net/smc: dynamic allocation of CLC proposal buffer

Reduce stack size for smc_listen_work() and smc_clc_send_proposal()
by dynamic allocation of the CLC buffer to be received or sent.

Signed-off-by: Ursula Braun <ubraun@linux.ibm.com>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c
index 8f6472f..00e2a4c 100644 (file)
--- a/net/smc/af_smc.c
+++ b/net/smc/af_smc.c
@@ -1276,10 +1276,10 @@ static void smc_listen_work(struct work_struct *work)
                                                smc_listen_work);
        struct socket *newclcsock = new_smc->clcsock;
        struct smc_clc_msg_accept_confirm cclc;
+       struct smc_clc_msg_proposal_area *buf;
        struct smc_clc_msg_proposal *pclc;
        struct smc_init_info ini = {0};
        bool ism_supported = false;
-       u8 buf[SMC_CLC_MAX_LEN];
        int rc = 0;
 
        if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
@@ -1301,8 +1301,13 @@ static void smc_listen_work(struct work_struct *work)
        /* do inband token exchange -
         * wait for and receive SMC Proposal CLC message
         */
-       pclc = (struct smc_clc_msg_proposal *)&buf;
-       rc = smc_clc_wait_msg(new_smc, pclc, SMC_CLC_MAX_LEN,
+       buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+       if (!buf) {
+               rc = SMC_CLC_DECL_MEM;
+               goto out_decl;
+       }
+       pclc = (struct smc_clc_msg_proposal *)buf;
+       rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
                              SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
        if (rc)
                goto out_decl;
@@ -1382,6 +1387,7 @@ static void smc_listen_work(struct work_struct *work)
        }
 
        /* finish worker */
+       kfree(buf);
        if (!ism_supported) {
                rc = smc_listen_rdma_finish(new_smc, &cclc,
                                            ini.first_contact_local);
@@ -1397,6 +1403,7 @@ out_unlock:
        mutex_unlock(&smc_server_lgr_pending);
 out_decl:
        smc_listen_decline(new_smc, rc, ini.first_contact_local);
+       kfree(buf);
 }
 
 static void smc_tcp_listen_work(struct work_struct *work)

diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c
index c30fad1..0c8e74f 100644 (file)
--- a/net/smc/smc_clc.c
+++ b/net/smc/smc_clc.c
@@ -153,7 +153,6 @@ static int smc_clc_prfx_set(struct socket *clcsock,
        struct sockaddr_in *addr;
        int rc = -ENOENT;
 
-       memset(prop, 0, sizeof(*prop));
        if (!dst) {
                rc = -ENOTCONN;
                goto out;
@@ -412,76 +411,89 @@ int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info)
 int smc_clc_send_proposal(struct smc_sock *smc, int smc_type,
                          struct smc_init_info *ini)
 {
-       struct smc_clc_ipv6_prefix ipv6_prfx[SMC_CLC_MAX_V6_PREFIX];
-       struct smc_clc_msg_proposal_prefix pclc_prfx;
-       struct smc_clc_msg_smcd pclc_smcd;
-       struct smc_clc_msg_proposal pclc;
-       struct smc_clc_msg_trail trl;
+       struct smc_clc_msg_proposal_prefix *pclc_prfx;
+       struct smc_clc_msg_proposal *pclc_base;
+       struct smc_clc_msg_proposal_area *pclc;
+       struct smc_clc_ipv6_prefix *ipv6_prfx;
+       struct smc_clc_msg_smcd *pclc_smcd;
+       struct smc_clc_msg_trail *trl;
        int len, i, plen, rc;
        int reason_code = 0;
        struct kvec vec[5];
        struct msghdr msg;
 
+       pclc = kzalloc(sizeof(*pclc), GFP_KERNEL);
+       if (!pclc)
+               return -ENOMEM;
+
+       pclc_base = &pclc->pclc_base;
+       pclc_smcd = &pclc->pclc_smcd;
+       pclc_prfx = &pclc->pclc_prfx;
+       ipv6_prfx = pclc->pclc_prfx_ipv6;
+       trl = &pclc->pclc_trl;
+
        /* retrieve ip prefixes for CLC proposal msg */
-       rc = smc_clc_prfx_set(smc->clcsock, &pclc_prfx, ipv6_prfx);
-       if (rc)
+       rc = smc_clc_prfx_set(smc->clcsock, pclc_prfx, ipv6_prfx);
+       if (rc) {
+               kfree(pclc);
                return SMC_CLC_DECL_CNFERR; /* configuration error */
+       }
 
        /* send SMC Proposal CLC message */
-       plen = sizeof(pclc) + sizeof(pclc_prfx) +
-              (pclc_prfx.ipv6_prefixes_cnt * sizeof(ipv6_prfx[0])) +
-              sizeof(trl);
-       memset(&pclc, 0, sizeof(pclc));
-       memcpy(pclc.hdr.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
-       pclc.hdr.type = SMC_CLC_PROPOSAL;
-       pclc.hdr.version = SMC_V1;              /* SMC version */
-       pclc.hdr.path = smc_type;
+       plen = sizeof(*pclc_base) + sizeof(*pclc_prfx) +
+              (pclc_prfx->ipv6_prefixes_cnt * sizeof(ipv6_prfx[0])) +
+              sizeof(*trl);
+       memcpy(pclc_base->hdr.eyecatcher, SMC_EYECATCHER,
+              sizeof(SMC_EYECATCHER));
+       pclc_base->hdr.type = SMC_CLC_PROPOSAL;
+       pclc_base->hdr.version = SMC_V1;                /* SMC version */
+       pclc_base->hdr.path = smc_type;
        if (smc_type == SMC_TYPE_R || smc_type == SMC_TYPE_B) {
                /* add SMC-R specifics */
-               memcpy(pclc.lcl.id_for_peer, local_systemid,
+               memcpy(pclc_base->lcl.id_for_peer, local_systemid,
                       sizeof(local_systemid));
-               memcpy(&pclc.lcl.gid, ini->ib_gid, SMC_GID_SIZE);
-               memcpy(&pclc.lcl.mac, &ini->ib_dev->mac[ini->ib_port - 1],
+               memcpy(pclc_base->lcl.gid, ini->ib_gid, SMC_GID_SIZE);
+               memcpy(pclc_base->lcl.mac, &ini->ib_dev->mac[ini->ib_port - 1],
                       ETH_ALEN);
-               pclc.iparea_offset = htons(0);
+               pclc_base->iparea_offset = htons(0);
        }
        if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
                /* add SMC-D specifics */
-               memset(&pclc_smcd, 0, sizeof(pclc_smcd));
-               plen += sizeof(pclc_smcd);
-               pclc.iparea_offset = htons(SMC_CLC_PROPOSAL_MAX_OFFSET);
-               pclc_smcd.gid = ini->ism_dev->local_gid;
+               plen += sizeof(*pclc_smcd);
+               pclc_base->iparea_offset = htons(sizeof(*pclc_smcd));
+               pclc_smcd->gid = ini->ism_dev->local_gid;
        }
-       pclc.hdr.length = htons(plen);
+       pclc_base->hdr.length = htons(plen);
 
-       memcpy(trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
+       memcpy(trl->eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));
        memset(&msg, 0, sizeof(msg));
        i = 0;
-       vec[i].iov_base = &pclc;
-       vec[i++].iov_len = sizeof(pclc);
+       vec[i].iov_base = pclc_base;
+       vec[i++].iov_len = sizeof(*pclc_base);
        if (smc_type == SMC_TYPE_D || smc_type == SMC_TYPE_B) {
-               vec[i].iov_base = &pclc_smcd;
-               vec[i++].iov_len = sizeof(pclc_smcd);
+               vec[i].iov_base = pclc_smcd;
+               vec[i++].iov_len = sizeof(*pclc_smcd);
        }
-       vec[i].iov_base = &pclc_prfx;
-       vec[i++].iov_len = sizeof(pclc_prfx);
-       if (pclc_prfx.ipv6_prefixes_cnt > 0) {
-               vec[i].iov_base = &ipv6_prfx[0];
-               vec[i++].iov_len = pclc_prfx.ipv6_prefixes_cnt *
+       vec[i].iov_base = pclc_prfx;
+       vec[i++].iov_len = sizeof(*pclc_prfx);
+       if (pclc_prfx->ipv6_prefixes_cnt > 0) {
+               vec[i].iov_base = ipv6_prfx;
+               vec[i++].iov_len = pclc_prfx->ipv6_prefixes_cnt *
                                   sizeof(ipv6_prfx[0]);
        }
-       vec[i].iov_base = &trl;
-       vec[i++].iov_len = sizeof(trl);
+       vec[i].iov_base = trl;
+       vec[i++].iov_len = sizeof(*trl);
        /* due to the few bytes needed for clc-handshake this cannot block */
        len = kernel_sendmsg(smc->clcsock, &msg, vec, i, plen);
        if (len < 0) {
                smc->sk.sk_err = smc->clcsock->sk->sk_err;
                reason_code = -smc->sk.sk_err;
-       } else if (len < (int)sizeof(pclc)) {
+       } else if (len < ntohs(pclc_base->hdr.length)) {
                reason_code = -ENETUNREACH;
                smc->sk.sk_err = -reason_code;
        }
 
+       kfree(pclc);
        return reason_code;
 }
 

diff --git a/net/smc/smc_clc.h b/net/smc/smc_clc.h
index f98ca84..7f7c55f 100644 (file)
--- a/net/smc/smc_clc.h
+++ b/net/smc/smc_clc.h
@@ -110,14 +110,13 @@ struct smc_clc_msg_proposal {     /* clc proposal message sent by Linux */
        __be16 iparea_offset;   /* offset to IP address information area */
 } __aligned(4);
 
-#define SMC_CLC_PROPOSAL_MAX_OFFSET    0x28
-#define SMC_CLC_PROPOSAL_MAX_PREFIX    (SMC_CLC_MAX_V6_PREFIX * \
-                                        sizeof(struct smc_clc_ipv6_prefix))
-#define SMC_CLC_MAX_LEN                (sizeof(struct smc_clc_msg_proposal) + \
-                                SMC_CLC_PROPOSAL_MAX_OFFSET + \
-                                sizeof(struct smc_clc_msg_proposal_prefix) + \
-                                SMC_CLC_PROPOSAL_MAX_PREFIX + \
-                                sizeof(struct smc_clc_msg_trail))
+struct smc_clc_msg_proposal_area {
+       struct smc_clc_msg_proposal             pclc_base;
+       struct smc_clc_msg_smcd                 pclc_smcd;
+       struct smc_clc_msg_proposal_prefix      pclc_prfx;
+       struct smc_clc_ipv6_prefix      pclc_prfx_ipv6[SMC_CLC_MAX_V6_PREFIX];
+       struct smc_clc_msg_trail                pclc_trl;
+};
 
 struct smc_clc_msg_accept_confirm {    /* clc accept / confirm message */
        struct smc_clc_msg_hdr hdr;