lkml.org 
[lkml]   [2017]   [Nov]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 4.9 073/138] igbvf: Use smp_rmb rather than read_barrier_depends
Date
4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Brian King <brking@linux.vnet.ibm.com>

commit 1e1f9ca546556e508d021545861f6b5fc75a95fe upstream.

The original issue being fixed in this patch was seen with the ixgbe
driver, but the same issue exists with igbvf as well, as the code is
very similar. read_barrier_depends is not sufficient to ensure
loads following it are not speculatively loaded out of order
by the CPU, which can result in stale data being loaded, causing
potential system crashes.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Acked-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/net/ethernet/intel/igbvf/netdev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/net/ethernet/intel/igbvf/netdev.c
+++ b/drivers/net/ethernet/intel/igbvf/netdev.c
@@ -810,7 +810,7 @@ static bool igbvf_clean_tx_irq(struct ig
break;

/* prevent any other reads prior to eop_desc */
- read_barrier_depends();
+ smp_rmb();

/* if DD is not set pending work has not been completed */
if (!(eop_desc->wb.status & cpu_to_le32(E1000_TXD_STAT_DD)))

\
 
 \ /
  Last update: 2017-11-28 11:37    [W:0.334 / U:5.168 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site