diff mbox series

[iwl-net,v2,4/6] ice: check ICE_VSI_DOWN under rtnl_lock when preparing for reset

Message ID 20240724164840.2536605-5-larysa.zaremba@intel.com (mailing list archive)
State Awaiting Upstream
Delegated to: Netdev Maintainers
Headers show
Series ice: fix synchronization between .ndo_bpf() and reset | expand

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Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 273 this patch: 273
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers fail 1 blamed authors not CCed: anirudh.venkataramanan@intel.com; 2 maintainers not CCed: przemyslaw.kitszel@intel.com anirudh.venkataramanan@intel.com
netdev/build_clang success Errors and warnings before: 281 this patch: 281
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 281 this patch: 281
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 29 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 74 this patch: 74
netdev/source_inline success Was 0 now: 0

Commit Message

Larysa Zaremba July 24, 2024, 4:48 p.m. UTC
Consider the following scenario:

.ndo_bpf()		| ice_prepare_for_reset()		|
________________________|_______________________________________|
rtnl_lock()		|					|
ice_down()		|					|
			| test_bit(ICE_VSI_DOWN) - true		|
			| ice_dis_vsi() returns			|
ice_up()		|					|
			| proceeds to rebuild a running VSI	|

.ndo_bpf() is not the only rtnl-locked callback that toggles the interface
to apply new configuration. Another example is .set_channels().

To avoid the race condition above, act only after reading ICE_VSI_DOWN
under rtnl_lock.

Fixes: 0f9d5027a749 ("ice: Refactor VSI allocation, deletion and rebuild flow")
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_lib.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

Comments

Jacob Keller July 24, 2024, 6:27 p.m. UTC | #1
On 7/24/2024 9:48 AM, Larysa Zaremba wrote:
> Consider the following scenario:
> 
> .ndo_bpf()		| ice_prepare_for_reset()		|
> ________________________|_______________________________________|
> rtnl_lock()		|					|
> ice_down()		|					|
> 			| test_bit(ICE_VSI_DOWN) - true		|
> 			| ice_dis_vsi() returns			|
> ice_up()		|					|
> 			| proceeds to rebuild a running VSI	|
> 
> .ndo_bpf() is not the only rtnl-locked callback that toggles the interface
> to apply new configuration. Another example is .set_channels().
> 
> To avoid the race condition above, act only after reading ICE_VSI_DOWN
> under rtnl_lock.
> 
> Fixes: 0f9d5027a749 ("ice: Refactor VSI allocation, deletion and rebuild flow")
> Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
> Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
> ---
>  drivers/net/ethernet/intel/ice/ice_lib.c | 12 ++++++------
>  1 file changed, 6 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
> index f9852f1a136e..b773078ad81a 100644
> --- a/drivers/net/ethernet/intel/ice/ice_lib.c
> +++ b/drivers/net/ethernet/intel/ice/ice_lib.c
> @@ -2665,8 +2665,7 @@ int ice_ena_vsi(struct ice_vsi *vsi, bool locked)
>   */
>  void ice_dis_vsi(struct ice_vsi *vsi, bool locked)
>  {
> -	if (test_bit(ICE_VSI_DOWN, vsi->state))
> -		return;
> +	bool already_down = test_bit(ICE_VSI_DOWN, vsi->state);
>  

Do we need to initialize already_down? I guess its because the other
initialization happens inside the conditional which may not be executed
in every flow. Ok.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>

>  	set_bit(ICE_VSI_NEEDS_RESTART, vsi->state);
>  
> @@ -2674,15 +2673,16 @@ void ice_dis_vsi(struct ice_vsi *vsi, bool locked)
>  		if (netif_running(vsi->netdev)) {
>  			if (!locked)
>  				rtnl_lock();
> -
> -			ice_vsi_close(vsi);
> +			already_down = test_bit(ICE_VSI_DOWN, vsi->state);
> +			if (!already_down)
> +				ice_vsi_close(vsi);
>  
>  			if (!locked)
>  				rtnl_unlock();
> -		} else {
> +		} else if (!already_down) {
>  			ice_vsi_close(vsi);
>  		}
> -	} else if (vsi->type == ICE_VSI_CTRL) {
> +	} else if (vsi->type == ICE_VSI_CTRL && !already_down) {
>  		ice_vsi_close(vsi);
>  	}
>  }
Rout, ChandanX Aug. 8, 2024, 2:15 a.m. UTC | #2
>-----Original Message-----
>From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
>Zaremba, Larysa
>Sent: Wednesday, July 24, 2024 10:19 PM
>To: intel-wired-lan@lists.osuosl.org
>Cc: Drewek, Wojciech <wojciech.drewek@intel.com>; Fijalkowski, Maciej
><maciej.fijalkowski@intel.com>; Jesper Dangaard Brouer <hawk@kernel.org>;
>Daniel Borkmann <daniel@iogearbox.net>; Zaremba, Larysa
><larysa.zaremba@intel.com>; netdev@vger.kernel.org; John Fastabend
><john.fastabend@gmail.com>; Alexei Starovoitov <ast@kernel.org>; linux-
>kernel@vger.kernel.org; Eric Dumazet <edumazet@google.com>; Kubiak,
>Michal <michal.kubiak@intel.com>; Nguyen, Anthony L
><anthony.l.nguyen@intel.com>; Nambiar, Amritha
><amritha.nambiar@intel.com>; Keller, Jacob E <jacob.e.keller@intel.com>;
>Jakub Kicinski <kuba@kernel.org>; bpf@vger.kernel.org; Paolo Abeni
><pabeni@redhat.com>; David S. Miller <davem@davemloft.net>; Karlsson,
>Magnus <magnus.karlsson@intel.com>
>Subject: [Intel-wired-lan] [PATCH iwl-net v2 4/6] ice: check ICE_VSI_DOWN
>under rtnl_lock when preparing for reset
>
>Consider the following scenario:
>
>.ndo_bpf()		| ice_prepare_for_reset()		|
>________________________|_______________________________________|
>rtnl_lock()		|					|
>ice_down()		|					|
>			| test_bit(ICE_VSI_DOWN) - true		|
>			| ice_dis_vsi() returns			|
>ice_up()		|					|
>			| proceeds to rebuild a running VSI	|
>
>.ndo_bpf() is not the only rtnl-locked callback that toggles the interface to apply
>new configuration. Another example is .set_channels().
>
>To avoid the race condition above, act only after reading ICE_VSI_DOWN under
>rtnl_lock.
>
>Fixes: 0f9d5027a749 ("ice: Refactor VSI allocation, deletion and rebuild flow")
>Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
>Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
>---
> drivers/net/ethernet/intel/ice/ice_lib.c | 12 ++++++------
> 1 file changed, 6 insertions(+), 6 deletions(-)
>

Tested-by: Chandan Kumar Rout <chandanx.rout@intel.com> (A Contingent Worker at Intel)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index f9852f1a136e..b773078ad81a 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -2665,8 +2665,7 @@  int ice_ena_vsi(struct ice_vsi *vsi, bool locked)
  */
 void ice_dis_vsi(struct ice_vsi *vsi, bool locked)
 {
-	if (test_bit(ICE_VSI_DOWN, vsi->state))
-		return;
+	bool already_down = test_bit(ICE_VSI_DOWN, vsi->state);
 
 	set_bit(ICE_VSI_NEEDS_RESTART, vsi->state);
 
@@ -2674,15 +2673,16 @@  void ice_dis_vsi(struct ice_vsi *vsi, bool locked)
 		if (netif_running(vsi->netdev)) {
 			if (!locked)
 				rtnl_lock();
-
-			ice_vsi_close(vsi);
+			already_down = test_bit(ICE_VSI_DOWN, vsi->state);
+			if (!already_down)
+				ice_vsi_close(vsi);
 
 			if (!locked)
 				rtnl_unlock();
-		} else {
+		} else if (!already_down) {
 			ice_vsi_close(vsi);
 		}
-	} else if (vsi->type == ICE_VSI_CTRL) {
+	} else if (vsi->type == ICE_VSI_CTRL && !already_down) {
 		ice_vsi_close(vsi);
 	}
 }