diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/tcsetattr.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/tcsetattr.c | 52 |
1 files changed, 50 insertions, 2 deletions
diff --git a/sysdeps/unix/sysv/linux/tcsetattr.c b/sysdeps/unix/sysv/linux/tcsetattr.c index dee491564f..4a352372c9 100644 --- a/sysdeps/unix/sysv/linux/tcsetattr.c +++ b/sysdeps/unix/sysv/linux/tcsetattr.c @@ -28,6 +28,24 @@ #include <kernel_termios.h> +/* This is a gross hack around a kernel bug. If the cfsetispeed functions + is called with the SPEED argument set to zero this means use the same + speed as for output. But we don't have independent input and output + speeds and therefore cannot record this. + + We use an unused bit in the `c_iflag' field to keep track of this + use of `cfsetispeed'. The value here must correspond to the one used + in `speed.c'. */ +#if !defined _HAVE_C_ISPEED || !defined _HAVE_C_OSPEED +# define IBAUD0 020000000000 +#else +/* If we have separate values for input and output speed don't bother + with this. Define the value as zero so the compiler sees we don't + have to do the AND below. */ +# define IBAUD0 0 +#endif + + /* Set the state of FD to *TERMIOS_P. */ int tcsetattr (fd, optional_actions, termios_p) @@ -37,6 +55,7 @@ tcsetattr (fd, optional_actions, termios_p) { struct __kernel_termios k_termios; unsigned long int cmd; + int retval; switch (optional_actions) { @@ -54,7 +73,7 @@ tcsetattr (fd, optional_actions, termios_p) return -1; } - k_termios.c_iflag = termios_p->c_iflag; + k_termios.c_iflag = termios_p->c_iflag & ~IBAUD0; k_termios.c_oflag = termios_p->c_oflag; k_termios.c_cflag = termios_p->c_cflag; k_termios.c_lflag = termios_p->c_lflag; @@ -68,5 +87,34 @@ tcsetattr (fd, optional_actions, termios_p) memcpy (&k_termios.c_cc[0], &termios_p->c_cc[0], __KERNEL_NCCS * sizeof (cc_t)); - return __ioctl (fd, cmd, &k_termios); + retval = __ioctl (fd, cmd, &k_termios); + + if (retval == 0 && cmd == TCSETS) + { + /* The Linux kernel has a bug which silently ignore the invalid + c_cflag on pty. We have to check it here. */ + int save = errno; + retval = __ioctl (fd, TCGETS, &k_termios); + if (retval) + { + /* We cannot verify if the setting is ok. We don't return + an error (?). */ + __set_errno (save); + retval = 0; + } + else if ((termios_p->c_cflag & (PARENB | CREAD)) + != (k_termios.c_cflag & (PARENB | CREAD)) + || ((termios_p->c_cflag & CSIZE) + && ((termios_p->c_cflag & CSIZE) + != (k_termios.c_cflag & CSIZE)))) + { + /* It looks like the Linux kernel silently changed the + PARENB/CREAD/CSIZE bits in c_cflag. Report it as an + error. */ + __set_errno (EINVAL); + retval = -1; + } + } + + return retval; } |