patch 'net/e1000/base: fix MAC address hash bit shift' has been queued to stable release 23.11.4

[Xueming Li]

Hi,

FYI, your patch has been queued to stable release 23.11.4

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
Please shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://git.dpdk.org/dpdk-stable/log/?h=23.11-staging

This queued commit can be viewed at:
https://git.dpdk.org/dpdk-stable/commit/?h=23.11-staging&id=5b1825dc24c291cd19f94bcb92c7947c5cc11e54

Thanks.

Xueming Li <xuemingl at nvidia.com>

---
>From 5b1825dc24c291cd19f94bcb92c7947c5cc11e54 Mon Sep 17 00:00:00 2001
From: Aleksandr Loktionov <aleksandr.loktionov at intel.com>
Date: Thu, 6 Feb 2025 16:08:40 +0000
Subject: [PATCH] net/e1000/base: fix MAC address hash bit shift
Cc: Xueming Li <xuemingl at nvidia.com>

[ upstream commit 1749e662f68ba6571ed81cd264cffd1107abc307 ]

In e1000_hash_mc_addr_generic() the expression:

"mc_addr[4] >> 8 - bit_shift", right shifting "mc_addr[4]"

shift by more than 7 bits always yields zero, so hash becomes not so
different. Add initialization with bit_shift = 1, and add a loop
condition to ensure bit_shift will be always in [1..8] range.

Fixes: af75078fece3 ("first public release")

Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov at intel.com>
Signed-off-by: Anatoly Burakov <anatoly.burakov at intel.com>
Acked-by: Bruce Richardson <bruce.richardson at intel.com>
---
 drivers/net/e1000/base/e1000_mac.c | 4 ++--
 drivers/net/e1000/base/e1000_vf.c  | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/e1000/base/e1000_mac.c b/drivers/net/e1000/base/e1000_mac.c
index cf0a9f21e1..2b8482e114 100644
--- a/drivers/net/e1000/base/e1000_mac.c
+++ b/drivers/net/e1000/base/e1000_mac.c
@@ -488,7 +488,7 @@ int e1000_rar_set_generic(struct e1000_hw *hw, u8 *addr, u32 index)
 u32 e1000_hash_mc_addr_generic(struct e1000_hw *hw, u8 *mc_addr)
 {
 	u32 hash_value, hash_mask;
-	u8 bit_shift = 0;
+	u8 bit_shift = 1;

 	DEBUGFUNC("e1000_hash_mc_addr_generic");

@@ -498,7 +498,7 @@ u32 e1000_hash_mc_addr_generic(struct e1000_hw *hw, u8 *mc_addr)
 	/* For a mc_filter_type of 0, bit_shift is the number of left-shifts
 	 * where 0xFF would still fall within the hash mask.
 	 */
-	while (hash_mask >> bit_shift != 0xFF)
+	while (hash_mask >> bit_shift != 0xFF && bit_shift < 4)
 		bit_shift++;

 	/* The portion of the address that is used for the hash table
diff --git a/drivers/net/e1000/base/e1000_vf.c b/drivers/net/e1000/base/e1000_vf.c
index 44ebe07ee4..3d0383fcbb 100644
--- a/drivers/net/e1000/base/e1000_vf.c
+++ b/drivers/net/e1000/base/e1000_vf.c
@@ -331,7 +331,7 @@ STATIC int e1000_rar_set_vf(struct e1000_hw *hw, u8 *addr,
 STATIC u32 e1000_hash_mc_addr_vf(struct e1000_hw *hw, u8 *mc_addr)
 {
 	u32 hash_value, hash_mask;
-	u8 bit_shift = 0;
+	u8 bit_shift = 1;

 	DEBUGFUNC("e1000_hash_mc_addr_generic");

@@ -342,7 +342,7 @@ STATIC u32 e1000_hash_mc_addr_vf(struct e1000_hw *hw, u8 *mc_addr)
 	 * The bit_shift is the number of left-shifts
 	 * where 0xFF would still fall within the hash mask.
 	 */
-	while (hash_mask >> bit_shift != 0xFF)
+	while (hash_mask >> bit_shift != 0xFF && bit_shift < 4)
 		bit_shift++;

 	hash_value = hash_mask & (((mc_addr[4] >> (8 - bit_shift)) |
--
2.34.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2025-02-18 19:39:02.870345661 +0800
+++ 0061-net-e1000-base-fix-MAC-address-hash-bit-shift.patch	2025-02-18 19:39:00.668244041 +0800
@@ -1 +1 @@
-From 1749e662f68ba6571ed81cd264cffd1107abc307 Mon Sep 17 00:00:00 2001
+From 5b1825dc24c291cd19f94bcb92c7947c5cc11e54 Mon Sep 17 00:00:00 2001
@@ -4,0 +5,3 @@
+Cc: Xueming Li <xuemingl at nvidia.com>
+
+[ upstream commit 1749e662f68ba6571ed81cd264cffd1107abc307 ]
@@ -15 +17,0 @@
-Cc: stable at dpdk.org
@@ -21,2 +23,2 @@
- drivers/net/intel/e1000/base/e1000_mac.c | 4 ++--
- drivers/net/intel/e1000/base/e1000_vf.c  | 4 ++--
+ drivers/net/e1000/base/e1000_mac.c | 4 ++--
+ drivers/net/e1000/base/e1000_vf.c  | 4 ++--
@@ -25 +27 @@
-diff --git a/drivers/net/intel/e1000/base/e1000_mac.c b/drivers/net/intel/e1000/base/e1000_mac.c
+diff --git a/drivers/net/e1000/base/e1000_mac.c b/drivers/net/e1000/base/e1000_mac.c
@@ -27,2 +29,2 @@
---- a/drivers/net/intel/e1000/base/e1000_mac.c
-+++ b/drivers/net/intel/e1000/base/e1000_mac.c
+--- a/drivers/net/e1000/base/e1000_mac.c
++++ b/drivers/net/e1000/base/e1000_mac.c
@@ -47 +49 @@
-diff --git a/drivers/net/intel/e1000/base/e1000_vf.c b/drivers/net/intel/e1000/base/e1000_vf.c
+diff --git a/drivers/net/e1000/base/e1000_vf.c b/drivers/net/e1000/base/e1000_vf.c
@@ -49,2 +51,2 @@
---- a/drivers/net/intel/e1000/base/e1000_vf.c
-+++ b/drivers/net/intel/e1000/base/e1000_vf.c
+--- a/drivers/net/e1000/base/e1000_vf.c
++++ b/drivers/net/e1000/base/e1000_vf.c