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
  ...

Author: torvalds

.mailmap

@@ -31,6 +31,13 @@ Alexander Lobakin <[email protected]> <[email protected]>
 Alexander Lobakin <[email protected]> <[email protected]>
 Alexander Mikhalitsyn <[email protected]> <[email protected]>
 Alexander Mikhalitsyn <[email protected]> <[email protected]>
+Alexander Sverdlin <[email protected]> <[email protected]>
+Alexander Sverdlin <[email protected]> <[email protected]>
+Alexander Sverdlin <[email protected]> <[email protected]>
+Alexander Sverdlin <[email protected]> <[email protected]>
+Alexander Sverdlin <[email protected]> <[email protected]>
+Alexander Sverdlin <[email protected]> <[email protected]>
+Alexander Sverdlin <[email protected]> <[email protected]>
 Alexandre Belloni <[email protected]> <[email protected]>
 Alexandre Ghiti <[email protected]> <[email protected]>
 Alexei Avshalom Lazar <[email protected]> <[email protected]>
@@ -153,7 +160,6 @@ Carlos Bilbao <[email protected]> <[email protected]>
 Carlos Bilbao <[email protected]> <[email protected]>
 Carlos Bilbao <[email protected]> <[email protected]>
 Changbin Du <[email protected]> <[email protected]>
-Changbin Du <[email protected]> <[email protected]>
 Chao Yu <[email protected]> <[email protected]>
 Chao Yu <[email protected]> <[email protected]>
 Chester Lin <[email protected]> <[email protected]>
@@ -271,6 +277,7 @@ Hamza Mahfooz <[email protected]> <[email protected]>
 Hanjun Guo <[email protected]> <[email protected]>
 Hans Verkuil <[email protected]> <[email protected]>
 Hans Verkuil <[email protected]> <[email protected]>
+Harry Yoo <[email protected]> <[email protected]>
 Heiko Carstens <[email protected]> <[email protected]>
 Heiko Carstens <[email protected]> <[email protected]>
 Heiko Stuebner <[email protected]> <[email protected]>
@@ -305,7 +312,6 @@ Jan Glauber <[email protected]> <[email protected]>
 Jan Kuliga <[email protected]> <[email protected]>
 Jarkko Sakkinen <[email protected]> <[email protected]>
 Jarkko Sakkinen <[email protected]> <[email protected]>
-Jarkko Sakkinen <[email protected]> <[email protected]>
 Jason Gunthorpe <[email protected]> <[email protected]>
 Jason Gunthorpe <[email protected]> <[email protected]>
 Jason Gunthorpe <[email protected]> <[email protected]>
@@ -762,7 +768,6 @@ Vinod Koul <[email protected]> <[email protected]>
 Viresh Kumar <[email protected]> <[email protected]>
 Viresh Kumar <[email protected]> <[email protected]>
 Viresh Kumar <[email protected]> <[email protected]>
-Viresh Kumar <[email protected]> <[email protected]>
 Viresh Kumar <[email protected]> <[email protected]>
 Vishnu Dasa <[email protected]> <[email protected]>
 Vivek Aknurwar <[email protected]> <[email protected]>

Documentation/ABI/testing/sysfs-kernel-reboot

@@ -30,3 +30,11 @@ KernelVersion:	5.11
 Contact:	Matteo Croce <[email protected]>
 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 <[email protected]>
+Description:	Hardware protection action taken on critical events like
+		overtemperature or imminent voltage loss.
+		Valid values are: reboot shutdown

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.

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

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.

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

MAINTAINERS

@@ -18802,6 +18802,7 @@ F:	mm/percpu*.c
 
 PER-TASK DELAY ACCOUNTING
 M:	Balbir Singh <[email protected]>
+M:	Yang Yang <[email protected]>
 S:	Maintained
 F:	include/linux/delayacct.h
 F:	kernel/delayacct.c
@@ -22153,7 +22154,7 @@ M:	Joonsoo Kim <[email protected]>
 M:	Andrew Morton <[email protected]>
 M:	Vlastimil Babka <[email protected]>
 R:	Roman Gushchin <[email protected]>
-R:	Hyeonggon Yoo <42.hyeyoo@gmail.com>
+R:	Harry Yoo <harry.yoo@oracle.com>
 L:	[email protected]
 S:	Maintained
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab.git

arch/arm64/mm/init.c

@@ -98,21 +98,19 @@ static void __init arch_reserve_crashkernel(void)
 {
 	unsigned long long low_size = 0;
 	unsigned long long crash_base, crash_size;
-	char *cmdline = boot_command_line;
 	bool high = false;
 	int ret;
 
 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
 		return;
 
-	ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
+	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 				&crash_size, &crash_base,
 				&low_size, &high);
 	if (ret)
 		return;
 
-	reserve_crashkernel_generic(cmdline, crash_size, crash_base,
-				    low_size, high);
+	reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
 }
 
 static phys_addr_t __init max_zone_phys(phys_addr_t zone_limit)

arch/loongarch/kernel/setup.c

@@ -259,18 +259,17 @@ static void __init arch_reserve_crashkernel(void)
 	int ret;
 	unsigned long long low_size = 0;
 	unsigned long long crash_base, crash_size;
-	char *cmdline = boot_command_line;
 	bool high = false;
 
 	if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
 		return;
 
-	ret = parse_crashkernel(cmdline, memblock_phys_mem_size(),
+	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 				&crash_size, &crash_base, &low_size, &high);
 	if (ret)
 		return;
 
-	reserve_crashkernel_generic(cmdline, crash_size, crash_base, low_size, high);
+	reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
 }
 
 static void __init fdt_setup(void)

arch/powerpc/Kconfig

@@ -716,6 +716,9 @@ config ARCH_SUPPORTS_CRASH_HOTPLUG
 	def_bool y
 	depends on PPC64
 
+config ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
+	def_bool CRASH_RESERVE
+
 config FA_DUMP
 	bool "Firmware-assisted dump"
 	depends on CRASH_DUMP && PPC64 && (PPC_RTAS || PPC_POWERNV)

arch/powerpc/include/asm/crash_reserve.h

@@ -0,0 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_POWERPC_CRASH_RESERVE_H
+#define _ASM_POWERPC_CRASH_RESERVE_H
+
+/* crash kernel regions are Page size agliged */
+#define CRASH_ALIGN             PAGE_SIZE
+
+#endif /* _ASM_POWERPC_CRASH_RESERVE_H */

arch/powerpc/include/asm/kexec.h

@@ -94,8 +94,10 @@ int arch_kexec_kernel_image_probe(struct kimage *image, void *buf, unsigned long
 int arch_kimage_file_post_load_cleanup(struct kimage *image);
 #define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup
 
-int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf);
-#define arch_kexec_locate_mem_hole arch_kexec_locate_mem_hole
+int arch_check_excluded_range(struct kimage *image, unsigned long start,
+			      unsigned long end);
+#define arch_check_excluded_range  arch_check_excluded_range
+
 
 int load_crashdump_segments_ppc64(struct kimage *image,
 				  struct kexec_buf *kbuf);
@@ -112,9 +114,9 @@ int setup_new_fdt_ppc64(const struct kimage *image, void *fdt, struct crash_mem
 
 #ifdef CONFIG_CRASH_RESERVE
 int __init overlaps_crashkernel(unsigned long start, unsigned long size);
-extern void reserve_crashkernel(void);
+extern void arch_reserve_crashkernel(void);
 #else
-static inline void reserve_crashkernel(void) {}
+static inline void arch_reserve_crashkernel(void) {}
 static inline int overlaps_crashkernel(unsigned long start, unsigned long size) { return 0; }
 #endif
 

arch/powerpc/kernel/prom.c

@@ -860,7 +860,7 @@ void __init early_init_devtree(void *params)
 	 */
 	if (fadump_reserve_mem() == 0)
 #endif
-		reserve_crashkernel();
+		arch_reserve_crashkernel();
 	early_reserve_mem();
 
 	if (memory_limit > memblock_phys_mem_size())

arch/powerpc/kexec/core.c

@@ -58,38 +58,20 @@ void machine_kexec(struct kimage *image)
 }
 
 #ifdef CONFIG_CRASH_RESERVE
-void __init reserve_crashkernel(void)
-{
-	unsigned long long crash_size, crash_base, total_mem_sz;
-	int ret;
 
-	total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
-	/* use common parsing */
-	ret = parse_crashkernel(boot_command_line, total_mem_sz,
-			&crash_size, &crash_base, NULL, NULL);
-	if (ret == 0 && crash_size > 0) {
-		crashk_res.start = crash_base;
-		crashk_res.end = crash_base + crash_size - 1;
-	}
-
-	if (crashk_res.end == crashk_res.start) {
-		crashk_res.start = crashk_res.end = 0;
-		return;
-	}
-
-	/* We might have got these values via the command line or the
-	 * device tree, either way sanitise them now. */
-
-	crash_size = resource_size(&crashk_res);
+static unsigned long long __init get_crash_base(unsigned long long crash_base)
+{
 
 #ifndef CONFIG_NONSTATIC_KERNEL
-	if (crashk_res.start != KDUMP_KERNELBASE)
+	if (crash_base != KDUMP_KERNELBASE)
 		printk("Crash kernel location must be 0x%x\n",
 				KDUMP_KERNELBASE);
 
-	crashk_res.start = KDUMP_KERNELBASE;
+	return KDUMP_KERNELBASE;
 #else
-	if (!crashk_res.start) {
+	unsigned long long crash_base_align;
+
+	if (!crash_base) {
 #ifdef CONFIG_PPC64
 		/*
 		 * On the LPAR platform place the crash kernel to mid of
@@ -101,53 +83,51 @@ void __init reserve_crashkernel(void)
 		 * kernel starts at 128MB offset on other platforms.
 		 */
 		if (firmware_has_feature(FW_FEATURE_LPAR))
-			crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_512M);
+			crash_base = min_t(u64, ppc64_rma_size / 2, SZ_512M);
 		else
-			crashk_res.start = min_t(u64, ppc64_rma_size / 2, SZ_128M);
+			crash_base = min_t(u64, ppc64_rma_size / 2, SZ_128M);
 #else
-		crashk_res.start = KDUMP_KERNELBASE;
+		crash_base = KDUMP_KERNELBASE;
 #endif
 	}
 
-	crash_base = PAGE_ALIGN(crashk_res.start);
-	if (crash_base != crashk_res.start) {
-		printk("Crash kernel base must be aligned to 0x%lx\n",
-				PAGE_SIZE);
-		crashk_res.start = crash_base;
-	}
+	crash_base_align = PAGE_ALIGN(crash_base);
+	if (crash_base != crash_base_align)
+		pr_warn("Crash kernel base must be aligned to 0x%lx\n", PAGE_SIZE);
 
+	return crash_base_align;
 #endif
-	crash_size = PAGE_ALIGN(crash_size);
-	crashk_res.end = crashk_res.start + crash_size - 1;
+}
 
-	/* The crash region must not overlap the current kernel */
-	if (overlaps_crashkernel(__pa(_stext), _end - _stext)) {
-		printk(KERN_WARNING
-			"Crash kernel can not overlap current kernel\n");
-		crashk_res.start = crashk_res.end = 0;
+void __init arch_reserve_crashkernel(void)
+{
+	unsigned long long crash_size, crash_base, crash_end;
+	unsigned long long kernel_start, kernel_size;
+	unsigned long long total_mem_sz;
+	int ret;
+
+	total_mem_sz = memory_limit ? memory_limit : memblock_phys_mem_size();
+
+	/* use common parsing */
+	ret = parse_crashkernel(boot_command_line, total_mem_sz, &crash_size,
+				&crash_base, NULL, NULL);
+
+	if (ret)
 		return;
-	}
 
-	/* Crash kernel trumps memory limit */
-	if (memory_limit && memory_limit <= crashk_res.end) {
-		memory_limit = crashk_res.end + 1;
-		total_mem_sz = memory_limit;
-		printk("Adjusted memory limit for crashkernel, now 0x%llx\n",
-		       memory_limit);
-	}
+	crash_base = get_crash_base(crash_base);
+	crash_end = crash_base + crash_size - 1;
 
-	printk(KERN_INFO "Reserving %ldMB of memory at %ldMB "
-			"for crashkernel (System RAM: %ldMB)\n",
-			(unsigned long)(crash_size >> 20),
-			(unsigned long)(crashk_res.start >> 20),
-			(unsigned long)(total_mem_sz >> 20));
+	kernel_start = __pa(_stext);
+	kernel_size = _end - _stext;
 
-	if (!memblock_is_region_memory(crashk_res.start, crash_size) ||
-	    memblock_reserve(crashk_res.start, crash_size)) {
-		pr_err("Failed to reserve memory for crashkernel!\n");
-		crashk_res.start = crashk_res.end = 0;
+	/* The crash region must not overlap the current kernel */
+	if ((kernel_start + kernel_size > crash_base) && (kernel_start <= crash_end)) {
+		pr_warn("Crash kernel can not overlap current kernel\n");
 		return;
 	}
+
+	reserve_crashkernel_generic(crash_size, crash_base, 0, false);
 }
 
 int __init overlaps_crashkernel(unsigned long start, unsigned long size)