linux-kernel - A question about break and sysrq on a serial console (2.6.19.1)

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 17 Jan 2007 15:56:54 -0800
From:	Brian Beattie <brianb@...on.com>
To:	linux-kernel@...r.kernel.org
Subject: A question about break and sysrq on a serial console (2.6.19.1)

I'm trying to do a SYSRQ over a serial console.  As I understand it a
break will do that, but I'm not seeing the SYSRQ.  In looking at
uart_handle_break() in drivers/serial/8250.c it looks like the code will
toggle port->sysrq, rather than just setting it when the port is a
console.  I think the correct code would be to move the "port->sysrq =
0;" to follow the closing brace on the next line, or am I missing
something.

--------------
/*
 * We do the SysRQ and SAK checking like this...
 */
static inline int uart_handle_break(struct uart_port *port)
{
    struct uart_info *info = port->info;
#ifdef SUPPORT_SYSRQ
    if (port->cons && port->cons->index == port->line) {
        if (!port->sysrq) {
            port->sysrq = jiffies + HZ*5;
            return 1;
        }
        port->sysrq = 0;
    }
#endif
    if (port->flags & UPF_SAK)
        do_SAK(info->tty);
    return 0;
}
-------------

It seem to me that this code will toggle port->sysrq.
-- 
Brian Beattie
Firmware Engineer
APCON, Inc.
BrianB@...on.com

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/