On Fri, Aug 12, 2016 at 8:00 PM, Petri Gynther <pgynt...@google.com> wrote:
> $ iwconfig mlan0 essid MySSID
> [ 36.930000] Path: /sbin/iwconfig
> [ 36.930000] CPU: 0 PID: 203 Comm: iwconfig Not tainted 4.7.0 #2
> [ 36.940000] task: 866f83a0 ti: 866a6000 task.ti: 866a6000
> [ 36.940000]
> [ECR ]: 0x00230400 => Misaligned r/w from 0x8677f403
> [ 36.960000] [EFA ]: 0x8677f403
> [ 36.960000] [BLINK ]: mwifiex_scan_networks+0x17a/0x198c [mwifiex]
> [ 36.960000] [ERET ]: mwifiex_scan_networks+0x18a/0x198c [mwifiex]
> [ 36.980000] [STAT32]: 0x00000206 : K E2 E1
> [ 36.980000] BTA: 0x700736e2 SP: 0x866a7d0c FP: 0x5faddc84
> [ 37.000000] LPS: 0x806a37ec LPE: 0x806a37fa LPC: 0x00000000
> [ 37.000000] r00: 0x8677f401 r01: 0x8668aa08 r02: 0x00000001
> r03: 0x00000000 r04: 0x8668b600 r05: 0x8677f406
> r06: 0x8702b600 r07: 0x00000000 r08: 0x8702b600
> r09: 0x00000000 r10: 0x870b3b00 r11: 0x00000000
> r12: 0x00000000
> [ 37.040000]
> [ 37.040000] Stack Trace:
> [ 37.040000] mwifiex_scan_networks+0x18a/0x198c [mwifiex]
>
> Root cause:
> mwifiex driver calls is_zero_ether_addr() against byte-aligned address:
>
> drivers/net/wireless/marvell/mwifiex/fw.h:
> struct mwifiex_scan_cmd_config {
> /*
> * BSS mode to be sent in the firmware command
> */
> u8 bss_mode;
>
> /* Specific BSSID used to filter scan results in the firmware */
> u8 specific_bssid[ETH_ALEN];
>
> ...
> } __packed;
>
> drivers/net/wireless/marvell/mwifiex/scan.c:
> mwifiex_config_scan(..., struct mwifiex_scan_cmd_config *scan_cfg_out, ...)
> ...
> if (adapter->ext_scan &&
> !is_zero_ether_addr(scan_cfg_out->specific_bssid)) {
> ...
> }
>
> Since firmware-related struct mwifiex_scan_cmd_config cannot be changed,
> we need to use the new function is_zero_ether_addr_unaligned() here.
>
> This is v2 of the original patch:
> [PATCH] Modify is_zero_ether_addr() to handle byte-aligned addresses
>
> Per Joe's suggestion -- instead of modifying is_zero_ether_addr() --
> add is_zero_ether_addr_unaligned() and use it where needed.
>
> Cc: Kalle Valo <kv...@codeaurora.org>
> Cc: David S. Miller <da...@davemloft.net>
> Cc: Joe Perches <j...@perches.com>
> Cc: Amitkumar Karwar <akar...@marvell.com>
> Signed-off-by: Petri Gynther <pgynt...@google.com>
> ---
> drivers/net/wireless/marvell/mwifiex/scan.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/marvell/mwifiex/scan.c
> b/drivers/net/wireless/marvell/mwifiex/scan.c
> index bc5e52c..d648c88 100644
> --- a/drivers/net/wireless/marvell/mwifiex/scan.c
> +++ b/drivers/net/wireless/marvell/mwifiex/scan.c
> @@ -883,7 +883,8 @@ mwifiex_config_scan(struct mwifiex_private *priv,
> sizeof(scan_cfg_out->specific_bssid));
>
> if (adapter->ext_scan &&
> - !is_zero_ether_addr(scan_cfg_out->specific_bssid)) {
> + !is_zero_ether_addr_unaligned(
> + scan_cfg_out->specific_bssid)) {
Any comments? Is this approach of adding
is_zero_ether_addr_unaligned() fine? We already have similar routine
ether_addr_equal_unaligned().
I don't see much benefit making a local, aligned copy here. It would
have to use memcpy w/ byte operations anyways and then still run
is_zero_ether_addr().
Amitkumar -- Is it possible to modify struct mwifiex_scan_cmd_config
{} and align specific_bssid field to u16 boundary?
> bssid_tlv =
> (struct mwifiex_ie_types_bssid_list *)tlv_pos;
> bssid_tlv->header.type = cpu_to_le16(TLV_TYPE_BSSID);
> --
> 2.8.0.rc3.226.g39d4020
>
