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

[Slava Ovsiienko <viacheslavo@mellanox.com>]

> -----Original Message-----
> From: Alexander Kozyrev <akozyrev@mellanox.com>
> Sent: Thursday, May 14, 2020 18:11
> To: Slava Ovsiienko <viacheslavo@mellanox.com>; dev@dpdk.org
> Cc: Matan Azrad <matan@mellanox.com>; Raslan Darawsheh
> <rasland@mellanox.com>; stephen@networkplumber.org; stable@dpdk.org
> Subject: RE: [PATCH v2] common/mlx5: fix bogus assert
> 
> These asserts seem redundant for me. Don't you think?
> EINVAL is returned, why bother to assert the same condition?
To stop the wrong conditions evolving on debug ?

> 
> 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%2Fpatch
> > es.d
> pdk.org%2Fpatch%2F67453%2F&amp;data=02%7C01%7Cakozyrev%40mella
> nox
> >
> .com%7C4f8e2cb5aacd4a33e22a08d7f7d5c7c4%7Ca652971c7d2e4d9ba6a4
> d14
> >
> 9256f461b%7C0%7C0%7C637250369858023357&amp;sdata=ZI7CTCQDnnm
> r6n
> > 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