• Jia-Ju Bai's avatar
    net: intel: e1000e: fix possible sleep-in-atomic-context bugs in e1000e_get_hw_semaphore() · 2e05f756
    Jia-Ju Bai authored
    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: default avatarJia-Ju Bai <baijiaju1990@gmail.com>
    Tested-by: default avatarAaron Brown <aaron.f.brown@intel.com>
    Signed-off-by: default avatarJeff Kirsher <jeffrey.t.kirsher@intel.com>
    2e05f756
mac.c 50.7 KB