Skip to content

L
linux
Switch branch/tag
  1. 20 Jun, 2017 11 commits
  3. 19 Jun, 2017 9 commits
  5. 18 Jun, 2017 20 commits
    • Florian Fainelli's avatar
      net: dsa: Fix legacy probing · 06d4d450
      Florian Fainelli authored 
      After commit 6d3c8c0d ("net: dsa: Remove master_netdev and
use dst->cpu_dp->netdev") and a29342e7 ("net: dsa: Associate
slave network device with CPU port") we would be seeing NULL pointer
dereferences when accessing dst->cpu_dp->netdev too early. In the legacy
code, we actually know early in advance the master network device, so
pass it down to the relevant functions.

Fixes: 6d3c8c0d ("net: dsa: Remove master_netdev and use dst->cpu_dp->netdev")
Fixes: a29342e7 ("net: dsa: Associate slave network device with CPU port")
Reported-by: default avatarJason Cobham <jcobham@questertangent.com>
Tested-by: default avatarJason Cobham <jcobham@questertangent.com>
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: default avatarVivien Didelot <vivien.didelot@savoirfairelinux.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      06d4d450
    • Dave Watson's avatar
      tls: update Kconfig · d807ec65
      Dave Watson authored 
      Missing crypto deps for some platforms.
Default to n for new module.

config: m68k-amcore_defconfig (attached as .config)
compiler: m68k-linux-gcc (GCC) 4.9.0

make.cross ARCH=m68k
All errors (new ones prefixed by >>):

   net/built-in.o: In function `tls_set_sw_offload':
>> (.text+0x732f8): undefined reference to `crypto_alloc_aead'
   net/built-in.o: In function `tls_set_sw_offload':
>> (.text+0x7333c): undefined reference to `crypto_aead_setkey'
   net/built-in.o: In function `tls_set_sw_offload':
>> (.text+0x73354): undefined reference to `crypto_aead_setauthsize'
Reported-by: default avatarkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: default avatarDave Watson <davejwatson@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      d807ec65
    • David S. Miller's avatar
      Merge branch 'net-remove-dst-garbage-collector-logic' · ffe95ecf
      David S. Miller authored 
      Wei Wang says:

====================
remove dst garbage collector logic

The current mechanism of dst release is a bit complicated. It is because
the users of dst get divided into 2 situations:
  1. Most users take the reference count when using a dst and release the
     reference count when done.
  2. Exceptional users like IPv4/IPv6/decnet/xfrm routing code do not take
     reference count when referencing to a dst due to some histotic reasons.

Due to those exceptional use cases in 2, reference count being 0 is not an
adequate evidence to indicate that no user is using this dst. So users in 1
can't free the dst simply based on reference count being 0 because users in
2 might still hold reference to it.
Instead, a dst garbage list is needed to hold the dst entries that already
get removed by the users in 2 but are still held by users in 1. And a periodic
garbage collector task is run to check all the dst entries in the list to see
if the users in 1 have released the reference to those dst entries.
If so, the dst is now ready to be freed.

This logic introduces unnecessary complications in the dst code which makes it
hard to understand and to debug.

In order to get rid of the whole dst garbage collector (gc) and make the dst
code more unified and simplified, we can make the users in 2 also take reference
count on the dst and release it properly when done.
This way, dst can be safely freed once the refcount drops to 0 and no gc
thread is needed anymore.

This patch series' target is to completely get rid of dst gc logic and free
dst based on reference count only.
Patch 1-3 are preparation patches to do some cleanup/improvement on the existing
code to make later work easier.
Patch 4-21 are real implementations.
In these patches, a temporary flag DST_NOGC is used to help transition
those exceptional users one by one. Once every component is transitioned,
this temporary flag is removed.
By the end of this patch series, all dst are refcounted when being used
and released when done. And dst will be freed when its refcount drops to 0.
No dst gc task is running anymore.

Note: This patch series depends on the decnet fix that was sent right before:
      "decnet: always not take dst->__refcnt when inserting dst into hash table"

v2:
  add curly braces in udp_v4/6_early_demux() in patch 02
  add EXPORT_SYMBOL() for dst_dev_put() in patch 05
====================
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ffe95ecf
    • Wei Wang's avatar
      net: add debug atomic_inc_not_zero() in dst_hold() · 44ebe791
      Wei Wang authored 
      This patch is meant to add a debug warning on the situation where dst is
being held during its destroy phase. This could potentially cause double
free issue on the dst.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      44ebe791
    • Wei Wang's avatar
      net: reorder all the dst flags · 1eb04e7c
      Wei Wang authored 
      As some dst flags are removed, reorder the dst flags to fill in the
blanks.
Note: these flags are not exposed into user space. So it is safe to
reorder.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1eb04e7c
    • Wei Wang's avatar
      net: remove DST_NOCACHE flag · a4c2fd7f
      Wei Wang authored 
      DST_NOCACHE flag check has been removed from dst_release() and
dst_hold_safe() in a previous patch because all the dst are now ref
counted properly and can be released based on refcnt only.
Looking at the rest of the DST_NOCACHE use, all of them can now be
removed or replaced with other checks.
So this patch gets rid of all the DST_NOCACHE usage and remove this flag
completely.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a4c2fd7f
    • Wei Wang's avatar
      net: remove DST_NOGC flag · b2a9c0ed
      Wei Wang authored 
      Now that all the components have been changed to release dst based on
refcnt only and not depend on dst gc anymore, we can remove the
temporary flag DST_NOGC.

Note that we also need to remove the DST_NOCACHE check in dst_release()
and dst_hold_safe() because now all the dst are released based on refcnt
and behaves as DST_NOCACHE.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b2a9c0ed
    • Wei Wang's avatar
      net: remove dst gc related code · 5b7c9a8f
      Wei Wang authored 
      This patch removes all dst gc related code and all the dst free
functions
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      5b7c9a8f
    • Wei Wang's avatar
      decnet: take dst->__refcnt when struct dn_route is created · 560fd93b
      Wei Wang authored 
      struct dn_route is inserted into dn_rt_hash_table but no dst->__refcnt
is taken.
This patch makes sure the dn_rt_hash_table's reference to the dst is ref
counted.

As the dst is always ref counted properly, we can safely mark
DST_NOGC flag so dst_release() will release dst based on refcnt only.
And dst gc is no longer needed and all dst_free() or its related
function calls should be replaced with dst_release() or
dst_release_immediate(). And dst_dev_put() is called when removing dst
from the hash table to release the reference on dst->dev before we lose
pointer to it.

Also, correct the logic in dn_dst_check_expire() and dn_dst_gc() to
check dst->__refcnt to be > 1 to indicate it is referenced by other
users.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      560fd93b
    • Wei Wang's avatar
      xfrm: take refcnt of dst when creating struct xfrm_dst bundle · 52df157f
      Wei Wang authored 
      During the creation of xfrm_dst bundle, always take ref count when
allocating the dst. This way, xfrm_bundle_create() will form a linked
list of dst with dst->child pointing to a ref counted dst child. And
the returned dst pointer is also ref counted. This makes the link from
the flow cache to this dst now ref counted properly.
As the dst is always ref counted properly, we can safely mark
DST_NOGC flag so dst_release() will release dst based on refcnt only.
And dst gc is no longer needed and all dst_free() and its related
function calls should be replaced with dst_release() or
dst_release_immediate().

The special handling logic for dst->child in dst_destroy() can be
replaced with a simple dst_release_immediate() call on the child to
release the whole list linked by dst->child pointer.
Previously used DST_NOHASH flag is not needed anymore as well. The
reason that DST_NOHASH is used in the existing code is mainly to prevent
the dst inserted in the fib tree to be wrongly destroyed during the
deletion of the xfrm_dst bundle. So in the existing code, DST_NOHASH
flag is marked in all the dst children except the one which is in the
fib tree.
However, with this patch series to remove dst gc logic and release dst
only based on ref count, it is safe to release all the children from a
xfrm_dst bundle as long as the dst children are all ref counted
properly which is already the case in the existing code.
So, this patch removes the use of DST_NOHASH flag.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      52df157f
    • Wei Wang's avatar
      ipv6: get rid of icmp6 dst garbage collector · db916649
      Wei Wang authored 
      icmp6 dst route is currently ref counted during creation and will be
freed by user during its call of dst_release(). So no need of a garbage
collector for it.
Remove all icmp6 dst garbage collector related code.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      db916649
    • Wei Wang's avatar
      ipv6: mark DST_NOGC and remove the operation of dst_free() · 587fea74
      Wei Wang authored 
      With the previous preparation patches, we are ready to get rid of the
dst gc operation in ipv6 code and release dst based on refcnt only.
So this patch adds DST_NOGC flag for all IPv6 dst and remove the calls
to dst_free() and its related functions.
At this point, all dst created in ipv6 code do not use the dst gc
anymore and will be destroyed at the point when refcnt drops to 0.

Also, as icmp6 dst route is refcounted during creation and will be freed
by user during its call of dst_release(), there is no need to add this
dst to the icmp6 gc list as well.
Instead, we need to add it into uncached list so that when a
NETDEV_DOWN/NETDEV_UNREGISRER event comes, we can properly go through
these icmp6 dst as well and release the net device properly.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      587fea74
    • Wei Wang's avatar
      ipv6: call dst_hold_safe() properly · ad65a2f0
      Wei Wang authored 
      Similar as ipv4, ipv6 path also needs to call dst_hold_safe() when
necessary to avoid double free issue on the dst.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ad65a2f0
    • Wei Wang's avatar
      ipv6: call dst_dev_put() properly · 9514528d
      Wei Wang authored 
      As the intend of this patch series is to completely remove dst gc,
we need to call dst_dev_put() to release the reference to dst->dev
when removing routes from fib because we won't keep the gc list anymore
and will lose the dst pointer right after removing the routes.
Without the gc list, there is no way to find all the dst's that have
dst->dev pointing to the going-down dev.
Hence, we are doing dst_dev_put() immediately before we lose the last
reference of the dst from the routing code. The next dst_check() will
trigger a route re-lookup to find another route (if there is any).
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      9514528d
    • Wei Wang's avatar
      ipv6: take dst->__refcnt for insertion into fib6 tree · 1cfb71ee
      Wei Wang authored 
      In IPv6 routing code, struct rt6_info is created for each static route
and RTF_CACHE route and inserted into fib6 tree. In both cases, dst
ref count is not taken.
As explained in the previous patch, this leads to the need of the dst
garbage collector.

This patch holds ref count of dst before inserting the route into fib6
tree and properly releases the dst when deleting it from the fib6 tree
as a preparation in order to fully get rid of dst gc later.

Also, correct fib6_age() logic to check dst->__refcnt to be 1 to indicate
no user is referencing the dst.

And remove dst_hold() in vrf_rt6_create() as ip6_dst_alloc() already puts
dst->__refcnt to 1.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      1cfb71ee
    • Wei Wang's avatar
      ipv4: mark DST_NOGC and remove the operation of dst_free() · b838d5e1
      Wei Wang authored 
      With the previous preparation patches, we are ready to get rid of the
dst gc operation in ipv4 code and release dst based on refcnt only.
So this patch adds DST_NOGC flag for all IPv4 dst and remove the calls
to dst_free().
At this point, all dst created in ipv4 code do not use the dst gc
anymore and will be destroyed at the point when refcnt drops to 0.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      b838d5e1
    • Wei Wang's avatar
      ipv4: call dst_hold_safe() properly · 9df16efa
      Wei Wang authored 
      This patch checks all the calls to
dst_hold()/skb_dst_force()/dst_clone()/dst_use() to see if
dst_hold_safe() is needed to avoid double free issue if dst
gc is removed and dst_release() directly destroys dst when
dst->__refcnt drops to 0.

In tx path, TCP hold sk->sk_rx_dst ref count and also hold sock_lock().
UDP and other similar protocols always hold refcount for
skb->_skb_refdst. So both paths seem to be safe.

In rx path, as it is lockless and skb_dst_set_noref() is likely to be
used, dst_hold_safe() should always be used when trying to hold dst.

In the routing code, if dst is held during an rcu protected session, it
is necessary to call dst_hold_safe() as the current dst might be in its
rcu grace period.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      9df16efa
    • Wei Wang's avatar
      ipv4: call dst_dev_put() properly · 95c47f9c
      Wei Wang authored 
      As the intend of this patch series is to completely remove dst gc,
we need to call dst_dev_put() to release the reference to dst->dev
when removing routes from fib because we won't keep the gc list anymore
and will lose the dst pointer right after removing the routes.
Without the gc list, there is no way to find all the dst's that have
dst->dev pointing to the going-down dev.
Hence, we are doing dst_dev_put() immediately before we lose the last
reference of the dst from the routing code. The next dst_check() will
trigger a route re-lookup to find another route (if there is any).
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      95c47f9c
    • Wei Wang's avatar
      ipv4: take dst->__refcnt when caching dst in fib · 0830106c
      Wei Wang authored 
      In IPv4 routing code, fib_nh and fib_nh_exception can hold pointers
to struct rtable but they never increment dst->__refcnt.
This leads to the need of the dst garbage collector because when user
is done with this dst and calls dst_release(), it can only decrement
dst->__refcnt and can not free the dst even it sees dst->__refcnt
drops from 1 to 0 (unless DST_NOCACHE flag is set) because the routing
code might still hold reference to it.
And when the routing code tries to delete a route, it has to put the
dst to the gc_list if dst->__refcnt is not yet 0 and have a gc thread
running periodically to check on dst->__refcnt and finally to free dst
when refcnt becomes 0.

This patch increments dst->__refcnt when
fib_nh/fib_nh_exception holds reference to this dst and properly release
the dst when fib_nh/fib_nh_exception has been updated with a new dst.

This patch is a preparation in order to fully get rid of dst gc later.
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      0830106c
    • Wei Wang's avatar
      net: introduce a new function dst_dev_put() · 4a6ce2b6
      Wei Wang authored 
      This function should be called when removing routes from fib tree after
the dst gc is no longer in use.
We first mark DST_OBSOLETE_DEAD on this dst to make sure next
dst_ops->check() fails and returns NULL.
Secondly, as we no longer keep the gc_list, we need to properly
release dst->dev right at the moment when the dst is removed from
the fib/fib6 tree.
It does the following:
1. change dst->input and output pointers to dst_discard/dst_dscard_out to
   discard all packets
2. replace dst->dev with loopback interface
Signed-off-by: default avatarWei Wang <weiwan@google.com>
Acked-by: default avatarMartin KaFai Lau <kafai@fb.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      4a6ce2b6
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7