[PATCH net v2] bnx2: fix locking when netconsole is used

[PATCH net v2] bnx2: fix locking when netconsole is used

[Ivan Vecera]

Functions bnx2_reg_rd_ind(), bnx2_reg_wr_ind() and bnx2_ctx_wr()
can be called with IRQs disabled when netconsole is enabled. So they
should use spin_{,un}lock_irq{save,restore} instead of _bh variants.

Example call flow:
bnx2_poll()
  ->bnx2_poll_link()
    ->bnx2_phy_int()
      ->bnx2_set_remote_link()
        ->bnx2_shmem_rd()
          ->bnx2_reg_rd_ind()
            -> spin_lock_bh(&bp->indirect_lock);
               spin_unlock_bh(&bp->indirect_lock);
               ...
               -> __local_bh_enable_ip

static inline void __local_bh_enable_ip(unsigned long ip)
      WARN_ON_ONCE(in_irq() || irqs_disabled());   <<<<<< WARN

Cc: Sony Chacko <sony.chacko@qlogic.com>
Cc: Dept-HSGLinuxNICDev@qlogic.com
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
---
 drivers/net/ethernet/broadcom/bnx2.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/net/ethernet/broadcom/bnx2.c b/drivers/net/ethernet/broadcom/bnx2.c
index 27f11a5..b3791b3 100644
--- a/drivers/net/ethernet/broadcom/bnx2.c
+++ b/drivers/net/ethernet/broadcom/bnx2.c
@@ -271,22 +271,25 @@ static inline u32 bnx2_tx_avail(struct bnx2 *bp, struct bnx2_tx_ring_info *txr)
 static u32
 bnx2_reg_rd_ind(struct bnx2 *bp, u32 offset)
 {
+	unsigned long flags;
 	u32 val;
 
-	spin_lock_bh(&bp->indirect_lock);
+	spin_lock_irqsave(&bp->indirect_lock, flags);
 	BNX2_WR(bp, BNX2_PCICFG_REG_WINDOW_ADDRESS, offset);
 	val = BNX2_RD(bp, BNX2_PCICFG_REG_WINDOW);
-	spin_unlock_bh(&bp->indirect_lock);
+	spin_unlock_irqrestore(&bp->indirect_lock, flags);
 	return val;
 }
 
 static void
 bnx2_reg_wr_ind(struct bnx2 *bp, u32 offset, u32 val)
 {
-	spin_lock_bh(&bp->indirect_lock);
+	unsigned long flags;
+
+	spin_lock_irqsave(&bp->indirect_lock, flags);
 	BNX2_WR(bp, BNX2_PCICFG_REG_WINDOW_ADDRESS, offset);
 	BNX2_WR(bp, BNX2_PCICFG_REG_WINDOW, val);
-	spin_unlock_bh(&bp->indirect_lock);
+	spin_unlock_irqrestore(&bp->indirect_lock, flags);
 }
 
 static void
@@ -304,8 +307,10 @@ bnx2_shmem_rd(struct bnx2 *bp, u32 offset)
 static void
 bnx2_ctx_wr(struct bnx2 *bp, u32 cid_addr, u32 offset, u32 val)
 {
+	unsigned long flags;
+
 	offset += cid_addr;
-	spin_lock_bh(&bp->indirect_lock);
+	spin_lock_irqsave(&bp->indirect_lock, flags);
 	if (BNX2_CHIP(bp) == BNX2_CHIP_5709) {
 		int i;
 
@@ -322,7 +327,7 @@ bnx2_ctx_wr(struct bnx2 *bp, u32 cid_addr, u32 offset, u32 val)
 		BNX2_WR(bp, BNX2_CTX_DATA_ADR, offset);
 		BNX2_WR(bp, BNX2_CTX_DATA, val);
 	}
-	spin_unlock_bh(&bp->indirect_lock);
+	spin_unlock_irqrestore(&bp->indirect_lock, flags);
 }
 
 #ifdef BCM_CNIC
-- 
2.7.3

Re: [PATCH net v2] bnx2: fix locking when netconsole is used

[David Miller]

From: Ivan Vecera <ivecera@redhat.com>
Date: Tue, 18 Oct 2016 08:16:03 +0200

> Functions bnx2_reg_rd_ind(), bnx2_reg_wr_ind() and bnx2_ctx_wr()
> can be called with IRQs disabled when netconsole is enabled. So they
> should use spin_{,un}lock_irq{save,restore} instead of _bh variants.
> 
> Example call flow:
> bnx2_poll()
>   ->bnx2_poll_link()
>     ->bnx2_phy_int()
>       ->bnx2_set_remote_link()
>         ->bnx2_shmem_rd()
>           ->bnx2_reg_rd_ind()
>             -> spin_lock_bh(&bp->indirect_lock);
>                spin_unlock_bh(&bp->indirect_lock);
>                ...
>                -> __local_bh_enable_ip
> 
> static inline void __local_bh_enable_ip(unsigned long ip)
>       WARN_ON_ONCE(in_irq() || irqs_disabled());   <<<<<< WARN
> 
> Cc: Sony Chacko <sony.chacko@qlogic.com>
> Cc: Dept-HSGLinuxNICDev@qlogic.com
> Signed-off-by: Ivan Vecera <ivecera@redhat.com>

Applied, thanks Ivan.