From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/hwmon/occ/sysfs.c | 257 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 257 insertions(+) create mode 100644 drivers/hwmon/occ/sysfs.c (limited to 'drivers/hwmon/occ/sysfs.c') diff --git a/drivers/hwmon/occ/sysfs.c b/drivers/hwmon/occ/sysfs.c new file mode 100644 index 000000000..2317301fc --- /dev/null +++ b/drivers/hwmon/occ/sysfs.c @@ -0,0 +1,257 @@ +// SPDX-License-Identifier: GPL-2.0+ +// Copyright IBM Corp 2019 + +#include +#include +#include +#include +#include +#include +#include + +#include "common.h" + +/* OCC status register */ +#define OCC_STAT_MASTER BIT(7) + +/* OCC extended status register */ +#define OCC_EXT_STAT_DVFS_OT BIT(7) +#define OCC_EXT_STAT_DVFS_POWER BIT(6) +#define OCC_EXT_STAT_MEM_THROTTLE BIT(5) +#define OCC_EXT_STAT_QUICK_DROP BIT(4) +#define OCC_EXT_STAT_DVFS_VDD BIT(3) +#define OCC_EXT_STAT_GPU_THROTTLE GENMASK(2, 0) + +static ssize_t occ_active_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + int rc; + bool active; + struct occ *occ = dev_get_drvdata(dev); + + rc = kstrtobool(buf, &active); + if (rc) + return rc; + + rc = occ_active(occ, active); + if (rc) + return rc; + + return count; +} + +static ssize_t occ_sysfs_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + int rc; + int val = 0; + struct occ *occ = dev_get_drvdata(dev); + struct occ_poll_response_header *header; + struct sensor_device_attribute *sattr = to_sensor_dev_attr(attr); + + if (occ->active) { + rc = occ_update_response(occ); + if (rc) + return rc; + + header = (struct occ_poll_response_header *)occ->resp.data; + + switch (sattr->index) { + case 0: + val = !!(header->status & OCC_STAT_MASTER); + break; + case 1: + val = 1; + break; + case 2: + val = !!(header->ext_status & OCC_EXT_STAT_DVFS_OT); + break; + case 3: + val = !!(header->ext_status & OCC_EXT_STAT_DVFS_POWER); + break; + case 4: + val = !!(header->ext_status & + OCC_EXT_STAT_MEM_THROTTLE); + break; + case 5: + val = !!(header->ext_status & OCC_EXT_STAT_QUICK_DROP); + break; + case 6: + val = header->occ_state; + break; + case 7: + if (header->status & OCC_STAT_MASTER) + val = hweight8(header->occs_present); + else + val = 1; + break; + case 8: + val = header->ips_status; + break; + case 9: + val = header->mode; + break; + case 10: + val = !!(header->ext_status & OCC_EXT_STAT_DVFS_VDD); + break; + case 11: + val = header->ext_status & OCC_EXT_STAT_GPU_THROTTLE; + break; + default: + return -EINVAL; + } + } else { + if (sattr->index == 1) + val = 0; + else if (sattr->index <= 11) + val = -ENODATA; + else + return -EINVAL; + } + + return sysfs_emit(buf, "%d\n", val); +} + +static ssize_t occ_error_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct occ *occ = dev_get_drvdata(dev); + + occ_update_response(occ); + + return sysfs_emit(buf, "%d\n", occ->error); +} + +static SENSOR_DEVICE_ATTR(occ_master, 0444, occ_sysfs_show, NULL, 0); +static SENSOR_DEVICE_ATTR(occ_active, 0644, occ_sysfs_show, occ_active_store, + 1); +static SENSOR_DEVICE_ATTR(occ_dvfs_overtemp, 0444, occ_sysfs_show, NULL, 2); +static SENSOR_DEVICE_ATTR(occ_dvfs_power, 0444, occ_sysfs_show, NULL, 3); +static SENSOR_DEVICE_ATTR(occ_mem_throttle, 0444, occ_sysfs_show, NULL, 4); +static SENSOR_DEVICE_ATTR(occ_quick_pwr_drop, 0444, occ_sysfs_show, NULL, 5); +static SENSOR_DEVICE_ATTR(occ_state, 0444, occ_sysfs_show, NULL, 6); +static SENSOR_DEVICE_ATTR(occs_present, 0444, occ_sysfs_show, NULL, 7); +static SENSOR_DEVICE_ATTR(occ_ips_status, 0444, occ_sysfs_show, NULL, 8); +static SENSOR_DEVICE_ATTR(occ_mode, 0444, occ_sysfs_show, NULL, 9); +static SENSOR_DEVICE_ATTR(occ_dvfs_vdd, 0444, occ_sysfs_show, NULL, 10); +static SENSOR_DEVICE_ATTR(occ_gpu_throttle, 0444, occ_sysfs_show, NULL, 11); +static DEVICE_ATTR_RO(occ_error); + +static struct attribute *occ_attributes[] = { + &sensor_dev_attr_occ_master.dev_attr.attr, + &sensor_dev_attr_occ_active.dev_attr.attr, + &sensor_dev_attr_occ_dvfs_overtemp.dev_attr.attr, + &sensor_dev_attr_occ_dvfs_power.dev_attr.attr, + &sensor_dev_attr_occ_mem_throttle.dev_attr.attr, + &sensor_dev_attr_occ_quick_pwr_drop.dev_attr.attr, + &sensor_dev_attr_occ_state.dev_attr.attr, + &sensor_dev_attr_occs_present.dev_attr.attr, + &sensor_dev_attr_occ_ips_status.dev_attr.attr, + &sensor_dev_attr_occ_mode.dev_attr.attr, + &sensor_dev_attr_occ_dvfs_vdd.dev_attr.attr, + &sensor_dev_attr_occ_gpu_throttle.dev_attr.attr, + &dev_attr_occ_error.attr, + NULL +}; + +static const struct attribute_group occ_sysfs = { + .attrs = occ_attributes, +}; + +void occ_sysfs_poll_done(struct occ *occ) +{ + const char *name; + struct occ_poll_response_header *header = + (struct occ_poll_response_header *)occ->resp.data; + + /* + * On the first poll response, we haven't yet created the sysfs + * attributes, so don't make any notify calls. + */ + if (!occ->active) + goto done; + + if ((header->status & OCC_STAT_MASTER) != + (occ->prev_stat & OCC_STAT_MASTER)) { + name = sensor_dev_attr_occ_master.dev_attr.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + if ((header->ext_status & OCC_EXT_STAT_DVFS_OT) != + (occ->prev_ext_stat & OCC_EXT_STAT_DVFS_OT)) { + name = sensor_dev_attr_occ_dvfs_overtemp.dev_attr.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + if ((header->ext_status & OCC_EXT_STAT_DVFS_POWER) != + (occ->prev_ext_stat & OCC_EXT_STAT_DVFS_POWER)) { + name = sensor_dev_attr_occ_dvfs_power.dev_attr.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + if ((header->ext_status & OCC_EXT_STAT_MEM_THROTTLE) != + (occ->prev_ext_stat & OCC_EXT_STAT_MEM_THROTTLE)) { + name = sensor_dev_attr_occ_mem_throttle.dev_attr.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + if ((header->ext_status & OCC_EXT_STAT_QUICK_DROP) != + (occ->prev_ext_stat & OCC_EXT_STAT_QUICK_DROP)) { + name = sensor_dev_attr_occ_quick_pwr_drop.dev_attr.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + if ((header->ext_status & OCC_EXT_STAT_DVFS_VDD) != + (occ->prev_ext_stat & OCC_EXT_STAT_DVFS_VDD)) { + name = sensor_dev_attr_occ_dvfs_vdd.dev_attr.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + if ((header->ext_status & OCC_EXT_STAT_GPU_THROTTLE) != + (occ->prev_ext_stat & OCC_EXT_STAT_GPU_THROTTLE)) { + name = sensor_dev_attr_occ_gpu_throttle.dev_attr.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + if ((header->status & OCC_STAT_MASTER) && + header->occs_present != occ->prev_occs_present) { + name = sensor_dev_attr_occs_present.dev_attr.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + if (header->ips_status != occ->prev_ips_status) { + name = sensor_dev_attr_occ_ips_status.dev_attr.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + if (header->mode != occ->prev_mode) { + name = sensor_dev_attr_occ_mode.dev_attr.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + if (occ->error && occ->error != occ->prev_error) { + name = dev_attr_occ_error.attr.name; + sysfs_notify(&occ->bus_dev->kobj, NULL, name); + } + + /* no notifications for OCC state; doesn't indicate error condition */ + +done: + occ->prev_error = occ->error; + occ->prev_stat = header->status; + occ->prev_ext_stat = header->ext_status; + occ->prev_occs_present = header->occs_present; + occ->prev_ips_status = header->ips_status; + occ->prev_mode = header->mode; +} + +int occ_setup_sysfs(struct occ *occ) +{ + return sysfs_create_group(&occ->bus_dev->kobj, &occ_sysfs); +} + +void occ_shutdown_sysfs(struct occ *occ) +{ + sysfs_remove_group(&occ->bus_dev->kobj, &occ_sysfs); +} -- cgit v1.3.1