On Fri, Nov 25, 2011 at 2:59 PM, Timo Lindhorst <tlnd@xxxxxxxxx> wrote: > Am Mittwoch, 23. November 2011, 16:04:46 schrieb Luis R. Rodriguez: >> There is a theoretical race that if hit will trigger >> a crash. The race is between when we issue the first >> regulatory hint, regulatory_hint_core(), gets processed >> by the workqueue and between when the first device >> gets registered to the wireless core. This is not easy >> to reproduce but it was easy to do so through the >> regulatory simulator I have been working on. This >> is a port of the fix I implemented there [1]. >> >> [1] >> https://github.com/mcgrof/regsim/commit/a246ccf81f059cb662eee288aa13100f63 >> 1e4cc8 >> >> Cc: stable@xxxxxxxxxxxxxxx >> Cc: Johannes Berg <johannes.berg@xxxxxxxxx> >> Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxxxxxxxx> >> --- >> net/wireless/reg.c | 28 ++++++++++++++++++++-------- >> 1 files changed, 20 insertions(+), 8 deletions(-) >> >> diff --git a/net/wireless/reg.c b/net/wireless/reg.c >> index 76b35df..df73b96 100644 >> --- a/net/wireless/reg.c >> +++ b/net/wireless/reg.c >> @@ -57,8 +57,17 @@ >> #define REG_DBG_PRINT(args...) >> #endif >> >> +static struct regulatory_request core_request_world = { >> + .initiator = NL80211_REGDOM_SET_BY_CORE, >> + .alpha2[0] = '0', >> + .alpha2[1] = '0', >> + .intersect = false, >> + .processed = true, >> + .country_ie_env = ENVIRON_ANY, >> +}; >> + >> /* Receipt of information from last regulatory request */ >> -static struct regulatory_request *last_request; >> +static struct regulatory_request *last_request = &core_request_world; >> >> /* To trigger userspace events */ >> static struct platform_device *reg_pdev; >> @@ -165,6 +174,10 @@ static void reset_regdomains(void) >> >> cfg80211_world_regdom = &world_regdom; >> cfg80211_regdomain = NULL; >> + >> + if (last_request != &core_request_world) >> + kfree(last_request); >> + last_request = &core_request_world; >> } > This breaks setting the regdom correctly! reset_regdomains() is called from > within set_regdom() (i.e. via __set_regdom()), however, the subsequent > functions called within set_regdom() expect last_request to still hold the > currently processed request: > > update_all_wiphy_regulatory(last_request->initiator); > print_regdomain(cfg80211_regdomain); > nl80211_send_reg_change_event(last_request); > reg_set_request_processed(); > > This, for instance, prevents to set the regdom from userspace -- or precisely: > the regdom is set, but the reg_timeout worker restores the settings after the > timeout, which is not canceled as intended within reg_set_request_processed(), > since last_request->initiator is not NL80211_REGDOM_SET_BY_USER anymore as > last_request was reset to &core_request_world. Thanks for testing, I really didn't have time. So I'll fix this by passing a flag to reset_regdomains()s. I see the issue you pointed out. I'll test this time before sending my new series. Luis -- 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
