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@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b5d281f6c16dd432b618bdfd36ddba1a58d5b603 Mon Sep 17 00:00:00 2001 From: Christian Marangi ansuelsmth@gmail.com Date: Mon, 20 Jun 2022 00:03:51 +0200 Subject: [PATCH] PM / devfreq: Rework freq_table to be local to devfreq struct

On a devfreq PROBE_DEFER, the freq_table in the driver profile struct, is never reset and may be leaved in an undefined state.

This comes from the fact that we store the freq_table in the driver profile struct that is commonly defined as static and not reset on PROBE_DEFER. We currently skip the reinit of the freq_table if we found it's already defined since a driver may declare his own freq_table.

This logic is flawed in the case devfreq core generate a freq_table, set it in the profile struct and then PROBE_DEFER, freeing the freq_table. In this case devfreq will found a NOT NULL freq_table that has been freed, skip the freq_table generation and probe the driver based on the wrong table.

To fix this and correctly handle PROBE_DEFER, use a local freq_table and max_state in the devfreq struct and never modify the freq_table present in the profile struct if it does provide it.

Fixes: 0ec09ac2cebe ("PM / devfreq: Set the freq_table of devfreq device") Cc: stable@vger.kernel.org Signed-off-by: Christian Marangi ansuelsmth@gmail.com Signed-off-by: Chanwoo Choi cw00.choi@samsung.com

diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 80a1235ef8fb..9602141bb8ec 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -123,7 +123,7 @@ void devfreq_get_freq_range(struct devfreq *devfreq, unsigned long *min_freq, unsigned long *max_freq) { - unsigned long *freq_table = devfreq->profile->freq_table; + unsigned long *freq_table = devfreq->freq_table; s32 qos_min_freq, qos_max_freq;

lockdep_assert_held(&devfreq->lock); @@ -133,11 +133,11 @@ void devfreq_get_freq_range(struct devfreq *devfreq, * The devfreq drivers can initialize this in either ascending or * descending order and devfreq core supports both. */ - if (freq_table[0] < freq_table[devfreq->profile->max_state - 1]) { + if (freq_table[0] < freq_table[devfreq->max_state - 1]) { *min_freq = freq_table[0]; - *max_freq = freq_table[devfreq->profile->max_state - 1]; + *max_freq = freq_table[devfreq->max_state - 1]; } else { - *min_freq = freq_table[devfreq->profile->max_state - 1]; + *min_freq = freq_table[devfreq->max_state - 1]; *max_freq = freq_table[0]; }

@@ -169,8 +169,8 @@ static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq) { int lev;

- for (lev = 0; lev < devfreq->profile->max_state; lev++) - if (freq == devfreq->profile->freq_table[lev]) + for (lev = 0; lev < devfreq->max_state; lev++) + if (freq == devfreq->freq_table[lev]) return lev;

return -EINVAL; @@ -178,7 +178,6 @@ static int devfreq_get_freq_level(struct devfreq *devfreq, unsigned long freq)

static int set_freq_table(struct devfreq *devfreq) { - struct devfreq_dev_profile *profile = devfreq->profile; struct dev_pm_opp *opp; unsigned long freq; int i, count; @@ -188,25 +187,22 @@ static int set_freq_table(struct devfreq *devfreq) if (count <= 0) return -EINVAL;

- profile->max_state = count; - profile->freq_table = devm_kcalloc(devfreq->dev.parent, - profile->max_state, - sizeof(*profile->freq_table), - GFP_KERNEL); - if (!profile->freq_table) { - profile->max_state = 0; + devfreq->max_state = count; + devfreq->freq_table = devm_kcalloc(devfreq->dev.parent, + devfreq->max_state, + sizeof(*devfreq->freq_table), + GFP_KERNEL); + if (!devfreq->freq_table) return -ENOMEM; - }

- for (i = 0, freq = 0; i < profile->max_state; i++, freq++) { + for (i = 0, freq = 0; i < devfreq->max_state; i++, freq++) { opp = dev_pm_opp_find_freq_ceil(devfreq->dev.parent, &freq); if (IS_ERR(opp)) { - devm_kfree(devfreq->dev.parent, profile->freq_table); - profile->max_state = 0; + devm_kfree(devfreq->dev.parent, devfreq->freq_table); return PTR_ERR(opp); } dev_pm_opp_put(opp); - profile->freq_table[i] = freq; + devfreq->freq_table[i] = freq; }

return 0; @@ -246,7 +242,7 @@ int devfreq_update_status(struct devfreq *devfreq, unsigned long freq)

if (lev != prev_lev) { devfreq->stats.trans_table[ - (prev_lev * devfreq->profile->max_state) + lev]++; + (prev_lev * devfreq->max_state) + lev]++; devfreq->stats.total_trans++; }

@@ -835,6 +831,9 @@ struct devfreq *devfreq_add_device(struct device *dev, if (err < 0) goto err_dev; mutex_lock(&devfreq->lock); + } else { + devfreq->freq_table = devfreq->profile->freq_table; + devfreq->max_state = devfreq->profile->max_state; }

devfreq->scaling_min_freq = find_available_min_freq(devfreq); @@ -870,8 +869,8 @@ struct devfreq *devfreq_add_device(struct device *dev,

devfreq->stats.trans_table = devm_kzalloc(&devfreq->dev, array3_size(sizeof(unsigned int), - devfreq->profile->max_state, - devfreq->profile->max_state), + devfreq->max_state, + devfreq->max_state), GFP_KERNEL); if (!devfreq->stats.trans_table) { mutex_unlock(&devfreq->lock); @@ -880,7 +879,7 @@ struct devfreq *devfreq_add_device(struct device *dev, }

devfreq->stats.time_in_state = devm_kcalloc(&devfreq->dev, - devfreq->profile->max_state, + devfreq->max_state, sizeof(*devfreq->stats.time_in_state), GFP_KERNEL); if (!devfreq->stats.time_in_state) { @@ -1666,9 +1665,9 @@ static ssize_t available_frequencies_show(struct device *d,

mutex_lock(&df->lock);

- for (i = 0; i < df->profile->max_state; i++) + for (i = 0; i < df->max_state; i++) count += scnprintf(&buf[count], (PAGE_SIZE - count - 2), - "%lu ", df->profile->freq_table[i]); + "%lu ", df->freq_table[i]);

mutex_unlock(&df->lock); /* Truncate the trailing space */ @@ -1691,7 +1690,7 @@ static ssize_t trans_stat_show(struct device *dev,

if (!df->profile) return -EINVAL; - max_state = df->profile->max_state; + max_state = df->max_state;

if (max_state == 0) return sprintf(buf, "Not Supported.\n"); @@ -1708,19 +1707,17 @@ static ssize_t trans_stat_show(struct device *dev, len += sprintf(buf + len, " :"); for (i = 0; i < max_state; i++) len += sprintf(buf + len, "%10lu", - df->profile->freq_table[i]); + df->freq_table[i]);

len += sprintf(buf + len, " time(ms)\n");

for (i = 0; i < max_state; i++) { - if (df->profile->freq_table[i] - == df->previous_freq) { + if (df->freq_table[i] == df->previous_freq) len += sprintf(buf + len, "*"); - } else { + else len += sprintf(buf + len, " "); - } - len += sprintf(buf + len, "%10lu:", - df->profile->freq_table[i]); + + len += sprintf(buf + len, "%10lu:", df->freq_table[i]); for (j = 0; j < max_state; j++) len += sprintf(buf + len, "%10u", df->stats.trans_table[(i * max_state) + j]); @@ -1744,7 +1741,7 @@ static ssize_t trans_stat_store(struct device *dev, if (!df->profile) return -EINVAL;

- if (df->profile->max_state == 0) + if (df->max_state == 0) return count;

err = kstrtoint(buf, 10, &value); @@ -1752,11 +1749,11 @@ static ssize_t trans_stat_store(struct device *dev, return -EINVAL;

mutex_lock(&df->lock); - memset(df->stats.time_in_state, 0, (df->profile->max_state * + memset(df->stats.time_in_state, 0, (df->max_state * sizeof(*df->stats.time_in_state))); memset(df->stats.trans_table, 0, array3_size(sizeof(unsigned int), - df->profile->max_state, - df->profile->max_state)); + df->max_state, + df->max_state)); df->stats.total_trans = 0; df->stats.last_update = get_jiffies_64(); mutex_unlock(&df->lock); diff --git a/drivers/devfreq/governor_passive.c b/drivers/devfreq/governor_passive.c index 69e06725d92b..406ef79c0c46 100644 --- a/drivers/devfreq/governor_passive.c +++ b/drivers/devfreq/governor_passive.c @@ -144,18 +144,18 @@ static int get_target_freq_with_devfreq(struct devfreq *devfreq, goto out;

/* Use interpolation if required opps is not available */ - for (i = 0; i < parent_devfreq->profile->max_state; i++) - if (parent_devfreq->profile->freq_table[i] == *freq) + for (i = 0; i < parent_devfreq->max_state; i++) + if (parent_devfreq->freq_table[i] == *freq) break;

- if (i == parent_devfreq->profile->max_state) + if (i == parent_devfreq->max_state) return -EINVAL;

- if (i < devfreq->profile->max_state) { - child_freq = devfreq->profile->freq_table[i]; + if (i < devfreq->max_state) { + child_freq = devfreq->freq_table[i]; } else { - count = devfreq->profile->max_state; - child_freq = devfreq->profile->freq_table[count - 1]; + count = devfreq->max_state; + child_freq = devfreq->freq_table[count - 1]; }

out: diff --git a/include/linux/devfreq.h b/include/linux/devfreq.h index dc10bee75a72..34aab4dd336c 100644 --- a/include/linux/devfreq.h +++ b/include/linux/devfreq.h @@ -148,6 +148,8 @@ struct devfreq_stats { * reevaluate operable frequencies. Devfreq users may use * devfreq.nb to the corresponding register notifier call chain. * @work: delayed work for load monitoring. + * @freq_table: current frequency table used by the devfreq driver. + * @max_state: count of entry present in the frequency table. * @previous_freq: previously configured frequency value. * @last_status: devfreq user device info, performance statistics * @data: Private data of the governor. The devfreq framework does not @@ -185,6 +187,9 @@ struct devfreq { struct notifier_block nb; struct delayed_work work;

+ unsigned long *freq_table; + unsigned int max_state; + unsigned long previous_freq; struct devfreq_dev_status last_status;