mirror of
https://github.com/sheumann/hush.git
synced 2024-08-26 12:29:04 +00:00
ash: fix bug where redirection of closed fd was leaving it open afterwards.
redirect 983 1024 +41 bb_echo 276 301 +25 popredir 118 132 +14 evalcommand 1163 1176 +13 bbunpack 358 366 +8 echocmd 13 5 -8 echo_main 13 5 -8 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 5/2 up/down: 101/-16) Total: 85 bytes text data bss dec hex filename 774999 962 9236 785197 bfb2d busybox_old 775084 962 9236 785282 bfb82 busybox_unstripped
This commit is contained in:
parent
705eaf8b40
commit
7d75a96b15
141
coreutils/echo.c
141
coreutils/echo.c
@ -25,7 +25,9 @@
|
||||
|
||||
#include "libbb.h"
|
||||
|
||||
int bb_echo(char **argv)
|
||||
/* argc is unused, but removing it precludes compiler from
|
||||
* using call -> jump optimization */
|
||||
int bb_echo(int argc, char **argv)
|
||||
{
|
||||
const char *arg;
|
||||
#if !ENABLE_FEATURE_FANCY_ECHO
|
||||
@ -33,6 +35,18 @@ int bb_echo(char **argv)
|
||||
eflag = '\\',
|
||||
nflag = 1, /* 1 -- print '\n' */
|
||||
};
|
||||
|
||||
/* We must check that stdout is not closed.
|
||||
* The reason for this is highly non-obvious.
|
||||
* bb_echo is used from shell. Shell must correctly handle "echo foo"
|
||||
* if stdout is closed. With stdio, output gets shoveled into
|
||||
* stdout buffer, and even fflush cannot clear it out. It seems that
|
||||
* even if libc receives EBADF on write attempts, it feels determined
|
||||
* to output data no matter what. So it will try later,
|
||||
* and possibly will clobber future output. Not good. */
|
||||
if (dup2(1, 1) != 1)
|
||||
return -1;
|
||||
|
||||
arg = *++argv;
|
||||
if (!arg)
|
||||
goto newline_ret;
|
||||
@ -41,6 +55,10 @@ int bb_echo(char **argv)
|
||||
char nflag = 1;
|
||||
char eflag = 0;
|
||||
|
||||
/* We must check that stdout is not closed. */
|
||||
if (dup2(1, 1) != 1)
|
||||
return -1;
|
||||
|
||||
while (1) {
|
||||
arg = *++argv;
|
||||
if (!arg)
|
||||
@ -122,7 +140,7 @@ int bb_echo(char **argv)
|
||||
int echo_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
||||
int echo_main(int argc, char **argv)
|
||||
{
|
||||
return bb_echo(argv);
|
||||
return bb_echo(argc, argv);
|
||||
}
|
||||
|
||||
/*-
|
||||
@ -163,3 +181,122 @@ int echo_main(int argc, char **argv)
|
||||
*
|
||||
* @(#)echo.c 8.1 (Berkeley) 5/31/93
|
||||
*/
|
||||
|
||||
#ifdef VERSION_WITH_WRITEV
|
||||
/* We can't use stdio.
|
||||
* The reason for this is highly non-obvious.
|
||||
* bb_echo is used from shell. Shell must correctly handle "echo foo"
|
||||
* if stdout is closed. With stdio, output gets shoveled into
|
||||
* stdout buffer, and even fflush cannot clear it out. It seems that
|
||||
* even if libc receives EBADF on write attempts, it feels determined
|
||||
* to output data no matter what. So it will try later,
|
||||
* and possibly will clobber future output. Not good.
|
||||
*
|
||||
* Using writev instead, with 'direct' conversion of argv vector.
|
||||
*/
|
||||
|
||||
int bb_echo(int argc, char **argv)
|
||||
{
|
||||
struct iovec io[argc];
|
||||
struct iovec *cur_io = io;
|
||||
char *arg;
|
||||
char *p;
|
||||
#if !ENABLE_FEATURE_FANCY_ECHO
|
||||
enum {
|
||||
eflag = '\\',
|
||||
nflag = 1, /* 1 -- print '\n' */
|
||||
};
|
||||
arg = *++argv;
|
||||
if (!arg)
|
||||
goto newline_ret;
|
||||
#else
|
||||
char nflag = 1;
|
||||
char eflag = 0;
|
||||
|
||||
while (1) {
|
||||
arg = *++argv;
|
||||
if (!arg)
|
||||
goto newline_ret;
|
||||
if (*arg != '-')
|
||||
break;
|
||||
|
||||
/* If it appears that we are handling options, then make sure
|
||||
* that all of the options specified are actually valid.
|
||||
* Otherwise, the string should just be echoed.
|
||||
*/
|
||||
p = arg + 1;
|
||||
if (!*p) /* A single '-', so echo it. */
|
||||
goto just_echo;
|
||||
|
||||
do {
|
||||
if (!strrchr("neE", *p))
|
||||
goto just_echo;
|
||||
} while (*++p);
|
||||
|
||||
/* All of the options in this arg are valid, so handle them. */
|
||||
p = arg + 1;
|
||||
do {
|
||||
if (*p == 'n')
|
||||
nflag = 0;
|
||||
if (*p == 'e')
|
||||
eflag = '\\';
|
||||
} while (*++p);
|
||||
}
|
||||
just_echo:
|
||||
#endif
|
||||
|
||||
while (1) {
|
||||
/* arg is already == *argv and isn't NULL */
|
||||
int c;
|
||||
|
||||
cur_io->iov_base = p = arg;
|
||||
|
||||
if (!eflag) {
|
||||
/* optimization for very common case */
|
||||
p += strlen(arg);
|
||||
} else while ((c = *arg++)) {
|
||||
if (c == eflag) { /* Check for escape seq. */
|
||||
if (*arg == 'c') {
|
||||
/* '\c' means cancel newline and
|
||||
* ignore all subsequent chars. */
|
||||
cur_io->iov_len = p - (char*)cur_io->iov_base;
|
||||
cur_io++;
|
||||
goto ret;
|
||||
}
|
||||
#if !ENABLE_FEATURE_FANCY_ECHO
|
||||
/* SUSv3 specifies that octal escapes must begin with '0'. */
|
||||
if ( (((unsigned char)*arg) - '1') >= 7)
|
||||
#endif
|
||||
{
|
||||
/* Since SUSv3 mandates a first digit of 0, 4-digit octals
|
||||
* of the form \0### are accepted. */
|
||||
if (*arg == '0' && ((unsigned char)(arg[1]) - '0') < 8) {
|
||||
arg++;
|
||||
}
|
||||
/* bb_process_escape_sequence can handle nul correctly */
|
||||
c = bb_process_escape_sequence( (void*) &arg);
|
||||
}
|
||||
}
|
||||
*p++ = c;
|
||||
}
|
||||
|
||||
arg = *++argv;
|
||||
if (arg)
|
||||
*p++ = ' ';
|
||||
cur_io->iov_len = p - (char*)cur_io->iov_base;
|
||||
cur_io++;
|
||||
if (!arg)
|
||||
break;
|
||||
}
|
||||
|
||||
newline_ret:
|
||||
if (nflag) {
|
||||
cur_io->iov_base = (char*)"\n";
|
||||
cur_io->iov_len = 1;
|
||||
cur_io++;
|
||||
}
|
||||
ret:
|
||||
/* TODO: implement and use full_writev? */
|
||||
return writev(1, io, (cur_io - io)) >= 0;
|
||||
}
|
||||
#endif
|
||||
|
@ -728,7 +728,7 @@ extern void bb_verror_msg(const char *s, va_list p, const char *strerr);
|
||||
|
||||
/* applets which are useful from another applets */
|
||||
int bb_cat(char** argv);
|
||||
int bb_echo(char** argv);
|
||||
int bb_echo(int argc, char** argv);
|
||||
int test_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
||||
int kill_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
||||
#if ENABLE_ROUTE
|
||||
|
35
shell/ash.c
35
shell/ash.c
@ -4567,6 +4567,7 @@ stoppedjobs(void)
|
||||
*/
|
||||
|
||||
#define EMPTY -2 /* marks an unused slot in redirtab */
|
||||
#define CLOSED -3 /* marks a slot of previously-closed fd */
|
||||
#ifndef PIPE_BUF
|
||||
# define PIPESIZE 4096 /* amount of buffering in a pipe */
|
||||
#else
|
||||
@ -4791,7 +4792,7 @@ redirect(union node *redir, int flags)
|
||||
int i;
|
||||
int fd;
|
||||
int newfd;
|
||||
int *p;
|
||||
|
||||
nullredirs++;
|
||||
if (!redir) {
|
||||
return;
|
||||
@ -4799,15 +4800,13 @@ redirect(union node *redir, int flags)
|
||||
sv = NULL;
|
||||
INT_OFF;
|
||||
if (flags & REDIR_PUSH) {
|
||||
struct redirtab *q;
|
||||
q = ckmalloc(sizeof(struct redirtab));
|
||||
q->next = redirlist;
|
||||
redirlist = q;
|
||||
q->nullredirs = nullredirs - 1;
|
||||
sv = ckmalloc(sizeof(*sv));
|
||||
sv->next = redirlist;
|
||||
redirlist = sv;
|
||||
sv->nullredirs = nullredirs - 1;
|
||||
for (i = 0; i < 10; i++)
|
||||
q->renamed[i] = EMPTY;
|
||||
sv->renamed[i] = EMPTY;
|
||||
nullredirs = 0;
|
||||
sv = q;
|
||||
}
|
||||
n = redir;
|
||||
do {
|
||||
@ -4817,9 +4816,14 @@ redirect(union node *redir, int flags)
|
||||
continue; /* redirect from/to same file descriptor */
|
||||
|
||||
newfd = openredirect(n);
|
||||
if (fd == newfd)
|
||||
if (fd == newfd) {
|
||||
/* Descriptor wasn't open before redirect.
|
||||
* Mark it for close in the future */
|
||||
if (sv && sv->renamed[fd] == EMPTY)
|
||||
sv->renamed[fd] = CLOSED;
|
||||
continue;
|
||||
if (sv && *(p = &sv->renamed[fd]) == EMPTY) {
|
||||
}
|
||||
if (sv && sv->renamed[fd] == EMPTY) {
|
||||
i = fcntl(fd, F_DUPFD, 10);
|
||||
|
||||
if (i == -1) {
|
||||
@ -4831,7 +4835,7 @@ redirect(union node *redir, int flags)
|
||||
/* NOTREACHED */
|
||||
}
|
||||
} else {
|
||||
*p = i;
|
||||
sv->renamed[fd] = i;
|
||||
close(fd);
|
||||
}
|
||||
} else {
|
||||
@ -4840,7 +4844,7 @@ redirect(union node *redir, int flags)
|
||||
dupredirect(n, newfd);
|
||||
} while ((n = n->nfile.next));
|
||||
INT_ON;
|
||||
if (flags & REDIR_SAVEFD2 && sv && sv->renamed[2] >= 0)
|
||||
if ((flags & REDIR_SAVEFD2) && sv && sv->renamed[2] >= 0)
|
||||
preverrout_fd = sv->renamed[2];
|
||||
}
|
||||
|
||||
@ -4858,6 +4862,11 @@ popredir(int drop)
|
||||
INT_OFF;
|
||||
rp = redirlist;
|
||||
for (i = 0; i < 10; i++) {
|
||||
if (rp->renamed[i] == CLOSED) {
|
||||
if (!drop)
|
||||
close(i);
|
||||
continue;
|
||||
}
|
||||
if (rp->renamed[i] != EMPTY) {
|
||||
if (!drop) {
|
||||
close(i);
|
||||
@ -10994,7 +11003,7 @@ exitcmd(int argc, char **argv)
|
||||
static int
|
||||
echocmd(int argc, char **argv)
|
||||
{
|
||||
return bb_echo(argv);
|
||||
return bb_echo(argc, argv);
|
||||
}
|
||||
#endif
|
||||
|
||||
|
1
shell/ash_test/ash-redir/redir.right
Normal file
1
shell/ash_test/ash-redir/redir.right
Normal file
@ -0,0 +1 @@
|
||||
TEST
|
6
shell/ash_test/ash-redir/redir.tests
Normal file
6
shell/ash_test/ash-redir/redir.tests
Normal file
@ -0,0 +1,6 @@
|
||||
# test: closed fds should stay closed
|
||||
exec 1>&-
|
||||
echo TEST >TEST
|
||||
echo JUNK # lost: stdout is closed
|
||||
cat TEST >&2
|
||||
rm TEST
|
Loading…
Reference in New Issue
Block a user