I met data misalignment exeception when using USB bt card. The fault
address is in l2cap_get_conf_opt() line 2296.
2290 switch (opt->len) {
2291 case 1:
2292 *val = *((u8 *) opt->val);
2293 break;
2294
2295 case 2:
2296 *val = __le16_to_cpu(*((__le16 *) opt->val));
2297 break;
2298
2299 case 4:
2300 *val = __le32_to_cpu(*((__le32 *) opt->val));
2301 break;
The address of opt->val is not 2-bytes aligned. actually this val is
read from conf_req[64] of struct l2cap_info, I think this opt->val can
not guarantee it is 2-bytes or 4-bytes aligned,
2296 *val = __le16_to_cpu(*((__le16 *) opt->val));
2300 *val = __le32_to_cpu(*((__le32 *) opt->val));
will cause misalignment fault in some processor that not support
unaligned access.
l2cap_pinfo struct:
306struct l2cap_pinfo {
307 struct bt_sock bt;
308 __le16 psm;
309 __u16 dcid;
310 __u16 scid;
311
312 __u16 imtu;
313 __u16 omtu;
314 __u16 flush_to;
315 __u8 mode;
316 __u8 num_conf_req;
317 __u8 num_conf_rsp;
318
319 __u8 fcs;
320 __u8 sec_level;
321 __u8 role_switch;
322 __u8 force_reliable;
323
324 __u8 conf_req[64];
...
Steven