net: intel: e1000e: fix possible sleep-in-atomic-context bugs in e1000e_get_hw_semaph...
authorJia-Ju Bai <baijiaju1990@gmail.com>
Wed, 18 Dec 2019 14:16:56 +0000 (22:16 +0800)
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>
Wed, 19 Feb 2020 23:25:59 +0000 (15:25 -0800)
commit2e05f756c7099c8991142382648a37b0d4c85943
tree6864292ee54a161474bee0a1c26f6c4d337f2e8b
parent99fe61b27774b5dcb06e77ab6a02ba26ebb1653c
net: intel: e1000e: fix possible sleep-in-atomic-context bugs in e1000e_get_hw_semaphore()

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@gmail.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
drivers/net/ethernet/intel/e1000e/mac.c