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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: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Arnd Bergmann 2018-01-16 17:34:00 +01:00 committed by David S. Miller
parent aa73dc95b2
commit ce6289661b
2 changed files with 49 additions and 28 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

27
include/net/caif/cfpkt.h
View File

@ -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.

50
net/caif/cfctrl.c
View File

@ -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: