-
Notifications
You must be signed in to change notification settings - Fork 204
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
[LibOS,PAL] Refactor LibOS's
/dev/tty and PAL's corresponding `dev:…
…tty`
Gramine's LibOS initialization routine can be compared to the Linux's
`init` process. Therefore, similar to what's done by the `init` process
(or more specifically, by one of its utilities `getty`), Gramine
initializes the stdin, stdout and stderr streams to file descriptors
0, 1 and 2, opened on the `/dev/tty` device (controlling terminal):
- `stdin = open("/dev/tty", O_RDONLY)`
- `stdout = stderr = open("/dev/tty", O_WRONLY | O_APPEND)`
Note that this initialization routine happens only in the first (aka
main, aka master) Gramine process. Child processes will not open this
`/dev/tty` device; instead they will inherit all the FDs from the parent
process.
On the LibOS side, the previous implementation was confusing: it mounted
`/dev/tty` device file in a special way: not via Gramine's devfs, but
instead via chrootfs. On the PAL side, the `/dev/tty` file was
confusingly mapped to PAL's `dev:tty`, which was implemented via
`PAL_TYPE_DEV` but in a special way: all device APIs in `pal_devices.c`
had a special code path for `dev:tty` (which was also erroneously
checked by comparing the FD to 0 or 1, even though these host FDs could
be different in the child).
This commit refactors this mess:
- In LibOS, `/dev/tty` becomes a pseudo-file mounted via devfs.
- In PAL, `/dev/tty` maps to `console:`, which is a new type of PAL
handle `PAL_TYPE_CONSOLE`. This new type is removed from
`pal_devices.c` and instead implemented in a new `pal_console.c`.
New LibOS test `console` is added to test the tty/console.
Signed-off-by: Dmitrii Kuvaiskii <[email protected]>- Loading branch information
Dmitrii Kuvaiskii
committed
Sep 28, 2023
1 parent
2ad54dd
commit c11f4c6
Showing
33 changed files
with
629 additions
and
281 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,113 @@ | ||
| /* SPDX-License-Identifier: LGPL-3.0-or-later */ | ||
| /* Copyright (C) 2023 Intel Corporation */ | ||
|
|
||
| #include <err.h> | ||
| #include <errno.h> | ||
| #include <fcntl.h> | ||
| #include <stdio.h> | ||
| #include <string.h> | ||
| #include <sys/wait.h> | ||
| #include <unistd.h> | ||
|
|
||
| #include "common.h" | ||
|
|
||
| #define FIRST_HELLO_STDOUT "First hello on stdout!\n" | ||
| #define FIRST_HELLO_STDERR "First hello on stderr!\n" | ||
| #define SECOND_HELLO_STDOUT "Second hello on stdout!\n" | ||
| #define SECOND_HELLO_STDERR "Second hello on stderr!\n" | ||
| #define IGNORED_HELLO_STDOUT "Ignored hello on stdout!\n" | ||
| #define IGNORED_HELLO_STDERR "Ignored hello on stderr!\n" | ||
|
|
||
| /* Notes: | ||
| * - stdout and stderr are periodically closed or redirected to /dev/null in this test, so | ||
| * diagnostic error messages will not appear on the terminal (like errx output). Use strace and | ||
| * Gramine logs to analyze and debug this test instead. | ||
| * - Under Gramine, app stdout and stderr streams are both redirected to host stdout. The host | ||
| * stderr only prints Gramine logs. So, don't be surprised that `console > /dev/null` and | ||
| * `gramine-direct console > /dev/null` show different results. | ||
| */ | ||
|
|
||
| int main(void) { | ||
| /* initialization -- write some messages and save stdout/stderr (for further restore) */ | ||
| ssize_t x = CHECK(write(STDOUT_FILENO, FIRST_HELLO_STDOUT, strlen(FIRST_HELLO_STDOUT))); | ||
| if (x != strlen(FIRST_HELLO_STDOUT)) | ||
| CHECK(-1); | ||
| x = CHECK(write(STDERR_FILENO, FIRST_HELLO_STDERR, strlen(FIRST_HELLO_STDERR))); | ||
| if (x != strlen(FIRST_HELLO_STDERR)) | ||
| CHECK(-1); | ||
|
|
||
| int saved_stdout = CHECK(dup(STDOUT_FILENO)); | ||
| int saved_stderr = CHECK(dup(STDERR_FILENO)); | ||
|
|
||
| /* test 1 -- close stdout/stderr, spawn a child, the child should *not* print anything */ | ||
| CHECK(close(STDOUT_FILENO)); | ||
| CHECK(close(STDERR_FILENO)); | ||
|
|
||
| pid_t p = CHECK(fork()); | ||
| if (p == 0) { | ||
| x = write(STDOUT_FILENO, IGNORED_HELLO_STDOUT, strlen(IGNORED_HELLO_STDOUT)); | ||
| if (x != -1 || errno != EBADF) | ||
| errx(1, "write(stdout) didn't fail with EBADF (returned: %ld, errno: %d)", x, errno); | ||
| x = write(STDERR_FILENO, IGNORED_HELLO_STDERR, strlen(IGNORED_HELLO_STDERR)); | ||
| if (x != -1 || errno != EBADF) | ||
| errx(1, "write(stderr) didn't fail with EBADF (returned: %ld, errno: %d)", x, errno); | ||
| return 0; | ||
| } | ||
|
|
||
| int status = 0; | ||
| CHECK(wait(&status)); | ||
| if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) | ||
| errx(1, "child died with status: %#x", status); | ||
|
|
||
| /* test 2 -- restore stdout/stderr and print one more message */ | ||
| CHECK(dup2(saved_stdout, STDOUT_FILENO)); | ||
| CHECK(dup2(saved_stderr, STDERR_FILENO)); | ||
|
|
||
| x = CHECK(write(STDOUT_FILENO, SECOND_HELLO_STDOUT, strlen(SECOND_HELLO_STDOUT))); | ||
| if (x != strlen(SECOND_HELLO_STDOUT)) | ||
| CHECK(-1); | ||
| x = CHECK(write(STDERR_FILENO, SECOND_HELLO_STDERR, strlen(SECOND_HELLO_STDERR))); | ||
| if (x != strlen(SECOND_HELLO_STDERR)) | ||
| CHECK(-1); | ||
|
|
||
| /* test 3 -- redirect stdout/stderr to null, the process should *not* print anything */ | ||
| int dev_null_fd = open("/dev/null", O_WRONLY, 0666); | ||
| CHECK(close(STDOUT_FILENO)); | ||
| CHECK(close(STDERR_FILENO)); | ||
| CHECK(dup2(dev_null_fd, STDOUT_FILENO)); | ||
| CHECK(dup2(dev_null_fd, STDERR_FILENO)); | ||
| CHECK(close(dev_null_fd)); /* not needed anymore */ | ||
|
|
||
| x = CHECK(write(STDOUT_FILENO, IGNORED_HELLO_STDOUT, strlen(IGNORED_HELLO_STDOUT))); | ||
| if (x != strlen(IGNORED_HELLO_STDOUT)) | ||
| CHECK(-1); | ||
| x = CHECK(write(STDERR_FILENO, IGNORED_HELLO_STDERR, strlen(IGNORED_HELLO_STDERR))); | ||
| if (x != strlen(IGNORED_HELLO_STDERR)) | ||
| CHECK(-1); | ||
|
|
||
| /* test 4 -- spawn a child, the child should *not* print anything */ | ||
| p = CHECK(fork()); | ||
| if (p == 0) { | ||
| x = CHECK(write(STDOUT_FILENO, IGNORED_HELLO_STDOUT, strlen(IGNORED_HELLO_STDOUT))); | ||
| if (x != strlen(IGNORED_HELLO_STDOUT)) | ||
| CHECK(-1); | ||
| x = CHECK(write(STDERR_FILENO, IGNORED_HELLO_STDERR, strlen(IGNORED_HELLO_STDERR))); | ||
| if (x != strlen(IGNORED_HELLO_STDERR)) | ||
| CHECK(-1); | ||
| return 0; | ||
| } | ||
|
|
||
| status = 0; | ||
| CHECK(wait(&status)); | ||
| if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) | ||
| errx(1, "child died with status: %#x", status); | ||
|
|
||
| /* finalization -- restore stdout/stderr and write some messages */ | ||
| CHECK(close(STDOUT_FILENO)); | ||
| CHECK(close(STDERR_FILENO)); | ||
| CHECK(dup2(saved_stdout, STDOUT_FILENO)); | ||
| CHECK(dup2(saved_stderr, STDERR_FILENO)); | ||
|
|
||
| puts("TEST OK"); | ||
| return 0; | ||
| } |
Oops, something went wrong.