2018-04-05 14:59:59

by Vadim Lomovtsev

[permalink] [raw]
Subject: [PATCH] net: thunderx: rework mac addresses list to u64 array

From: Vadim Lomovtsev <[email protected]>

It is too expensive to pass u64 values via linked list, instead
allocate array for them by overall number of mac addresses from netdev.

This eventually removes multiple kmalloc() calls, aviod memory
fragmentation and allow to put single null check on kmalloc
return value in order to prevent a potential null pointer dereference.

Addresses-Coverity-ID: 1467429 ("Dereference null return value")
Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
Signed-off-by: Vadim Lomovtsev <[email protected]>
---
drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
2 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
index 5fc46c5a4f36..da052159f014 100644
--- a/drivers/net/ethernet/cavium/thunder/nic.h
+++ b/drivers/net/ethernet/cavium/thunder/nic.h
@@ -265,14 +265,9 @@ struct nicvf_drv_stats {

struct cavium_ptp;

-struct xcast_addr {
- struct list_head list;
- u64 addr;
-};
-
struct xcast_addr_list {
- struct list_head list;
int count;
+ u64 mc[0];
};

struct nicvf_work {
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
index 1e9a31fef729..a26d8bc92e01 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
work.work);
struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
union nic_mbx mbx = {};
- struct xcast_addr *xaddr, *next;
+ u8 idx = 0;

if (!vf_work)
return;
@@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
/* check if we have any specific MACs to be added to PF DMAC filter */
if (vf_work->mc) {
/* now go through kernel list of MACs and add them one by one */
- list_for_each_entry_safe(xaddr, next,
- &vf_work->mc->list, list) {
+ for (idx = 0; idx < vf_work->mc->count; idx++) {
mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
- mbx.xcast.data.mac = xaddr->addr;
+ mbx.xcast.data.mac = vf_work->mc->mc[idx];
nicvf_send_msg_to_pf(nic, &mbx);
-
- /* after receiving ACK from PF release memory */
- list_del(&xaddr->list);
- kfree(xaddr);
- vf_work->mc->count--;
}
kfree(vf_work->mc);
}
@@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
mode |= BGX_XCAST_MCAST_FILTER;
/* here we need to copy mc addrs */
if (netdev_mc_count(netdev)) {
- struct xcast_addr *xaddr;
-
- mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
- INIT_LIST_HEAD(&mc_list->list);
+ mc_list = kmalloc(sizeof(*mc_list) +
+ sizeof(u64) * netdev_mc_count(netdev),
+ GFP_ATOMIC);
+ if (unlikely(!mc_list))
+ return;
+ mc_list->count = 0;
netdev_hw_addr_list_for_each(ha, &netdev->mc) {
- xaddr = kmalloc(sizeof(*xaddr),
- GFP_ATOMIC);
- xaddr->addr =
+ mc_list->mc[mc_list->count] =
ether_addr_to_u64(ha->addr);
- list_add_tail(&xaddr->list,
- &mc_list->list);
mc_list->count++;
}
}
--
2.14.3



2018-04-05 15:01:46

by Vadim Lomovtsev

[permalink] [raw]
Subject: Re: [PATCH] net: thunderx: rework mac addresses list to u64 array

[correct Roberts' address]

On Thu, Apr 05, 2018 at 07:57:56AM -0700, Vadim Lomovtsev wrote:
> From: Vadim Lomovtsev <[email protected]>
>
> It is too expensive to pass u64 values via linked list, instead
> allocate array for them by overall number of mac addresses from netdev.
>
> This eventually removes multiple kmalloc() calls, aviod memory
> fragmentation and allow to put single null check on kmalloc
> return value in order to prevent a potential null pointer dereference.
>
> Addresses-Coverity-ID: 1467429 ("Dereference null return value")
> Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
> Signed-off-by: Vadim Lomovtsev <[email protected]>
> ---
> drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
> drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
> 2 files changed, 11 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
> index 5fc46c5a4f36..da052159f014 100644
> --- a/drivers/net/ethernet/cavium/thunder/nic.h
> +++ b/drivers/net/ethernet/cavium/thunder/nic.h
> @@ -265,14 +265,9 @@ struct nicvf_drv_stats {
>
> struct cavium_ptp;
>
> -struct xcast_addr {
> - struct list_head list;
> - u64 addr;
> -};
> -
> struct xcast_addr_list {
> - struct list_head list;
> int count;
> + u64 mc[0];
> };
>
> struct nicvf_work {
> diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> index 1e9a31fef729..a26d8bc92e01 100644
> --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> work.work);
> struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> union nic_mbx mbx = {};
> - struct xcast_addr *xaddr, *next;
> + u8 idx = 0;
>
> if (!vf_work)
> return;
> @@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> /* check if we have any specific MACs to be added to PF DMAC filter */
> if (vf_work->mc) {
> /* now go through kernel list of MACs and add them one by one */
> - list_for_each_entry_safe(xaddr, next,
> - &vf_work->mc->list, list) {
> + for (idx = 0; idx < vf_work->mc->count; idx++) {
> mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
> - mbx.xcast.data.mac = xaddr->addr;
> + mbx.xcast.data.mac = vf_work->mc->mc[idx];
> nicvf_send_msg_to_pf(nic, &mbx);
> -
> - /* after receiving ACK from PF release memory */
> - list_del(&xaddr->list);
> - kfree(xaddr);
> - vf_work->mc->count--;
> }
> kfree(vf_work->mc);
> }
> @@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
> mode |= BGX_XCAST_MCAST_FILTER;
> /* here we need to copy mc addrs */
> if (netdev_mc_count(netdev)) {
> - struct xcast_addr *xaddr;
> -
> - mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
> - INIT_LIST_HEAD(&mc_list->list);
> + mc_list = kmalloc(sizeof(*mc_list) +
> + sizeof(u64) * netdev_mc_count(netdev),
> + GFP_ATOMIC);
> + if (unlikely(!mc_list))
> + return;
> + mc_list->count = 0;
> netdev_hw_addr_list_for_each(ha, &netdev->mc) {
> - xaddr = kmalloc(sizeof(*xaddr),
> - GFP_ATOMIC);
> - xaddr->addr =
> + mc_list->mc[mc_list->count] =
> ether_addr_to_u64(ha->addr);
> - list_add_tail(&xaddr->list,
> - &mc_list->list);
> mc_list->count++;
> }
> }
> --
> 2.14.3
>

2018-04-05 15:09:14

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH] net: thunderx: rework mac addresses list to u64 array

> struct xcast_addr_list {
> - struct list_head list;
> int count;
> + u64 mc[0];

Please use the standard C99 syntax here:

u64 mc[];

> + mc_list = kmalloc(sizeof(*mc_list) +
> + sizeof(u64) * netdev_mc_count(netdev),
> + GFP_ATOMIC);

kmalloc_array(), please.

2018-04-05 16:09:30

by Vadim Lomovtsev

[permalink] [raw]
Subject: Re: [PATCH] net: thunderx: rework mac addresses list to u64 array

Hi Christoph,

Thank you for your feedback and time.

On Thu, Apr 05, 2018 at 08:07:48AM -0700, Christoph Hellwig wrote:
> > struct xcast_addr_list {
> > - struct list_head list;
> > int count;
> > + u64 mc[0];
>
> Please use the standard C99 syntax here:
>
> u64 mc[];

Ok, will update.

>
> > + mc_list = kmalloc(sizeof(*mc_list) +
> > + sizeof(u64) * netdev_mc_count(netdev),
> > + GFP_ATOMIC);
>
> kmalloc_array(), please.

In this case it would require two memory allocation calls to kmalloc() for
xcast_addr_list struct and to kmalloc_array() for 'mc' addresses, becasue of
different data types and so two null-ptr checks .. this is what I'd like get rid off.

My idea of this was to keep number of array elements and themselves within the
same memory block/page to reduce number of memory allocation requests, number
of allocated pages/blocks and avoid possible memory fragmentation (however, I believe
the latter is already handled at the mm layer).

WBR,
Vadim

2018-04-05 16:17:48

by Christoph Hellwig

[permalink] [raw]
Subject: Re: [PATCH] net: thunderx: rework mac addresses list to u64 array

On Thu, Apr 05, 2018 at 09:07:49AM -0700, Vadim Lomovtsev wrote:
> >
> > > + mc_list = kmalloc(sizeof(*mc_list) +
> > > + sizeof(u64) * netdev_mc_count(netdev),
> > > + GFP_ATOMIC);
> >
> > kmalloc_array(), please.
>
> In this case it would require two memory allocation calls to kmalloc() for
> xcast_addr_list struct and to kmalloc_array() for 'mc' addresses, becasue of
> different data types and so two null-ptr checks .. this is what I'd like get rid off.
>
> My idea of this was to keep number of array elements and themselves within the
> same memory block/page to reduce number of memory allocation requests, number
> of allocated pages/blocks and avoid possible memory fragmentation (however, I believe
> the latter is already handled at the mm layer).

Indeed, lets keep it as-is.

2018-04-06 11:16:06

by Vadim Lomovtsev

[permalink] [raw]
Subject: [PATCH v2] net: thunderx: rework mac addresses list to u64 array

From: Vadim Lomovtsev <[email protected]>

It is too expensive to pass u64 values via linked list, instead
allocate array for them by overall number of mac addresses from netdev.

This eventually removes multiple kmalloc() calls, aviod memory
fragmentation and allow to put single null check on kmalloc
return value in order to prevent a potential null pointer dereference.

Addresses-Coverity-ID: 1467429 ("Dereference null return value")
Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
Signed-off-by: Vadim Lomovtsev <[email protected]>
---
Changes from v1 to v2:
- C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];

---
drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
2 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
index 5fc46c5a4f36..448d1fafc827 100644
--- a/drivers/net/ethernet/cavium/thunder/nic.h
+++ b/drivers/net/ethernet/cavium/thunder/nic.h
@@ -265,14 +265,9 @@ struct nicvf_drv_stats {

struct cavium_ptp;

-struct xcast_addr {
- struct list_head list;
- u64 addr;
-};
-
struct xcast_addr_list {
- struct list_head list;
int count;
+ u64 mc[];
};

struct nicvf_work {
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
index 1e9a31fef729..a26d8bc92e01 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
work.work);
struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
union nic_mbx mbx = {};
- struct xcast_addr *xaddr, *next;
+ u8 idx = 0;

if (!vf_work)
return;
@@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
/* check if we have any specific MACs to be added to PF DMAC filter */
if (vf_work->mc) {
/* now go through kernel list of MACs and add them one by one */
- list_for_each_entry_safe(xaddr, next,
- &vf_work->mc->list, list) {
+ for (idx = 0; idx < vf_work->mc->count; idx++) {
mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
- mbx.xcast.data.mac = xaddr->addr;
+ mbx.xcast.data.mac = vf_work->mc->mc[idx];
nicvf_send_msg_to_pf(nic, &mbx);
-
- /* after receiving ACK from PF release memory */
- list_del(&xaddr->list);
- kfree(xaddr);
- vf_work->mc->count--;
}
kfree(vf_work->mc);
}
@@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
mode |= BGX_XCAST_MCAST_FILTER;
/* here we need to copy mc addrs */
if (netdev_mc_count(netdev)) {
- struct xcast_addr *xaddr;
-
- mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
- INIT_LIST_HEAD(&mc_list->list);
+ mc_list = kmalloc(sizeof(*mc_list) +
+ sizeof(u64) * netdev_mc_count(netdev),
+ GFP_ATOMIC);
+ if (unlikely(!mc_list))
+ return;
+ mc_list->count = 0;
netdev_hw_addr_list_for_each(ha, &netdev->mc) {
- xaddr = kmalloc(sizeof(*xaddr),
- GFP_ATOMIC);
- xaddr->addr =
+ mc_list->mc[mc_list->count] =
ether_addr_to_u64(ha->addr);
- list_add_tail(&xaddr->list,
- &mc_list->list);
mc_list->count++;
}
}
--
2.14.3


2018-04-06 11:38:10

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH v2] net: thunderx: rework mac addresses list to u64 array

Hi Vadim,

On 04/06/2018 06:14 AM, Vadim Lomovtsev wrote:
> From: Vadim Lomovtsev <[email protected]>
>
> It is too expensive to pass u64 values via linked list, instead
> allocate array for them by overall number of mac addresses from netdev.
>
> This eventually removes multiple kmalloc() calls, aviod memory
> fragmentation and allow to put single null check on kmalloc
> return value in order to prevent a potential null pointer dereference.
>
> Addresses-Coverity-ID: 1467429 ("Dereference null return value")
> Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")

It'd be nice if you add:

Reported-by: Gustavo A. R. Silva <[email protected]>

Thanks
--
Gustavo

> Signed-off-by: Vadim Lomovtsev <[email protected]>
> ---
> Changes from v1 to v2:
> - C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];
>
> ---
> drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
> drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
> 2 files changed, 11 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
> index 5fc46c5a4f36..448d1fafc827 100644
> --- a/drivers/net/ethernet/cavium/thunder/nic.h
> +++ b/drivers/net/ethernet/cavium/thunder/nic.h
> @@ -265,14 +265,9 @@ struct nicvf_drv_stats {
>
> struct cavium_ptp;
>
> -struct xcast_addr {
> - struct list_head list;
> - u64 addr;
> -};
> -
> struct xcast_addr_list {
> - struct list_head list;
> int count;
> + u64 mc[];
> };
>
> struct nicvf_work {
> diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> index 1e9a31fef729..a26d8bc92e01 100644
> --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> work.work);
> struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> union nic_mbx mbx = {};
> - struct xcast_addr *xaddr, *next;
> + u8 idx = 0;
>
> if (!vf_work)
> return;
> @@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> /* check if we have any specific MACs to be added to PF DMAC filter */
> if (vf_work->mc) {
> /* now go through kernel list of MACs and add them one by one */
> - list_for_each_entry_safe(xaddr, next,
> - &vf_work->mc->list, list) {
> + for (idx = 0; idx < vf_work->mc->count; idx++) {
> mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
> - mbx.xcast.data.mac = xaddr->addr;
> + mbx.xcast.data.mac = vf_work->mc->mc[idx];
> nicvf_send_msg_to_pf(nic, &mbx);
> -
> - /* after receiving ACK from PF release memory */
> - list_del(&xaddr->list);
> - kfree(xaddr);
> - vf_work->mc->count--;
> }
> kfree(vf_work->mc);
> }
> @@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
> mode |= BGX_XCAST_MCAST_FILTER;
> /* here we need to copy mc addrs */
> if (netdev_mc_count(netdev)) {
> - struct xcast_addr *xaddr;
> -
> - mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
> - INIT_LIST_HEAD(&mc_list->list);
> + mc_list = kmalloc(sizeof(*mc_list) +
> + sizeof(u64) * netdev_mc_count(netdev),
> + GFP_ATOMIC);
> + if (unlikely(!mc_list))
> + return;
> + mc_list->count = 0;
> netdev_hw_addr_list_for_each(ha, &netdev->mc) {
> - xaddr = kmalloc(sizeof(*xaddr),
> - GFP_ATOMIC);
> - xaddr->addr =
> + mc_list->mc[mc_list->count] =
> ether_addr_to_u64(ha->addr);
> - list_add_tail(&xaddr->list,
> - &mc_list->list);
> mc_list->count++;
> }
> }
>

2018-04-06 11:45:13

by Vadim Lomovtsev

[permalink] [raw]
Subject: Re: [PATCH v2] net: thunderx: rework mac addresses list to u64 array

Hi Gustavo,

On Fri, Apr 06, 2018 at 06:36:28AM -0500, Gustavo A. R. Silva wrote:
> Hi Vadim,
>
> On 04/06/2018 06:14 AM, Vadim Lomovtsev wrote:
> > From: Vadim Lomovtsev <[email protected]>
> >
> > It is too expensive to pass u64 values via linked list, instead
> > allocate array for them by overall number of mac addresses from netdev.
> >
> > This eventually removes multiple kmalloc() calls, aviod memory
> > fragmentation and allow to put single null check on kmalloc
> > return value in order to prevent a potential null pointer dereference.
> >
> > Addresses-Coverity-ID: 1467429 ("Dereference null return value")
> > Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
>
> It'd be nice if you add:
>
> Reported-by: Gustavo A. R. Silva <[email protected]>

Ok, I could do that.

Just to explain .. I didn't do it yet since I get such report from
Dan Carpenter intially (https://www.spinics.net/lists/linux-kernel-janitors/msg40720.html)
and was working on it when found you patches, so then asking you to give
me some time to prepare and test update to driver.

So would it be acceptable put two tags 'Reported-by:' then ?

WBR,
Vadim

>
> Thanks
> --
> Gustavo
>
> > Signed-off-by: Vadim Lomovtsev <[email protected]>
> > ---
> > Changes from v1 to v2:
> > - C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];
> >
> > ---
> > drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
> > drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
> > 2 files changed, 11 insertions(+), 24 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
> > index 5fc46c5a4f36..448d1fafc827 100644
> > --- a/drivers/net/ethernet/cavium/thunder/nic.h
> > +++ b/drivers/net/ethernet/cavium/thunder/nic.h
> > @@ -265,14 +265,9 @@ struct nicvf_drv_stats {
> > struct cavium_ptp;
> > -struct xcast_addr {
> > - struct list_head list;
> > - u64 addr;
> > -};
> > -
> > struct xcast_addr_list {
> > - struct list_head list;
> > int count;
> > + u64 mc[];
> > };
> > struct nicvf_work {
> > diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > index 1e9a31fef729..a26d8bc92e01 100644
> > --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> > work.work);
> > struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> > union nic_mbx mbx = {};
> > - struct xcast_addr *xaddr, *next;
> > + u8 idx = 0;
> > if (!vf_work)
> > return;
> > @@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> > /* check if we have any specific MACs to be added to PF DMAC filter */
> > if (vf_work->mc) {
> > /* now go through kernel list of MACs and add them one by one */
> > - list_for_each_entry_safe(xaddr, next,
> > - &vf_work->mc->list, list) {
> > + for (idx = 0; idx < vf_work->mc->count; idx++) {
> > mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
> > - mbx.xcast.data.mac = xaddr->addr;
> > + mbx.xcast.data.mac = vf_work->mc->mc[idx];
> > nicvf_send_msg_to_pf(nic, &mbx);
> > -
> > - /* after receiving ACK from PF release memory */
> > - list_del(&xaddr->list);
> > - kfree(xaddr);
> > - vf_work->mc->count--;
> > }
> > kfree(vf_work->mc);
> > }
> > @@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
> > mode |= BGX_XCAST_MCAST_FILTER;
> > /* here we need to copy mc addrs */
> > if (netdev_mc_count(netdev)) {
> > - struct xcast_addr *xaddr;
> > -
> > - mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
> > - INIT_LIST_HEAD(&mc_list->list);
> > + mc_list = kmalloc(sizeof(*mc_list) +
> > + sizeof(u64) * netdev_mc_count(netdev),
> > + GFP_ATOMIC);
> > + if (unlikely(!mc_list))
> > + return;
> > + mc_list->count = 0;
> > netdev_hw_addr_list_for_each(ha, &netdev->mc) {
> > - xaddr = kmalloc(sizeof(*xaddr),
> > - GFP_ATOMIC);
> > - xaddr->addr =
> > + mc_list->mc[mc_list->count] =
> > ether_addr_to_u64(ha->addr);
> > - list_add_tail(&xaddr->list,
> > - &mc_list->list);
> > mc_list->count++;
> > }
> > }
> >

2018-04-06 11:48:58

by Gustavo A. R. Silva

[permalink] [raw]
Subject: Re: [PATCH v2] net: thunderx: rework mac addresses list to u64 array



On 04/06/2018 06:43 AM, Vadim Lomovtsev wrote:
> Hi Gustavo,
>
> On Fri, Apr 06, 2018 at 06:36:28AM -0500, Gustavo A. R. Silva wrote:
>> Hi Vadim,
>>
>> On 04/06/2018 06:14 AM, Vadim Lomovtsev wrote:
>>> From: Vadim Lomovtsev <[email protected]>
>>>
>>> It is too expensive to pass u64 values via linked list, instead
>>> allocate array for them by overall number of mac addresses from netdev.
>>>
>>> This eventually removes multiple kmalloc() calls, aviod memory
>>> fragmentation and allow to put single null check on kmalloc
>>> return value in order to prevent a potential null pointer dereference.
>>>
>>> Addresses-Coverity-ID: 1467429 ("Dereference null return value")
>>> Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
>>
>> It'd be nice if you add:
>>
>> Reported-by: Gustavo A. R. Silva <[email protected]>
>
> Ok, I could do that.
>
> Just to explain .. I didn't do it yet since I get such report from
> Dan Carpenter intially (https://www.spinics.net/lists/linux-kernel-janitors/msg40720.html)
> and was working on it when found you patches, so then asking you to give
> me some time to prepare and test update to driver.
>

Oh I got it. Not big deal. I think in this case you should add Dan's
Reported-by instead.

BTW nice patch. :)

Thanks
--
Gustavo

> So would it be acceptable put two tags 'Reported-by:' then ?
>
> WBR,
> Vadim
>
>>
>> Thanks
>> --
>> Gustavo
>>
>>> Signed-off-by: Vadim Lomovtsev <[email protected]>
>>> ---
>>> Changes from v1 to v2:
>>> - C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];
>>>
>>> ---
>>> drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
>>> drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
>>> 2 files changed, 11 insertions(+), 24 deletions(-)
>>>
>>> diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
>>> index 5fc46c5a4f36..448d1fafc827 100644
>>> --- a/drivers/net/ethernet/cavium/thunder/nic.h
>>> +++ b/drivers/net/ethernet/cavium/thunder/nic.h
>>> @@ -265,14 +265,9 @@ struct nicvf_drv_stats {
>>> struct cavium_ptp;
>>> -struct xcast_addr {
>>> - struct list_head list;
>>> - u64 addr;
>>> -};
>>> -
>>> struct xcast_addr_list {
>>> - struct list_head list;
>>> int count;
>>> + u64 mc[];
>>> };
>>> struct nicvf_work {
>>> diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
>>> index 1e9a31fef729..a26d8bc92e01 100644
>>> --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
>>> +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
>>> @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
>>> work.work);
>>> struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
>>> union nic_mbx mbx = {};
>>> - struct xcast_addr *xaddr, *next;
>>> + u8 idx = 0;
>>> if (!vf_work)
>>> return;
>>> @@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
>>> /* check if we have any specific MACs to be added to PF DMAC filter */
>>> if (vf_work->mc) {
>>> /* now go through kernel list of MACs and add them one by one */
>>> - list_for_each_entry_safe(xaddr, next,
>>> - &vf_work->mc->list, list) {
>>> + for (idx = 0; idx < vf_work->mc->count; idx++) {
>>> mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
>>> - mbx.xcast.data.mac = xaddr->addr;
>>> + mbx.xcast.data.mac = vf_work->mc->mc[idx];
>>> nicvf_send_msg_to_pf(nic, &mbx);
>>> -
>>> - /* after receiving ACK from PF release memory */
>>> - list_del(&xaddr->list);
>>> - kfree(xaddr);
>>> - vf_work->mc->count--;
>>> }
>>> kfree(vf_work->mc);
>>> }
>>> @@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
>>> mode |= BGX_XCAST_MCAST_FILTER;
>>> /* here we need to copy mc addrs */
>>> if (netdev_mc_count(netdev)) {
>>> - struct xcast_addr *xaddr;
>>> -
>>> - mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
>>> - INIT_LIST_HEAD(&mc_list->list);
>>> + mc_list = kmalloc(sizeof(*mc_list) +
>>> + sizeof(u64) * netdev_mc_count(netdev),
>>> + GFP_ATOMIC);
>>> + if (unlikely(!mc_list))
>>> + return;
>>> + mc_list->count = 0;
>>> netdev_hw_addr_list_for_each(ha, &netdev->mc) {
>>> - xaddr = kmalloc(sizeof(*xaddr),
>>> - GFP_ATOMIC);
>>> - xaddr->addr =
>>> + mc_list->mc[mc_list->count] =
>>> ether_addr_to_u64(ha->addr);
>>> - list_add_tail(&xaddr->list,
>>> - &mc_list->list);
>>> mc_list->count++;
>>> }
>>> }
>>>

2018-04-06 11:50:08

by Robin Murphy

[permalink] [raw]
Subject: Re: [PATCH v2] net: thunderx: rework mac addresses list to u64 array

On 06/04/18 12:14, Vadim Lomovtsev wrote:
> From: Vadim Lomovtsev <[email protected]>
>
> It is too expensive to pass u64 values via linked list, instead
> allocate array for them by overall number of mac addresses from netdev.
>
> This eventually removes multiple kmalloc() calls, aviod memory
> fragmentation and allow to put single null check on kmalloc
> return value in order to prevent a potential null pointer dereference.
>
> Addresses-Coverity-ID: 1467429 ("Dereference null return value")
> Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
> Signed-off-by: Vadim Lomovtsev <[email protected]>
> ---
> Changes from v1 to v2:
> - C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];
>
> ---
> drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
> drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
> 2 files changed, 11 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
> index 5fc46c5a4f36..448d1fafc827 100644
> --- a/drivers/net/ethernet/cavium/thunder/nic.h
> +++ b/drivers/net/ethernet/cavium/thunder/nic.h
> @@ -265,14 +265,9 @@ struct nicvf_drv_stats {
>
> struct cavium_ptp;
>
> -struct xcast_addr {
> - struct list_head list;
> - u64 addr;
> -};
> -
> struct xcast_addr_list {
> - struct list_head list;
> int count;
> + u64 mc[];
> };
>
> struct nicvf_work {
> diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> index 1e9a31fef729..a26d8bc92e01 100644
> --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> work.work);
> struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> union nic_mbx mbx = {};
> - struct xcast_addr *xaddr, *next;
> + u8 idx = 0;
>
> if (!vf_work)
> return;
> @@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> /* check if we have any specific MACs to be added to PF DMAC filter */
> if (vf_work->mc) {
> /* now go through kernel list of MACs and add them one by one */
> - list_for_each_entry_safe(xaddr, next,
> - &vf_work->mc->list, list) {
> + for (idx = 0; idx < vf_work->mc->count; idx++) {
> mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
> - mbx.xcast.data.mac = xaddr->addr;
> + mbx.xcast.data.mac = vf_work->mc->mc[idx];
> nicvf_send_msg_to_pf(nic, &mbx);
> -
> - /* after receiving ACK from PF release memory */
> - list_del(&xaddr->list);
> - kfree(xaddr);
> - vf_work->mc->count--;
> }
> kfree(vf_work->mc);
> }
> @@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
> mode |= BGX_XCAST_MCAST_FILTER;
> /* here we need to copy mc addrs */
> if (netdev_mc_count(netdev)) {
> - struct xcast_addr *xaddr;
> -
> - mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
> - INIT_LIST_HEAD(&mc_list->list);
> + mc_list = kmalloc(sizeof(*mc_list) +
> + sizeof(u64) * netdev_mc_count(netdev),

FWIW if you really wanted to disambiguate that it's a structure and not
just an array being allocated, then it could be expressed without
explicit arithmetic:

size = offsetof(typeof(*mc_list), mc[netdev_mc_count(netdev)]);

but that's probably just a matter of personal preference at this point.

Robin.

> + GFP_ATOMIC);
> + if (unlikely(!mc_list))
> + return;
> + mc_list->count = 0;
> netdev_hw_addr_list_for_each(ha, &netdev->mc) {
> - xaddr = kmalloc(sizeof(*xaddr),
> - GFP_ATOMIC);
> - xaddr->addr =
> + mc_list->mc[mc_list->count] =
> ether_addr_to_u64(ha->addr);
> - list_add_tail(&xaddr->list,
> - &mc_list->list);
> mc_list->count++;
> }
> }
>

2018-04-06 11:55:36

by Vadim Lomovtsev

[permalink] [raw]
Subject: Re: [PATCH v2] net: thunderx: rework mac addresses list to u64 array

On Fri, Apr 06, 2018 at 06:47:26AM -0500, Gustavo A. R. Silva wrote:
>
>
> On 04/06/2018 06:43 AM, Vadim Lomovtsev wrote:
> > Hi Gustavo,
> >
> > On Fri, Apr 06, 2018 at 06:36:28AM -0500, Gustavo A. R. Silva wrote:
> > > Hi Vadim,
> > >
> > > On 04/06/2018 06:14 AM, Vadim Lomovtsev wrote:
> > > > From: Vadim Lomovtsev <[email protected]>
> > > >
> > > > It is too expensive to pass u64 values via linked list, instead
> > > > allocate array for them by overall number of mac addresses from netdev.
> > > >
> > > > This eventually removes multiple kmalloc() calls, aviod memory
> > > > fragmentation and allow to put single null check on kmalloc
> > > > return value in order to prevent a potential null pointer dereference.
> > > >
> > > > Addresses-Coverity-ID: 1467429 ("Dereference null return value")
> > > > Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
> > >
> > > It'd be nice if you add:
> > >
> > > Reported-by: Gustavo A. R. Silva <[email protected]>
> >
> > Ok, I could do that.
> >
> > Just to explain .. I didn't do it yet since I get such report from
> > Dan Carpenter intially (https://www.spinics.net/lists/linux-kernel-janitors/msg40720.html)
> > and was working on it when found you patches, so then asking you to give
> > me some time to prepare and test update to driver.
> >
>
> Oh I got it. Not big deal. I think in this case you should add Dan's
> Reported-by instead.

Ok then.

>
> BTW nice patch. :)
>

Thank you for reviewing it.

WBR,
Vadim

> Thanks
> --
> Gustavo
>
> > So would it be acceptable put two tags 'Reported-by:' then ?
> >
> > WBR,
> > Vadim
> >
> > >
> > > Thanks
> > > --
> > > Gustavo
> > >
> > > > Signed-off-by: Vadim Lomovtsev <[email protected]>
> > > > ---
> > > > Changes from v1 to v2:
> > > > - C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];
> > > >
> > > > ---
> > > > drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
> > > > drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
> > > > 2 files changed, 11 insertions(+), 24 deletions(-)
> > > >
> > > > diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
> > > > index 5fc46c5a4f36..448d1fafc827 100644
> > > > --- a/drivers/net/ethernet/cavium/thunder/nic.h
> > > > +++ b/drivers/net/ethernet/cavium/thunder/nic.h
> > > > @@ -265,14 +265,9 @@ struct nicvf_drv_stats {
> > > > struct cavium_ptp;
> > > > -struct xcast_addr {
> > > > - struct list_head list;
> > > > - u64 addr;
> > > > -};
> > > > -
> > > > struct xcast_addr_list {
> > > > - struct list_head list;
> > > > int count;
> > > > + u64 mc[];
> > > > };
> > > > struct nicvf_work {
> > > > diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > > > index 1e9a31fef729..a26d8bc92e01 100644
> > > > --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > > > +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > > > @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> > > > work.work);
> > > > struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> > > > union nic_mbx mbx = {};
> > > > - struct xcast_addr *xaddr, *next;
> > > > + u8 idx = 0;
> > > > if (!vf_work)
> > > > return;
> > > > @@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> > > > /* check if we have any specific MACs to be added to PF DMAC filter */
> > > > if (vf_work->mc) {
> > > > /* now go through kernel list of MACs and add them one by one */
> > > > - list_for_each_entry_safe(xaddr, next,
> > > > - &vf_work->mc->list, list) {
> > > > + for (idx = 0; idx < vf_work->mc->count; idx++) {
> > > > mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
> > > > - mbx.xcast.data.mac = xaddr->addr;
> > > > + mbx.xcast.data.mac = vf_work->mc->mc[idx];
> > > > nicvf_send_msg_to_pf(nic, &mbx);
> > > > -
> > > > - /* after receiving ACK from PF release memory */
> > > > - list_del(&xaddr->list);
> > > > - kfree(xaddr);
> > > > - vf_work->mc->count--;
> > > > }
> > > > kfree(vf_work->mc);
> > > > }
> > > > @@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
> > > > mode |= BGX_XCAST_MCAST_FILTER;
> > > > /* here we need to copy mc addrs */
> > > > if (netdev_mc_count(netdev)) {
> > > > - struct xcast_addr *xaddr;
> > > > -
> > > > - mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
> > > > - INIT_LIST_HEAD(&mc_list->list);
> > > > + mc_list = kmalloc(sizeof(*mc_list) +
> > > > + sizeof(u64) * netdev_mc_count(netdev),
> > > > + GFP_ATOMIC);
> > > > + if (unlikely(!mc_list))
> > > > + return;
> > > > + mc_list->count = 0;
> > > > netdev_hw_addr_list_for_each(ha, &netdev->mc) {
> > > > - xaddr = kmalloc(sizeof(*xaddr),
> > > > - GFP_ATOMIC);
> > > > - xaddr->addr =
> > > > + mc_list->mc[mc_list->count] =
> > > > ether_addr_to_u64(ha->addr);
> > > > - list_add_tail(&xaddr->list,
> > > > - &mc_list->list);
> > > > mc_list->count++;
> > > > }
> > > > }
> > > >

2018-04-06 12:09:20

by Vadim Lomovtsev

[permalink] [raw]
Subject: Re: [PATCH v2] net: thunderx: rework mac addresses list to u64 array

Hi Robin,

On Fri, Apr 06, 2018 at 12:48:40PM +0100, Robin Murphy wrote:
> On 06/04/18 12:14, Vadim Lomovtsev wrote:
> > From: Vadim Lomovtsev <[email protected]>
> >
> > It is too expensive to pass u64 values via linked list, instead
> > allocate array for them by overall number of mac addresses from netdev.
> >
> > This eventually removes multiple kmalloc() calls, aviod memory
> > fragmentation and allow to put single null check on kmalloc
> > return value in order to prevent a potential null pointer dereference.
> >
> > Addresses-Coverity-ID: 1467429 ("Dereference null return value")
> > Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
> > Signed-off-by: Vadim Lomovtsev <[email protected]>
> > ---
> > Changes from v1 to v2:
> > - C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];
> >
> > ---
> > drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
> > drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
> > 2 files changed, 11 insertions(+), 24 deletions(-)
> >
> > diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
> > index 5fc46c5a4f36..448d1fafc827 100644
> > --- a/drivers/net/ethernet/cavium/thunder/nic.h
> > +++ b/drivers/net/ethernet/cavium/thunder/nic.h
> > @@ -265,14 +265,9 @@ struct nicvf_drv_stats {
> > struct cavium_ptp;
> > -struct xcast_addr {
> > - struct list_head list;
> > - u64 addr;
> > -};
> > -
> > struct xcast_addr_list {
> > - struct list_head list;
> > int count;
> > + u64 mc[];
> > };
> > struct nicvf_work {
> > diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > index 1e9a31fef729..a26d8bc92e01 100644
> > --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> > work.work);
> > struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> > union nic_mbx mbx = {};
> > - struct xcast_addr *xaddr, *next;
> > + u8 idx = 0;
> > if (!vf_work)
> > return;
> > @@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> > /* check if we have any specific MACs to be added to PF DMAC filter */
> > if (vf_work->mc) {
> > /* now go through kernel list of MACs and add them one by one */
> > - list_for_each_entry_safe(xaddr, next,
> > - &vf_work->mc->list, list) {
> > + for (idx = 0; idx < vf_work->mc->count; idx++) {
> > mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
> > - mbx.xcast.data.mac = xaddr->addr;
> > + mbx.xcast.data.mac = vf_work->mc->mc[idx];
> > nicvf_send_msg_to_pf(nic, &mbx);
> > -
> > - /* after receiving ACK from PF release memory */
> > - list_del(&xaddr->list);
> > - kfree(xaddr);
> > - vf_work->mc->count--;
> > }
> > kfree(vf_work->mc);
> > }
> > @@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
> > mode |= BGX_XCAST_MCAST_FILTER;
> > /* here we need to copy mc addrs */
> > if (netdev_mc_count(netdev)) {
> > - struct xcast_addr *xaddr;
> > -
> > - mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
> > - INIT_LIST_HEAD(&mc_list->list);
> > + mc_list = kmalloc(sizeof(*mc_list) +
> > + sizeof(u64) * netdev_mc_count(netdev),
>
> FWIW if you really wanted to disambiguate that it's a structure and not just
> an array being allocated, then it could be expressed without explicit
> arithmetic:
>
> size = offsetof(typeof(*mc_list), mc[netdev_mc_count(netdev)]);
>
> but that's probably just a matter of personal preference at this point.
>
> Robin.
>

Thanks for reviewing it and for hint. From style perspective, I believe,
I should get rid off direct types names also, and use your suggestion here.

I'll update patch to v3, test and re-post.
Thank you for your time.

WBR,
Vadim

> > + GFP_ATOMIC);
> > + if (unlikely(!mc_list))
> > + return;
> > + mc_list->count = 0;
> > netdev_hw_addr_list_for_each(ha, &netdev->mc) {
> > - xaddr = kmalloc(sizeof(*xaddr),
> > - GFP_ATOMIC);
> > - xaddr->addr =
> > + mc_list->mc[mc_list->count] =
> > ether_addr_to_u64(ha->addr);
> > - list_add_tail(&xaddr->list,
> > - &mc_list->list);
> > mc_list->count++;
> > }
> > }
> >

2018-04-06 14:06:30

by Vadim Lomovtsev

[permalink] [raw]
Subject: [PATCH v3] net: thunderx: rework mac addresses list to u64 array

From: Vadim Lomovtsev <[email protected]>

It is too expensive to pass u64 values via linked list, instead
allocate array for them by overall number of mac addresses from netdev.

This eventually removes multiple kmalloc() calls, aviod memory
fragmentation and allow to put single null check on kmalloc
return value in order to prevent a potential null pointer dereference.

Addresses-Coverity-ID: 1467429 ("Dereference null return value")
Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Vadim Lomovtsev <[email protected]>
---
Changes from v1 to v2:
- C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];
Changes from v2 to v3:
- update commit description with 'Reported-by: Dan Carpenter';
- update size calculations for mc list to offsetof() call
instead of explicit arithmetic;
---
drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
2 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
index 5fc46c5a4f36..448d1fafc827 100644
--- a/drivers/net/ethernet/cavium/thunder/nic.h
+++ b/drivers/net/ethernet/cavium/thunder/nic.h
@@ -265,14 +265,9 @@ struct nicvf_drv_stats {

struct cavium_ptp;

-struct xcast_addr {
- struct list_head list;
- u64 addr;
-};
-
struct xcast_addr_list {
- struct list_head list;
int count;
+ u64 mc[];
};

struct nicvf_work {
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
index 1e9a31fef729..7d9e58533a83 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
work.work);
struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
union nic_mbx mbx = {};
- struct xcast_addr *xaddr, *next;
+ u8 idx = 0;

if (!vf_work)
return;
@@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
/* check if we have any specific MACs to be added to PF DMAC filter */
if (vf_work->mc) {
/* now go through kernel list of MACs and add them one by one */
- list_for_each_entry_safe(xaddr, next,
- &vf_work->mc->list, list) {
+ for (idx = 0; idx < vf_work->mc->count; idx++) {
mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
- mbx.xcast.data.mac = xaddr->addr;
+ mbx.xcast.data.mac = vf_work->mc->mc[idx];
nicvf_send_msg_to_pf(nic, &mbx);
-
- /* after receiving ACK from PF release memory */
- list_del(&xaddr->list);
- kfree(xaddr);
- vf_work->mc->count--;
}
kfree(vf_work->mc);
}
@@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
mode |= BGX_XCAST_MCAST_FILTER;
/* here we need to copy mc addrs */
if (netdev_mc_count(netdev)) {
- struct xcast_addr *xaddr;
-
- mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
- INIT_LIST_HEAD(&mc_list->list);
+ mc_list = kmalloc(offsetof(typeof(*mc_list),
+ mc[netdev_mc_count(netdev)]),
+ GFP_ATOMIC);
+ if (unlikely(!mc_list))
+ return;
+ mc_list->count = 0;
netdev_hw_addr_list_for_each(ha, &netdev->mc) {
- xaddr = kmalloc(sizeof(*xaddr),
- GFP_ATOMIC);
- xaddr->addr =
+ mc_list->mc[mc_list->count] =
ether_addr_to_u64(ha->addr);
- list_add_tail(&xaddr->list,
- &mc_list->list);
mc_list->count++;
}
}
--
2.14.3


2018-04-06 15:10:17

by David Miller

[permalink] [raw]
Subject: Re: [PATCH v2] net: thunderx: rework mac addresses list to u64 array

From: Vadim Lomovtsev <[email protected]>
Date: Fri, 6 Apr 2018 04:14:25 -0700

> diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
> index 5fc46c5a4f36..448d1fafc827 100644
> --- a/drivers/net/ethernet/cavium/thunder/nic.h
> +++ b/drivers/net/ethernet/cavium/thunder/nic.h
> @@ -265,14 +265,9 @@ struct nicvf_drv_stats {
>
> struct cavium_ptp;
>
> -struct xcast_addr {
> - struct list_head list;
> - u64 addr;
> -};
> -
> struct xcast_addr_list {
> - struct list_head list;
> int count;
> + u64 mc[];
> };
>
> struct nicvf_work {
> diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> index 1e9a31fef729..a26d8bc92e01 100644
> --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> work.work);
> struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> union nic_mbx mbx = {};
> - struct xcast_addr *xaddr, *next;
> + u8 idx = 0;
^^^^^^^^^^^

>
> if (!vf_work)
> return;
> @@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> /* check if we have any specific MACs to be added to PF DMAC filter */
> if (vf_work->mc) {
> /* now go through kernel list of MACs and add them one by one */
> - list_for_each_entry_safe(xaddr, next,
> - &vf_work->mc->list, list) {
> + for (idx = 0; idx < vf_work->mc->count; idx++) {

vf_work->mx->count is an 'int' therefore 'idx' should be declared 'int' as well,
not a 'u8'.

2018-04-06 15:16:01

by Vadim Lomovtsev

[permalink] [raw]
Subject: Re: [PATCH v2] net: thunderx: rework mac addresses list to u64 array

On Fri, Apr 06, 2018 at 11:06:03AM -0400, David Miller wrote:
> From: Vadim Lomovtsev <[email protected]>
> Date: Fri, 6 Apr 2018 04:14:25 -0700
>
> > diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
> > index 5fc46c5a4f36..448d1fafc827 100644
> > --- a/drivers/net/ethernet/cavium/thunder/nic.h
> > +++ b/drivers/net/ethernet/cavium/thunder/nic.h
> > @@ -265,14 +265,9 @@ struct nicvf_drv_stats {
> >
> > struct cavium_ptp;
> >
> > -struct xcast_addr {
> > - struct list_head list;
> > - u64 addr;
> > -};
> > -
> > struct xcast_addr_list {
> > - struct list_head list;
> > int count;
> > + u64 mc[];
> > };
> >
> > struct nicvf_work {
> > diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > index 1e9a31fef729..a26d8bc92e01 100644
> > --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> > @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> > work.work);
> > struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> > union nic_mbx mbx = {};
> > - struct xcast_addr *xaddr, *next;
> > + u8 idx = 0;
> ^^^^^^^^^^^
>
> >
> > if (!vf_work)
> > return;
> > @@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> > /* check if we have any specific MACs to be added to PF DMAC filter */
> > if (vf_work->mc) {
> > /* now go through kernel list of MACs and add them one by one */
> > - list_for_each_entry_safe(xaddr, next,
> > - &vf_work->mc->list, list) {
> > + for (idx = 0; idx < vf_work->mc->count; idx++) {
>
> vf_work->mx->count is an 'int' therefore 'idx' should be declared 'int' as well,
> not a 'u8'.

My bad, sorry.
Will post v4 shortly then.


WBR,
Vadim

2018-04-06 15:19:36

by Vadim Lomovtsev

[permalink] [raw]
Subject: Re: [PATCH v3] net: thunderx: rework mac addresses list to u64 array

Self-NACK here, because of https://lkml.org/lkml/2018/4/6/724

Sorry for noise.

Vadim

On Fri, Apr 06, 2018 at 07:04:43AM -0700, Vadim Lomovtsev wrote:
> From: Vadim Lomovtsev <[email protected]>
>
> It is too expensive to pass u64 values via linked list, instead
> allocate array for them by overall number of mac addresses from netdev.
>
> This eventually removes multiple kmalloc() calls, aviod memory
> fragmentation and allow to put single null check on kmalloc
> return value in order to prevent a potential null pointer dereference.
>
> Addresses-Coverity-ID: 1467429 ("Dereference null return value")
> Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
> Reported-by: Dan Carpenter <[email protected]>
> Signed-off-by: Vadim Lomovtsev <[email protected]>
> ---
> Changes from v1 to v2:
> - C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];
> Changes from v2 to v3:
> - update commit description with 'Reported-by: Dan Carpenter';
> - update size calculations for mc list to offsetof() call
> instead of explicit arithmetic;
> ---
> drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
> drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
> 2 files changed, 11 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
> index 5fc46c5a4f36..448d1fafc827 100644
> --- a/drivers/net/ethernet/cavium/thunder/nic.h
> +++ b/drivers/net/ethernet/cavium/thunder/nic.h
> @@ -265,14 +265,9 @@ struct nicvf_drv_stats {
>
> struct cavium_ptp;
>
> -struct xcast_addr {
> - struct list_head list;
> - u64 addr;
> -};
> -
> struct xcast_addr_list {
> - struct list_head list;
> int count;
> + u64 mc[];
> };
>
> struct nicvf_work {
> diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> index 1e9a31fef729..7d9e58533a83 100644
> --- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> +++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
> @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> work.work);
> struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> union nic_mbx mbx = {};
> - struct xcast_addr *xaddr, *next;
> + u8 idx = 0;
>
> if (!vf_work)
> return;
> @@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> /* check if we have any specific MACs to be added to PF DMAC filter */
> if (vf_work->mc) {
> /* now go through kernel list of MACs and add them one by one */
> - list_for_each_entry_safe(xaddr, next,
> - &vf_work->mc->list, list) {
> + for (idx = 0; idx < vf_work->mc->count; idx++) {
> mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
> - mbx.xcast.data.mac = xaddr->addr;
> + mbx.xcast.data.mac = vf_work->mc->mc[idx];
> nicvf_send_msg_to_pf(nic, &mbx);
> -
> - /* after receiving ACK from PF release memory */
> - list_del(&xaddr->list);
> - kfree(xaddr);
> - vf_work->mc->count--;
> }
> kfree(vf_work->mc);
> }
> @@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
> mode |= BGX_XCAST_MCAST_FILTER;
> /* here we need to copy mc addrs */
> if (netdev_mc_count(netdev)) {
> - struct xcast_addr *xaddr;
> -
> - mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
> - INIT_LIST_HEAD(&mc_list->list);
> + mc_list = kmalloc(offsetof(typeof(*mc_list),
> + mc[netdev_mc_count(netdev)]),
> + GFP_ATOMIC);
> + if (unlikely(!mc_list))
> + return;
> + mc_list->count = 0;
> netdev_hw_addr_list_for_each(ha, &netdev->mc) {
> - xaddr = kmalloc(sizeof(*xaddr),
> - GFP_ATOMIC);
> - xaddr->addr =
> + mc_list->mc[mc_list->count] =
> ether_addr_to_u64(ha->addr);
> - list_add_tail(&xaddr->list,
> - &mc_list->list);
> mc_list->count++;
> }
> }
> --
> 2.14.3
>

2018-04-06 19:58:50

by Vadim Lomovtsev

[permalink] [raw]
Subject: [PATCH v4] net: thunderx: rework mac addresses list to u64 array

From: Vadim Lomovtsev <[email protected]>

It is too expensive to pass u64 values via linked list, instead
allocate array for them by overall number of mac addresses from netdev.

This eventually removes multiple kmalloc() calls, aviod memory
fragmentation and allow to put single null check on kmalloc
return value in order to prevent a potential null pointer dereference.

Addresses-Coverity-ID: 1467429 ("Dereference null return value")
Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Vadim Lomovtsev <[email protected]>
---
Changes from v1 to v2:
- C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];
Changes from v2 to v3:
- update commit description with 'Reported-by: Dan Carpenter';
- update size calculations for mc list to offsetof() call
instead of explicit arithmetic;
Changes from v3 to v4:
- change loop control variable type from u8 to int, accordingly
to mc_count size;
---
drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
2 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
index 5fc46c5..448d1fa 100644
--- a/drivers/net/ethernet/cavium/thunder/nic.h
+++ b/drivers/net/ethernet/cavium/thunder/nic.h
@@ -265,14 +265,9 @@ struct nicvf_drv_stats {

struct cavium_ptp;

-struct xcast_addr {
- struct list_head list;
- u64 addr;
-};
-
struct xcast_addr_list {
- struct list_head list;
int count;
+ u64 mc[];
};

struct nicvf_work {
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
index 1e9a31f..6bd5658 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
work.work);
struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
union nic_mbx mbx = {};
- struct xcast_addr *xaddr, *next;
+ int idx = 0;

if (!vf_work)
return;
@@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
/* check if we have any specific MACs to be added to PF DMAC filter */
if (vf_work->mc) {
/* now go through kernel list of MACs and add them one by one */
- list_for_each_entry_safe(xaddr, next,
- &vf_work->mc->list, list) {
+ for (idx = 0; idx < vf_work->mc->count; idx++) {
mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
- mbx.xcast.data.mac = xaddr->addr;
+ mbx.xcast.data.mac = vf_work->mc->mc[idx];
nicvf_send_msg_to_pf(nic, &mbx);
-
- /* after receiving ACK from PF release memory */
- list_del(&xaddr->list);
- kfree(xaddr);
- vf_work->mc->count--;
}
kfree(vf_work->mc);
}
@@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
mode |= BGX_XCAST_MCAST_FILTER;
/* here we need to copy mc addrs */
if (netdev_mc_count(netdev)) {
- struct xcast_addr *xaddr;
-
- mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
- INIT_LIST_HEAD(&mc_list->list);
+ mc_list = kmalloc(offsetof(typeof(*mc_list),
+ mc[netdev_mc_count(netdev)]),
+ GFP_ATOMIC);
+ if (unlikely(!mc_list))
+ return;
+ mc_list->count = 0;
netdev_hw_addr_list_for_each(ha, &netdev->mc) {
- xaddr = kmalloc(sizeof(*xaddr),
- GFP_ATOMIC);
- xaddr->addr =
+ mc_list->mc[mc_list->count] =
ether_addr_to_u64(ha->addr);
- list_add_tail(&xaddr->list,
- &mc_list->list);
mc_list->count++;
}
}
--
1.8.3.1


2018-04-08 17:26:29

by David Miller

[permalink] [raw]
Subject: Re: [PATCH v4] net: thunderx: rework mac addresses list to u64 array

From: Vadim Lomovtsev <[email protected]>
Date: Fri, 6 Apr 2018 12:53:54 -0700

> @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> work.work);
> struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> union nic_mbx mbx = {};
> - struct xcast_addr *xaddr, *next;
> + int idx = 0;

No need to initialize idx.

> + for (idx = 0; idx < vf_work->mc->count; idx++) {

As it is always explicitly initialized at, and only used inside of,
this loop.

2018-04-09 09:47:59

by Vadim Lomovtsev

[permalink] [raw]
Subject: Re: [PATCH v4] net: thunderx: rework mac addresses list to u64 array

On Sun, Apr 08, 2018 at 12:42:00PM -0400, David Miller wrote:
> From: Vadim Lomovtsev <[email protected]>
> Date: Fri, 6 Apr 2018 12:53:54 -0700
>
> > @@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
> > work.work);
> > struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
> > union nic_mbx mbx = {};
> > - struct xcast_addr *xaddr, *next;
> > + int idx = 0;
>
> No need to initialize idx.
>
> > + for (idx = 0; idx < vf_work->mc->count; idx++) {
>
> As it is always explicitly initialized at, and only used inside of,
> this loop.

Ok, will post next version shortly.
Thanks for your time.

Vadim

2018-04-09 13:28:21

by Vadim Lomovtsev

[permalink] [raw]
Subject: [PATCH v5] net: thunderx: rework mac addresses list to u64 array

From: Vadim Lomovtsev <[email protected]>

It is too expensive to pass u64 values via linked list, instead
allocate array for them by overall number of mac addresses from netdev.

This eventually removes multiple kmalloc() calls, aviod memory
fragmentation and allow to put single null check on kmalloc
return value in order to prevent a potential null pointer dereference.

Addresses-Coverity-ID: 1467429 ("Dereference null return value")
Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
Reported-by: Dan Carpenter <[email protected]>
Signed-off-by: Vadim Lomovtsev <[email protected]>
---
Changes from v1 to v2:
- C99 syntax: update xcast_addr_list struct field mc[0] -> mc[];
Changes from v2 to v3:
- update commit description with 'Reported-by: Dan Carpenter';
- update size calculations for mc list to offsetof() call
instead of explicit arithmetic;
Changes from v3 to v4:
- change loop control variable type from u8 to int, accordingly
to mc_count size;
Changes from v4 to v5:
- remove explicit initialization of 'idx' variable as per review comment;
---
drivers/net/ethernet/cavium/thunder/nic.h | 7 +-----
drivers/net/ethernet/cavium/thunder/nicvf_main.c | 28 +++++++++---------------
2 files changed, 11 insertions(+), 24 deletions(-)

diff --git a/drivers/net/ethernet/cavium/thunder/nic.h b/drivers/net/ethernet/cavium/thunder/nic.h
index 5fc46c5a4f36..448d1fafc827 100644
--- a/drivers/net/ethernet/cavium/thunder/nic.h
+++ b/drivers/net/ethernet/cavium/thunder/nic.h
@@ -265,14 +265,9 @@ struct nicvf_drv_stats {

struct cavium_ptp;

-struct xcast_addr {
- struct list_head list;
- u64 addr;
-};
-
struct xcast_addr_list {
- struct list_head list;
int count;
+ u64 mc[];
};

struct nicvf_work {
diff --git a/drivers/net/ethernet/cavium/thunder/nicvf_main.c b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
index 1e9a31fef729..707db3304396 100644
--- a/drivers/net/ethernet/cavium/thunder/nicvf_main.c
+++ b/drivers/net/ethernet/cavium/thunder/nicvf_main.c
@@ -1929,7 +1929,7 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
work.work);
struct nicvf *nic = container_of(vf_work, struct nicvf, rx_mode_work);
union nic_mbx mbx = {};
- struct xcast_addr *xaddr, *next;
+ int idx;

if (!vf_work)
return;
@@ -1956,16 +1956,10 @@ static void nicvf_set_rx_mode_task(struct work_struct *work_arg)
/* check if we have any specific MACs to be added to PF DMAC filter */
if (vf_work->mc) {
/* now go through kernel list of MACs and add them one by one */
- list_for_each_entry_safe(xaddr, next,
- &vf_work->mc->list, list) {
+ for (idx = 0; idx < vf_work->mc->count; idx++) {
mbx.xcast.msg = NIC_MBOX_MSG_ADD_MCAST;
- mbx.xcast.data.mac = xaddr->addr;
+ mbx.xcast.data.mac = vf_work->mc->mc[idx];
nicvf_send_msg_to_pf(nic, &mbx);
-
- /* after receiving ACK from PF release memory */
- list_del(&xaddr->list);
- kfree(xaddr);
- vf_work->mc->count--;
}
kfree(vf_work->mc);
}
@@ -1996,17 +1990,15 @@ static void nicvf_set_rx_mode(struct net_device *netdev)
mode |= BGX_XCAST_MCAST_FILTER;
/* here we need to copy mc addrs */
if (netdev_mc_count(netdev)) {
- struct xcast_addr *xaddr;
-
- mc_list = kmalloc(sizeof(*mc_list), GFP_ATOMIC);
- INIT_LIST_HEAD(&mc_list->list);
+ mc_list = kmalloc(offsetof(typeof(*mc_list),
+ mc[netdev_mc_count(netdev)]),
+ GFP_ATOMIC);
+ if (unlikely(!mc_list))
+ return;
+ mc_list->count = 0;
netdev_hw_addr_list_for_each(ha, &netdev->mc) {
- xaddr = kmalloc(sizeof(*xaddr),
- GFP_ATOMIC);
- xaddr->addr =
+ mc_list->mc[mc_list->count] =
ether_addr_to_u64(ha->addr);
- list_add_tail(&xaddr->list,
- &mc_list->list);
mc_list->count++;
}
}
--
2.14.3


2018-04-09 15:05:12

by David Miller

[permalink] [raw]
Subject: Re: [PATCH v5] net: thunderx: rework mac addresses list to u64 array

From: Vadim Lomovtsev <[email protected]>
Date: Mon, 9 Apr 2018 06:24:48 -0700

> From: Vadim Lomovtsev <[email protected]>
>
> It is too expensive to pass u64 values via linked list, instead
> allocate array for them by overall number of mac addresses from netdev.
>
> This eventually removes multiple kmalloc() calls, aviod memory
> fragmentation and allow to put single null check on kmalloc
> return value in order to prevent a potential null pointer dereference.
>
> Addresses-Coverity-ID: 1467429 ("Dereference null return value")
> Fixes: 37c3347eb247 ("net: thunderx: add ndo_set_rx_mode callback implementation for VF")
> Reported-by: Dan Carpenter <[email protected]>
> Signed-off-by: Vadim Lomovtsev <[email protected]>

Applied, thanks.