From: Jia-Ju Bai baijiaju1990@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@gmail.com Tested-by: Aaron Brown aaron.f.brown@intel.com Signed-off-by: Jeff Kirsher jeffrey.t.kirsher@intel.com Signed-off-by: Sasha Levin sashal@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) {