FAILED: patch "[PATCH] ACPI: TAD: Add locking around AML evaluations" failed to apply to 6.6-stable tree

FAILED: patch "[PATCH] ACPI: TAD: Add locking around AML evaluations" failed to apply to 6.6-stable tree

[gregkh]

The patch below does not apply to the 6.6-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>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x a3df8bbe0a704fa5c1609b9666b594f350558fe0
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026090332-delighted-felt-tip-2059@gregkh' --subject-prefix 'PATCH 6.6.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From a3df8bbe0a704fa5c1609b9666b594f350558fe0 Mon Sep 17 00:00:00 2001
From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
Date: Wed, 5 Aug 2026 20:53:32 +0200
Subject: [PATCH] ACPI: TAD: Add locking around AML evaluations

In the ACPI TAD driver, there are hidden assumptions that the ACPI
control methods used by it will not be evaluated concurrently due
to ACPICA namespace and interpreter locking.

However, that may not be the case since ACPICA may drop and re-acquire
the namespace and interpreter locks during the evaluation of a given
object in a few cases, including the one in which the AML in question
sleeps causing acpi_ex_system_do_sleep() to be called.  In that case,
the evaluation of one control method may be started while the
evaluation of another one is still in progress.

For this reason, add a global lock to the ACPI TAD driver and
acquire it every time before evaluating an ACPI control method,
except for the initial evaluation of _GCP in acpi_tad_probe().

Fixes: 95c513ec84f7 ("ACPI: Add Time and Alarm Device (TAD) driver")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/12951141.O9o76ZdvQC@rafael.j.wysocki

diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c
index fc43df083738..45459a4cafae 100644
--- a/drivers/acpi/acpi_tad.c
+++ b/drivers/acpi/acpi_tad.c
@@ -27,6 +27,7 @@
 #include <linux/kernel.h>
 #include <linux/ktime.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/rtc.h>
@@ -86,6 +87,8 @@ static bool acpi_tad_rt_is_invalid(struct acpi_tad_rt *rt)
 	    rt->daylight > 3;
 }
 
+static DEFINE_MUTEX(acpi_tad_aml_lock);
+
 static int acpi_tad_set_real_time(struct device *dev, struct acpi_tad_rt *rt)
 {
 	acpi_handle handle = ACPI_HANDLE(dev);
@@ -113,6 +116,8 @@ static int acpi_tad_set_real_time(struct device *dev, struct acpi_tad_rt *rt)
 	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
 		return -ENXIO;
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_integer(handle, "_SRT", &arg_list, &retval);
 	if (ACPI_FAILURE(status) || retval)
 		return -EIO;
@@ -124,30 +129,27 @@ static int acpi_tad_evaluate_grt(struct device *dev, struct acpi_tad_rt *rt)
 {
 	acpi_handle handle = ACPI_HANDLE(dev);
 	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER };
-	union acpi_object *out_obj;
-	struct acpi_tad_rt *data;
 	acpi_status status;
 	int ret = -EIO;
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_object(handle, "_GRT", NULL, &output);
-	if (ACPI_FAILURE(status))
-		goto out_free;
+	if (ACPI_SUCCESS(status)) {
+		union acpi_object *out_obj;
 
-	out_obj = output.pointer;
-	if (out_obj->type != ACPI_TYPE_BUFFER)
-		goto out_free;
+		out_obj = output.pointer;
+		if (out_obj->type == ACPI_TYPE_BUFFER &&
+		    out_obj->buffer.length == sizeof(*rt)) {
+			struct acpi_tad_rt *data;
 
-	if (out_obj->buffer.length != sizeof(*rt))
-		goto out_free;
-
-	data = (struct acpi_tad_rt *)(out_obj->buffer.pointer);
-	if (!data->valid)
-		goto out_free;
-
-	memcpy(rt, data, sizeof(*rt));
-	ret = 0;
-
-out_free:
+			data = (struct acpi_tad_rt *)(out_obj->buffer.pointer);
+			if (data->valid) {
+				memcpy(rt, data, sizeof(*rt));
+				ret = 0;
+			}
+		}
+	}
 	ACPI_FREE(output.pointer);
 	return ret;
 }
@@ -193,6 +195,8 @@ static int __acpi_tad_wake_set(struct device *dev, char *method, u32 timer_id,
 	args[0].integer.value = timer_id;
 	args[1].integer.value = value;
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_integer(handle, method, &arg_list, &retval);
 	if (ACPI_FAILURE(status) || retval)
 		return -EIO;
@@ -215,6 +219,8 @@ static int __acpi_tad_wake_read(struct device *dev, char *method, u32 timer_id,
 
 	args[0].integer.value = timer_id;
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_integer(handle, method, &arg_list, retval);
 	if (ACPI_FAILURE(status))
 		return -EIO;
@@ -416,6 +422,8 @@ static int acpi_tad_clear_status(struct device *dev, u32 timer_id)
 	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
 		return -ENXIO;
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_integer(handle, "_CWS", &arg_list, &retval);
 	if (ACPI_FAILURE(status) || retval)
 		return -EIO;
@@ -456,6 +464,8 @@ static ssize_t acpi_tad_status_read(struct device *dev, char *buf, u32 timer_id)
 	if (PM_RUNTIME_ACQUIRE_ERR(&pm))
 		return -ENXIO;
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_integer(handle, "_GWS", &arg_list, &retval);
 	if (ACPI_FAILURE(status))
 		return -EIO;

[PATCH 6.6.y 1/3] ACPI: TAD: Rearrange RT data validation checking

[Sasha Levin]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

[ Upstream commit 3329a1416c3350449081ca5daaa94802a65b2992 ]

Move RT data validation checks from acpi_tad_set_real_time() to
a separate function called acpi_tad_rt_is_invalid() and use it
also in acpi_tad_get_real_time() to validate data coming from
the platform firmware.

Also make acpi_tad_set_real_time() return -EINVAL when the RT data
passed to it is invalid (instead of -ERANGE which is somewhat
confusing) and introduce ACPI_TAD_TZ_UNSPEC to represent the
"unspecified timezone" value.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/3409319.aeNJFYEL58@rafael.j.wysocki
Stable-dep-of: a3df8bbe0a70 ("ACPI: TAD: Add locking around AML evaluations")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/acpi/acpi_tad.c | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c
index 542e16c3ab9f6..7af8e6b833533 100644
--- a/drivers/acpi/acpi_tad.c
+++ b/drivers/acpi/acpi_tad.c
@@ -48,6 +48,9 @@ MODULE_AUTHOR("Rafael J. Wysocki");
 /* Special value for disabled timer or expired timer wake policy. */
 #define ACPI_TAD_WAKE_DISABLED	(~(u32)0)
 
+/* ACPI TAD RTC */
+#define ACPI_TAD_TZ_UNSPEC	2047
+
 struct acpi_tad_driver_data {
 	u32 capabilities;
 };
@@ -66,6 +69,16 @@ struct acpi_tad_rt {
 	u8 padding[3]; /* must be 0 */
 } __packed;
 
+static bool acpi_tad_rt_is_invalid(struct acpi_tad_rt *rt)
+{
+	return rt->year < 1900 || rt->year > 9999 ||
+	    rt->month < 1 || rt->month > 12 ||
+	    rt->hour > 23 || rt->minute > 59 || rt->second > 59 ||
+	    rt->tz < -1440 ||
+	    (rt->tz > 1440 && rt->tz != ACPI_TAD_TZ_UNSPEC) ||
+	    rt->daylight > 3;
+}
+
 static int acpi_tad_set_real_time(struct device *dev, struct acpi_tad_rt *rt)
 {
 	acpi_handle handle = ACPI_HANDLE(dev);
@@ -79,12 +92,8 @@ static int acpi_tad_set_real_time(struct device *dev, struct acpi_tad_rt *rt)
 	unsigned long long retval;
 	acpi_status status;
 
-	if (rt->year < 1900 || rt->year > 9999 ||
-	    rt->month < 1 || rt->month > 12 ||
-	    rt->hour > 23 || rt->minute > 59 || rt->second > 59 ||
-	    rt->tz < -1440 || (rt->tz > 1440 && rt->tz != 2047) ||
-	    rt->daylight > 3)
-		return -ERANGE;
+	if (acpi_tad_rt_is_invalid(rt))
+		return -EINVAL;
 
 	args[0].buffer.pointer = (u8 *)rt;
 	args[0].buffer.length = sizeof(*rt);
@@ -131,6 +140,11 @@ static int acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
 		goto out_free;
 
 	memcpy(rt, data, sizeof(*rt));
+	if (acpi_tad_rt_is_invalid(rt)) {
+		ret = -ENODATA;
+		goto out_free;
+	}
+
 	ret = 0;
 
 out_free:
-- 
2.53.0

[PATCH 6.6.y 2/3] ACPI: TAD: Split three functions to untangle runtime PM handling

[Sasha Levin]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

[ Upstream commit b14b77bbea0a82cb66f1538824783e63d4128510 ]

Move the core functionality of acpi_tad_get_real_time(),
acpi_tad_wake_set(), and acpi_tad_wake_read() into separate functions
called __acpi_tad_get_real_time(), __acpi_tad_wake_set(), and
__acpi_tad_wake_read(), respectively, which can be called from
code blocks following a single runtime resume of the device.

This will facilitate adding alarm support to the RTC class device
interface of the driver going forward.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Link: https://patch.msgid.link/23076728.EfDdHjke4D@rafael.j.wysocki
Stable-dep-of: a3df8bbe0a70 ("ACPI: TAD: Add locking around AML evaluations")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/acpi/acpi_tad.c | 128 ++++++++++++++++++++++++++--------------
 1 file changed, 84 insertions(+), 44 deletions(-)

diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c
index 7af8e6b833533..8fb892424cfb2 100644
--- a/drivers/acpi/acpi_tad.c
+++ b/drivers/acpi/acpi_tad.c
@@ -110,7 +110,7 @@ static int acpi_tad_set_real_time(struct device *dev, struct acpi_tad_rt *rt)
 	return 0;
 }
 
-static int acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
+static int acpi_tad_evaluate_grt(struct device *dev, struct acpi_tad_rt *rt)
 {
 	acpi_handle handle = ACPI_HANDLE(dev);
 	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER };
@@ -119,12 +119,7 @@ static int acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
 	acpi_status status;
 	int ret = -EIO;
 
-	pm_runtime_get_sync(dev);
-
 	status = acpi_evaluate_object(handle, "_GRT", NULL, &output);
-
-	pm_runtime_put_sync(dev);
-
 	if (ACPI_FAILURE(status))
 		goto out_free;
 
@@ -140,11 +135,6 @@ static int acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
 		goto out_free;
 
 	memcpy(rt, data, sizeof(*rt));
-	if (acpi_tad_rt_is_invalid(rt)) {
-		ret = -ENODATA;
-		goto out_free;
-	}
-
 	ret = 0;
 
 out_free:
@@ -152,6 +142,82 @@ static int acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
 	return ret;
 }
 
+static int __acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
+{
+	int ret;
+
+	ret = acpi_tad_evaluate_grt(dev, rt);
+	if (ret)
+		return ret;
+
+	if (acpi_tad_rt_is_invalid(rt))
+		return -ENODATA;
+
+	return 0;
+}
+
+static int acpi_tad_get_real_time(struct device *dev, struct acpi_tad_rt *rt)
+{
+	int ret;
+
+	pm_runtime_get_sync(dev);
+
+	ret = __acpi_tad_get_real_time(dev, rt);
+
+	pm_runtime_put_sync(dev);
+
+	return ret;
+}
+
+static int __acpi_tad_wake_set(struct device *dev, char *method, u32 timer_id,
+			       u32 value)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object args[] = {
+		{ .type = ACPI_TYPE_INTEGER, },
+		{ .type = ACPI_TYPE_INTEGER, },
+	};
+	struct acpi_object_list arg_list = {
+		.pointer = args,
+		.count = ARRAY_SIZE(args),
+	};
+	unsigned long long retval;
+	acpi_status status;
+
+	args[0].integer.value = timer_id;
+	args[1].integer.value = value;
+
+	status = acpi_evaluate_integer(handle, method, &arg_list, &retval);
+	if (ACPI_FAILURE(status) || retval)
+		return -EIO;
+
+	return 0;
+}
+
+static int __acpi_tad_wake_read(struct device *dev, char *method, u32 timer_id,
+				unsigned long long *retval)
+{
+	acpi_handle handle = ACPI_HANDLE(dev);
+	union acpi_object args[] = {
+		{ .type = ACPI_TYPE_INTEGER, },
+	};
+	struct acpi_object_list arg_list = {
+		.pointer = args,
+		.count = ARRAY_SIZE(args),
+	};
+	acpi_status status;
+
+	args[0].integer.value = timer_id;
+
+	status = acpi_evaluate_integer(handle, method, &arg_list, retval);
+	if (ACPI_FAILURE(status))
+		return -EIO;
+
+	return 0;
+}
+
+/* sysfs interface */
+
 static char *acpi_tad_rt_next_field(char *s, int *val)
 {
 	char *p;
@@ -264,31 +330,15 @@ static const struct attribute_group acpi_tad_time_attr_group = {
 static int acpi_tad_wake_set(struct device *dev, char *method, u32 timer_id,
 			     u32 value)
 {
-	acpi_handle handle = ACPI_HANDLE(dev);
-	union acpi_object args[] = {
-		{ .type = ACPI_TYPE_INTEGER, },
-		{ .type = ACPI_TYPE_INTEGER, },
-	};
-	struct acpi_object_list arg_list = {
-		.pointer = args,
-		.count = ARRAY_SIZE(args),
-	};
-	unsigned long long retval;
-	acpi_status status;
-
-	args[0].integer.value = timer_id;
-	args[1].integer.value = value;
+	int ret;
 
 	pm_runtime_get_sync(dev);
 
-	status = acpi_evaluate_integer(handle, method, &arg_list, &retval);
+	ret = __acpi_tad_wake_set(dev, method, timer_id, value);
 
 	pm_runtime_put_sync(dev);
 
-	if (ACPI_FAILURE(status) || retval)
-		return -EIO;
-
-	return 0;
+	return ret;
 }
 
 static int acpi_tad_wake_write(struct device *dev, const char *buf, char *method,
@@ -314,27 +364,17 @@ static int acpi_tad_wake_write(struct device *dev, const char *buf, char *method
 static ssize_t acpi_tad_wake_read(struct device *dev, char *buf, char *method,
 				  u32 timer_id, const char *specval)
 {
-	acpi_handle handle = ACPI_HANDLE(dev);
-	union acpi_object args[] = {
-		{ .type = ACPI_TYPE_INTEGER, },
-	};
-	struct acpi_object_list arg_list = {
-		.pointer = args,
-		.count = ARRAY_SIZE(args),
-	};
 	unsigned long long retval;
-	acpi_status status;
-
-	args[0].integer.value = timer_id;
+	int ret;
 
 	pm_runtime_get_sync(dev);
 
-	status = acpi_evaluate_integer(handle, method, &arg_list, &retval);
+	ret = __acpi_tad_wake_read(dev, method, timer_id, &retval);
 
 	pm_runtime_put_sync(dev);
 
-	if (ACPI_FAILURE(status))
-		return -EIO;
+	if (ret)
+		return ret;
 
 	if ((u32)retval == ACPI_TAD_WAKE_DISABLED)
 		return sprintf(buf, "%s\n", specval);
-- 
2.53.0

[PATCH 6.6.y 3/3] ACPI: TAD: Add locking around AML evaluations

[Sasha Levin]

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

[ Upstream commit a3df8bbe0a704fa5c1609b9666b594f350558fe0 ]

In the ACPI TAD driver, there are hidden assumptions that the ACPI
control methods used by it will not be evaluated concurrently due
to ACPICA namespace and interpreter locking.

However, that may not be the case since ACPICA may drop and re-acquire
the namespace and interpreter locks during the evaluation of a given
object in a few cases, including the one in which the AML in question
sleeps causing acpi_ex_system_do_sleep() to be called.  In that case,
the evaluation of one control method may be started while the
evaluation of another one is still in progress.

For this reason, add a global lock to the ACPI TAD driver and
acquire it every time before evaluating an ACPI control method,
except for the initial evaluation of _GCP in acpi_tad_probe().

Fixes: 95c513ec84f7 ("ACPI: Add Time and Alarm Device (TAD) driver")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://patch.msgid.link/12951141.O9o76ZdvQC@rafael.j.wysocki
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/acpi/acpi_tad.c | 50 ++++++++++++++++++++++++-----------------
 1 file changed, 30 insertions(+), 20 deletions(-)

diff --git a/drivers/acpi/acpi_tad.c b/drivers/acpi/acpi_tad.c
index 8fb892424cfb2..ca0d5640de052 100644
--- a/drivers/acpi/acpi_tad.c
+++ b/drivers/acpi/acpi_tad.c
@@ -23,6 +23,7 @@
 #include <linux/acpi.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
 #include <linux/suspend.h>
@@ -79,6 +80,8 @@ static bool acpi_tad_rt_is_invalid(struct acpi_tad_rt *rt)
 	    rt->daylight > 3;
 }
 
+static DEFINE_MUTEX(acpi_tad_aml_lock);
+
 static int acpi_tad_set_real_time(struct device *dev, struct acpi_tad_rt *rt)
 {
 	acpi_handle handle = ACPI_HANDLE(dev);
@@ -100,6 +103,8 @@ static int acpi_tad_set_real_time(struct device *dev, struct acpi_tad_rt *rt)
 
 	pm_runtime_get_sync(dev);
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_integer(handle, "_SRT", &arg_list, &retval);
 
 	pm_runtime_put_sync(dev);
@@ -114,30 +119,27 @@ static int acpi_tad_evaluate_grt(struct device *dev, struct acpi_tad_rt *rt)
 {
 	acpi_handle handle = ACPI_HANDLE(dev);
 	struct acpi_buffer output = { ACPI_ALLOCATE_BUFFER };
-	union acpi_object *out_obj;
-	struct acpi_tad_rt *data;
 	acpi_status status;
 	int ret = -EIO;
 
-	status = acpi_evaluate_object(handle, "_GRT", NULL, &output);
-	if (ACPI_FAILURE(status))
-		goto out_free;
-
-	out_obj = output.pointer;
-	if (out_obj->type != ACPI_TYPE_BUFFER)
-		goto out_free;
+	guard(mutex)(&acpi_tad_aml_lock);
 
-	if (out_obj->buffer.length != sizeof(*rt))
-		goto out_free;
-
-	data = (struct acpi_tad_rt *)(out_obj->buffer.pointer);
-	if (!data->valid)
-		goto out_free;
-
-	memcpy(rt, data, sizeof(*rt));
-	ret = 0;
-
-out_free:
+	status = acpi_evaluate_object(handle, "_GRT", NULL, &output);
+	if (ACPI_SUCCESS(status)) {
+		union acpi_object *out_obj;
+
+		out_obj = output.pointer;
+		if (out_obj->type == ACPI_TYPE_BUFFER &&
+		    out_obj->buffer.length == sizeof(*rt)) {
+			struct acpi_tad_rt *data;
+
+			data = (struct acpi_tad_rt *)(out_obj->buffer.pointer);
+			if (data->valid) {
+				memcpy(rt, data, sizeof(*rt));
+				ret = 0;
+			}
+		}
+	}
 	ACPI_FREE(output.pointer);
 	return ret;
 }
@@ -187,6 +189,8 @@ static int __acpi_tad_wake_set(struct device *dev, char *method, u32 timer_id,
 	args[0].integer.value = timer_id;
 	args[1].integer.value = value;
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_integer(handle, method, &arg_list, &retval);
 	if (ACPI_FAILURE(status) || retval)
 		return -EIO;
@@ -209,6 +213,8 @@ static int __acpi_tad_wake_read(struct device *dev, char *method, u32 timer_id,
 
 	args[0].integer.value = timer_id;
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_integer(handle, method, &arg_list, retval);
 	if (ACPI_FAILURE(status))
 		return -EIO;
@@ -425,6 +431,8 @@ static int acpi_tad_clear_status(struct device *dev, u32 timer_id)
 
 	pm_runtime_get_sync(dev);
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_integer(handle, "_CWS", &arg_list, &retval);
 
 	pm_runtime_put_sync(dev);
@@ -466,6 +474,8 @@ static ssize_t acpi_tad_status_read(struct device *dev, char *buf, u32 timer_id)
 
 	pm_runtime_get_sync(dev);
 
+	guard(mutex)(&acpi_tad_aml_lock);
+
 	status = acpi_evaluate_integer(handle, "_GWS", &arg_list, &retval);
 
 	pm_runtime_put_sync(dev);
-- 
2.53.0