On Fri, 2009-04-10 at 17:18 +0100, Alan Jenkins wrote: > [ 65.062652] BUG: unable to handle kernel NULL pointer dereference at > 00000004 ... > [ 65.063330] Code: b8 da 17 e0 83 c0 04 e8 92 f9 ff ff 84 c0 75 2a 8b > 55 d4 8b 42 28 85 c0 74 0c 83 c0 04 e8 7c f9 ff ff 84 c0 75 14 a1 bc da > 17 e0 <83> 78 04 03 74 66 8b 4d d4 80 79 08 00 74 5d a1 e0 d2 17 e0 48 "<83> 78 04 03" is "cmpl $0x3,0x4(%rax)", which I can find in disassemly of reg_is_world_roaming(), which was inlined into wiphy_update_regulatory(). 0x3 is almost certainly NL80211_REGDOM_SET_BY_COUNTRY_IE in reg_is_world_roaming(). %rax must be 0, so we have a read at address 0x4. last_request must be NULL. The "initiator" field is at offset 4, which is consistent with the assembly. Thus, wiphy_update_regulatory() is called before last_request was assigned a value. last_request only seems to get a value in __regulatory_hint(), which is ultimately called by reg_todo(), a work handler. -- Regards, Pavel Roskin -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
