From 876aa9f527cd0ddc857337aba3683298b3abe6ab Mon Sep 17 00:00:00 2001
From: Ayush Sawal <ayush.sawal@chelsio.com>
Date: Mon, 30 Mar 2020 20:48:53 +0530
Subject: [PATCH] Crypto: chelsio - Fixes a deadlock between rtnl_lock and uld_mutex
Git-commit: 876aa9f527cd0ddc857337aba3683298b3abe6ab
Patch-mainline: v5.7-rc1
References: bsc#1111666

The locks are taken in this order during driver registration
(uld_mutex), at: cxgb4_register_uld.part.14+0x49/0xd60 [cxgb4]
(rtnl_mutex), at: rtnetlink_rcv_msg+0x2db/0x400
(uld_mutex), at: cxgb_up+0x3a/0x7b0 [cxgb4]
(rtnl_mutex), at: chcr_add_xfrmops+0x83/0xa0 [chcr](stucked here)

To avoid this now the netdev features are updated after the
cxgb4_register_uld function is completed.

Fixes: 6dad4e8ab3ec6 ("chcr: Add support for Inline IPSec").

Signed-off-by: Ayush Sawal <ayush.sawal@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/crypto/chelsio/chcr_core.c  |   32 ++++++++++++++++++++++++++++----
 drivers/crypto/chelsio/chcr_ipsec.c |    2 --
 2 files changed, 28 insertions(+), 6 deletions(-)

--- a/drivers/crypto/chelsio/chcr_core.c
+++ b/drivers/crypto/chelsio/chcr_core.c
@@ -33,6 +33,10 @@ static int cpl_fw6_pld_handler(struct ch
 static void *chcr_uld_add(const struct cxgb4_lld_info *lld);
 static int chcr_uld_state_change(void *handle, enum cxgb4_state state);
 
+#ifdef CONFIG_CHELSIO_IPSEC_INLINE
+static void update_netdev_features(void);
+#endif /* CONFIG_CHELSIO_IPSEC_INLINE */
+
 static chcr_handler_func work_handlers[NUM_CPL_CMDS] = {
 	[CPL_FW6_PLD] = cpl_fw6_pld_handler,
 };
@@ -203,10 +207,6 @@ static void *chcr_uld_add(const struct c
 	}
 	u_ctx->lldi = *lld;
 	chcr_dev_init(u_ctx);
-#ifdef CONFIG_CHELSIO_IPSEC_INLINE
-	if (lld->crypto & ULP_CRYPTO_IPSEC_INLINE)
-		chcr_add_xfrmops(lld);
-#endif /* CONFIG_CHELSIO_IPSEC_INLINE */
 out:
 	return u_ctx;
 }
@@ -282,6 +282,24 @@ static int chcr_uld_state_change(void *h
 	return ret;
 }
 
+#ifdef CONFIG_CHELSIO_IPSEC_INLINE
+static void update_netdev_features(void)
+{
+	struct uld_ctx *u_ctx, *tmp;
+
+	mutex_lock(&drv_data.drv_mutex);
+	list_for_each_entry_safe(u_ctx, tmp, &drv_data.inact_dev, entry) {
+		if (u_ctx->lldi.crypto & ULP_CRYPTO_IPSEC_INLINE)
+			chcr_add_xfrmops(&u_ctx->lldi);
+	}
+	list_for_each_entry_safe(u_ctx, tmp, &drv_data.act_dev, entry) {
+		if (u_ctx->lldi.crypto & ULP_CRYPTO_IPSEC_INLINE)
+			chcr_add_xfrmops(&u_ctx->lldi);
+	}
+	mutex_unlock(&drv_data.drv_mutex);
+}
+#endif /* CONFIG_CHELSIO_IPSEC_INLINE */
+
 static int __init chcr_crypto_init(void)
 {
 	INIT_LIST_HEAD(&drv_data.act_dev);
@@ -291,6 +309,12 @@ static int __init chcr_crypto_init(void)
 	drv_data.last_dev = NULL;
 	cxgb4_register_uld(CXGB4_ULD_CRYPTO, &chcr_uld_info);
 
+	#ifdef CONFIG_CHELSIO_IPSEC_INLINE
+	rtnl_lock();
+	update_netdev_features();
+	rtnl_unlock();
+	#endif /* CONFIG_CHELSIO_IPSEC_INLINE */
+
 	return 0;
 }
 
--- a/drivers/crypto/chelsio/chcr_ipsec.c
+++ b/drivers/crypto/chelsio/chcr_ipsec.c
@@ -99,9 +99,7 @@ void chcr_add_xfrmops(const struct cxgb4
 		netdev->xfrmdev_ops = &chcr_xfrmdev_ops;
 		netdev->hw_enc_features |= NETIF_F_HW_ESP;
 		netdev->features |= NETIF_F_HW_ESP;
-		rtnl_lock();
 		netdev_change_features(netdev);
-		rtnl_unlock();
 	}
 }