From c1924684369762b112428a333ad00eac6ca89d96 Mon Sep 17 00:00:00 2001 From: Horatiu Vultur Date: Thu, 14 Jul 2022 21:40:39 +0200 Subject: [PATCH] net: lan966x: Fix usage of lan966x->mac_lock inside lan966x_mac_irq_handler The problem with this spin lock is that it was just protecting the list of the MAC entries in SW and not also the access to the MAC entries in HW. Because the access to HW is indirect, then it could happen to have race conditions. For example when SW introduced an entry in MAC table and the irq mac is trying to read something from the MAC. Update such that also the access to MAC entries in HW is protected by this lock. Fixes: 5ccd66e01cbef ("net: lan966x: add support for interrupts from analyzer") Signed-off-by: Horatiu Vultur Reviewed-by: Vladimir Oltean Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/microchip/lan966x/lan966x_mac.c | 19 ++++++++++++------- 1 file changed, 12 insertions(+), 7 deletions(-) diff --git a/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c b/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c index d0b8eba..69e343b 100644 --- a/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c +++ b/drivers/net/ethernet/microchip/lan966x/lan966x_mac.c @@ -183,7 +183,7 @@ static struct lan966x_mac_entry *lan966x_mac_alloc_entry(const unsigned char *ma { struct lan966x_mac_entry *mac_entry; - mac_entry = kzalloc(sizeof(*mac_entry), GFP_KERNEL); + mac_entry = kzalloc(sizeof(*mac_entry), GFP_ATOMIC); if (!mac_entry) return NULL; @@ -310,8 +310,8 @@ void lan966x_mac_purge_entries(struct lan966x *lan966x) spin_lock(&lan966x->mac_lock); list_for_each_entry_safe(mac_entry, tmp, &lan966x->mac_entries, list) { - lan966x_mac_forget(lan966x, mac_entry->mac, mac_entry->vid, - ENTRYTYPE_LOCKED); + lan966x_mac_forget_locked(lan966x, mac_entry->mac, + mac_entry->vid, ENTRYTYPE_LOCKED); list_del(&mac_entry->list); kfree(mac_entry); @@ -427,13 +427,14 @@ static void lan966x_mac_irq_process(struct lan966x *lan966x, u32 row, if (WARN_ON(dest_idx >= lan966x->num_phys_ports)) continue; + spin_lock(&lan966x->mac_lock); mac_entry = lan966x_mac_alloc_entry(mac, vid, dest_idx); - if (!mac_entry) + if (!mac_entry) { + spin_unlock(&lan966x->mac_lock); return; + } mac_entry->row = row; - - spin_lock(&lan966x->mac_lock); list_add_tail(&mac_entry->list, &lan966x->mac_entries); spin_unlock(&lan966x->mac_lock); @@ -455,6 +456,7 @@ irqreturn_t lan966x_mac_irq_handler(struct lan966x *lan966x) lan966x, ANA_MACTINDX); while (1) { + spin_lock(&lan966x->mac_lock); lan_rmw(ANA_MACACCESS_MAC_TABLE_CMD_SET(MACACCESS_CMD_SYNC_GET_NEXT), ANA_MACACCESS_MAC_TABLE_CMD, lan966x, ANA_MACACCESS); @@ -478,12 +480,15 @@ irqreturn_t lan966x_mac_irq_handler(struct lan966x *lan966x) stop = false; if (column == LAN966X_MAC_COLUMNS - 1 && - index == 0 && stop) + index == 0 && stop) { + spin_unlock(&lan966x->mac_lock); break; + } entry[column].mach = lan_rd(lan966x, ANA_MACHDATA); entry[column].macl = lan_rd(lan966x, ANA_MACLDATA); entry[column].maca = lan_rd(lan966x, ANA_MACACCESS); + spin_unlock(&lan966x->mac_lock); /* Once all the columns are read process them */ if (column == LAN966X_MAC_COLUMNS - 1) { -- 2.7.4