Commit 69a4e06c authored by Paulo Alcantara's avatar Paulo Alcantara Committed by Steve French
Browse files

smb: client: reduce stack usage in cifs_try_adding_channels() 



Clang warns about exceeded stack frame size

  fs/smb/client/sess.c:160:5: warning: stack frame size (1368) exceeds
  limit (1024) in 'cifs_try_adding_channels' [-Wframe-larger-than]

It turns out that cifs_ses_add_channel() got inlined into
cifs_try_adding_channels() which had a stack-allocated variable @ctx
of 624 bytes in size.  Fix this by making it heap-allocated.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307270640.5ODmPwDl-lkp@intel.com/


Signed-off-by: default avatarPaulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent a18280e7

fs/smb/client/sess.c

+41 −27
Original line number Diff line number Diff line
@@ -360,11 +360,11 @@ cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses, 
{

	struct TCP_Server_Info *chan_server;

	struct cifs_chan *chan;

	struct smb3_fs_context ctx = {NULL};

	struct smb3_fs_context *ctx;

	static const char unc_fmt[] = "\\%s\\foo";

	char unc[sizeof(unc_fmt)+SERVER_NAME_LEN_WITH_NULL] = {0};

	struct sockaddr_in *ipv4 = (struct sockaddr_in *)&iface->sockaddr;

	struct sockaddr_in6 *ipv6 = (struct sockaddr_in6 *)&iface->sockaddr;

	size_t len;

	int rc;

	unsigned int xid = get_xid();
@@ -388,54 +388,64 @@ cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses, 
	 * the session and server without caring about memory

	 * management.

	 */

	ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);

	if (!ctx) {

		rc = -ENOMEM;

		goto out_free_xid;

	}



	/* Always make new connection for now (TODO?) */

	ctx.nosharesock = true;

	ctx->nosharesock = true;



	/* Auth */

	ctx.domainauto = ses->domainAuto;

	ctx.domainname = ses->domainName;

	ctx->domainauto = ses->domainAuto;

	ctx->domainname = ses->domainName;



	/* no hostname for extra channels */

	ctx.server_hostname = "";

	ctx->server_hostname = "";



	ctx.username = ses->user_name;

	ctx.password = ses->password;

	ctx.sectype = ses->sectype;

	ctx.sign = ses->sign;

	ctx->username = ses->user_name;

	ctx->password = ses->password;

	ctx->sectype = ses->sectype;

	ctx->sign = ses->sign;



	/* UNC and paths */

	/* XXX: Use ses->server->hostname? */

	sprintf(unc, unc_fmt, ses->ip_addr);

	ctx.UNC = unc;

	ctx.prepath = "";

	len = sizeof(unc_fmt) + SERVER_NAME_LEN_WITH_NULL;

	ctx->UNC = kzalloc(len, GFP_KERNEL);

	if (!ctx->UNC) {

		rc = -ENOMEM;

		goto out_free_ctx;

	}

	scnprintf(ctx->UNC, len, unc_fmt, ses->ip_addr);

	ctx->prepath = "";



	/* Reuse same version as master connection */

	ctx.vals = ses->server->vals;

	ctx.ops = ses->server->ops;

	ctx->vals = ses->server->vals;

	ctx->ops = ses->server->ops;



	ctx.noblocksnd = ses->server->noblocksnd;

	ctx.noautotune = ses->server->noautotune;

	ctx.sockopt_tcp_nodelay = ses->server->tcp_nodelay;

	ctx.echo_interval = ses->server->echo_interval / HZ;

	ctx.max_credits = ses->server->max_credits;

	ctx->noblocksnd = ses->server->noblocksnd;

	ctx->noautotune = ses->server->noautotune;

	ctx->sockopt_tcp_nodelay = ses->server->tcp_nodelay;

	ctx->echo_interval = ses->server->echo_interval / HZ;

	ctx->max_credits = ses->server->max_credits;



	/*

	 * This will be used for encoding/decoding user/domain/pw

	 * during sess setup auth.

	 */

	ctx.local_nls = cifs_sb->local_nls;

	ctx->local_nls = cifs_sb->local_nls;



	/* Use RDMA if possible */

	ctx.rdma = iface->rdma_capable;

	memcpy(&ctx.dstaddr, &iface->sockaddr, sizeof(struct sockaddr_storage));

	ctx->rdma = iface->rdma_capable;

	memcpy(&ctx->dstaddr, &iface->sockaddr, sizeof(ctx->dstaddr));



	/* reuse master con client guid */

	memcpy(&ctx.client_guid, ses->server->client_guid,

	       SMB2_CLIENT_GUID_SIZE);

	ctx.use_client_guid = true;

	memcpy(&ctx->client_guid, ses->server->client_guid,

	       sizeof(ctx->client_guid));

	ctx->use_client_guid = true;



	chan_server = cifs_get_tcp_session(&ctx, ses->server);

	chan_server = cifs_get_tcp_session(ctx, ses->server);



	spin_lock(&ses->chan_lock);

	chan = &ses->chans[ses->chan_count];
@@ -497,6 +507,10 @@ cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses, 
		cifs_put_tcp_session(chan->server, 0);

	}



	kfree(ctx->UNC);

out_free_ctx:

	kfree(ctx);

out_free_xid:

	free_xid(xid);

	return rc;

}