd = opt & RUN_EXEC_CMD ? 1 : 0; cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;}
int run_command_v_opt(const char **argv, int opt){ struct child_process cmd; prepare_run_command_v_opt(&cmd, argv, opt); return run_command(&cmd);}