There were crashes reported in this code, and the timer_shutdown()
warning in one of the previous patches indicates that the timeout
timer for the AP response (addba_resp_timer) is still armed while
we're stopping the aggregation session.
After a very long deliberation of the code, so far the only way I
could find that might cause this would be the following sequence:
- session start requested
- session start indicated to driver, but driver returns
IEEE80211_AMPDU_TX_START_DELAY_ADDBA
- session stop requested, sets HT_AGG_STATE_WANT_STOP
- session stop worker runs ___ieee80211_stop_tx_ba_session(),
sets HT_AGG_STATE_STOPPING
From here on, the order doesn't matter exactly, but:
1. driver calls ieee80211_start_tx_ba_cb_irqsafe(),
setting HT_AGG_STATE_START_CB
2. driver calls ieee80211_stop_tx_ba_cb_irqsafe(),
setting HT_AGG_STATE_STOP_CB
3. the worker will run ieee80211_start_tx_ba_cb() for
HT_AGG_STATE_START_CB
4. the worker will run ieee80211_stop_tx_ba_cb() for
HT_AGG_STATE_STOP_CB
(the order could also be 1./3./2./4.)
This will cause ieee80211_start_tx_ba_cb() to send out the AddBA
request frame to the AP and arm the timer, but we're already in
the middle of stopping and so the ieee80211_stop_tx_ba_cb() will
no longer assume it needs to stop anything.
Prevent this by checking for WANT_STOP/STOPPING in the start CB,
and warn if we're sending a frame on a stopping session.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230618214436.e5b52777462a.I0b2ed6658e81804279f5d7c9c1918cb1f6626bf2@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There are cases where keeping sdata locked for an operation. Add a
variant that does not take sdata lock to permit these usecases.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There are cases where keeping sdata locked for an operation. Add a
variant that does not take sdata lock to permit these usecases.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
STA MLD setup links may get removed if AP MLD remove the corresponding
affiliated APs with Multi-Link reconfiguration as described in
P802.11be_D3.0, section 35.3.6.2.2 Removing affiliated APs. Currently,
there is no support to notify such operation to cfg80211 and userspace.
Add support for the drivers to indicate STA MLD setup links removal to
cfg80211 and notify the same to userspace. Upon receiving such
indication from the driver, clear the MLO links information of the
removed links in the WDEV.
Signed-off-by: Veerendranath Jakkam <quic_vjakkam@quicinc.com>
Link: https://lore.kernel.org/r/20230317142153.237900-1-quic_vjakkam@quicinc.com
[rename function and attribute, fix kernel-doc]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The basic multi-link element within an multi-link probe response will
contain full information about BSSes that are part of an MLD AP. This
BSS information may be used to associate with a link of an MLD AP
without having received a beacon from the BSS itself.
This patch adds parsing of the data and adding/updating the BSS using
the received elements. Doing this means that userspace can discover the
BSSes using an ML probe request and request association on these links.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230618214436.29593bd0ae1f.Ic9a67b8f022360aa202b870a932897a389171b14@changeid
[swap loop conditions smatch complained about]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The removed code ran for any BSS that was not included in the MBSSID
element in order to update it. However, instead of using the correct
inheritance rules, it would simply copy the elements from the
transmitting AP. The result is that we would report incorrect elements
in this case.
After some discussions, it seems that there are likely not even APs
actually using this feature. Either way, removing the code decreases
complexity and makes the cfg80211 behaviour more correct.
Fixes: 0b8fb8235b ("cfg80211: Parsing of Multiple BSSID information in scanning")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230616094949.cfd6d8db1f26.Ia1044902b86cd7d366400a4bfb93691b8f05d68c@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The cfg80211_gen_new_ie function merges the IEs using inheritance rules.
Rewrite this function to fix issues around inheritance rules. In
particular, vendor elements do not require any special handling, as they
are either all inherited or overridden by the subprofile.
Also, add fragmentation handling as this may be needed in some cases.
This also changes the function to not require making a copy. The new
version could be optimized a bit by explicitly tracking which IEs have
been handled already rather than looking that up again every time.
Note that a small behavioural change is the removal of the SSID special
handling. This should be fine for the MBSSID element, as the SSID must
be included in the subelement.
Fixes: 0b8fb8235b ("cfg80211: Parsing of Multiple BSSID information in scanning")
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230616094949.bc6152e146db.I2b5f3bc45085e1901e5b5192a674436adaf94748@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Doing this simplifies the code somewhat, as iteration over the
nontransmitted BSSs is not required anymore. Also, mac80211 should
not be iterating over the nontrans_list as it should only be accessed
while the bss_lock is held.
It also simplifies parsing of the IEs somewhat, as cfg80211 already
extracts the IEs and passes them to the callback.
Note that the only user left requiring parsing a specific BSS is the
association code if a beacon is required by the hardware.
Signed-off-by: Benjamin Berg <benjamin.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230616094949.39ebfe2f9e59.Ia012b08e0feed8ec431b666888b459f6366f7bd1@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
-Wstringop-overflow is legitimately warning us about extra_size
pontentially being zero at some point, hence potenially ending
up _allocating_ zero bytes of memory for extra pointer and then
trying to access such object in a call to copy_from_user().
Fix this by adding a sanity check to ensure we never end up
trying to allocate zero bytes of data for extra pointer, before
continue executing the rest of the code in the function.
Address the following -Wstringop-overflow warning seen when built
m68k architecture with allyesconfig configuration:
from net/wireless/wext-core.c:11:
In function '_copy_from_user',
inlined from 'copy_from_user' at include/linux/uaccess.h:183:7,
inlined from 'ioctl_standard_iw_point' at net/wireless/wext-core.c:825:7:
arch/m68k/include/asm/string.h:48:25: warning: '__builtin_memset' writing 1 or more bytes into a region of size 0 overflows the destination [-Wstringop-overflow=]
48 | #define memset(d, c, n) __builtin_memset(d, c, n)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/uaccess.h:153:17: note: in expansion of macro 'memset'
153 | memset(to + (n - res), 0, res);
| ^~~~~~
In function 'kmalloc',
inlined from 'kzalloc' at include/linux/slab.h:694:9,
inlined from 'ioctl_standard_iw_point' at net/wireless/wext-core.c:819:10:
include/linux/slab.h:577:16: note: at offset 1 into destination object of size 0 allocated by '__kmalloc'
577 | return __kmalloc(size, flags);
| ^~~~~~~~~~~~~~~~~~~~~~
This help with the ongoing efforts to globally enable
-Wstringop-overflow.
Link: https://github.com/KSPP/linux/issues/315
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/ZItSlzvIpjdjNfd8@work
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
There are some locking changes that will later otherwise
cause conflicts, so merge wireless into wireless-next to
avoid those.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
The double ifdefs (one for the variable declaration and
one around the code) are quite aesthetically displeasing.
Factor this code out into a helper for easier wrapping.
This will become even more ugly when another skb ext
comparison is added in the future.
The resulting machine code looks the same, the compiler
seems to try to use %rax more and some blocks more around
but I haven't spotted minor differences.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 7d81ee8722 ("svcrdma: Single-stage RDMA Read") changed the
behavior of svc_rdma_recvfrom() but neglected to update the
documenting comment.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Per-VMA locking allows us to lock a struct vm_area_struct without
taking the process-wide mmap lock in read mode.
Consider a process workload where the mmap lock is taken constantly in
write mode. In this scenario, all zerocopy receives are periodically
blocked during that period of time - though in principle, the memory
ranges being used by TCP are not touched by the operations that need
the mmap write lock. This results in performance degradation.
Now consider another workload where the mmap lock is never taken in
write mode, but there are many TCP connections using receive zerocopy
that are concurrently receiving. These connections all take the mmap
lock in read mode, but this does induce a lot of contention and atomic
ops for this process-wide lock. This results in additional CPU
overhead caused by contending on the cache line for this lock.
However, with per-vma locking, both of these problems can be avoided.
As a test, I ran an RPC-style request/response workload with 4KB
payloads and receive zerocopy enabled, with 100 simultaneous TCP
connections. I measured perf cycles within the
find_tcp_vma/mmap_read_lock/mmap_read_unlock codepath, with and
without per-vma locking enabled.
When using process-wide mmap semaphore read locking, about 1% of
measured perf cycles were within this path. With per-VMA locking, this
value dropped to about 0.45%.
Signed-off-by: Arjun Roy <arjunroy@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
