The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 63ef91f24f9bfc70b6446319f6cabfd094481372 Mon Sep 17 00:00:00 2001
From: Marc Zyngier <maz(a)kernel.org>
Date: Tue, 30 Jun 2020 11:05:46 +0100
Subject: [PATCH] PM / devfreq: rk3399_dmc: Fix kernel oops when rockchip,pmu
is absent
Booting a recent kernel on a rk3399-based system (nanopc-t4),
equipped with a recent u-boot and ATF results in an Oops due
to a NULL pointer dereference.
This turns out to be due to the rk3399-dmc driver looking for
an *undocumented* property (rockchip,pmu), and happily using
a NULL pointer when the property isn't there.
Instead, make most of what was brought in with 9173c5ceb035
("PM / devfreq: rk3399_dmc: Pass ODT and auto power down parameters
to TF-A.") conditioned on finding this property in the device-tree,
preventing the driver from exploding.
Cc: stable(a)vger.kernel.org
Fixes: 9173c5ceb035 ("PM / devfreq: rk3399_dmc: Pass ODT and auto power down parameters to TF-A.")
Signed-off-by: Marc Zyngier <maz(a)kernel.org>
Signed-off-by: Chanwoo Choi <cw00.choi(a)samsung.com>
diff --git a/drivers/devfreq/rk3399_dmc.c b/drivers/devfreq/rk3399_dmc.c
index 24f04f78285b..027769e39f9b 100644
--- a/drivers/devfreq/rk3399_dmc.c
+++ b/drivers/devfreq/rk3399_dmc.c
@@ -95,18 +95,20 @@ static int rk3399_dmcfreq_target(struct device *dev, unsigned long *freq,
mutex_lock(&dmcfreq->lock);
- if (target_rate >= dmcfreq->odt_dis_freq)
- odt_enable = true;
-
- /*
- * This makes a SMC call to the TF-A to set the DDR PD (power-down)
- * timings and to enable or disable the ODT (on-die termination)
- * resistors.
- */
- arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, dmcfreq->odt_pd_arg0,
- dmcfreq->odt_pd_arg1,
- ROCKCHIP_SIP_CONFIG_DRAM_SET_ODT_PD,
- odt_enable, 0, 0, 0, &res);
+ if (dmcfreq->regmap_pmu) {
+ if (target_rate >= dmcfreq->odt_dis_freq)
+ odt_enable = true;
+
+ /*
+ * This makes a SMC call to the TF-A to set the DDR PD
+ * (power-down) timings and to enable or disable the
+ * ODT (on-die termination) resistors.
+ */
+ arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, dmcfreq->odt_pd_arg0,
+ dmcfreq->odt_pd_arg1,
+ ROCKCHIP_SIP_CONFIG_DRAM_SET_ODT_PD,
+ odt_enable, 0, 0, 0, &res);
+ }
/*
* If frequency scaling from low to high, adjust voltage first.
@@ -371,13 +373,14 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
}
node = of_parse_phandle(np, "rockchip,pmu", 0);
- if (node) {
- data->regmap_pmu = syscon_node_to_regmap(node);
- of_node_put(node);
- if (IS_ERR(data->regmap_pmu)) {
- ret = PTR_ERR(data->regmap_pmu);
- goto err_edev;
- }
+ if (!node)
+ goto no_pmu;
+
+ data->regmap_pmu = syscon_node_to_regmap(node);
+ of_node_put(node);
+ if (IS_ERR(data->regmap_pmu)) {
+ ret = PTR_ERR(data->regmap_pmu);
+ goto err_edev;
}
regmap_read(data->regmap_pmu, RK3399_PMUGRF_OS_REG2, &val);
@@ -399,6 +402,7 @@ static int rk3399_dmcfreq_probe(struct platform_device *pdev)
goto err_edev;
};
+no_pmu:
arm_smccc_smc(ROCKCHIP_SIP_DRAM_FREQ, 0, 0,
ROCKCHIP_SIP_CONFIG_DRAM_INIT,
0, 0, 0, 0, &res);
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From de002c55cadfc2f6cdf0ed427526f6085d240238 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com>
Date: Tue, 28 Jul 2020 19:09:32 +0200
Subject: [PATCH] cpufreq: intel_pstate: Fix EPP setting via sysfs in active
mode
Because intel_pstate_set_energy_pref_index() reads and writes the
MSR_HWP_REQUEST register without using the cached value of it used by
intel_pstate_hwp_boost_up() and intel_pstate_hwp_boost_down(), those
functions may overwrite the value written by it and so the EPP value
set via sysfs may be lost.
To avoid that, make intel_pstate_set_energy_pref_index() take the
cached value of MSR_HWP_REQUEST just like the other two routines
mentioned above and update it with the new EPP value coming from
user space in addition to updating the MSR.
Note that the MSR itself still needs to be updated too in case
hwp_boost is unset or the boosting mechanism is not active at the
EPP change time.
Fixes: e0efd5be63e8 ("cpufreq: intel_pstate: Add HWP boost utility and sched util hooks")
Reported-by: Francisco Jerez <currojerez(a)riseup.net>
Cc: 4.18+ <stable(a)vger.kernel.org> # 4.18+: 3da97d4db8ee cpufreq: intel_pstate: Rearrange ...
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Reviewed-by: Francisco Jerez <currojerez(a)riseup.net>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index c55f6e35a1e3..7f5d81931483 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -650,11 +650,12 @@ static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
epp = cpu_data->epp_default;
if (boot_cpu_has(X86_FEATURE_HWP_EPP)) {
- u64 value;
-
- ret = rdmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, &value);
- if (ret)
- return ret;
+ /*
+ * Use the cached HWP Request MSR value, because the register
+ * itself may be updated by intel_pstate_hwp_boost_up() or
+ * intel_pstate_hwp_boost_down() at any time.
+ */
+ u64 value = READ_ONCE(cpu_data->hwp_req_cached);
value &= ~GENMASK_ULL(31, 24);
@@ -664,6 +665,12 @@ static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
epp = epp_values[pref_index - 1];
value |= (u64)epp << 24;
+ /*
+ * The only other updater of hwp_req_cached in the active mode,
+ * intel_pstate_hwp_set(), is called under the same lock as this
+ * function, so it cannot run in parallel with the update below.
+ */
+ WRITE_ONCE(cpu_data->hwp_req_cached, value);
ret = wrmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, value);
} else {
if (epp == -EINVAL)
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From de002c55cadfc2f6cdf0ed427526f6085d240238 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com>
Date: Tue, 28 Jul 2020 19:09:32 +0200
Subject: [PATCH] cpufreq: intel_pstate: Fix EPP setting via sysfs in active
mode
Because intel_pstate_set_energy_pref_index() reads and writes the
MSR_HWP_REQUEST register without using the cached value of it used by
intel_pstate_hwp_boost_up() and intel_pstate_hwp_boost_down(), those
functions may overwrite the value written by it and so the EPP value
set via sysfs may be lost.
To avoid that, make intel_pstate_set_energy_pref_index() take the
cached value of MSR_HWP_REQUEST just like the other two routines
mentioned above and update it with the new EPP value coming from
user space in addition to updating the MSR.
Note that the MSR itself still needs to be updated too in case
hwp_boost is unset or the boosting mechanism is not active at the
EPP change time.
Fixes: e0efd5be63e8 ("cpufreq: intel_pstate: Add HWP boost utility and sched util hooks")
Reported-by: Francisco Jerez <currojerez(a)riseup.net>
Cc: 4.18+ <stable(a)vger.kernel.org> # 4.18+: 3da97d4db8ee cpufreq: intel_pstate: Rearrange ...
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Reviewed-by: Francisco Jerez <currojerez(a)riseup.net>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index c55f6e35a1e3..7f5d81931483 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -650,11 +650,12 @@ static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
epp = cpu_data->epp_default;
if (boot_cpu_has(X86_FEATURE_HWP_EPP)) {
- u64 value;
-
- ret = rdmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, &value);
- if (ret)
- return ret;
+ /*
+ * Use the cached HWP Request MSR value, because the register
+ * itself may be updated by intel_pstate_hwp_boost_up() or
+ * intel_pstate_hwp_boost_down() at any time.
+ */
+ u64 value = READ_ONCE(cpu_data->hwp_req_cached);
value &= ~GENMASK_ULL(31, 24);
@@ -664,6 +665,12 @@ static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
epp = epp_values[pref_index - 1];
value |= (u64)epp << 24;
+ /*
+ * The only other updater of hwp_req_cached in the active mode,
+ * intel_pstate_hwp_set(), is called under the same lock as this
+ * function, so it cannot run in parallel with the update below.
+ */
+ WRITE_ONCE(cpu_data->hwp_req_cached, value);
ret = wrmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, value);
} else {
if (epp == -EINVAL)
The patch below does not apply to the 5.7-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From de002c55cadfc2f6cdf0ed427526f6085d240238 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com>
Date: Tue, 28 Jul 2020 19:09:32 +0200
Subject: [PATCH] cpufreq: intel_pstate: Fix EPP setting via sysfs in active
mode
Because intel_pstate_set_energy_pref_index() reads and writes the
MSR_HWP_REQUEST register without using the cached value of it used by
intel_pstate_hwp_boost_up() and intel_pstate_hwp_boost_down(), those
functions may overwrite the value written by it and so the EPP value
set via sysfs may be lost.
To avoid that, make intel_pstate_set_energy_pref_index() take the
cached value of MSR_HWP_REQUEST just like the other two routines
mentioned above and update it with the new EPP value coming from
user space in addition to updating the MSR.
Note that the MSR itself still needs to be updated too in case
hwp_boost is unset or the boosting mechanism is not active at the
EPP change time.
Fixes: e0efd5be63e8 ("cpufreq: intel_pstate: Add HWP boost utility and sched util hooks")
Reported-by: Francisco Jerez <currojerez(a)riseup.net>
Cc: 4.18+ <stable(a)vger.kernel.org> # 4.18+: 3da97d4db8ee cpufreq: intel_pstate: Rearrange ...
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Reviewed-by: Francisco Jerez <currojerez(a)riseup.net>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index c55f6e35a1e3..7f5d81931483 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -650,11 +650,12 @@ static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
epp = cpu_data->epp_default;
if (boot_cpu_has(X86_FEATURE_HWP_EPP)) {
- u64 value;
-
- ret = rdmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, &value);
- if (ret)
- return ret;
+ /*
+ * Use the cached HWP Request MSR value, because the register
+ * itself may be updated by intel_pstate_hwp_boost_up() or
+ * intel_pstate_hwp_boost_down() at any time.
+ */
+ u64 value = READ_ONCE(cpu_data->hwp_req_cached);
value &= ~GENMASK_ULL(31, 24);
@@ -664,6 +665,12 @@ static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
epp = epp_values[pref_index - 1];
value |= (u64)epp << 24;
+ /*
+ * The only other updater of hwp_req_cached in the active mode,
+ * intel_pstate_hwp_set(), is called under the same lock as this
+ * function, so it cannot run in parallel with the update below.
+ */
+ WRITE_ONCE(cpu_data->hwp_req_cached, value);
ret = wrmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, value);
} else {
if (epp == -EINVAL)
The patch below does not apply to the 5.8-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From de002c55cadfc2f6cdf0ed427526f6085d240238 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com>
Date: Tue, 28 Jul 2020 19:09:32 +0200
Subject: [PATCH] cpufreq: intel_pstate: Fix EPP setting via sysfs in active
mode
Because intel_pstate_set_energy_pref_index() reads and writes the
MSR_HWP_REQUEST register without using the cached value of it used by
intel_pstate_hwp_boost_up() and intel_pstate_hwp_boost_down(), those
functions may overwrite the value written by it and so the EPP value
set via sysfs may be lost.
To avoid that, make intel_pstate_set_energy_pref_index() take the
cached value of MSR_HWP_REQUEST just like the other two routines
mentioned above and update it with the new EPP value coming from
user space in addition to updating the MSR.
Note that the MSR itself still needs to be updated too in case
hwp_boost is unset or the boosting mechanism is not active at the
EPP change time.
Fixes: e0efd5be63e8 ("cpufreq: intel_pstate: Add HWP boost utility and sched util hooks")
Reported-by: Francisco Jerez <currojerez(a)riseup.net>
Cc: 4.18+ <stable(a)vger.kernel.org> # 4.18+: 3da97d4db8ee cpufreq: intel_pstate: Rearrange ...
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com>
Reviewed-by: Francisco Jerez <currojerez(a)riseup.net>
diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index c55f6e35a1e3..7f5d81931483 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -650,11 +650,12 @@ static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
epp = cpu_data->epp_default;
if (boot_cpu_has(X86_FEATURE_HWP_EPP)) {
- u64 value;
-
- ret = rdmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, &value);
- if (ret)
- return ret;
+ /*
+ * Use the cached HWP Request MSR value, because the register
+ * itself may be updated by intel_pstate_hwp_boost_up() or
+ * intel_pstate_hwp_boost_down() at any time.
+ */
+ u64 value = READ_ONCE(cpu_data->hwp_req_cached);
value &= ~GENMASK_ULL(31, 24);
@@ -664,6 +665,12 @@ static int intel_pstate_set_energy_pref_index(struct cpudata *cpu_data,
epp = epp_values[pref_index - 1];
value |= (u64)epp << 24;
+ /*
+ * The only other updater of hwp_req_cached in the active mode,
+ * intel_pstate_hwp_set(), is called under the same lock as this
+ * function, so it cannot run in parallel with the update below.
+ */
+ WRITE_ONCE(cpu_data->hwp_req_cached, value);
ret = wrmsrl_on_cpu(cpu_data->cpu, MSR_HWP_REQUEST, value);
} else {
if (epp == -EINVAL)
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b292b50b0efcc7095d8bf15505fba6909bb35dce Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Date: Mon, 13 Jul 2020 11:12:54 +0900
Subject: [PATCH] driver core: Fix probe_count imbalance in really_probe()
syzbot is reporting hung task in wait_for_device_probe() [1]. At least,
we always need to decrement probe_count if we incremented probe_count in
really_probe().
However, since I can't find "Resources present before probing" message in
the console log, both "this message simply flowed off" and "syzbot is not
hitting this path" will be possible. Therefore, while we are at it, let's
also prepare for concurrent wait_for_device_probe() calls by replacing
wake_up() with wake_up_all().
[1] https://syzkaller.appspot.com/bug?id=25c833f1983c9c1d512f4ff860dd0d7f5a2e2c…
Reported-by: syzbot <syzbot+805f5f6ae37411f15b64(a)syzkaller.appspotmail.com>
Fixes: 7c35e699c88bd607 ("driver core: Print device when resources present in really_probe()")
Cc: Geert Uytterhoeven <geert+renesas(a)glider.be>
Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Cc: stable <stable(a)kernel.org>
Link: https://lore.kernel.org/r/20200713021254.3444-1-penguin-kernel@I-love.SAKUR…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 2306b481109a..fce8e35b6367 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -276,7 +276,7 @@ static void deferred_probe_timeout_work_func(struct work_struct *work)
list_for_each_entry_safe(private, p, &deferred_probe_pending_list, deferred_probe)
dev_info(private->device, "deferred probe pending\n");
- wake_up(&probe_timeout_waitqueue);
+ wake_up_all(&probe_timeout_waitqueue);
}
static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func);
@@ -498,7 +498,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
drv->bus->name, __func__, drv->name, dev_name(dev));
if (!list_empty(&dev->devres_head)) {
dev_crit(dev, "Resources present before probing\n");
- return -EBUSY;
+ ret = -EBUSY;
+ goto done;
}
re_probe:
@@ -627,7 +628,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
ret = 0;
done:
atomic_dec(&probe_count);
- wake_up(&probe_waitqueue);
+ wake_up_all(&probe_waitqueue);
return ret;
}
The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b292b50b0efcc7095d8bf15505fba6909bb35dce Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Date: Mon, 13 Jul 2020 11:12:54 +0900
Subject: [PATCH] driver core: Fix probe_count imbalance in really_probe()
syzbot is reporting hung task in wait_for_device_probe() [1]. At least,
we always need to decrement probe_count if we incremented probe_count in
really_probe().
However, since I can't find "Resources present before probing" message in
the console log, both "this message simply flowed off" and "syzbot is not
hitting this path" will be possible. Therefore, while we are at it, let's
also prepare for concurrent wait_for_device_probe() calls by replacing
wake_up() with wake_up_all().
[1] https://syzkaller.appspot.com/bug?id=25c833f1983c9c1d512f4ff860dd0d7f5a2e2c…
Reported-by: syzbot <syzbot+805f5f6ae37411f15b64(a)syzkaller.appspotmail.com>
Fixes: 7c35e699c88bd607 ("driver core: Print device when resources present in really_probe()")
Cc: Geert Uytterhoeven <geert+renesas(a)glider.be>
Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Cc: stable <stable(a)kernel.org>
Link: https://lore.kernel.org/r/20200713021254.3444-1-penguin-kernel@I-love.SAKUR…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 2306b481109a..fce8e35b6367 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -276,7 +276,7 @@ static void deferred_probe_timeout_work_func(struct work_struct *work)
list_for_each_entry_safe(private, p, &deferred_probe_pending_list, deferred_probe)
dev_info(private->device, "deferred probe pending\n");
- wake_up(&probe_timeout_waitqueue);
+ wake_up_all(&probe_timeout_waitqueue);
}
static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func);
@@ -498,7 +498,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
drv->bus->name, __func__, drv->name, dev_name(dev));
if (!list_empty(&dev->devres_head)) {
dev_crit(dev, "Resources present before probing\n");
- return -EBUSY;
+ ret = -EBUSY;
+ goto done;
}
re_probe:
@@ -627,7 +628,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
ret = 0;
done:
atomic_dec(&probe_count);
- wake_up(&probe_waitqueue);
+ wake_up_all(&probe_waitqueue);
return ret;
}
The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b292b50b0efcc7095d8bf15505fba6909bb35dce Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Date: Mon, 13 Jul 2020 11:12:54 +0900
Subject: [PATCH] driver core: Fix probe_count imbalance in really_probe()
syzbot is reporting hung task in wait_for_device_probe() [1]. At least,
we always need to decrement probe_count if we incremented probe_count in
really_probe().
However, since I can't find "Resources present before probing" message in
the console log, both "this message simply flowed off" and "syzbot is not
hitting this path" will be possible. Therefore, while we are at it, let's
also prepare for concurrent wait_for_device_probe() calls by replacing
wake_up() with wake_up_all().
[1] https://syzkaller.appspot.com/bug?id=25c833f1983c9c1d512f4ff860dd0d7f5a2e2c…
Reported-by: syzbot <syzbot+805f5f6ae37411f15b64(a)syzkaller.appspotmail.com>
Fixes: 7c35e699c88bd607 ("driver core: Print device when resources present in really_probe()")
Cc: Geert Uytterhoeven <geert+renesas(a)glider.be>
Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Cc: stable <stable(a)kernel.org>
Link: https://lore.kernel.org/r/20200713021254.3444-1-penguin-kernel@I-love.SAKUR…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 2306b481109a..fce8e35b6367 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -276,7 +276,7 @@ static void deferred_probe_timeout_work_func(struct work_struct *work)
list_for_each_entry_safe(private, p, &deferred_probe_pending_list, deferred_probe)
dev_info(private->device, "deferred probe pending\n");
- wake_up(&probe_timeout_waitqueue);
+ wake_up_all(&probe_timeout_waitqueue);
}
static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func);
@@ -498,7 +498,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
drv->bus->name, __func__, drv->name, dev_name(dev));
if (!list_empty(&dev->devres_head)) {
dev_crit(dev, "Resources present before probing\n");
- return -EBUSY;
+ ret = -EBUSY;
+ goto done;
}
re_probe:
@@ -627,7 +628,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
ret = 0;
done:
atomic_dec(&probe_count);
- wake_up(&probe_waitqueue);
+ wake_up_all(&probe_waitqueue);
return ret;
}
The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From b292b50b0efcc7095d8bf15505fba6909bb35dce Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Date: Mon, 13 Jul 2020 11:12:54 +0900
Subject: [PATCH] driver core: Fix probe_count imbalance in really_probe()
syzbot is reporting hung task in wait_for_device_probe() [1]. At least,
we always need to decrement probe_count if we incremented probe_count in
really_probe().
However, since I can't find "Resources present before probing" message in
the console log, both "this message simply flowed off" and "syzbot is not
hitting this path" will be possible. Therefore, while we are at it, let's
also prepare for concurrent wait_for_device_probe() calls by replacing
wake_up() with wake_up_all().
[1] https://syzkaller.appspot.com/bug?id=25c833f1983c9c1d512f4ff860dd0d7f5a2e2c…
Reported-by: syzbot <syzbot+805f5f6ae37411f15b64(a)syzkaller.appspotmail.com>
Fixes: 7c35e699c88bd607 ("driver core: Print device when resources present in really_probe()")
Cc: Geert Uytterhoeven <geert+renesas(a)glider.be>
Signed-off-by: Tetsuo Handa <penguin-kernel(a)I-love.SAKURA.ne.jp>
Cc: stable <stable(a)kernel.org>
Link: https://lore.kernel.org/r/20200713021254.3444-1-penguin-kernel@I-love.SAKUR…
Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org>
diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index 2306b481109a..fce8e35b6367 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -276,7 +276,7 @@ static void deferred_probe_timeout_work_func(struct work_struct *work)
list_for_each_entry_safe(private, p, &deferred_probe_pending_list, deferred_probe)
dev_info(private->device, "deferred probe pending\n");
- wake_up(&probe_timeout_waitqueue);
+ wake_up_all(&probe_timeout_waitqueue);
}
static DECLARE_DELAYED_WORK(deferred_probe_timeout_work, deferred_probe_timeout_work_func);
@@ -498,7 +498,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
drv->bus->name, __func__, drv->name, dev_name(dev));
if (!list_empty(&dev->devres_head)) {
dev_crit(dev, "Resources present before probing\n");
- return -EBUSY;
+ ret = -EBUSY;
+ goto done;
}
re_probe:
@@ -627,7 +628,7 @@ static int really_probe(struct device *dev, struct device_driver *drv)
ret = 0;
done:
atomic_dec(&probe_count);
- wake_up(&probe_waitqueue);
+ wake_up_all(&probe_waitqueue);
return ret;
}