#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); } t info' class='commit-info'> authorIago Abal <mail@iagoabal.eu>2017-01-11 14:00:21 +0100 committerVinod Koul <vinod.koul@intel.com>2017-01-25 15:35:11 +0530 commit91539eb1fda2d530d3b268eef542c5414e54bf1a (patch) tree960f5ca6342ad20837aff18aad6e8ecd7da32fd6 /include/net/caif parent6610d0edf6dc7ee97e46ab3a538a565c79d26199 (diff)
dmaengine: pl330: fix double lock
The static bug finder EBA (http://www.iagoabal.eu/eba/) reported the following double-lock bug: Double lock: 1. spin_lock_irqsave(pch->lock, flags) at pl330_free_chan_resources:2236; 2. call to function `pl330_release_channel' immediately after; 3. call to function `dma_pl330_rqcb' in line 1753; 4. spin_lock_irqsave(pch->lock, flags) at dma_pl330_rqcb:1505. I have fixed it as suggested by Marek Szyprowski. First, I have replaced `pch->lock' with `pl330->lock' in functions `pl330_alloc_chan_resources' and `pl330_free_chan_resources'. This avoids the double-lock by acquiring a different lock than `dma_pl330_rqcb'. NOTE that, as a result, `pl330_free_chan_resources' executes `list_splice_tail_init' on `pch->work_list' under lock `pl330->lock', whereas in the rest of the code `pch->work_list' is protected by `pch->lock'. I don't know if this may cause race conditions. Similarly `pch->cyclic' is written by `pl330_alloc_chan_resources' under `pl330->lock' but read by `pl330_tx_submit' under `pch->lock'. Second, I have removed locking from `pl330_request_channel' and `pl330_release_channel' functions. Function `pl330_request_channel' is only called from `pl330_alloc_chan_resources', so the lock is already held. Function `pl330_release_channel' is called from `pl330_free_chan_resources', which already holds the lock, and from `pl330_del'. Function `pl330_del' is called in an error path of `pl330_probe' and at the end of `pl330_remove', but I assume that there cannot be concurrent accesses to the protected data at those points. Signed-off-by: Iago Abal <mail@iagoabal.eu> Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Diffstat (limited to 'include/net/caif')