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linux-next/net/Kconfig.debug

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net: add net device refcount tracker infrastructure net device are refcounted. Over the years we had numerous bugs caused by imbalanced dev_hold() and dev_put() calls. The general idea is to be able to precisely pair each decrement with a corresponding prior increment. Both share a cookie, basically a pointer to private data storing stack traces. This patch adds dev_hold_track() and dev_put_track(). To use these helpers, each data structure owning a refcount should also use a "netdevice_tracker" to pair the hold and put. netdevice_tracker dev_tracker; ... dev_hold_track(dev, &dev_tracker, GFP_ATOMIC); ... dev_put_track(dev, &dev_tracker); Whenever a leak happens, we will get precise stack traces of the point dev_hold_track() happened, at device dismantle phase. We will also get a stack trace if too many dev_put_track() for the same netdevice_tracker are attempted. This is guarded by CONFIG_NET_DEV_REFCNT_TRACKER option. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-05 04:21:57 +00:00
# SPDX-License-Identifier: GPL-2.0-only
config NET_DEV_REFCNT_TRACKER
bool "Enable net device refcount tracking"
net: make NET_(DEV|NS)_REFCNT_TRACKER depend on NET It makes little sense to ask if networking namespace or net device refcount tracking shall be enabled for debug kernel builds without network support. This is similar to the commit eb0b39efb7d9 ("net: CONFIG_DEBUG_NET depends on CONFIG_NET"). Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Link: https://lore.kernel.org/r/20220915124256.32512-1-lukas.bulwahn@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-15 12:42:56 +00:00
depends on DEBUG_KERNEL && STACKTRACE_SUPPORT && NET
net: add net device refcount tracker infrastructure net device are refcounted. Over the years we had numerous bugs caused by imbalanced dev_hold() and dev_put() calls. The general idea is to be able to precisely pair each decrement with a corresponding prior increment. Both share a cookie, basically a pointer to private data storing stack traces. This patch adds dev_hold_track() and dev_put_track(). To use these helpers, each data structure owning a refcount should also use a "netdevice_tracker" to pair the hold and put. netdevice_tracker dev_tracker; ... dev_hold_track(dev, &dev_tracker, GFP_ATOMIC); ... dev_put_track(dev, &dev_tracker); Whenever a leak happens, we will get precise stack traces of the point dev_hold_track() happened, at device dismantle phase. We will also get a stack trace if too many dev_put_track() for the same netdevice_tracker are attempted. This is guarded by CONFIG_NET_DEV_REFCNT_TRACKER option. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-05 04:21:57 +00:00
select REF_TRACKER
default n
help
Enable debugging feature to track device references.
This adds memory and cpu costs.
net: add networking namespace refcount tracker We have 100+ syzbot reports about netns being dismantled too soon, still unresolved as of today. We think a missing get_net() or an extra put_net() is the root cause. In order to find the bug(s), and be able to spot future ones, this patch adds CONFIG_NET_NS_REFCNT_TRACKER and new helpers to precisely pair all put_net() with corresponding get_net(). To use these helpers, each data structure owning a refcount should also use a "netns_tracker" to pair the get and put. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-10 07:44:21 +00:00
config NET_NS_REFCNT_TRACKER
bool "Enable networking namespace refcount tracking"
net: make NET_(DEV|NS)_REFCNT_TRACKER depend on NET It makes little sense to ask if networking namespace or net device refcount tracking shall be enabled for debug kernel builds without network support. This is similar to the commit eb0b39efb7d9 ("net: CONFIG_DEBUG_NET depends on CONFIG_NET"). Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Link: https://lore.kernel.org/r/20220915124256.32512-1-lukas.bulwahn@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-15 12:42:56 +00:00
depends on DEBUG_KERNEL && STACKTRACE_SUPPORT && NET
net: add networking namespace refcount tracker We have 100+ syzbot reports about netns being dismantled too soon, still unresolved as of today. We think a missing get_net() or an extra put_net() is the root cause. In order to find the bug(s), and be able to spot future ones, this patch adds CONFIG_NET_NS_REFCNT_TRACKER and new helpers to precisely pair all put_net() with corresponding get_net(). To use these helpers, each data structure owning a refcount should also use a "netns_tracker" to pair the get and put. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-10 07:44:21 +00:00
select REF_TRACKER
default n
help
Enable debugging feature to track netns references.
This adds memory and cpu costs.
net: add CONFIG_DEBUG_NET This config option enables network debugging checks. This patch adds DEBUG_NET_WARN_ON_ONCE(cond) Note that this is not a replacement for WARN_ON_ONCE(cond) as (cond) is not evaluated if CONFIG_DEBUG_NET is not set. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-10 03:57:38 +00:00
config DEBUG_NET
bool "Add generic networking debug"
net: CONFIG_DEBUG_NET depends on CONFIG_NET It makes little sense to debug networking stacks if networking is not compiled in. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-02 16:18:57 +00:00
depends on DEBUG_KERNEL && NET
net: add CONFIG_DEBUG_NET This config option enables network debugging checks. This patch adds DEBUG_NET_WARN_ON_ONCE(cond) Note that this is not a replacement for WARN_ON_ONCE(cond) as (cond) is not evaluated if CONFIG_DEBUG_NET is not set. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2022-05-10 03:57:38 +00:00
help
Enable extra sanity checks in networking.
This is mostly used by fuzzers, but is safe to select.
rtnetlink: Add per-netns RTNL. The goal is to break RTNL down into per-netns mutex. This patch adds per-netns mutex and its helper functions, rtnl_net_lock() and rtnl_net_unlock(). rtnl_net_lock() acquires the global RTNL and per-netns RTNL mutex, and rtnl_net_unlock() releases them. We will replace 800+ rtnl_lock() with rtnl_net_lock() and finally removes rtnl_lock() in rtnl_net_lock(). When we need to nest per-netns RTNL mutex, we will use __rtnl_net_lock(), and its locking order is defined by rtnl_net_lock_cmp_fn() as follows: 1. init_net is first 2. netns address ascending order Note that the conversion will be done under CONFIG_DEBUG_NET_SMALL_RTNL with LOCKDEP so that we can carefully add the extra mutex without slowing down RTNL operations during conversion. Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2024-10-04 22:10:29 +00:00
config DEBUG_NET_SMALL_RTNL
bool "Add extra per-netns mutex inside RTNL"
depends on DEBUG_KERNEL && NET && LOCK_DEBUGGING_SUPPORT
select PROVE_LOCKING
default n
help
rtnl_lock() is being replaced with rtnl_net_lock() that
acquires the global RTNL and a small per-netns RTNL mutex.
During the conversion, rtnl_net_lock() just adds an extra
mutex in every RTNL scope and slows down the operations.
Once the conversion completes, rtnl_lock() will be removed
and rtnetlink will gain per-netns scalability.
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