Merge tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - The series "powerpc/crash: use generic crashkernel reservation" from
   Sourabh Jain changes powerpc's kexec code to use more of the generic
   layers.

 - The series "get_maintainer: report subsystem status separately" from
   Vlastimil Babka makes some long-requested improvements to the
   get_maintainer output.

 - The series "ucount: Simplify refcounting with rcuref_t" from
   Sebastian Siewior cleans up and optimizing the refcounting in the
   ucount code.

 - The series "reboot: support runtime configuration of emergency
   hw_protection action" from Ahmad Fatoum improves the ability for a
   driver to perform an emergency system shutdown or reboot.

 - The series "Converge on using secs_to_jiffies() part two" from Easwar
   Hariharan performs further migrations from msecs_to_jiffies() to
   secs_to_jiffies().

 - The series "lib/interval_tree: add some test cases and cleanup" from
   Wei Yang permits more userspace testing of kernel library code, adds
   some more tests and performs some cleanups.

 - The series "hung_task: Dump the blocking task stacktrace" from Masami
   Hiramatsu arranges for the hung_task detector to dump the stack of
   the blocking task and not just that of the blocked task.

 - The series "resource: Split and use DEFINE_RES*() macros" from Andy
   Shevchenko provides some cleanups to the resource definition macros.

 - Plus the usual shower of singleton patches - please see the
   individual changelogs for details.

* tag 'mm-nonmm-stable-2025-03-30-18-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (77 commits)
  mailmap: consolidate email addresses of Alexander Sverdlin
  fs/procfs: fix the comment above proc_pid_wchan()
  relay: use kasprintf() instead of fixed buffer formatting
  resource: replace open coded variant of DEFINE_RES()
  resource: replace open coded variants of DEFINE_RES_*_NAMED()
  resource: replace open coded variant of DEFINE_RES_NAMED_DESC()
  resource: split DEFINE_RES_NAMED_DESC() out of DEFINE_RES_NAMED()
  samples: add hung_task detector mutex blocking sample
  hung_task: show the blocker task if the task is hung on mutex
  kexec_core: accept unaccepted kexec segments' destination addresses
  watchdog/perf: optimize bytes copied and remove manual NUL-termination
  lib/interval_tree: fix the comment of interval_tree_span_iter_next_gap()
  lib/interval_tree: skip the check before go to the right subtree
  lib/interval_tree: add test case for span iteration
  lib/interval_tree: add test case for interval_tree_iter_xxx() helpers
  lib/rbtree: add random seed
  lib/rbtree: split tests
  lib/rbtree: enable userland test suite for rbtree related data structure
  checkpatch: describe --min-conf-desc-length
  scripts/gdb/symbols: determine KASLR offset on s390
  ...

5 files changed, 40 insertions, 14 deletions

diff --git a/Documentation/ABI/testing/sysfs-kernel-reboot b/Documentation/ABI/testing/sysfs-kernel-reboot
index 837330fb2511..e117aba46be0 100644
--- a/Documentation/ABI/testing/sysfs-kernel-reboot
+++ b/Documentation/ABI/testing/sysfs-kernel-reboot
@@ -30,3 +30,11 @@ KernelVersion:	5.11
 Contact:	Matteo Croce <mcroce@microsoft.com>
 Description:	Don't wait for any other CPUs on reboot and
 		avoid anything that could hang.
+
+What:		/sys/kernel/reboot/hw_protection
+Date:		April 2025
+KernelVersion:	6.15
+Contact:	Ahmad Fatoum <a.fatoum@pengutronix.de>
+Description:	Hardware protection action taken on critical events like
+		overtemperature or imminent voltage loss.
+		Valid values are: reboot shutdown
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 559f4fe51824..3f35d5b8c296 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1954,6 +1954,12 @@
 			which allow the hypervisor to 'idle' the guest
 			on lock contention.
 
+	hw_protection=	[HW]
+			Format: reboot | shutdown
+
+			Hardware protection action taken on critical events like
+			overtemperature or imminent voltage loss.
+
 	i2c_bus=	[HW]	Override the default board specific I2C bus speed
 				or register an additional I2C bus that is not
 				registered from board initialization code.
diff --git a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
index 0f435be1dbd8..0de0a9757ccc 100644
--- a/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
+++ b/Documentation/devicetree/bindings/thermal/thermal-zones.yaml
@@ -82,9 +82,8 @@ patternProperties:
         $ref: /schemas/types.yaml#/definitions/string
         description: |
           The action the OS should perform after the critical temperature is reached.
-          By default the system will shutdown as a safe action to prevent damage
-          to the hardware, if the property is not set.
-          The shutdown action should be always the default and preferred one.
+          If the property is not set, it is up to the system to select the correct
+          action. The recommended and preferred default is shutdown.
           Choose 'reboot' with care, as the hardware may be in thermal stress,
           thus leading to infinite reboots that may cause damage to the hardware.
           Make sure the firmware/bootloader will act as the last resort and take
diff --git a/Documentation/driver-api/thermal/sysfs-api.rst b/Documentation/driver-api/thermal/sysfs-api.rst
index c803b89b7248..f73de211bdce 100644
--- a/Documentation/driver-api/thermal/sysfs-api.rst
+++ b/Documentation/driver-api/thermal/sysfs-api.rst
@@ -413,18 +413,21 @@ This function serves as an arbitrator to set the state of a cooling
 device. It sets the cooling device to the deepest cooling state if
 possible.
 
-5. thermal_emergency_poweroff
-=============================
+5. Critical Events
+==================
+
+On an event of critical trip temperature crossing, the thermal framework
+will trigger a hardware protection power-off (shutdown) or reboot,
+depending on configuration.
 
-On an event of critical trip temperature crossing the thermal framework
-shuts down the system by calling hw_protection_shutdown(). The
-hw_protection_shutdown() first attempts to perform an orderly shutdown
-but accepts a delay after which it proceeds doing a forced power-off
-or as last resort an emergency_restart.
+At first, the kernel will attempt an orderly power-off or reboot, but
+accepts a delay after which it proceeds to do a forced power-off or
+reboot, respectively. If this fails, ``emergency_restart()`` is invoked
+as last resort.
 
 The delay should be carefully profiled so as to give adequate time for
-orderly poweroff.
+orderly power-off or reboot.
 
-If the delay is set to 0 emergency poweroff will not be supported. So a
-carefully profiled non-zero positive value is a must for emergency
-poweroff to be triggered.
+If the delay is set to 0, the emergency action will not be supported. So a
+carefully profiled non-zero positive value is a must for the emergency
+action to be triggered.
diff --git a/Documentation/filesystems/proc.rst b/Documentation/filesystems/proc.rst
index f97692b31a2d..2a17865dfe39 100644
--- a/Documentation/filesystems/proc.rst
+++ b/Documentation/filesystems/proc.rst
@@ -128,6 +128,16 @@ process running on the system, which is named after the process ID (PID).
 The link  'self'  points to  the process reading the file system. Each process
 subdirectory has the entries listed in Table 1-1.
 
+A process can read its own information from /proc/PID/* with no extra
+permissions. When reading /proc/PID/* information for other processes, reading
+process is required to have either CAP_SYS_PTRACE capability with
+PTRACE_MODE_READ access permissions, or, alternatively, CAP_PERFMON
+capability. This applies to all read-only information like `maps`, `environ`,
+`pagemap`, etc. The only exception is `mem` file due to its read-write nature,
+which requires CAP_SYS_PTRACE capabilities with more elevated
+PTRACE_MODE_ATTACH permissions; CAP_PERFMON capability does not grant access
+to /proc/PID/mem for other processes.
+
 Note that an open file descriptor to /proc/<pid> or to any of its
 contained files or subdirectories does not prevent <pid> being reused
 for some other process in the event that <pid> exits. Operations on