[Intel-wired-lan] [PATCH AUTOSEL 4.4 08/16] net: intel: e1000e: fix possible sleep-in-atomic-context bugs in e1000e_get_hw_semaphore()
Sasha Levin
sashal at kernel.org
Sat Apr 11 23:14:38 UTC 2020
From: Jia-Ju Bai <baijiaju1990 at gmail.com>
[ Upstream commit 2e05f756c7099c8991142382648a37b0d4c85943 ]
The driver may sleep while holding a spinlock.
The function call path (from bottom to top) in Linux 4.19 is:
drivers/net/ethernet/intel/e1000e/mac.c, 1366:
usleep_range in e1000e_get_hw_semaphore
drivers/net/ethernet/intel/e1000e/80003es2lan.c, 322:
e1000e_get_hw_semaphore in e1000_release_swfw_sync_80003es2lan
drivers/net/ethernet/intel/e1000e/80003es2lan.c, 197:
e1000_release_swfw_sync_80003es2lan in e1000_release_phy_80003es2lan
drivers/net/ethernet/intel/e1000e/netdev.c, 4883:
(FUNC_PTR) e1000_release_phy_80003es2lan in e1000e_update_phy_stats
drivers/net/ethernet/intel/e1000e/netdev.c, 4917:
e1000e_update_phy_stats in e1000e_update_stats
drivers/net/ethernet/intel/e1000e/netdev.c, 5945:
e1000e_update_stats in e1000e_get_stats64
drivers/net/ethernet/intel/e1000e/netdev.c, 5944:
spin_lock in e1000e_get_stats64
drivers/net/ethernet/intel/e1000e/mac.c, 1384:
usleep_range in e1000e_get_hw_semaphore
drivers/net/ethernet/intel/e1000e/80003es2lan.c, 322:
e1000e_get_hw_semaphore in e1000_release_swfw_sync_80003es2lan
drivers/net/ethernet/intel/e1000e/80003es2lan.c, 197:
e1000_release_swfw_sync_80003es2lan in e1000_release_phy_80003es2lan
drivers/net/ethernet/intel/e1000e/netdev.c, 4883:
(FUNC_PTR) e1000_release_phy_80003es2lan in e1000e_update_phy_stats
drivers/net/ethernet/intel/e1000e/netdev.c, 4917:
e1000e_update_phy_stats in e1000e_update_stats
drivers/net/ethernet/intel/e1000e/netdev.c, 5945:
e1000e_update_stats in e1000e_get_stats64
drivers/net/ethernet/intel/e1000e/netdev.c, 5944:
spin_lock in e1000e_get_stats64
(FUNC_PTR) means a function pointer is called.
To fix these bugs, usleep_range() is replaced with udelay().
These bugs are found by a static analysis tool STCheck written by myself.
Signed-off-by: Jia-Ju Bai <baijiaju1990 at gmail.com>
Tested-by: Aaron Brown <aaron.f.brown at intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher at intel.com>
Signed-off-by: Sasha Levin <sashal at kernel.org>
---
drivers/net/ethernet/intel/e1000e/mac.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/net/ethernet/intel/e1000e/mac.c b/drivers/net/ethernet/intel/e1000e/mac.c
index fe133f33a6c6a..e0b187dc37385 100644
--- a/drivers/net/ethernet/intel/e1000e/mac.c
+++ b/drivers/net/ethernet/intel/e1000e/mac.c
@@ -1386,7 +1386,7 @@ s32 e1000e_get_hw_semaphore(struct e1000_hw *hw)
if (!(swsm & E1000_SWSM_SMBI))
break;
- usleep_range(50, 100);
+ udelay(100);
i++;
}
@@ -1404,7 +1404,7 @@ s32 e1000e_get_hw_semaphore(struct e1000_hw *hw)
if (er32(SWSM) & E1000_SWSM_SWESMBI)
break;
- usleep_range(50, 100);
+ udelay(100);
}
if (i == timeout) {
--
2.20.1
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