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LinuxKPI: 802.11: adjust locking

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Split up the lhw lock and the scan lock.  The latter is a mtx
while the former changes from mtx to sx as mac80211 downcalls may
sleep (and the ic lock is not usable in that case either and a larger
project to fix).
This will also enforce some lookups under lock (mostly scan) as well
as general protection for more compat code and avoid a possible
deadlock with one of the upcoming callbacks from driver into the
compat code.

Sponsored by:	The FreeBSD Foundation
MFC after:	7 days
This commit is contained in:
Bjoern A. Zeeb 2023-03-31 19:52:19 +00:00
parent 6f9cba8f8b
commit 8ac540d3b8
2 changed files with 104 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

92
sys/compat/linuxkpi/common/src/linux_80211.c
View File

@ -1,5 +1,5 @@
/*-
* Copyright (c) 2020-2022 The FreeBSD Foundation
* Copyright (c) 2020-2023 The FreeBSD Foundation
* Copyright (c) 2020-2022 Bjoern A. Zeeb
*
* This software was developed by Björn Zeeb under sponsorship from
@ -792,8 +792,12 @@ lkpi_stop_hw_scan(struct lkpi_hw *lhw, struct ieee80211_vif *vif)
{
struct ieee80211_hw *hw;
int error;
bool cancel;
if ((lhw->scan_flags & LKPI_LHW_SCAN_RUNNING) == 0)
LKPI_80211_LHW_SCAN_LOCK(lhw);
cancel = (lhw->scan_flags & LKPI_LHW_SCAN_RUNNING) != 0;
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
if (!cancel)
return;
hw = LHW_TO_HW(lhw);
@ -802,13 +806,18 @@ lkpi_stop_hw_scan(struct lkpi_hw *lhw, struct ieee80211_vif *vif)
LKPI_80211_LHW_LOCK(lhw);
/* Need to cancel the scan. */
lkpi_80211_mo_cancel_hw_scan(hw, vif);
LKPI_80211_LHW_UNLOCK(lhw);
/* Need to make sure we see ieee80211_scan_completed. */
error = msleep(lhw, &lhw->mtx, 0, "lhwscanstop", hz/2);
LKPI_80211_LHW_UNLOCK(lhw);
LKPI_80211_LHW_SCAN_LOCK(lhw);
if ((lhw->scan_flags & LKPI_LHW_SCAN_RUNNING) != 0)
error = msleep(lhw, &lhw->scan_mtx, 0, "lhwscanstop", hz/2);
cancel = (lhw->scan_flags & LKPI_LHW_SCAN_RUNNING) != 0;
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
IEEE80211_LOCK(lhw->ic);
if ((lhw->scan_flags & LKPI_LHW_SCAN_RUNNING) != 0)
if (cancel)
ic_printf(lhw->ic, "%s: failed to cancel scan: %d (%p, %p)\n",
__func__, error, lhw, vif);
}
@ -935,6 +944,7 @@ lkpi_sta_scan_to_auth(struct ieee80211vap *vap, enum ieee80211_state nstate, int
ni = ieee80211_ref_node(vap->iv_bss);
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
/* Add chanctx (or if exists, change it). */
if (vif->chanctx_conf != NULL) {
@ -1078,6 +1088,7 @@ lkpi_sta_scan_to_auth(struct ieee80211vap *vap, enum ieee80211_state nstate, int
*/
out:
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
if (ni != NULL)
ieee80211_free_node(ni);
@ -1110,6 +1121,7 @@ lkpi_sta_auth_to_scan(struct ieee80211vap *vap, enum ieee80211_state nstate, int
lkpi_lsta_dump(lsta, ni, __func__, __LINE__);
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
/* flush, drop. */
lkpi_80211_mo_flush(hw, vif, nitems(sta->txq), true);
@ -1170,6 +1182,7 @@ lkpi_sta_auth_to_scan(struct ieee80211vap *vap, enum ieee80211_state nstate, int
}
out:
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
if (ni != NULL)
ieee80211_free_node(ni);
@ -1205,6 +1218,7 @@ lkpi_sta_auth_to_assoc(struct ieee80211vap *vap, enum ieee80211_state nstate, in
vif = LVIF_TO_VIF(lvif);
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
ni = NULL;
/* Finish auth. */
@ -1252,6 +1266,7 @@ lkpi_sta_auth_to_assoc(struct ieee80211vap *vap, enum ieee80211_state nstate, in
*/
out:
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
if (ni != NULL)
ieee80211_free_node(ni);
@ -1278,6 +1293,7 @@ lkpi_sta_a_to_a(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
ni = ieee80211_ref_node(vap->iv_bss);
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
lsta = ni->ni_drv_data;
IMPROVE("event callback?");
@ -1300,6 +1316,7 @@ lkpi_sta_a_to_a(struct ieee80211vap *vap, enum ieee80211_state nstate, int arg)
lsta->in_mgd = true;
}
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
if (ni != NULL)
ieee80211_free_node(ni);
@ -1334,6 +1351,7 @@ _lkpi_sta_assoc_to_down(struct ieee80211vap *vap, enum ieee80211_state nstate, i
lkpi_lsta_dump(lsta, ni, __func__, __LINE__);
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
/* flush, drop. */
lkpi_80211_mo_flush(hw, vif, nitems(sta->txq), true);
@ -1347,6 +1365,7 @@ _lkpi_sta_assoc_to_down(struct ieee80211vap *vap, enum ieee80211_state nstate, i
lsta->in_mgd = true;
}
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
/* Call iv_newstate first so we get potential DISASSOC packet out. */
@ -1355,6 +1374,7 @@ _lkpi_sta_assoc_to_down(struct ieee80211vap *vap, enum ieee80211_state nstate, i
goto outni;
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
lkpi_lsta_dump(lsta, ni, __func__, __LINE__);
@ -1438,6 +1458,7 @@ _lkpi_sta_assoc_to_down(struct ieee80211vap *vap, enum ieee80211_state nstate, i
error = EALREADY;
out:
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
outni:
if (ni != NULL)
@ -1498,6 +1519,7 @@ lkpi_sta_assoc_to_run(struct ieee80211vap *vap, enum ieee80211_state nstate, int
vif = LVIF_TO_VIF(lvif);
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
ni = NULL;
IMPROVE("ponder some of this moved to ic_newassoc, scan_assoc_success, "
@ -1608,6 +1630,7 @@ lkpi_sta_assoc_to_run(struct ieee80211vap *vap, enum ieee80211_state nstate, int
lkpi_80211_mo_bss_info_changed(hw, vif, &vif->bss_conf, bss_changed);
out:
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
if (ni != NULL)
ieee80211_free_node(ni);
@ -1654,6 +1677,7 @@ lkpi_sta_run_to_assoc(struct ieee80211vap *vap, enum ieee80211_state nstate, int
lkpi_lsta_dump(lsta, ni, __func__, __LINE__);
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
/* flush, drop. */
lkpi_80211_mo_flush(hw, vif, nitems(sta->txq), true);
@ -1667,6 +1691,7 @@ lkpi_sta_run_to_assoc(struct ieee80211vap *vap, enum ieee80211_state nstate, int
lsta->in_mgd = true;
}
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
/* Call iv_newstate first so we get potential DISASSOC packet out. */
@ -1675,6 +1700,7 @@ lkpi_sta_run_to_assoc(struct ieee80211vap *vap, enum ieee80211_state nstate, int
goto outni;
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
lkpi_lsta_dump(lsta, ni, __func__, __LINE__);
@ -1729,6 +1755,7 @@ lkpi_sta_run_to_assoc(struct ieee80211vap *vap, enum ieee80211_state nstate, int
error = EALREADY;
out:
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
outni:
if (ni != NULL)
@ -1763,6 +1790,7 @@ lkpi_sta_run_to_init(struct ieee80211vap *vap, enum ieee80211_state nstate, int
lkpi_lsta_dump(lsta, ni, __func__, __LINE__);
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
/* flush, drop. */
lkpi_80211_mo_flush(hw, vif, nitems(sta->txq), true);
@ -1776,6 +1804,7 @@ lkpi_sta_run_to_init(struct ieee80211vap *vap, enum ieee80211_state nstate, int
lsta->in_mgd = true;
}
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
/* Call iv_newstate first so we get potential DISASSOC packet out. */
@ -1784,6 +1813,7 @@ lkpi_sta_run_to_init(struct ieee80211vap *vap, enum ieee80211_state nstate, int
goto outni;
IEEE80211_UNLOCK(vap->iv_ic);
LKPI_80211_LHW_LOCK(lhw);
lkpi_lsta_dump(lsta, ni, __func__, __LINE__);
@ -1890,6 +1920,7 @@ lkpi_sta_run_to_init(struct ieee80211vap *vap, enum ieee80211_state nstate, int
error = EALREADY;
out:
LKPI_80211_LHW_UNLOCK(lhw);
IEEE80211_LOCK(vap->iv_ic);
outni:
if (ni != NULL)
@ -2439,6 +2470,8 @@ lkpi_ic_parent(struct ieee80211com *ic)
hw = LHW_TO_HW(lhw);
start_all = false;
/* IEEE80211_UNLOCK(ic); */
LKPI_80211_LHW_LOCK(lhw);
if (ic->ic_nrunning > 0) {
error = lkpi_80211_mo_start(hw);
if (error == 0)
@ -2446,6 +2479,8 @@ lkpi_ic_parent(struct ieee80211com *ic)
} else {
lkpi_80211_mo_stop(hw);
}
LKPI_80211_LHW_UNLOCK(lhw);
/* IEEE80211_LOCK(ic); */
if (start_all)
ieee80211_start_all(ic);
@ -2587,12 +2622,17 @@ lkpi_ic_scan_start(struct ieee80211com *ic)
struct ieee80211_scan_state *ss;
struct ieee80211vap *vap;
int error;
bool is_hw_scan;
lhw = ic->ic_softc;
LKPI_80211_LHW_SCAN_LOCK(lhw);
if ((lhw->scan_flags & LKPI_LHW_SCAN_RUNNING) != 0) {
/* A scan is still running. */
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
return;
}
is_hw_scan = (lhw->scan_flags & LKPI_LHW_SCAN_HW) != 0;
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
ss = ic->ic_scan;
vap = ss->ss_vap;
@ -2602,7 +2642,7 @@ lkpi_ic_scan_start(struct ieee80211com *ic)
}
hw = LHW_TO_HW(lhw);
if ((lhw->scan_flags & LKPI_LHW_SCAN_HW) == 0) {
if (!is_hw_scan) {
/* If hw_scan is cleared clear FEXT_SCAN_OFFLOAD too. */
vap->iv_flags_ext &= ~IEEE80211_FEXT_SCAN_OFFLOAD;
sw_scan:
@ -2747,7 +2787,9 @@ lkpi_ic_scan_start(struct ieee80211com *ic)
* not possible. Fall back to sw scan in that case.
*/
if (error == 1) {
LKPI_80211_LHW_SCAN_LOCK(lhw);
lhw->scan_flags &= ~LKPI_LHW_SCAN_HW;
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
ieee80211_start_scan(vap,
IEEE80211_SCAN_ACTIVE |
IEEE80211_SCAN_NOPICK |
@ -2769,13 +2811,18 @@ static void
lkpi_ic_scan_end(struct ieee80211com *ic)
{
struct lkpi_hw *lhw;
bool is_hw_scan;
lhw = ic->ic_softc;
LKPI_80211_LHW_SCAN_LOCK(lhw);
if ((lhw->scan_flags & LKPI_LHW_SCAN_RUNNING) == 0) {
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
return;
}
is_hw_scan = (lhw->scan_flags & LKPI_LHW_SCAN_HW) != 0;
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
if ((lhw->scan_flags & LKPI_LHW_SCAN_HW) == 0) {
if (!is_hw_scan) {
struct ieee80211_scan_state *ss;
struct ieee80211vap *vap;
struct ieee80211_hw *hw;
@ -2802,9 +2849,13 @@ lkpi_ic_scan_curchan(struct ieee80211_scan_state *ss,
unsigned long maxdwell)
{
struct lkpi_hw *lhw;
bool is_hw_scan;
lhw = ss->ss_ic->ic_softc;
if ((lhw->scan_flags & LKPI_LHW_SCAN_HW) == 0)
LKPI_80211_LHW_SCAN_LOCK(lhw);
is_hw_scan = (lhw->scan_flags & LKPI_LHW_SCAN_HW) != 0;
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
if (!is_hw_scan)
lhw->ic_scan_curchan(ss, maxdwell);
}
@ -2812,9 +2863,13 @@ static void
lkpi_ic_scan_mindwell(struct ieee80211_scan_state *ss)
{
struct lkpi_hw *lhw;
bool is_hw_scan;
lhw = ss->ss_ic->ic_softc;
if ((lhw->scan_flags & LKPI_LHW_SCAN_HW) == 0)
LKPI_80211_LHW_SCAN_LOCK(lhw);
is_hw_scan = (lhw->scan_flags & LKPI_LHW_SCAN_HW) != 0;
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
if (!is_hw_scan)
lhw->ic_scan_mindwell(ss);
}
@ -2826,6 +2881,7 @@ lkpi_ic_set_channel(struct ieee80211com *ic)
struct ieee80211_channel *c;
struct linuxkpi_ieee80211_channel *chan;
int error;
bool hw_scan_running;
lhw = ic->ic_softc;
@ -2834,8 +2890,12 @@ lkpi_ic_set_channel(struct ieee80211com *ic)
return;
/* If we have a hw_scan running do not switch channels. */
if ((lhw->scan_flags & (LKPI_LHW_SCAN_RUNNING|LKPI_LHW_SCAN_HW)) ==
(LKPI_LHW_SCAN_RUNNING|LKPI_LHW_SCAN_HW))
LKPI_80211_LHW_SCAN_LOCK(lhw);
hw_scan_running =
(lhw->scan_flags & (LKPI_LHW_SCAN_RUNNING|LKPI_LHW_SCAN_HW)) ==
(LKPI_LHW_SCAN_RUNNING|LKPI_LHW_SCAN_HW);
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
if (hw_scan_running)
return;
c = ic->ic_curchan;
@ -3424,7 +3484,8 @@ linuxkpi_ieee80211_alloc_hw(size_t priv_len, const struct ieee80211_ops *ops)
lhw = wiphy_priv(wiphy);
lhw->ops = ops;
mtx_init(&lhw->mtx, "lhw", NULL, MTX_DEF | MTX_RECURSE);
LKPI_80211_LHW_LOCK_INIT(lhw);
LKPI_80211_LHW_SCAN_LOCK_INIT(lhw);
sx_init_flags(&lhw->lvif_sx, "lhw-lvif", SX_RECURSE | SX_DUPOK);
TAILQ_INIT(&lhw->lvif_head);
@ -3460,7 +3521,8 @@ linuxkpi_ieee80211_iffree(struct ieee80211_hw *hw)
/* Cleanup more of lhw here or in wiphy_free()? */
sx_destroy(&lhw->lvif_sx);
mtx_destroy(&lhw->mtx);
LKPI_80211_LHW_LOCK_DESTROY(lhw);
LKPI_80211_LHW_SCAN_LOCK_DESTROY(lhw);
IMPROVE();
}
@ -3867,12 +3929,12 @@ linuxkpi_ieee80211_scan_completed(struct ieee80211_hw *hw,
ieee80211_scan_done(ss->ss_vap);
LKPI_80211_LHW_LOCK(lhw);
LKPI_80211_LHW_SCAN_LOCK(lhw);
free(lhw->hw_req, M_LKPI80211);
lhw->hw_req = NULL;
lhw->scan_flags &= ~LKPI_LHW_SCAN_RUNNING;
wakeup(lhw);
LKPI_80211_LHW_UNLOCK(lhw);
LKPI_80211_LHW_SCAN_UNLOCK(lhw);
return;
}

35
sys/compat/linuxkpi/common/src/linux_80211.h
View File

@ -1,5 +1,5 @@
/*-
* Copyright (c) 2020-2022 The FreeBSD Foundation
* Copyright (c) 2020-2023 The FreeBSD Foundation
* Copyright (c) 2020-2021 Bjoern A. Zeeb
*
* This software was developed by Björn Zeeb under sponsorship from
@ -173,7 +173,7 @@ struct lkpi_hw { /* name it mac80211_sc? */
TAILQ_HEAD(, lkpi_vif) lvif_head;
struct sx lvif_sx;
struct mtx mtx;
struct sx sx;
uint32_t txq_generation[IEEE80211_NUM_ACS];
TAILQ_HEAD(, lkpi_txq) scheduled_txqs[IEEE80211_NUM_ACS];
@ -195,6 +195,7 @@ struct lkpi_hw { /* name it mac80211_sc? */
#define LKPI_LHW_SCAN_RUNNING 0x00000001
#define LKPI_LHW_SCAN_HW 0x00000002
uint32_t scan_flags;
struct mtx scan_mtx;
int supbands; /* Number of supported bands. */
int max_rates; /* Maximum number of bitrates supported in any channel. */
@ -218,13 +219,31 @@ struct lkpi_wiphy {
#define WIPHY_TO_LWIPHY(_wiphy) container_of(_wiphy, struct lkpi_wiphy, wiphy)
#define LWIPHY_TO_WIPHY(_lwiphy) (&(_lwiphy)->wiphy)
#define LKPI_80211_LHW_LOCK_INIT(_lhw) \
sx_init_flags(&(_lhw)->sx, "lhw", SX_RECURSE);
#define LKPI_80211_LHW_LOCK_DESTROY(_lhw) \
sx_destroy(&(_lhw)->sx);
#define LKPI_80211_LHW_LOCK(_lhw) \
sx_xlock(&(_lhw)->sx)
#define LKPI_80211_LHW_UNLOCK(_lhw) \
sx_xunlock(&(_lhw)->sx)
#define LKPI_80211_LHW_LOCK_ASSERT(_lhw) \
sx_assert(&(_lhw)->sx, SA_LOCKED)
#define LKPI_80211_LHW_UNLOCK_ASSERT(_lhw) \
sx_assert(&(_lhw)->sx, SA_UNLOCKED)
#define LKPI_80211_LHW_LOCK(_lhw) mtx_lock(&(_lhw)->mtx)
#define LKPI_80211_LHW_UNLOCK(_lhw) mtx_unlock(&(_lhw)->mtx)
#define LKPI_80211_LHW_LOCK_ASSERT(_lhw) \
mtx_assert(&(_lhw)->mtx, MA_OWNED)
#define LKPI_80211_LHW_UNLOCK_ASSERT(_lhw) \
mtx_assert(&(_lhw)->mtx, MA_NOTOWNED)
#define LKPI_80211_LHW_SCAN_LOCK_INIT(_lhw) \
mtx_init(&(_lhw)->scan_mtx, "lhw-scan", NULL, MTX_DEF | MTX_RECURSE);
#define LKPI_80211_LHW_SCAN_LOCK_DESTROY(_lhw) \
mtx_destroy(&(_lhw)->scan_mtx);
#define LKPI_80211_LHW_SCAN_LOCK(_lhw) \
mtx_lock(&(_lhw)->scan_mtx)
#define LKPI_80211_LHW_SCAN_UNLOCK(_lhw) \
mtx_unlock(&(_lhw)->scan_mtx)
#define LKPI_80211_LHW_SCAN_LOCK_ASSERT(_lhw) \
mtx_assert(&(_lhw)->scan_mtx, MA_OWNED)
#define LKPI_80211_LHW_SCAN_UNLOCK_ASSERT(_lhw) \
mtx_assert(&(_lhw)->scan_mtx, MA_NOTOWNED)
#define LKPI_80211_LHW_LVIF_LOCK(_lhw) sx_xlock(&(_lhw)->lvif_sx)
#define LKPI_80211_LHW_LVIF_UNLOCK(_lhw) sx_xunlock(&(_lhw)->lvif_sx)