diff options
Diffstat (limited to 'drivers/tty/serial/kgdb_nmi.c')
-rw-r--r-- | drivers/tty/serial/kgdb_nmi.c | 101 |
1 files changed, 0 insertions, 101 deletions
diff --git a/drivers/tty/serial/kgdb_nmi.c b/drivers/tty/serial/kgdb_nmi.c index e93850f6447a..2833708e369f 100644 --- a/drivers/tty/serial/kgdb_nmi.c +++ b/drivers/tty/serial/kgdb_nmi.c @@ -27,18 +27,6 @@ #include <linux/kgdb.h> #include <linux/kdb.h> -static int kgdb_nmi_knock = 1; -module_param_named(knock, kgdb_nmi_knock, int, 0600); -MODULE_PARM_DESC(knock, "if set to 1 (default), the special '$3#33' command " \ - "must be used to enter the debugger; when set to 0, " \ - "hitting return key is enough to enter the debugger; " \ - "when set to -1, the debugger is entered immediately " \ - "upon NMI"); - -static char *kgdb_nmi_magic = "$3#33"; -module_param_named(magic, kgdb_nmi_magic, charp, 0600); -MODULE_PARM_DESC(magic, "magic sequence to enter NMI debugger (default $3#33)"); - static atomic_t kgdb_nmi_num_readers = ATOMIC_INIT(0); static int kgdb_nmi_console_setup(struct console *co, char *options) @@ -95,95 +83,6 @@ struct kgdb_nmi_tty_priv { static struct tty_port *kgdb_nmi_port; -static void kgdb_tty_recv(int ch) -{ - struct kgdb_nmi_tty_priv *priv; - char c = ch; - - if (!kgdb_nmi_port || ch < 0) - return; - /* - * Can't use port->tty->driver_data as tty might be not there. Timer - * will check for tty and will get the ref, but here we don't have to - * do that, and actually, we can't: we're in NMI context, no locks are - * possible. - */ - priv = container_of(kgdb_nmi_port, struct kgdb_nmi_tty_priv, port); - kfifo_in(&priv->fifo, &c, 1); -} - -static int kgdb_nmi_poll_one_knock(void) -{ - static int n; - int c; - const char *magic = kgdb_nmi_magic; - size_t m = strlen(magic); - bool printch = false; - - c = dbg_io_ops->read_char(); - if (c == NO_POLL_CHAR) - return c; - - if (!kgdb_nmi_knock && (c == '\r' || c == '\n')) { - return 1; - } else if (c == magic[n]) { - n = (n + 1) % m; - if (!n) - return 1; - printch = true; - } else { - n = 0; - } - - if (atomic_read(&kgdb_nmi_num_readers)) { - kgdb_tty_recv(c); - return 0; - } - - if (printch) { - kdb_printf("%c", c); - return 0; - } - - kdb_printf("\r%s %s to enter the debugger> %*s", - kgdb_nmi_knock ? "Type" : "Hit", - kgdb_nmi_knock ? magic : "<return>", (int)m, ""); - while (m--) - kdb_printf("\b"); - return 0; -} - -/** - * kgdb_nmi_poll_knock - Check if it is time to enter the debugger - * - * "Serial ports are often noisy, especially when muxed over another port (we - * often use serial over the headset connector). Noise on the async command - * line just causes characters that are ignored, on a command line that blocked - * execution noise would be catastrophic." -- Colin Cross - * - * So, this function implements KGDB/KDB knocking on the serial line: we won't - * enter the debugger until we receive a known magic phrase (which is actually - * "$3#33", known as "escape to KDB" command. There is also a relaxed variant - * of knocking, i.e. just pressing the return key is enough to enter the - * debugger. And if knocking is disabled, the function always returns 1. - */ -bool kgdb_nmi_poll_knock(void) -{ - if (kgdb_nmi_knock < 0) - return true; - - while (1) { - int ret; - - ret = kgdb_nmi_poll_one_knock(); - if (ret == NO_POLL_CHAR) - return false; - else if (ret == 1) - break; - } - return true; -} - /* * The tasklet is cheap, it does not cause wakeups when reschedules itself, * instead it waits for the next tick. |