Commit ce628966 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by David S. Miller
Browse files

caif: reduce stack size with KASAN 



When CONFIG_KASAN is set, we can use relatively large amounts of kernel
stack space:

net/caif/cfctrl.c:555:1: warning: the frame size of 1600 bytes is larger than 1280 bytes [-Wframe-larger-than=]

This adds convenience wrappers around cfpkt_extr_head(), which is responsible
for most of the stack growth. With those wrapper functions, gcc apparently
starts reusing the stack slots for each instance, thus avoiding the
problem.

Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent aa73dc95

include/net/caif/cfpkt.h

+27 −0
Original line number Diff line number Diff line
@@ -32,6 +32,33 @@ void cfpkt_destroy(struct cfpkt *pkt); 
 */

int cfpkt_extr_head(struct cfpkt *pkt, void *data, u16 len);



static inline u8 cfpkt_extr_head_u8(struct cfpkt *pkt)

{

	u8 tmp;



	cfpkt_extr_head(pkt, &tmp, 1);



	return tmp;

}



static inline u16 cfpkt_extr_head_u16(struct cfpkt *pkt)

{

	__le16 tmp;



	cfpkt_extr_head(pkt, &tmp, 2);



	return le16_to_cpu(tmp);

}



static inline u32 cfpkt_extr_head_u32(struct cfpkt *pkt)

{

	__le32 tmp;



	cfpkt_extr_head(pkt, &tmp, 4);



	return le32_to_cpu(tmp);

}



/*

 * Peek header from packet.

 * Reads data from packet without changing packet.

net/caif/cfctrl.c

+22 −28
Original line number Diff line number Diff line
@@ -352,15 +352,14 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt) 
	u8 cmdrsp;

	u8 cmd;

	int ret = -1;

	u16 tmp16;

	u8 len;

	u8 param[255];

	u8 linkid;

	u8 linkid = 0;

	struct cfctrl *cfctrl = container_obj(layer);

	struct cfctrl_request_info rsp, *req;





	cfpkt_extr_head(pkt, &cmdrsp, 1);

	cmdrsp = cfpkt_extr_head_u8(pkt);

	cmd = cmdrsp & CFCTRL_CMD_MASK;

	if (cmd != CFCTRL_CMD_LINK_ERR

	    && CFCTRL_RSP_BIT != (CFCTRL_RSP_BIT & cmdrsp)
@@ -378,13 +377,12 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt) 
			u8 physlinkid;

			u8 prio;

			u8 tmp;

			u32 tmp32;

			u8 *cp;

			int i;

			struct cfctrl_link_param linkparam;

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



			cfpkt_extr_head(pkt, &tmp, 1);

			tmp = cfpkt_extr_head_u8(pkt);



			serv = tmp & CFCTRL_SRV_MASK;

			linkparam.linktype = serv;
@@ -392,13 +390,13 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt) 
			servtype = tmp >> 4;

			linkparam.chtype = servtype;



			cfpkt_extr_head(pkt, &tmp, 1);

			tmp = cfpkt_extr_head_u8(pkt);

			physlinkid = tmp & 0x07;

			prio = tmp >> 3;



			linkparam.priority = prio;

			linkparam.phyid = physlinkid;

			cfpkt_extr_head(pkt, &endpoint, 1);

			endpoint = cfpkt_extr_head_u8(pkt);

			linkparam.endpoint = endpoint & 0x03;



			switch (serv) {
@@ -407,45 +405,43 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt) 
				if (CFCTRL_ERR_BIT & cmdrsp)

					break;

				/* Link ID */

				cfpkt_extr_head(pkt, &linkid, 1);

				linkid = cfpkt_extr_head_u8(pkt);

				break;

			case CFCTRL_SRV_VIDEO:

				cfpkt_extr_head(pkt, &tmp, 1);

				tmp = cfpkt_extr_head_u8(pkt);

				linkparam.u.video.connid = tmp;

				if (CFCTRL_ERR_BIT & cmdrsp)

					break;

				/* Link ID */

				cfpkt_extr_head(pkt, &linkid, 1);

				linkid = cfpkt_extr_head_u8(pkt);

				break;



			case CFCTRL_SRV_DATAGRAM:

				cfpkt_extr_head(pkt, &tmp32, 4);

				linkparam.u.datagram.connid =

				    le32_to_cpu(tmp32);

				    cfpkt_extr_head_u32(pkt);

				if (CFCTRL_ERR_BIT & cmdrsp)

					break;

				/* Link ID */

				cfpkt_extr_head(pkt, &linkid, 1);

				linkid = cfpkt_extr_head_u8(pkt);

				break;

			case CFCTRL_SRV_RFM:

				/* Construct a frame, convert

				 * DatagramConnectionID

				 * to network format long and copy it out...

				 */

				cfpkt_extr_head(pkt, &tmp32, 4);

				linkparam.u.rfm.connid =

				  le32_to_cpu(tmp32);

				    cfpkt_extr_head_u32(pkt);

				cp = (u8 *) linkparam.u.rfm.volume;

				for (cfpkt_extr_head(pkt, &tmp, 1);

				for (tmp = cfpkt_extr_head_u8(pkt);

				     cfpkt_more(pkt) && tmp != '\0';

				     cfpkt_extr_head(pkt, &tmp, 1))

				     tmp = cfpkt_extr_head_u8(pkt))

					*cp++ = tmp;

				*cp = '\0';



				if (CFCTRL_ERR_BIT & cmdrsp)

					break;

				/* Link ID */

				cfpkt_extr_head(pkt, &linkid, 1);

				linkid = cfpkt_extr_head_u8(pkt);



				break;

			case CFCTRL_SRV_UTIL:
@@ -454,13 +450,11 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt) 
				 * to network format long and copy it out...

				 */

				/* Fifosize KB */

				cfpkt_extr_head(pkt, &tmp16, 2);

				linkparam.u.utility.fifosize_kb =

				    le16_to_cpu(tmp16);

				    cfpkt_extr_head_u16(pkt);

				/* Fifosize bufs */

				cfpkt_extr_head(pkt, &tmp16, 2);

				linkparam.u.utility.fifosize_bufs =

				    le16_to_cpu(tmp16);

				    cfpkt_extr_head_u16(pkt);

				/* name */

				cp = (u8 *) linkparam.u.utility.name;

				caif_assert(sizeof(linkparam.u.utility.name)
@@ -468,24 +462,24 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt) 
				for (i = 0;

				     i < UTILITY_NAME_LENGTH

				     && cfpkt_more(pkt); i++) {

					cfpkt_extr_head(pkt, &tmp, 1);

					tmp = cfpkt_extr_head_u8(pkt);

					*cp++ = tmp;

				}

				/* Length */

				cfpkt_extr_head(pkt, &len, 1);

				len = cfpkt_extr_head_u8(pkt);

				linkparam.u.utility.paramlen = len;

				/* Param Data */

				cp = linkparam.u.utility.params;

				while (cfpkt_more(pkt) && len--) {

					cfpkt_extr_head(pkt, &tmp, 1);

					tmp = cfpkt_extr_head_u8(pkt);

					*cp++ = tmp;

				}

				if (CFCTRL_ERR_BIT & cmdrsp)

					break;

				/* Link ID */

				cfpkt_extr_head(pkt, &linkid, 1);

				linkid = cfpkt_extr_head_u8(pkt);

				/* Length */

				cfpkt_extr_head(pkt, &len, 1);

				len = cfpkt_extr_head_u8(pkt);

				/* Param Data */

				cfpkt_extr_head(pkt, &param, len);

				break;
@@ -522,7 +516,7 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt) 
		}

		break;

	case CFCTRL_CMD_LINK_DESTROY:

		cfpkt_extr_head(pkt, &linkid, 1);

		linkid = cfpkt_extr_head_u8(pkt);

		cfctrl->res.linkdestroy_rsp(cfctrl->serv.layer.up, linkid);

		break;

	case CFCTRL_CMD_LINK_ERR:

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