Commit 7909a590 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Kalle Valo
Browse files

airo: work around stack usage warning 



gcc-11 with KASAN on 32-bit arm produces a warning about a function
that needs a lot of stack space:

drivers/net/wireless/cisco/airo.c: In function 'setup_card.constprop':
drivers/net/wireless/cisco/airo.c:3960:1: error: the frame size of 1512 bytes is larger than 1400 bytes [-Werror=frame-larger-than=]

Most of this is from a single large structure that could be dynamically
allocated or moved into the per-device structure.  However, as the callers
all seem to have a fairly well bounded call chain, the easiest change
is to pull out the part of the function that needs the large variables
into a separate function and mark that as noinline_for_stack. This does
not reduce the total stack usage, but it gets rid of the warning and
requires minimal changes otherwise.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarKalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210323131634.2669455-1-arnd@kernel.org
parent 7b0e2c4f

drivers/net/wireless/cisco/airo.c

+65 −52
Original line number Diff line number Diff line
@@ -3817,53 +3817,12 @@ static inline void set_auth_type(struct airo_info *local, int auth_type) 
		local->last_auth = auth_type;

}



static u16 setup_card(struct airo_info *ai, u8 *mac, int lock)

static int noinline_for_stack airo_readconfig(struct airo_info *ai, u8 *mac, int lock)

{

	Cmd cmd;

	Resp rsp;

	int status;

	SsidRid mySsid;

	__le16 lastindex;

	WepKeyRid wkr;

	int rc;



	memset(&mySsid, 0, sizeof(mySsid));

	kfree (ai->flash);

	ai->flash = NULL;



	/* The NOP is the first step in getting the card going */

	cmd.cmd = NOP;

	cmd.parm0 = cmd.parm1 = cmd.parm2 = 0;

	if (lock && down_interruptible(&ai->sem))

		return ERROR;

	if (issuecommand(ai, &cmd, &rsp, true) != SUCCESS) {

		if (lock)

			up(&ai->sem);

		return ERROR;

	}

	disable_MAC(ai, 0);



	// Let's figure out if we need to use the AUX port

	if (!test_bit(FLAG_MPI,&ai->flags)) {

		cmd.cmd = CMD_ENABLEAUX;

		if (issuecommand(ai, &cmd, &rsp, true) != SUCCESS) {

			if (lock)

				up(&ai->sem);

			airo_print_err(ai->dev->name, "Error checking for AUX port");

			return ERROR;

		}

		if (!aux_bap || rsp.status & 0xff00) {

			ai->bap_read = fast_bap_read;

			airo_print_dbg(ai->dev->name, "Doing fast bap_reads");

		} else {

			ai->bap_read = aux_bap_read;

			airo_print_dbg(ai->dev->name, "Doing AUX bap_reads");

		}

	}

	if (lock)

		up(&ai->sem);

	if (ai->config.len == 0) {

		int i;

	int i, status;

	/* large variables, so don't inline this function,

	 * maybe change to kmalloc

	 */

	tdsRssiRid rssi_rid;

	CapabilityRid cap_rid;
@@ -3915,6 +3874,60 @@ static u16 setup_card(struct airo_info *ai, u8 *mac, int lock) 
		}

	}

	set_bit (FLAG_COMMIT, &ai->flags);



	return SUCCESS;

}





static u16 setup_card(struct airo_info *ai, u8 *mac, int lock)

{

	Cmd cmd;

	Resp rsp;

	int status;

	SsidRid mySsid;

	__le16 lastindex;

	WepKeyRid wkr;

	int rc;



	memset(&mySsid, 0, sizeof(mySsid));

	kfree (ai->flash);

	ai->flash = NULL;



	/* The NOP is the first step in getting the card going */

	cmd.cmd = NOP;

	cmd.parm0 = cmd.parm1 = cmd.parm2 = 0;

	if (lock && down_interruptible(&ai->sem))

		return ERROR;

	if (issuecommand(ai, &cmd, &rsp, true) != SUCCESS) {

		if (lock)

			up(&ai->sem);

		return ERROR;

	}

	disable_MAC(ai, 0);



	// Let's figure out if we need to use the AUX port

	if (!test_bit(FLAG_MPI,&ai->flags)) {

		cmd.cmd = CMD_ENABLEAUX;

		if (issuecommand(ai, &cmd, &rsp, true) != SUCCESS) {

			if (lock)

				up(&ai->sem);

			airo_print_err(ai->dev->name, "Error checking for AUX port");

			return ERROR;

		}

		if (!aux_bap || rsp.status & 0xff00) {

			ai->bap_read = fast_bap_read;

			airo_print_dbg(ai->dev->name, "Doing fast bap_reads");

		} else {

			ai->bap_read = aux_bap_read;

			airo_print_dbg(ai->dev->name, "Doing AUX bap_reads");

		}

	}

	if (lock)

		up(&ai->sem);

	if (ai->config.len == 0) {

		status = airo_readconfig(ai, mac, lock);

		if (status != SUCCESS)

			return ERROR;

	}



	/* Setup the SSIDs if present */