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SubjectRe: [PATCHv3] tty: Set correct tty name in 'active' sysfs attribute
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Hi

On Mon, Feb 24, 2014 at 3:50 PM, Hannes Reinecke <hare@suse.de> wrote:
> The 'active' sysfs attribute should refer to the currently
> active tty devices the console is running on, not the currently
> active console.
> The console structure doesn't refer to any device in sysfs,
> only the tty the console is running on has.
> So we need to print out the tty names in 'active', not
> the console names.
> But we need to take care for the virtual console to always display
> 'tty0' so as not to break existing programs.
>
> Cc: Lennart Poettering <lennart@poettering.net>
> Cc: Kay Sievers <kay@vrfy.org>
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Jiri Slaby <jslaby@suse.cz>
> Signed-off-by: Werner Fink <werner@suse.de>
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
> drivers/tty/tty_io.c | 24 ++++++++++++++++++------
> 1 file changed, 18 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
> index c74a00a..96eb462 100644
> --- a/drivers/tty/tty_io.c
> +++ b/drivers/tty/tty_io.c
> @@ -1271,12 +1271,13 @@ static void pty_line_name(struct tty_driver *driver, int index, char *p)
> *
> * Locking: None
> */
> -static void tty_line_name(struct tty_driver *driver, int index, char *p)
> +static ssize_t tty_line_name(struct tty_driver *driver, int index, char *p)
> {
> if (driver->flags & TTY_DRIVER_UNNUMBERED_NODE)
> - strcpy(p, driver->name);
> + return sprintf(p, "%s", driver->name);
> else
> - sprintf(p, "%s%d", driver->name, index + driver->name_base);
> + return sprintf(p, "%s%d", driver->name,
> + index + driver->name_base);
> }
>
> /**
> @@ -3545,9 +3546,20 @@ static ssize_t show_cons_active(struct device *dev,
> if (i >= ARRAY_SIZE(cs))
> break;
> }
> - while (i--)
> - count += sprintf(buf + count, "%s%d%c",
> - cs[i]->name, cs[i]->index, i ? ' ':'\n');
> + while (i--) {
> + struct tty_driver *driver;
> + const char *name = cs[i]->name;
> + int index = cs[i]->index;
> +
> + driver = cs[i]->device(cs[i], &index);
> + /* Some programs rely on 'tty0' for console */
> + if (driver && (index > 0 || driver->major != TTY_MAJOR)) {

As Ray mentioned in the previous discussion, this has to be
cs[i]->index instead of "index" as ->device() changes the parameter.
See drivers/tty/vt/vt.c vt_console_device().

Thanks
David

> + count += tty_line_name(driver, index, buf + count);
> + count += sprintf(buf + count, "%c", i ? ' ':'\n');
> + } else
> + count += sprintf(buf + count, "%s%d%c",
> + name, cs[i]->index, i ? ' ':'\n');
> + }
> console_unlock();
>
> return count;
> --
> 1.7.12.4
>


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