Patch "net/mlx4_en: Fix type mismatch for 32-bit systems" has been added to the 4.9-stable tree

Patch "net/mlx4_en: Fix type mismatch for 32-bit systems" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    net/mlx4_en: Fix type mismatch for 32-bit systems

to the 4.9-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:
     net-mlx4_en-fix-type-mismatch-for-32-bit-systems.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Wed Dec  6 17:39:55 CET 2017
From: Slava Shwartsman <slavash@mellanox.com>
Date: Thu, 29 Dec 2016 18:37:12 +0200
Subject: net/mlx4_en: Fix type mismatch for 32-bit systems

From: Slava Shwartsman <slavash@mellanox.com>


[ Upstream commit 61b6034c6cfdcb265bb453505c3d688e7567727a ]

is_power_of_2 expects unsigned long and we pass u64 max_val_cycles,
this will be truncated on 32 bit systems, and the result is not what we
were expecting.
div_u64 expects u32 as a second argument and we pass
max_val_cycles_rounded which is u64 hence it will always be truncated.
Fix was tested on both 64 and 32 bit systems and got same results for
max_val_cycles and max_val_cycles_rounded.

Fixes: 4850cf458157 ("net/mlx4_en: Resolve dividing by zero in 32-bit system")
Signed-off-by: Slava Shwartsman <slavash@mellanox.com>
Signed-off-by: Tariq Toukan <tariqt@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/net/ethernet/mellanox/mlx4/en_clock.c |    8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

--- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c
+++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c
@@ -251,13 +251,9 @@ static u32 freq_to_shift(u16 freq)
 {
 	u32 freq_khz = freq * 1000;
 	u64 max_val_cycles = freq_khz * 1000 * MLX4_EN_WRAP_AROUND_SEC;
-	u64 tmp_rounded =
-		roundup_pow_of_two(max_val_cycles) > max_val_cycles ?
-		roundup_pow_of_two(max_val_cycles) - 1 : UINT_MAX;
-	u64 max_val_cycles_rounded = is_power_of_2(max_val_cycles + 1) ?
-		max_val_cycles : tmp_rounded;
+	u64 max_val_cycles_rounded = 1ULL << fls64(max_val_cycles - 1);
 	/* calculate max possible multiplier in order to fit in 64bit */
-	u64 max_mul = div_u64(0xffffffffffffffffULL, max_val_cycles_rounded);
+	u64 max_mul = div64_u64(ULLONG_MAX, max_val_cycles_rounded);
 
 	/* This comes from the reverse of clocksource_khz2mult */
 	return ilog2(div_u64(max_mul * freq_khz, 1000000));


Patches currently in stable-queue which might be from slavash@mellanox.com are

queue-4.9/net-mlx4_en-fix-type-mismatch-for-32-bit-systems.patch