621fc50e8
Denys Vlasenko
2017-07-24
Subject
hush: fix a case when redirect to a closed fd #1 is not restoring (closing) it
Binary
No binary (build failed)
Architecture & Compiler Flags
—
Build Log
(log yok)
Commit Diff GitHub →
shell/hush.c +27 -7shell/hush_test/hush-redir/redir.right +2 -0shell/hush_test/hush-redir/redir.tests +6 -0
shell/hush.c+27 -7
| @@ -6643,8 +6643,18 @@ struct squirrel { | |
| /* moved_to = -1: fd was opened by redirect; close orig_fd after redir */ | |
| }; | |
| + | static struct squirrel *append_squirrel(struct squirrel *sq, int i, int orig, int moved) |
| + | { |
| + | sq = xrealloc(sq, (i + 2) * sizeof(sq[0])); |
| + | sq[i].orig_fd = orig; |
| + | sq[i].moved_to = moved; |
| + | sq[i+1].orig_fd = -1; /* end marker */ |
| + | return sq; |
| + | } |
| + | |
| static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd) | |
| { | |
| + | int moved_to; |
| int i = 0; | |
| if (sq) while (sq[i].orig_fd >= 0) { | |
| @@ -6664,15 +6674,12 @@ static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd) | |
| i++; | |
| } | |
| - | sq = xrealloc(sq, (i + 2) * sizeof(sq[0])); |
| - | sq[i].orig_fd = fd; |
| /* If this fd is open, we move and remember it; if it's closed, moved_to = -1 */ | |
| - | sq[i].moved_to = fcntl_F_DUPFD(fd, avoid_fd); |
| - | debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, sq[i].moved_to); |
| - | if (sq[i].moved_to < 0 && errno != EBADF) |
| + | moved_to = fcntl_F_DUPFD(fd, avoid_fd); |
| + | debug_printf_redir("redirect_fd %d: previous fd is moved to %d (-1 if it was closed)\n", fd, moved_to); |
| + | if (moved_to < 0 && errno != EBADF) |
| xfunc_die(); | |
| - | sq[i+1].orig_fd = -1; /* end marker */ |
| - | return sq; |
| + | return append_squirrel(sq, i, fd, moved_to); |
| } | |
| /* fd: redirect wants this fd to be used (e.g. 3>file). | |
| @@ -6778,6 +6785,19 @@ static int setup_redirects(struct command *prog, struct squirrel **sqp) | |
| */ | |
| return 1; | |
| } | |
| + | if (openfd == redir->rd_fd && sqp) { |
| + | /* open() gave us precisely the fd we wanted. |
| + | * This means that this fd was not busy |
| + | * (not opened to anywhere). |
| + | * Remember to close it on restore: |
| + | */ |
| + | struct squirrel *sq = *sqp; |
| + | int i = 0; |
| + | if (sq) while (sq[i].orig_fd >= 0) |
| + | i++; |
| + | *sqp = append_squirrel(sq, i, openfd, -1); /* -1 = "it was closed" */ |
| + | debug_printf_redir("redir to previously closed fd %d\n", openfd); |
| + | } |
| } else { | |
| /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */ | |
| openfd = redir->rd_dup; | |
shell/hush_test/hush-redir/redir.right+2 -0
| @@ -0,0 +1,2 @@ | |
| + | hush: write error: Bad file descriptor |
| + | TEST |
shell/hush_test/hush-redir/redir.tests+6 -0
| @@ -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 |