[LTP] [PATCH] pty: fix some issues in pty02
Cyril Hrubis
chrubis@suse.cz
Thu Aug 16 12:28:16 CEST 2018
Hi!
> 1. Add EXTPROC into lapi
>
> 2. Exit the test with TCONF if we get EINVAL from tcsetattr()
>
> 3. Giving newline('\n') to ptmx to avoid reading pts block on rhel6
>
> 4. Using tcgetattr() to get attributes before re-setting it
> Fix this error:
> tst_test.c:1015: INFO: Timeout per run is 0h 50m 00s
> pty02.c:42: BROK: tcsetattr() failed: EINVAL
>
> POSIX.1 General description:
> Changes the attributes associated with a terminal. New attributes are
> specified with a termios control structure. Programs should always
> issue a tcgetattr() first, modify the desired fields, and then issue
> a tcsetattr(). tcsetattr() should never be issued using a termios
> structure that was not obtained using tcgetattr(). tcsetattr() should
> use only a termios structure that was obtained by tcgetattr().
I've tried the test with this patch applied and I still got soft-lockup
on unpatched kernel, so it seems like the reproducer works fine with
these changes.
> diff --git a/testcases/kernel/pty/pty02.c b/testcases/kernel/pty/pty02.c
> index fd3d26b..8720407 100644
> --- a/testcases/kernel/pty/pty02.c
> +++ b/testcases/kernel/pty/pty02.c
> @@ -25,27 +25,42 @@
> */
>
> #include <stdlib.h>
> +#include <errno.h>
> #include <termio.h>
>
> #include "tst_test.h"
> +#include "lapi/termbits.h"
>
> static void do_test(void)
> {
> - struct termios io = { .c_lflag = EXTPROC | ICANON };
> + struct termios io;
> int ptmx, pts;
> char c = 'A';
> + char n = '\n';
> int nbytes;
>
> ptmx = SAFE_OPEN("/dev/ptmx", O_WRONLY);
>
> - if (tcsetattr(ptmx, TCSANOW, &io) != 0)
> - tst_brk(TBROK | TERRNO, "tcsetattr() failed");
> + if (tcgetattr(ptmx, &io) != 0)
> + tst_brk(TBROK | TERRNO, "tcgetattr() failed");
> +
> + io.c_lflag = EXTPROC | ICANON;
> +
> + TEST(tcsetattr(ptmx, TCSANOW, &io));
> + if (TEST_RETURN == -1) {
> + if (TEST_ERRNO == EINVAL)
> + tst_res(TCONF, "tcsetattr(, , EXTPROC | ICANON) is not supported");
> + else
> + tst_brk(TBROK | TERRNO, "tcsetattr() failed");
> + }
We changed the TEST_RETURN to TST_RET and TEST_ERRNO to TST_ERR a few
weeks ago, can you please update you git tree?
> if (unlockpt(ptmx) != 0)
> tst_brk(TBROK | TERRNO, "unlockpt() failed");
>
> pts = SAFE_OPEN(ptsname(ptmx), O_RDONLY);
> SAFE_WRITE(1, ptmx, &c, 1);
> + /* giving newline('\n') to ptmx to avoid reading pts block */
> + SAFE_WRITE(1, ptmx, &n, 1);
I wonder if we can just do SAFE_WRITE(1, ptmx, "A\n", 2) here instead?
Also the comment is a bit misleading, I was thinking for a while about
what is pts block and why do we need to avoid reading it. So maybe we
should reword it as:
/* write newline to ptmx to avoid read() on pts to block */
> SAFE_READ(1, pts, &c, 1);
>
> tst_res(TINFO, "Calling FIONREAD, this will hang in n_tty_ioctl() if the bug is present...");
> --
> 2.9.5
>
--
Cyril Hrubis
chrubis@suse.cz
More information about the ltp
mailing list