[<prev] [next>] [day] [month] [year] [list]
Message-Id: <20250620112244.3425554-1-arnd@kernel.org>
Date: Fri, 20 Jun 2025 13:22:39 +0200
From: Arnd Bergmann <arnd@...nel.org>
To: "David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Arnd Bergmann <arnd@...db.de>
Cc: Simon Horman <horms@...nel.org>,
netdev@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH] caif: reduce stack size, again
From: Arnd Bergmann <arnd@...db.de>
I tried to fix the stack usage in this function a couple of years ago,
but there is still a problem with the latest gcc versions in some
configurations:
net/caif/cfctrl.c:553:1: error: the frame size of 1296 bytes is larger than 1280 bytes [-Werror=frame-larger-than=]
Reduce this once again, with a separate cfctrl_link_setup() function that
holds the bulk of all the local variables. It also turns out that the
param[] array that takes up a large portion of the stack is write-only
and can be left out here.
Fixes: ce6289661b14 ("caif: reduce stack size with KASAN")
Signed-off-by: Arnd Bergmann <arnd@...db.de>
---
net/caif/cfctrl.c | 294 +++++++++++++++++++++++-----------------------
1 file changed, 144 insertions(+), 150 deletions(-)
diff --git a/net/caif/cfctrl.c b/net/caif/cfctrl.c
index 20139fa1be1f..06b604cf9d58 100644
--- a/net/caif/cfctrl.c
+++ b/net/caif/cfctrl.c
@@ -351,17 +351,154 @@ int cfctrl_cancel_req(struct cflayer *layr, struct cflayer *adap_layer)
return found;
}
+static int cfctrl_link_setup(struct cfctrl *cfctrl, struct cfpkt *pkt, u8 cmdrsp)
+{
+ u8 len;
+ u8 linkid = 0;
+ enum cfctrl_srv serv;
+ enum cfctrl_srv servtype;
+ u8 endpoint;
+ u8 physlinkid;
+ u8 prio;
+ u8 tmp;
+ u8 *cp;
+ int i;
+ struct cfctrl_link_param linkparam;
+ struct cfctrl_request_info rsp, *req;
+
+ memset(&linkparam, 0, sizeof(linkparam));
+
+ tmp = cfpkt_extr_head_u8(pkt);
+
+ serv = tmp & CFCTRL_SRV_MASK;
+ linkparam.linktype = serv;
+
+ servtype = tmp >> 4;
+ linkparam.chtype = servtype;
+
+ tmp = cfpkt_extr_head_u8(pkt);
+ physlinkid = tmp & 0x07;
+ prio = tmp >> 3;
+
+ linkparam.priority = prio;
+ linkparam.phyid = physlinkid;
+ endpoint = cfpkt_extr_head_u8(pkt);
+ linkparam.endpoint = endpoint & 0x03;
+
+ switch (serv) {
+ case CFCTRL_SRV_VEI:
+ case CFCTRL_SRV_DBG:
+ if (CFCTRL_ERR_BIT & cmdrsp)
+ break;
+ /* Link ID */
+ linkid = cfpkt_extr_head_u8(pkt);
+ break;
+ case CFCTRL_SRV_VIDEO:
+ tmp = cfpkt_extr_head_u8(pkt);
+ linkparam.u.video.connid = tmp;
+ if (CFCTRL_ERR_BIT & cmdrsp)
+ break;
+ /* Link ID */
+ linkid = cfpkt_extr_head_u8(pkt);
+ break;
+
+ case CFCTRL_SRV_DATAGRAM:
+ linkparam.u.datagram.connid = cfpkt_extr_head_u32(pkt);
+ if (CFCTRL_ERR_BIT & cmdrsp)
+ break;
+ /* Link ID */
+ linkid = cfpkt_extr_head_u8(pkt);
+ break;
+ case CFCTRL_SRV_RFM:
+ /* Construct a frame, convert
+ * DatagramConnectionID
+ * to network format long and copy it out...
+ */
+ linkparam.u.rfm.connid = cfpkt_extr_head_u32(pkt);
+ cp = (u8 *) linkparam.u.rfm.volume;
+ for (tmp = cfpkt_extr_head_u8(pkt);
+ cfpkt_more(pkt) && tmp != '\0';
+ tmp = cfpkt_extr_head_u8(pkt))
+ *cp++ = tmp;
+ *cp = '\0';
+
+ if (CFCTRL_ERR_BIT & cmdrsp)
+ break;
+ /* Link ID */
+ linkid = cfpkt_extr_head_u8(pkt);
+
+ break;
+ case CFCTRL_SRV_UTIL:
+ /* Construct a frame, convert
+ * DatagramConnectionID
+ * to network format long and copy it out...
+ */
+ /* Fifosize KB */
+ linkparam.u.utility.fifosize_kb = cfpkt_extr_head_u16(pkt);
+ /* Fifosize bufs */
+ linkparam.u.utility.fifosize_bufs = cfpkt_extr_head_u16(pkt);
+ /* name */
+ cp = (u8 *) linkparam.u.utility.name;
+ caif_assert(sizeof(linkparam.u.utility.name)
+ >= UTILITY_NAME_LENGTH);
+ for (i = 0; i < UTILITY_NAME_LENGTH && cfpkt_more(pkt); i++) {
+ tmp = cfpkt_extr_head_u8(pkt);
+ *cp++ = tmp;
+ }
+ /* Length */
+ len = cfpkt_extr_head_u8(pkt);
+ linkparam.u.utility.paramlen = len;
+ /* Param Data */
+ cp = linkparam.u.utility.params;
+ while (cfpkt_more(pkt) && len--) {
+ tmp = cfpkt_extr_head_u8(pkt);
+ *cp++ = tmp;
+ }
+ if (CFCTRL_ERR_BIT & cmdrsp)
+ break;
+ /* Link ID */
+ linkid = cfpkt_extr_head_u8(pkt);
+ /* Length */
+ len = cfpkt_extr_head_u8(pkt);
+ /* Param Data */
+ cfpkt_extr_head(pkt, NULL, len);
+ break;
+ default:
+ pr_warn("Request setup, invalid type (%d)\n", serv);
+ return -1;
+ }
+
+ rsp.cmd = CFCTRL_CMD_LINK_SETUP;
+ rsp.param = linkparam;
+ spin_lock_bh(&cfctrl->info_list_lock);
+ req = cfctrl_remove_req(cfctrl, &rsp);
+
+ if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
+ cfpkt_erroneous(pkt)) {
+ pr_err("Invalid O/E bit or parse error "
+ "on CAIF control channel\n");
+ cfctrl->res.reject_rsp(cfctrl->serv.layer.up, 0,
+ req ? req->client_layer : NULL);
+ } else {
+ cfctrl->res.linksetup_rsp(cfctrl->serv.layer.up, linkid,
+ serv, physlinkid,
+ req ? req->client_layer : NULL);
+ }
+
+ kfree(req);
+
+ spin_unlock_bh(&cfctrl->info_list_lock);
+
+ return 0;
+}
+
static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
{
u8 cmdrsp;
u8 cmd;
- int ret = -1;
- u8 len;
- u8 param[255];
+ int ret = 0;
u8 linkid = 0;
struct cfctrl *cfctrl = container_obj(layer);
- struct cfctrl_request_info rsp, *req;
-
cmdrsp = cfpkt_extr_head_u8(pkt);
cmd = cmdrsp & CFCTRL_CMD_MASK;
@@ -374,150 +511,7 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
switch (cmd) {
case CFCTRL_CMD_LINK_SETUP:
- {
- enum cfctrl_srv serv;
- enum cfctrl_srv servtype;
- u8 endpoint;
- u8 physlinkid;
- u8 prio;
- u8 tmp;
- u8 *cp;
- int i;
- struct cfctrl_link_param linkparam;
- memset(&linkparam, 0, sizeof(linkparam));
-
- tmp = cfpkt_extr_head_u8(pkt);
-
- serv = tmp & CFCTRL_SRV_MASK;
- linkparam.linktype = serv;
-
- servtype = tmp >> 4;
- linkparam.chtype = servtype;
-
- tmp = cfpkt_extr_head_u8(pkt);
- physlinkid = tmp & 0x07;
- prio = tmp >> 3;
-
- linkparam.priority = prio;
- linkparam.phyid = physlinkid;
- endpoint = cfpkt_extr_head_u8(pkt);
- linkparam.endpoint = endpoint & 0x03;
-
- switch (serv) {
- case CFCTRL_SRV_VEI:
- case CFCTRL_SRV_DBG:
- if (CFCTRL_ERR_BIT & cmdrsp)
- break;
- /* Link ID */
- linkid = cfpkt_extr_head_u8(pkt);
- break;
- case CFCTRL_SRV_VIDEO:
- tmp = cfpkt_extr_head_u8(pkt);
- linkparam.u.video.connid = tmp;
- if (CFCTRL_ERR_BIT & cmdrsp)
- break;
- /* Link ID */
- linkid = cfpkt_extr_head_u8(pkt);
- break;
-
- case CFCTRL_SRV_DATAGRAM:
- linkparam.u.datagram.connid =
- cfpkt_extr_head_u32(pkt);
- if (CFCTRL_ERR_BIT & cmdrsp)
- break;
- /* Link ID */
- linkid = cfpkt_extr_head_u8(pkt);
- break;
- case CFCTRL_SRV_RFM:
- /* Construct a frame, convert
- * DatagramConnectionID
- * to network format long and copy it out...
- */
- linkparam.u.rfm.connid =
- cfpkt_extr_head_u32(pkt);
- cp = (u8 *) linkparam.u.rfm.volume;
- for (tmp = cfpkt_extr_head_u8(pkt);
- cfpkt_more(pkt) && tmp != '\0';
- tmp = cfpkt_extr_head_u8(pkt))
- *cp++ = tmp;
- *cp = '\0';
-
- if (CFCTRL_ERR_BIT & cmdrsp)
- break;
- /* Link ID */
- linkid = cfpkt_extr_head_u8(pkt);
-
- break;
- case CFCTRL_SRV_UTIL:
- /* Construct a frame, convert
- * DatagramConnectionID
- * to network format long and copy it out...
- */
- /* Fifosize KB */
- linkparam.u.utility.fifosize_kb =
- cfpkt_extr_head_u16(pkt);
- /* Fifosize bufs */
- linkparam.u.utility.fifosize_bufs =
- cfpkt_extr_head_u16(pkt);
- /* name */
- cp = (u8 *) linkparam.u.utility.name;
- caif_assert(sizeof(linkparam.u.utility.name)
- >= UTILITY_NAME_LENGTH);
- for (i = 0;
- i < UTILITY_NAME_LENGTH
- && cfpkt_more(pkt); i++) {
- tmp = cfpkt_extr_head_u8(pkt);
- *cp++ = tmp;
- }
- /* Length */
- len = cfpkt_extr_head_u8(pkt);
- linkparam.u.utility.paramlen = len;
- /* Param Data */
- cp = linkparam.u.utility.params;
- while (cfpkt_more(pkt) && len--) {
- tmp = cfpkt_extr_head_u8(pkt);
- *cp++ = tmp;
- }
- if (CFCTRL_ERR_BIT & cmdrsp)
- break;
- /* Link ID */
- linkid = cfpkt_extr_head_u8(pkt);
- /* Length */
- len = cfpkt_extr_head_u8(pkt);
- /* Param Data */
- cfpkt_extr_head(pkt, ¶m, len);
- break;
- default:
- pr_warn("Request setup, invalid type (%d)\n",
- serv);
- goto error;
- }
-
- rsp.cmd = cmd;
- rsp.param = linkparam;
- spin_lock_bh(&cfctrl->info_list_lock);
- req = cfctrl_remove_req(cfctrl, &rsp);
-
- if (CFCTRL_ERR_BIT == (CFCTRL_ERR_BIT & cmdrsp) ||
- cfpkt_erroneous(pkt)) {
- pr_err("Invalid O/E bit or parse error "
- "on CAIF control channel\n");
- cfctrl->res.reject_rsp(cfctrl->serv.layer.up,
- 0,
- req ? req->client_layer
- : NULL);
- } else {
- cfctrl->res.linksetup_rsp(cfctrl->serv.
- layer.up, linkid,
- serv, physlinkid,
- req ? req->
- client_layer : NULL);
- }
-
- kfree(req);
-
- spin_unlock_bh(&cfctrl->info_list_lock);
- }
+ ret = cfctrl_link_setup(cfctrl, pkt, cmdrsp);
break;
case CFCTRL_CMD_LINK_DESTROY:
linkid = cfpkt_extr_head_u8(pkt);
@@ -544,9 +538,9 @@ static int cfctrl_recv(struct cflayer *layer, struct cfpkt *pkt)
break;
default:
pr_err("Unrecognized Control Frame\n");
+ ret = -1;
goto error;
}
- ret = 0;
error:
cfpkt_destroy(pkt);
return ret;
--
2.39.5
Powered by blists - more mailing lists