#include #include #include #include #include #include #include #include #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->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(pid_t pid) { char sbuf[STRERR_BUFSIZE]; for (;;) { int status, code; pid_t waiting = waitpid(pid, &status, 0); if (waiting < 0) { if (errno == EINTR) continue; fprintf(stderr, " Error: waitpid failed (%s)", str_error_r(errno, sbuf, sizeof(sbuf))); return -ERR_RUN_COMMAND_WAITPID; } if (waiting != pid) return -ERR_RUN_COMMAND_WAITPID_WRONG_PID; if (WIFSIGNALED(status)) return -ERR_RUN_COMMAND_WAITPID_SIGNAL; if (!WIFEXITED(status)) return -ERR_RUN_COMMAND_WAITPID_NOEXIT; code = WEXITSTATUS(status); switch (code) { case 127: return -ERR_RUN_COMMAND_EXEC; case 0: return 0; default: return -code; } } } int finish_command(struct child_process *cmd) { return wait_or_whine(cmd->pid); } 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); } option>mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-01-18 11:13:41 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-01-18 11:13:41 -0800
commitca92e6c7e6329029d7188487a5c32e86ef471977 (patch)
tree704fb5c2ca533cdb569826522eed0dbbcf31f316 /tools/perf/perf.c
parent0b75f821ec8be459dd4dec77be39595d989d77ac (diff)
parent4205e4786d0b9fc3b4fec7b1910cf645a0468307 (diff)
Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP hotplug update from Thomas Gleixner: "This contains a trivial typo fix and an extension to the core code for dynamically allocating states in the prepare stage. The extension is necessary right now because we need a proper way to unbreak LTTNG, which iscurrently non functional due to the removal of the notifiers. Surely it's out of tree, but it's widely used by distros. The simple solution would have been to reserve a state for LTTNG, but I'm not fond about unused crap in the kernel and the dynamic range, which we admittedly should have done right away, allows us to remove quite some of the hardcoded states, i.e. those which have no ordering requirements. So doing the right thing now is better than having an smaller intermediate solution which needs to be reworked anyway" * 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: cpu/hotplug: Provide dynamic range for prepare stage perf/x86/amd/ibs: Fix typo after cleanup state names in cpu/hotplug
Diffstat (limited to 'tools/perf/perf.c')