The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200507185914.GA15124@embeddedor
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Ganapathi Bhat <ganapathi.bhat@nxp.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200225020413.GA8057@embeddedor
There really is no need to make drivers call the
ieee80211_start_tx_ba_cb_irqsafe() function and then
schedule the worker if all we want is to set a bit.
Add a new return value (that was previously considered
invalid) to indicate that the driver is immediately
ready for the session, and make drivers use it. The
only drivers that remain different are the Intel ones
as they need to negotiate more with the firmware.
Link: https://lore.kernel.org/r/1570007543-I152912660131cbab2e5d80b4218238c20f8a06e5@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
It was reported on OpenWrt bug tracking system[1], that several users
are affected by the endless reboot of their routers if they configure
5GHz interface with channel 44 or 48.
The reboot loop is caused by the following excessive number of WARN_ON
messages:
WARNING: CPU: 0 PID: 0 at backports-4.19.23-1/net/mac80211/rx.c:4516
ieee80211_rx_napi+0x1fc/0xa54 [mac80211]
as the messages are being correctly emitted by the following guard:
case RX_ENC_LEGACY:
if (WARN_ON(status->rate_idx >= sband->n_bitrates))
as the rate_idx is in this case erroneously set to 251 (0xfb). This fix
simply converts previously used magic number to proper constant and
guards against substraction which is leading to the currently observed
underflow.
1. https://bugs.openwrt.org/index.php?do=details&task_id=2218
Fixes: 854783444b ("mwl8k: properly set receive status rate index on 5 GHz receive")
Cc: <stable@vger.kernel.org>
Tested-by: Eubert Bao <bunnier@gmail.com>
Reported-by: Eubert Bao <bunnier@gmail.com>
Signed-off-by: Petr Štetiar <ynezz@true.cz>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
If pci_map_single() fails in mwl8k_post_cmd(),
it returns -ENOMEM immediately, while cleanup is required.
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Set the NL80211_EXT_FEATURE_CQM_RSSI_LIST wiphy extended feature
wholesale in all mac80211-based drivers that do not set the
IEEE80211_VIF_BEACON_FILTER flags on their interfaces. mac80211 will
be processing supplied RSSI values in ieee80211_rx_mgmt_beacon and
will detect when the thresholds set by
ieee80211_set_cqm_rssi_range_config are crossed. Remaining (few)
drivers need code to enable the firmware to monitor the thresholds.
This is mostly only compile-tested.
Signed-off-by: Andrew Zaborowski <andrew.zaborowski@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This enum is already perfectly aliased to enum nl80211_band, and
the only reason for it is that we get IEEE80211_NUM_BANDS out of
it. There's no really good reason to not declare the number of
bands in nl80211 though, so do that and remove the cfg80211 one.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Currently mac80211 does not inform the driver of the session
block ack timeout when starting a rx aggregation session.
Drivers that manage the reorder buffer need to know this
parameter.
Seeing that there are now too many arguments for the
drv_ampdu_action() function, wrap them inside a structure.
Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Gustavo A. R. Silva