Commit 668f272e authored by Ian Abbott's avatar Ian Abbott Committed by Greg Kroah-Hartman
Browse files

Staging: comedi: serial2002: Reduce stack usage on 'open' 



Reduce stack usage in serial_2002_open() by allocating dig_in_config,
dig_out_config, chan_in_config, and chan_out_config temporary arrays
using kcalloc() and freeing them when done with.

Signed-off-by: default avatarIan Abbott <abbotti@mev.co.uk>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent fa3b5d9a

drivers/staging/comedi/drivers/serial2002.c

+23 −21
Original line number Diff line number Diff line
@@ -412,30 +412,25 @@ static int serial_2002_open(struct comedi_device *dev) 
			int max;

		};



		struct config_t dig_in_config[32];

		struct config_t dig_out_config[32];

		struct config_t chan_in_config[32];

		struct config_t chan_out_config[32];

		struct config_t *dig_in_config;

		struct config_t *dig_out_config;

		struct config_t *chan_in_config;

		struct config_t *chan_out_config;

		int i;



		result = 0;

		for (i = 0; i < 32; i++) {

			dig_in_config[i].kind = 0;

			dig_in_config[i].bits = 0;

			dig_in_config[i].min = 0;

			dig_in_config[i].max = 0;

			dig_out_config[i].kind = 0;

			dig_out_config[i].bits = 0;

			dig_out_config[i].min = 0;

			dig_out_config[i].max = 0;

			chan_in_config[i].kind = 0;

			chan_in_config[i].bits = 0;

			chan_in_config[i].min = 0;

			chan_in_config[i].max = 0;

			chan_out_config[i].kind = 0;

			chan_out_config[i].bits = 0;

			chan_out_config[i].min = 0;

			chan_out_config[i].max = 0;

		dig_in_config = kcalloc(32, sizeof(struct config_t),

				GFP_KERNEL);

		dig_out_config = kcalloc(32, sizeof(struct config_t),

				GFP_KERNEL);

		chan_in_config = kcalloc(32, sizeof(struct config_t),

				GFP_KERNEL);

		chan_out_config = kcalloc(32, sizeof(struct config_t),

				GFP_KERNEL);

		if (!dig_in_config || !dig_out_config

		    || !chan_in_config || !chan_out_config) {

			result = -ENOMEM;

			goto err_alloc_configs;

		}



		tty_setspeed(devpriv->tty, devpriv->speed);
@@ -690,6 +685,13 @@ static int serial_2002_open(struct comedi_device *dev) 
				s->range_table_list = NULL;

			}

		}



err_alloc_configs:

		kfree(dig_in_config);

		kfree(dig_out_config);

		kfree(chan_in_config);

		kfree(chan_out_config);



		if (result) {

			if (devpriv->tty) {

				filp_close(devpriv->tty, 0);

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