This is a note to let you know that I've just added the patch titled
igc: Fix infinite loop in release_swfw_sync
to the 5.17-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
igc-fix-infinite-loop-in-release_swfw_sync.patch
and it can be found in the queue-5.17 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit a11d48f5df0f622620d3b68a1763529ebda3c1b6
Author: Sasha Neftin <sasha.neftin@xxxxxxxxx>
Date: Tue Mar 1 15:32:10 2022 +0200
igc: Fix infinite loop in release_swfw_sync
[ Upstream commit 907862e9aef75bf89e2b265efcc58870be06081e ]
An infinite loop may occur if we fail to acquire the HW semaphore,
which is needed for resource release.
This will typically happen if the hardware is surprise-removed.
At this stage there is nothing to do, except log an error and quit.
Fixes: c0071c7aa5fe ("igc: Add HW initialization code")
Suggested-by: Dima Ruinskiy <dima.ruinskiy@xxxxxxxxx>
Signed-off-by: Sasha Neftin <sasha.neftin@xxxxxxxxx>
Tested-by: Naama Meir <naamax.meir@xxxxxxxxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/intel/igc/igc_i225.c b/drivers/net/ethernet/intel/igc/igc_i225.c
index 66ea566488d1..59d5c467ea6e 100644
--- a/drivers/net/ethernet/intel/igc/igc_i225.c
+++ b/drivers/net/ethernet/intel/igc/igc_i225.c
@@ -156,8 +156,15 @@ void igc_release_swfw_sync_i225(struct igc_hw *hw, u16 mask)
{
u32 swfw_sync;
- while (igc_get_hw_semaphore_i225(hw))
- ; /* Empty */
+ /* Releasing the resource requires first getting the HW semaphore.
+ * If we fail to get the semaphore, there is nothing we can do,
+ * except log an error and quit. We are not allowed to hang here
+ * indefinitely, as it may cause denial of service or system crash.
+ */
+ if (igc_get_hw_semaphore_i225(hw)) {
+ hw_dbg("Failed to release SW_FW_SYNC.\n");
+ return;
+ }
swfw_sync = rd32(IGC_SW_FW_SYNC);
swfw_sync &= ~mask;
