Re: [dpdk-dev] [PATCH v2] common/mlx5: fix bogus assert

[Alexander Kozyrev <akozyrev@mellanox.com>]

These asserts seem redundant for me. Don't you think?
EINVAL is returned, why bother to assert the same condition?

Regards,
Alex  

> -----Original Message-----
> From: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> Sent: Thursday, May 14, 2020 3:09
> To: dev@dpdk.org
> Cc: Matan Azrad <matan@mellanox.com>; Raslan Darawsheh
> <rasland@mellanox.com>; stephen@networkplumber.org; Alexander Kozyrev
> <akozyrev@mellanox.com>; stable@dpdk.org
> Subject: [PATCH v2] common/mlx5: fix bogus assert
> 
> The MLX5 device supports up to MLX5_MAX_MAC_ADDRESSES (256) MAC
> addresses.
> The code flushes all MAC devices.
> 
> If DPDK is compiled with MLX5_DEBUG this would an assert.
> PANIC in mlx5_nl_mac_addr_flush():
> line 775	assert "(size_t)(i) < sizeof(mac_own) * 8" failed
> 
> The root cause is that mac_own is a pointer and is being used as a bitmap array.
> The sizeof(mac_own) would therefore be 64 but the number of entries to be
> flushed would be 256.
> 
> There is a whole set of asserts in MLX5 netlink code with the same bug; that
> should just be changed into proper error checks.
> 
> Fixes: 8e46d4e18f09 ("common/mlx5: improve assert control")
> Cc: akozyrev@mellanox.com
> Cc: stable@dpdk.org
> 
> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
> Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>
> 
> ---
> v2: fix asserts
> v1:
> https://eur03.safelinks.protection.outlook.com/?url=http%3A%2F%2Fpatches.d
> pdk.org%2Fpatch%2F67453%2F&amp;data=02%7C01%7Cakozyrev%40mellanox
> .com%7C4f8e2cb5aacd4a33e22a08d7f7d5c7c4%7Ca652971c7d2e4d9ba6a4d14
> 9256f461b%7C0%7C0%7C637250369858023357&amp;sdata=ZI7CTCQDnnmr6n
> pYXTOxOf4%2BBktSgmE%2F3rC4NG3QXxc%3D&amp;reserved=0
> ---
>  drivers/common/mlx5/mlx5_nl.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/common/mlx5/mlx5_nl.c b/drivers/common/mlx5/mlx5_nl.c
> index c144223..65efcd3 100644
> --- a/drivers/common/mlx5/mlx5_nl.c
> +++ b/drivers/common/mlx5/mlx5_nl.c
> @@ -671,7 +671,10 @@ struct mlx5_nl_ifindex_data {
> 
>  	ret = mlx5_nl_mac_addr_modify(nlsk_fd, iface_idx, mac, 1);
>  	if (!ret) {
> -		MLX5_ASSERT((size_t)(index) < sizeof(mac_own) * CHAR_BIT);
> +		MLX5_ASSERT(index < MLX5_MAX_MAC_ADDRESSES);
> +		if (index >= MLX5_MAX_MAC_ADDRESSES)
> +			return -EINVAL;
> +
>  		BITFIELD_SET(mac_own, index);
>  	}
>  	if (ret == -EEXIST)
> @@ -700,7 +703,10 @@ struct mlx5_nl_ifindex_data {
> mlx5_nl_mac_addr_remove(int nlsk_fd, unsigned int iface_idx, uint64_t
> *mac_own,
>  			struct rte_ether_addr *mac, uint32_t index)  {
> -	MLX5_ASSERT((size_t)(index) < sizeof(mac_own) * CHAR_BIT);
> +	MLX5_ASSERT(index < MLX5_MAX_MAC_ADDRESSES);
> +	if (index >= MLX5_MAX_MAC_ADDRESSES)
> +		return -EINVAL;
> +
>  	BITFIELD_RESET(mac_own, index);
>  	return mlx5_nl_mac_addr_modify(nlsk_fd, iface_idx, mac, 0);  } @@ -
> 769,10 +775,12 @@ struct mlx5_nl_ifindex_data {  {
>  	int i;
> 
> +	if (n <= 0 || n >= MLX5_MAX_MAC_ADDRESSES)
> +		return;
> +
>  	for (i = n - 1; i >= 0; --i) {
>  		struct rte_ether_addr *m = &mac_addrs[i];
> 
> -		MLX5_ASSERT((size_t)(i) < sizeof(mac_own) * CHAR_BIT);
>  		if (BITFIELD_ISSET(mac_own, i))
>  			mlx5_nl_mac_addr_remove(nlsk_fd, iface_idx,
> mac_own, m,
>  						i);
> --
> 1.8.3.1