some more optimizations by spandruvada · Pull Request #574 · intel/thermal_daemon

spandruvada · 2026-06-05T00:09:44Z

No description provided.

Copilot

Pull request overview

This PR adds several hardening and behavior-gating changes across thermald’s config parsing, sysfs writes, D-Bus entrypoints, and Intel platform detection, along with a new RAPL “restore-on-exit” mechanism.

Changes:

Add shared validation helpers (thermal object names, finite numeric ranges, validated config open) and apply them across D-Bus, engine, and zone user-config paths.
Harden XML parsing by using a validated open path + restrictive libxml2 parse options and rejecting any config that includes a DTD.
Tighten platform and power-control behavior: gate select Intel CPUs to adaptive mode and add RAPL limit restoration support; restrict sysfs writes to resolved paths under /sys/.

Reviewed changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
src/thermald.h	Adds global flag for adaptive perf enable.
src/main.cpp	Defines/sets `adaptive_perf_enable` when `--adaptive` is used.
src/thd_platform_intel.cpp	Adds adaptive-only CPU gating and removes `/dev/mem` MMIO workaround code.
src/thd_util.h	Declares new validation + validated XML-open helpers.
src/thd_util.cpp	Implements name validation, finite-range checks, and validated XML file opening.
src/thd_parse.cpp	Switches to validated XML FD open, restrictive parse flags, and DTD rejection.
src/thd_features_parse.cpp	Same validated XML FD open + restrictive parsing + DTD rejection for features config.
src/thd_cdev_order_parser.cpp	Same validated XML FD open + restrictive parsing + DTD rejection for cdev-order config.
src/thd_sys_fs.cpp	Adds validated sysfs write open that resolves paths and restricts writes to `/sys`.
src/thd_zone.cpp	Validates zone type names before using them to build runtime config filenames.
src/thd_engine.cpp	Validates user-provided names and virtual sensor parameters before acting.
src/thd_dbus_interface.cpp	Adds D-Bus input validation for names and virtual sensor numeric params.
src/thd_cdev_rapl.h	Adds private `register_for_restoration()` hook.
src/thd_cdev_rapl.cpp	Calls restoration registration during RAPL cdev update.
src/thd_cdev_rapl_restore.cpp	New file: global registry + atexit handler to restore RAPL limits.
Makefile.am	Adds new RAPL restore source file to build.
README.txt	Adds 2.5.12-rc1 release notes entry.
configure.ac	Updates version to `2.5.12-rc1`.

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+/*
+ * cthd_cdev_rapl.cpp: thermal cooling class implementation
+ *	using RAPL


+void cthd_sysfs_cdev_rapl::register_for_restoration() {
+	std::lock_guard<std::mutex> lock(registry_mutex);
+
+	// Register atexit handler on first call
+	if (!atexit_registered) {
+		std::atexit(restore_rapl_limits);
+		atexit_registered = true;
+		thd_log_info("Registered RAPL power limit restoration handler\n");
+	}
+
+	rapl_restore_info info;
+	info.sysfs_path = cdev_sysfs.get_base_path();
+	info.constraint_index = constraint_index;
+	info.power_limit = rapl_read_pl1();
+	info.time_window = rapl_read_time_window();
+	info.enable_status = rapl_read_enable_status();
+
+	restore_registry.push_back(info);
+
+	thd_log_info("Registered RAPL %s: PL1=%d uW, window=%d us, enable=%d\n",
+		info.sysfs_path.c_str(), info.power_limit, info.time_window, info.enable_status);
+}


+	if (!is_valid_thermal_object_name(zone_name))
+		return FALSE;


+	if (!is_valid_thermal_object_name(zone_name))
+		return FALSE;


 	g_assert(obj != nullptr);
+	if (!is_valid_thermal_object_name(name))
+		return FALSE;
+	if (!is_valid_finite_value(slope, -1000.0, 1000.0)
+			|| !is_valid_finite_value(intercept, -1000.0, 1000.0))
+		return FALSE;


+	if (!is_valid_thermal_object_name(zone_name))
+		return FALSE;


Copilot

Pull request overview

Copilot reviewed 18 out of 18 changed files in this pull request and generated 4 comments.

 extern std::unique_ptr<cthd_engine> thd_engine;
 extern int thd_poll_interval;
 extern bool thd_ignore_default_control;
 extern bool workaround_enabled;
 extern bool disable_active_power;
 extern bool ignore_critical;
 extern bool power_floor_enable;
-
+extern bool adaptive_perf_enable;


+bool is_valid_thermal_object_name(const std::string &name);
+bool is_valid_finite_value(double value, double min_val, double max_val);
+
+int open_validated_xml_file(const std::string &filename, bool require_root_owner = true);
+


 	if (rapl_sysfs_valid())
 		return THD_ERROR;

+	register_for_restoration();
+


+static constexpr int thd_xml_parse_options = XML_PARSE_NONET | XML_PARSE_NOERROR
+		| XML_PARSE_NOWARNING;
+


Copilot

Pull request overview

Copilot reviewed 20 out of 20 changed files in this pull request and generated 8 comments.

 	if (adaptive) {
+		adaptive_perf_enable = true;
 		ret = thd_engine_create_adaptive_engine((bool) ignore_cpuid_check, (bool) test_mode);
 		if (ret != THD_SUCCESS) {
 			thd_log_info("--adaptive option failed on this platform\n");


+	int fd = ::open(resolved_path, O_WRONLY | O_NOFOLLOW);
+	if (fd < 0)
+		return -errno;


+	void restore_rapl_limits() {
+		std::lock_guard<std::mutex> lock(registry_mutex);
+
+		thd_log_info("Restoring %zu RAPL power limits on exit\n",
+			restore_registry.size());


Copilot

Pull request overview

Copilot reviewed 20 out of 20 changed files in this pull request and generated 6 comments.

+	void restore_rapl_limits() {
+		std::unique_lock<std::mutex> lock(registry_mutex, std::try_to_lock);
+		if (!lock.owns_lock())
+			return;
+
+		thd_log_info("Restoring %zu RAPL power limits on exit\n",
+			restore_registry.size());
+
+		for (const auto& info : restore_registry) {
+			csys_fs sysfs(info.sysfs_path);


spandruvada · 2026-06-05T01:49:54Z

 	std::string p = base_path + path;
-	int fd = ::open(p.c_str(), O_WRONLY | O_NOFOLLOW);
+	int fd = open_validated_sysfs_write_fd(p);
 	if (fd < 0) {
-		thd_log_info("sysfs write failed %s\n", p.c_str());
-		return -errno;
+		thd_log_info("sysfs write failed %s\n", path.c_str());
+		return fd;


intentional

spandruvada · 2026-06-05T01:49:45Z

 	int ret = ::write(fd, buf.c_str(), buf.size());
 	if (ret < 0) {
 		ret = -errno;
-		thd_log_info("sysfs write failed %s\n", p.c_str());
+		thd_log_info("sysfs write failed %s\n", path.c_str());
 	}


intentional

spandruvada · 2026-06-05T01:49:38Z

 	std::string p = base_path + path;
-	int fd = ::open(p.c_str(), O_WRONLY | O_NOFOLLOW);
+	int fd = open_validated_sysfs_write_fd(p);
 	if (fd < 0) {
-		thd_log_info("sysfs write failed %s\n", p.c_str());
-		return -errno;
+		thd_log_info("sysfs write failed %s\n", path.c_str());
+		return fd;


intentional

spandruvada · 2026-06-05T01:49:30Z

 	if (::lseek(fd, position, SEEK_CUR) == -1) {
-		thd_log_info("sysfs write failed %s\n", p.c_str());
+		thd_log_info("sysfs write failed %s\n", path.c_str());
 		close(fd);
 		return -errno;


Intentional

spandruvada · 2026-06-05T01:49:08Z

 	int ret = ::write(fd, &data, sizeof(data));
 	if (ret < 0)
-		thd_log_info("sysfs write failed %s\n", p.c_str());
+		thd_log_info("sysfs write failed %s\n", path.c_str());
 	close(fd);


This was intentional. Don't comment again.

Capture current RAPL PL1 power, time window and enabled status at startup and restore on exit. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

--adaptive option is enabled for a while. For newer platform only support this mode starting from Lunar Lake. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

We have proper driver interface. The direct /dev/mem access is not required. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Copilot

Pull request overview

Copilot reviewed 20 out of 20 changed files in this pull request and generated 1 comment.

Add an API open_validated_xml_file(), which can be used by all XML files opens. Also add API to sanitize zone names, which can only contain [A-Za-z0-9_.- ' '] Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Copilot

Pull request overview

Copilot reviewed 20 out of 20 changed files in this pull request and generated 3 comments.

-	doc = xmlReadFile(filename.c_str(), nullptr, 0);
+	int fd = open_validated_xml_file(filename);
+	if (fd < 0)
+		return THD_ERROR;


spandruvada · 2026-06-05T02:14:36Z

+static constexpr int thd_xml_parse_options = XML_PARSE_NONET | XML_PARSE_NOERROR
+		| XML_PARSE_NOWARNING;
+


spandruvada · 2026-06-05T02:15:41Z

 typedef struct {
 	unsigned int family;
 	unsigned int model;
+    unsigned int adaptive_only;
 } supported_ids_t;


ok with me.

Use open_validated_xml_file() and check for XML files without DTD. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Check for canonicalized sysfs paths rooted under /sys. Also reduce full path name prints in errors. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Use is_valid_thermal_object_name() to check for valid ASCII file names. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Add new files to Android build. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Refer to README.txt for details. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Copilot

Pull request overview

Copilot reviewed 20 out of 20 changed files in this pull request and generated 1 comment.

spandruvada requested a review from Copilot June 5, 2026 00:11

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spandruvada added 3 commits June 4, 2026 18:39

Store and restore RAPL register at exit

6bcb400

Capture current RAPL PL1 power, time window and enabled status at startup and restore on exit. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Support new platforms in adaptive mode only

1ed9a7f

--adaptive option is enabled for a while. For newer platform only support this mode starting from Lunar Lake. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Remove /dev/mem workaround

8913bee

We have proper driver interface. The direct /dev/mem access is not required. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

spandruvada force-pushed the thermald_next branch from 306e1a3 to 82ca371 Compare June 5, 2026 01:50

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Comment thread src/thd_util.cpp

Add new API to open XML files

bcb34ac

Add an API open_validated_xml_file(), which can be used by all XML files opens. Also add API to sanitize zone names, which can only contain [A-Za-z0-9_.- ' '] Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

spandruvada force-pushed the thermald_next branch from 82ca371 to f3b92ae Compare June 5, 2026 02:06

spandruvada requested a review from Copilot June 5, 2026 02:08

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spandruvada added 3 commits June 4, 2026 19:18

Use new open_validated_xml_file() API

4dc91fa

Use open_validated_xml_file() and check for XML files without DTD. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Restrict only to /sys writes

7c81181

Check for canonicalized sysfs paths rooted under /sys. Also reduce full path name prints in errors. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Sanitize zone names added via dbus

d0f328a

Use is_valid_thermal_object_name() to check for valid ASCII file names. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

spandruvada added 2 commits June 4, 2026 19:18

Add new files to Android build

2d68c8f

Add new files to Android build. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Release 2.5.12-rc1

3944dcf

Refer to README.txt for details. Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

spandruvada force-pushed the thermald_next branch from f3b92ae to 3944dcf Compare June 5, 2026 02:18

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Comment thread src/thd_platform_intel.cpp

spandruvada merged commit 7cd8e3f into master Jun 5, 2026
3 checks passed

		static constexpr int thd_xml_parse_options = XML_PARSE_NONET \| XML_PARSE_NOERROR
		\| XML_PARSE_NOWARNING;

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