Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 992dbb2a authored by Colin Cross's avatar Colin Cross Committed by Amit Pundir
Browse files

ANDROID: ARM: fiq_debugger: add support for kgdb 



Adds polling tty ops to the fiq debugger console tty, which allows
kgdb to run against an fiq debugger console.

Add a check in do_sysrq to prevent enabling kgdb from the fiq
debugger unless a flag (writable only by root) has been set. This
should make it safe to enable KGDB on a production device.

Also add a shortcut to enable the console and kgdb together, to
allow kgdb to be enabled when the shell on the console is not
responding.

Change-Id: Ifc65239ca96c9887431a6a36b9b44a539002f544
Signed-off-by: default avatarColin Cross <ccross@android.com>
parent 5d12c56f

arch/arm/common/fiq_debugger.c

+72 −1
Original line number Original line Diff line number Diff line
@@ -107,9 +107,12 @@ static bool initial_debug_enable; 
static bool initial_console_enable;

static bool initial_console_enable;

#endif

#endif





static bool fiq_kgdb_enable;



module_param_named(no_sleep, initial_no_sleep, bool, 0644);

module_param_named(no_sleep, initial_no_sleep, bool, 0644);

module_param_named(debug_enable, initial_debug_enable, bool, 0644);

module_param_named(debug_enable, initial_debug_enable, bool, 0644);

module_param_named(console_enable, initial_console_enable, bool, 0644);

module_param_named(console_enable, initial_console_enable, bool, 0644);

module_param_named(kgdb_enable, fiq_kgdb_enable, bool, 0644);





#ifdef CONFIG_FIQ_DEBUGGER_WAKEUP_IRQ_ALWAYS_ON

#ifdef CONFIG_FIQ_DEBUGGER_WAKEUP_IRQ_ALWAYS_ON

static inline void enable_wakeup_irq(struct fiq_debugger_state *state) {}

static inline void enable_wakeup_irq(struct fiq_debugger_state *state) {}
@@ -507,11 +510,29 @@ static void end_syslog_dump(struct fiq_debugger_state *state) 




static void do_sysrq(struct fiq_debugger_state *state, char rq)

static void do_sysrq(struct fiq_debugger_state *state, char rq)

{

{

	if ((rq == 'g' || rq == 'G') && !fiq_kgdb_enable) {

		debug_printf(state, "sysrq-g blocked\n");

		return;

	}

	begin_syslog_dump(state);

	begin_syslog_dump(state);

	handle_sysrq(rq);

	handle_sysrq(rq);

	end_syslog_dump(state);

	end_syslog_dump(state);

}

}





#ifdef CONFIG_KGDB

static void do_kgdb(struct fiq_debugger_state *state)

{

	if (!fiq_kgdb_enable) {

		debug_printf(state, "kgdb through fiq debugger not enabled\n");

		return;

	}



	debug_printf(state, "enabling console and triggering kgdb\n");

	state->console_enable = true;

	handle_sysrq('g');

}

#endif



/* This function CANNOT be called in FIQ context */

/* This function CANNOT be called in FIQ context */

static void debug_irq_exec(struct fiq_debugger_state *state, char *cmd)

static void debug_irq_exec(struct fiq_debugger_state *state, char *cmd)

{

{
@@ -521,6 +542,10 @@ static void debug_irq_exec(struct fiq_debugger_state *state, char *cmd) 
		do_sysrq(state, 'h');

		do_sysrq(state, 'h');

	if (!strncmp(cmd, "sysrq ", 6))

	if (!strncmp(cmd, "sysrq ", 6))

		do_sysrq(state, cmd[6]);

		do_sysrq(state, cmd[6]);

#ifdef CONFIG_KGDB

	if (!strcmp(cmd, "kgdb"))

		do_kgdb(state);

#endif

}

}





static void debug_help(struct fiq_debugger_state *state)

static void debug_help(struct fiq_debugger_state *state)
@@ -542,6 +567,9 @@ static void debug_help(struct fiq_debugger_state *state) 
	debug_printf(state,	" ps            Process list\n"

	debug_printf(state,	" ps            Process list\n"

				" sysrq         sysrq options\n"

				" sysrq         sysrq options\n"

				" sysrq <param> Execute sysrq with <param>\n");

				" sysrq <param> Execute sysrq with <param>\n");

#ifdef CONFIG_KGDB

	debug_printf(state,	" kgdb          Enter kernel debugger\n");

#endif

}

}





static void take_affinity(void *info)

static void take_affinity(void *info)
@@ -705,6 +733,7 @@ static void debug_handle_irq_context(struct fiq_debugger_state *state) 
#endif

#endif

	if (state->debug_busy) {

	if (state->debug_busy) {

		debug_irq_exec(state, state->debug_cmd);

		debug_irq_exec(state, state->debug_cmd);

		if (!state->console_enable)

			debug_prompt(state);

			debug_prompt(state);

		state->debug_busy = 0;

		state->debug_busy = 0;

	}

	}
@@ -938,11 +967,53 @@ int fiq_tty_write_room(struct tty_struct *tty) 
	return 1024;

	return 1024;

}

}





#ifdef CONFIG_CONSOLE_POLL

static int fiq_tty_poll_init(struct tty_driver *driver, int line, char *options)

{

	return 0;

}



static int fiq_tty_poll_get_char(struct tty_driver *driver, int line)

{

	struct fiq_debugger_state *state = driver->ttys[line]->driver_data;

	int c = NO_POLL_CHAR;



	debug_uart_enable(state);

	if (debug_have_fiq(state)) {

		int count = fiq_debugger_ringbuf_level(state->tty_rbuf);

		if (count > 0) {

			c = fiq_debugger_ringbuf_peek(state->tty_rbuf, 0);

			fiq_debugger_ringbuf_consume(state->tty_rbuf, 1);

		}

	} else {

		c = debug_getc(state);

		if (c == FIQ_DEBUGGER_NO_CHAR)

			c = NO_POLL_CHAR;

	}

	debug_uart_disable(state);



	return c;

}



static void fiq_tty_poll_put_char(struct tty_driver *driver, int line, char ch)

{

	struct fiq_debugger_state *state = driver->ttys[line]->driver_data;

	debug_uart_enable(state);

	debug_putc(state, ch);

	debug_uart_disable(state);

}

#endif



static const struct tty_operations fiq_tty_driver_ops = {

static const struct tty_operations fiq_tty_driver_ops = {

	.write = fiq_tty_write,

	.write = fiq_tty_write,

	.write_room = fiq_tty_write_room,

	.write_room = fiq_tty_write_room,

	.open = fiq_tty_open,

	.open = fiq_tty_open,

	.close = fiq_tty_close,

	.close = fiq_tty_close,

#ifdef CONFIG_CONSOLE_POLL

	.poll_init = fiq_tty_poll_init,

	.poll_get_char = fiq_tty_poll_get_char,

	.poll_put_char = fiq_tty_poll_put_char,

#endif

};

};





static int fiq_debugger_tty_init(struct fiq_debugger_state *state)

static int fiq_debugger_tty_init(struct fiq_debugger_state *state)