diff options
Diffstat (limited to 'posix/wordexp.c')
| -rw-r--r-- | posix/wordexp.c | 151 |
1 files changed, 65 insertions, 86 deletions
diff --git a/posix/wordexp.c b/posix/wordexp.c index 6a6e3a8e11..2aa6085fb2 100644 --- a/posix/wordexp.c +++ b/posix/wordexp.c @@ -25,33 +25,18 @@ #include <libintl.h> #include <paths.h> #include <pwd.h> -#include <signal.h> #include <stdbool.h> #include <stdio.h> -#include <stdlib.h> #include <string.h> #include <sys/param.h> -#include <sys/stat.h> -#include <sys/time.h> -#include <sys/types.h> -#include <sys/types.h> #include <sys/wait.h> #include <unistd.h> -#include <wchar.h> #include <wordexp.h> -#include <kernel-features.h> +#include <spawn.h> #include <scratch_buffer.h> - -#include <libc-lock.h> #include <_itoa.h> - -/* Undefine the following line for the production version. */ -/* #define NDEBUG 1 */ #include <assert.h> -/* Get some device information. */ -#include <device-nrs.h> - /* * This is a recursive-descent-style word expansion routine. */ @@ -812,61 +797,76 @@ parse_arith (char **word, size_t *word_length, size_t *max_length, return WRDE_SYNTAX; } +#define DYNARRAY_STRUCT strlist +#define DYNARRAY_ELEMENT char * +#define DYNARRAY_PREFIX strlist_ +/* Allocates about 512/1024 (32/64 bit) on stack. */ +#define DYNARRAY_INITIAL_SIZE 128 +#include <malloc/dynarray-skeleton.c> + /* Function called by child process in exec_comm() */ -static inline void -__attribute__ ((always_inline)) -exec_comm_child (char *comm, int *fildes, int showerr, int noexec) +static pid_t +exec_comm_child (char *comm, int *fildes, bool showerr, bool noexec) { - const char *args[4] = { _PATH_BSHELL, "-c", comm, NULL }; + pid_t pid = -1; - /* Execute the command, or just check syntax? */ - if (noexec) - args[1] = "-nc"; + /* Execute the command, or just check syntax? */ + const char *args[] = { _PATH_BSHELL, noexec ? "-nc" : "-c", comm, NULL }; + + posix_spawn_file_actions_t fa; + /* posix_spawn_file_actions_init does not fail. */ + __posix_spawn_file_actions_init (&fa); - /* Redirect output. */ - if (__glibc_likely (fildes[1] != STDOUT_FILENO)) + /* Redirect output. For check syntax only (noexec being true), exec_comm + explicits sets fildes[1] to -1, so check its value to avoid a failure in + __posix_spawn_file_actions_adddup2. */ + if (fildes[1] != -1) { - __dup2 (fildes[1], STDOUT_FILENO); - __close (fildes[1]); + if (__glibc_likely (fildes[1] != STDOUT_FILENO)) + { + if (__posix_spawn_file_actions_adddup2 (&fa, fildes[1], + STDOUT_FILENO) != 0 + || __posix_spawn_file_actions_addclose (&fa, fildes[1]) != 0) + goto out; + } + else + /* Reset the close-on-exec flag (if necessary). */ + if (__posix_spawn_file_actions_adddup2 (&fa, fildes[1], fildes[1]) + != 0) + goto out; } - else - /* Reset the close-on-exec flag (if necessary). */ - __fcntl (fildes[1], F_SETFD, 0); /* Redirect stderr to /dev/null if we have to. */ - if (showerr == 0) + if (!showerr) + if (__posix_spawn_file_actions_addopen (&fa, STDERR_FILENO, _PATH_DEVNULL, + O_WRONLY, 0) != 0) + goto out; + + struct strlist newenv; + strlist_init (&newenv); + + bool recreate_env = getenv ("IFS") != NULL; + if (recreate_env) { - struct stat64 st; - int fd; - __close (STDERR_FILENO); - fd = __open (_PATH_DEVNULL, O_WRONLY); - if (fd >= 0 && fd != STDERR_FILENO) - { - __dup2 (fd, STDERR_FILENO); - __close (fd); - } - /* Be paranoid. Check that we actually opened the /dev/null - device. */ - if (__builtin_expect (__fxstat64 (_STAT_VER, STDERR_FILENO, &st), 0) != 0 - || __builtin_expect (S_ISCHR (st.st_mode), 1) == 0 -#if defined DEV_NULL_MAJOR && defined DEV_NULL_MINOR - || st.st_rdev != __gnu_dev_makedev (DEV_NULL_MAJOR, DEV_NULL_MINOR) -#endif - ) - /* It's not the /dev/null device. Stop right here. The - problem is: how do we stop? We use _exit() with an - hopefully unusual exit code. */ - _exit (90); + for (char **ep = __environ; *ep != NULL; ep++) + if (strncmp (*ep, "IFS=", strlen ("IFS=")) != 0) + strlist_add (&newenv, *ep); + strlist_add (&newenv, NULL); + if (strlist_has_failed (&newenv)) + goto out; } - /* Make sure the subshell doesn't field-split on our behalf. */ - __unsetenv ("IFS"); + /* pid is not set if posix_spawn fails, so it keep the original value + of -1. */ + __posix_spawn (&pid, _PATH_BSHELL, &fa, NULL, (char *const *) args, + recreate_env ? strlist_begin (&newenv) : __environ); - __close (fildes[0]); - __execve (_PATH_BSHELL, (char *const *) args, __environ); + strlist_free (&newenv); + +out: + __posix_spawn_file_actions_destroy (&fa); - /* Bad. What now? */ - abort (); + return pid; } /* Function to execute a command and retrieve the results */ @@ -884,13 +884,13 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, size_t maxnewlines = 0; char buffer[bufsize]; pid_t pid; - int noexec = 0; + bool noexec = false; /* Do nothing if command substitution should not succeed. */ if (flags & WRDE_NOCMD) return WRDE_CMDSUB; - /* Don't fork() unless necessary */ + /* Don't posix_spawn unless necessary */ if (!comm || !*comm) return 0; @@ -898,19 +898,15 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, return WRDE_NOSPACE; again: - if ((pid = __fork ()) < 0) + pid = exec_comm_child (comm, fildes, noexec ? false : flags & WRDE_SHOWERR, + noexec); + if (pid < 0) { - /* Bad */ __close (fildes[0]); __close (fildes[1]); return WRDE_NOSPACE; } - if (pid == 0) - exec_comm_child (comm, fildes, noexec ? 0 : flags & WRDE_SHOWERR, noexec); - - /* Parent */ - /* If we are just testing the syntax, only wait. */ if (noexec) return (TEMP_FAILURE_RETRY (__waitpid (pid, &status, 0)) == pid @@ -1091,7 +1087,7 @@ exec_comm (char *comm, char **word, size_t *word_length, size_t *max_length, /* Check for syntax error (re-execute but with "-n" flag) */ if (buflen < 1 && status != 0) { - noexec = 1; + noexec = true; goto again; } @@ -1143,26 +1139,9 @@ parse_comm (char **word, size_t *word_length, size_t *max_length, /* Go -- give script to the shell */ if (comm) { -#ifdef __libc_ptf_call - /* We do not want the exec_comm call to be cut short - by a thread cancellation since cleanup is very - ugly. Therefore disable cancellation for - now. */ - // XXX Ideally we do want the thread being cancelable. - // XXX If demand is there we'll change it. - int state = PTHREAD_CANCEL_ENABLE; - __libc_ptf_call (__pthread_setcancelstate, - (PTHREAD_CANCEL_DISABLE, &state), 0); -#endif - + /* posix_spawn already handles thread cancellation. */ error = exec_comm (comm, word, word_length, max_length, flags, pwordexp, ifs, ifs_white); - -#ifdef __libc_ptf_call - __libc_ptf_call (__pthread_setcancelstate, - (state, NULL), 0); -#endif - free (comm); } |