Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "Significant patch series in this pull request:

   - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets
     us closer to being able to remove page->mapping

   - "relayfs: misc changes" (Jason Xing) does some maintenance and
     minor feature addition work in relayfs

   - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
     us from static preallocation of the kdump crashkernel's working
     memory over to dynamic allocation. So the difficulty of a-priori
     estimation of the second kernel's needs is removed and the first
     kernel obtains extra memory

   - "generalize panic_print's dump function to be used by other
     kernel parts" (Feng Tang) implements some consolidation and
     rationalization of the various ways in which a failing kernel
     splats information at the operator

* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
  tools/getdelays: add backward compatibility for taskstats version
  kho: add test for kexec handover
  delaytop: enhance error logging and add PSI feature description
  samples: Kconfig: fix spelling mistake "instancess" -> "instances"
  fat: fix too many log in fat_chain_add()
  scripts/spelling.txt: add notifer||notifier to spelling.txt
  xen/xenbus: fix typo "notifer"
  net: mvneta: fix typo "notifer"
  drm/xe: fix typo "notifer"
  cxl: mce: fix typo "notifer"
  KVM: x86: fix typo "notifer"
  MAINTAINERS: add maintainers for delaytop
  ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
  ucount: fix atomic_long_inc_below() argument type
  kexec: enable CMA based contiguous allocation
  stackdepot: make max number of pools boot-time configurable
  lib/xxhash: remove unused functions
  init/Kconfig: restore CONFIG_BROKEN help text
  lib/raid6: update recov_rvv.c zero page usage
  docs: update docs after introducing delaytop
  ...

10 files changed, 110 insertions, 46 deletions

diff --git a/include/linux/crash_reserve.h b/include/linux/crash_reserve.h
index 1fe7e7d1b214..7b44b41d0a20 100644
--- a/include/linux/crash_reserve.h
+++ b/include/linux/crash_reserve.h
@@ -13,10 +13,23 @@
  */
 extern struct resource crashk_res;
 extern struct resource crashk_low_res;
+extern struct range crashk_cma_ranges[];
+#if defined(CONFIG_CMA) && defined(CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION)
+#define CRASHKERNEL_CMA
+#define CRASHKERNEL_CMA_RANGES_MAX 4
+extern int crashk_cma_cnt;
+#else
+#define crashk_cma_cnt 0
+#define CRASHKERNEL_CMA_RANGES_MAX 0
+#endif
+
 
 int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
 		unsigned long long *crash_size, unsigned long long *crash_base,
-		unsigned long long *low_size, bool *high);
+		unsigned long long *low_size, unsigned long long *cma_size,
+		bool *high);
+
+void __init reserve_crashkernel_cma(unsigned long long cma_size);
 
 #ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
 #ifndef DEFAULT_CRASH_KERNEL_LOW_SIZE
diff --git a/include/linux/gcd.h b/include/linux/gcd.h
index cb572677fd7f..616e81a7f7e3 100644
--- a/include/linux/gcd.h
+++ b/include/linux/gcd.h
@@ -3,6 +3,9 @@
 #define _GCD_H
 
 #include <linux/compiler.h>
+#include <linux/jump_label.h>
+
+DECLARE_STATIC_KEY_TRUE(efficient_ffs_key);
 
 unsigned long gcd(unsigned long a, unsigned long b) __attribute_const__;
 
diff --git a/include/linux/hung_task.h b/include/linux/hung_task.h
index 1bc2b3244613..34e615c76ca5 100644
--- a/include/linux/hung_task.h
+++ b/include/linux/hung_task.h
@@ -21,17 +21,17 @@
  * type.
  *
  * Type encoding:
- * 00 - Blocked on mutex        (BLOCKER_TYPE_MUTEX)
- * 01 - Blocked on semaphore    (BLOCKER_TYPE_SEM)
- * 10 - Blocked on rt-mutex     (BLOCKER_TYPE_RTMUTEX)
- * 11 - Blocked on rw-semaphore (BLOCKER_TYPE_RWSEM)
+ * 00 - Blocked on mutex			(BLOCKER_TYPE_MUTEX)
+ * 01 - Blocked on semaphore			(BLOCKER_TYPE_SEM)
+ * 10 - Blocked on rw-semaphore as READER	(BLOCKER_TYPE_RWSEM_READER)
+ * 11 - Blocked on rw-semaphore as WRITER	(BLOCKER_TYPE_RWSEM_WRITER)
  */
-#define BLOCKER_TYPE_MUTEX      0x00UL
-#define BLOCKER_TYPE_SEM        0x01UL
-#define BLOCKER_TYPE_RTMUTEX    0x02UL
-#define BLOCKER_TYPE_RWSEM      0x03UL
+#define BLOCKER_TYPE_MUTEX		0x00UL
+#define BLOCKER_TYPE_SEM		0x01UL
+#define BLOCKER_TYPE_RWSEM_READER	0x02UL
+#define BLOCKER_TYPE_RWSEM_WRITER	0x03UL
 
-#define BLOCKER_TYPE_MASK       0x03UL
+#define BLOCKER_TYPE_MASK		0x03UL
 
 #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
 static inline void hung_task_set_blocker(void *lock, unsigned long type)
diff --git a/include/linux/jhash.h b/include/linux/jhash.h
index fa26a2dd3b52..7c1c1821c694 100644
--- a/include/linux/jhash.h
+++ b/include/linux/jhash.h
@@ -24,7 +24,7 @@
  * Jozsef
  */
 #include <linux/bitops.h>
-#include <linux/unaligned/packed_struct.h>
+#include <linux/unaligned.h>
 
 /* Best hash sizes are of power of two */
 #define jhash_size(n)   ((u32)1<<(n))
@@ -77,9 +77,9 @@ static inline u32 jhash(const void *key, u32 length, u32 initval)
 
 	/* All but the last block: affect some 32 bits of (a,b,c) */
 	while (length > 12) {
-		a += __get_unaligned_cpu32(k);
-		b += __get_unaligned_cpu32(k + 4);
-		c += __get_unaligned_cpu32(k + 8);
+		a += get_unaligned((u32 *)k);
+		b += get_unaligned((u32 *)(k + 4));
+		c += get_unaligned((u32 *)(k + 8));
 		__jhash_mix(a, b, c);
 		length -= 12;
 		k += 12;
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 03f85ad03025..1b10a5d84b68 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -79,6 +79,12 @@ extern note_buf_t __percpu *crash_notes;
 
 typedef unsigned long kimage_entry_t;
 
+/*
+ * This is a copy of the UAPI struct kexec_segment and must be identical
+ * to it because it gets copied straight from user space into kernel
+ * memory. Do not modify this structure unless you change the way segments
+ * get ingested from user space.
+ */
 struct kexec_segment {
 	/*
 	 * This pointer can point to user memory if kexec_load() system
@@ -172,6 +178,7 @@ int kexec_image_post_load_cleanup_default(struct kimage *image);
  * @buf_align:	Minimum alignment needed.
  * @buf_min:	The buffer can't be placed below this address.
  * @buf_max:	The buffer can't be placed above this address.
+ * @cma:	CMA page if the buffer is backed by CMA.
  * @top_down:	Allocate from top of memory.
  * @random:	Place the buffer at a random position.
  */
@@ -184,6 +191,7 @@ struct kexec_buf {
 	unsigned long buf_align;
 	unsigned long buf_min;
 	unsigned long buf_max;
+	struct page *cma;
 	bool top_down;
 #ifdef CONFIG_CRASH_DUMP
 	bool random;
@@ -340,6 +348,7 @@ struct kimage {
 
 	unsigned long nr_segments;
 	struct kexec_segment segment[KEXEC_SEGMENT_MAX];
+	struct page *segment_cma[KEXEC_SEGMENT_MAX];
 
 	struct list_head control_pages;
 	struct list_head dest_pages;
@@ -361,6 +370,7 @@ struct kimage {
 	 */
 	unsigned int hotplug_support:1;
 #endif
+	unsigned int no_cma:1;
 
 #ifdef ARCH_HAS_KIMAGE_ARCH
 	struct kimage_arch arch;
diff --git a/include/linux/raid/pq.h b/include/linux/raid/pq.h
index 72ff44cca864..2467b3be15c9 100644
--- a/include/linux/raid/pq.h
+++ b/include/linux/raid/pq.h
@@ -11,8 +11,13 @@
 #ifdef __KERNEL__
 
 #include <linux/blkdev.h>
+#include <linux/mm.h>
 
-extern const char raid6_empty_zero_page[PAGE_SIZE];
+/* This should be const but the raid6 code is too convoluted for that. */
+static inline void *raid6_get_zero_page(void)
+{
+	return page_address(ZERO_PAGE(0));
+}
 
 #else /* ! __KERNEL__ */
 /* Used for testing in user space */
@@ -191,6 +196,11 @@ static inline uint32_t raid6_jiffies(void)
 	return tv.tv_sec*1000 + tv.tv_usec/1000;
 }
 
+static inline void *raid6_get_zero_page(void)
+{
+	return raid6_empty_zero_page;
+}
+
 #endif /* ! __KERNEL__ */
 
 #endif /* LINUX_RAID_RAID6_H */
diff --git a/include/linux/relay.h b/include/linux/relay.h
index b3224111d074..6772a7075840 100644
--- a/include/linux/relay.h
+++ b/include/linux/relay.h
@@ -29,6 +29,22 @@
 #define RELAYFS_CHANNEL_VERSION		7
 
 /*
+ * Relay buffer statistics
+ */
+enum {
+	RELAY_STATS_BUF_FULL = (1 << 0),
+	RELAY_STATS_WRT_BIG = (1 << 1),
+
+	RELAY_STATS_LAST = RELAY_STATS_WRT_BIG,
+};
+
+struct rchan_buf_stats
+{
+	unsigned int full_count;	/* counter for buffer full */
+	unsigned int big_count;		/* counter for too big to write */
+};
+
+/*
  * Per-cpu relay channel buffer
  */
 struct rchan_buf
@@ -43,11 +59,11 @@ struct rchan_buf
 	struct irq_work wakeup_work;	/* reader wakeup */
 	struct dentry *dentry;		/* channel file dentry */
 	struct kref kref;		/* channel buffer refcount */
+	struct rchan_buf_stats stats;	/* buffer stats */
 	struct page **page_array;	/* array of current buffer pages */
 	unsigned int page_count;	/* number of current buffer pages */
 	unsigned int finalized;		/* buffer has been finalized */
 	size_t *padding;		/* padding counts per sub-buffer */
-	size_t prev_padding;		/* temporary variable */
 	size_t bytes_consumed;		/* bytes consumed in cur read subbuf */
 	size_t early_bytes;		/* bytes consumed before VFS inited */
 	unsigned int cpu;		/* this buf's cpu */
@@ -65,7 +81,6 @@ struct rchan
 	const struct rchan_callbacks *cb; /* client callbacks */
 	struct kref kref;		/* channel refcount */
 	void *private_data;		/* for user-defined data */
-	size_t last_toobig;		/* tried to log event > subbuf size */
 	struct rchan_buf * __percpu *buf; /* per-cpu channel buffers */
 	int is_global;			/* One global buffer ? */
 	struct list_head list;		/* for channel list */
@@ -84,7 +99,6 @@ struct rchan_callbacks
 	 * @buf: the channel buffer containing the new sub-buffer
 	 * @subbuf: the start of the new sub-buffer
 	 * @prev_subbuf: the start of the previous sub-buffer
-	 * @prev_padding: unused space at the end of previous sub-buffer
 	 *
 	 * The client should return 1 to continue logging, 0 to stop
 	 * logging.
@@ -100,8 +114,7 @@ struct rchan_callbacks
 	 */
 	int (*subbuf_start) (struct rchan_buf *buf,
 			     void *subbuf,
-			     void *prev_subbuf,
-			     size_t prev_padding);
+			     void *prev_subbuf);
 
 	/*
 	 * create_buf_file - create file to represent a relay channel buffer
@@ -161,6 +174,7 @@ struct rchan *relay_open(const char *base_filename,
 			 void *private_data);
 extern void relay_close(struct rchan *chan);
 extern void relay_flush(struct rchan *chan);
+size_t relay_stats(struct rchan *chan, int flags);
 extern void relay_subbufs_consumed(struct rchan *chan,
 				   unsigned int cpu,
 				   size_t consumed);
diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
index cbafdc12e743..f1aaf676a874 100644
--- a/include/linux/rwsem.h
+++ b/include/linux/rwsem.h
@@ -132,6 +132,18 @@ static inline int rwsem_is_contended(struct rw_semaphore *sem)
 	return !list_empty(&sem->wait_list);
 }
 
+#if defined(CONFIG_DEBUG_RWSEMS) || defined(CONFIG_DETECT_HUNG_TASK_BLOCKER)
+/*
+ * Return just the real task structure pointer of the owner
+ */
+extern struct task_struct *rwsem_owner(struct rw_semaphore *sem);
+
+/*
+ * Return true if the rwsem is owned by a reader.
+ */
+extern bool is_rwsem_reader_owned(struct rw_semaphore *sem);
+#endif
+
 #else /* !CONFIG_PREEMPT_RT */
 
 #include <linux/rwbase_rt.h>
diff --git a/include/linux/sys_info.h b/include/linux/sys_info.h
new file mode 100644
index 000000000000..89d77dc4f2ed
--- /dev/null
+++ b/include/linux/sys_info.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_SYS_INFO_H
+#define _LINUX_SYS_INFO_H
+
+#include <linux/sysctl.h>
+
+/*
+ * SYS_INFO_PANIC_CONSOLE_REPLAY is for panic case only, as it needs special
+ * handling which only fits panic case.
+ */
+#define SYS_INFO_TASKS			0x00000001
+#define SYS_INFO_MEM			0x00000002
+#define SYS_INFO_TIMERS			0x00000004
+#define SYS_INFO_LOCKS			0x00000008
+#define SYS_INFO_FTRACE			0x00000010
+#define SYS_INFO_PANIC_CONSOLE_REPLAY	0x00000020
+#define SYS_INFO_ALL_CPU_BT		0x00000040
+#define SYS_INFO_BLOCKED_TASKS		0x00000080
+
+void sys_info(unsigned long si_mask);
+unsigned long sys_info_parse_param(char *str);
+
+#ifdef CONFIG_SYSCTL
+int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
+					  void *buffer, size_t *lenp,
+					  loff_t *ppos);
+#endif
+#endif	/* _LINUX_SYS_INFO_H */
diff --git a/include/linux/xxhash.h b/include/linux/xxhash.h
index df42511438d0..27f57eca8cb1 100644
--- a/include/linux/xxhash.h
+++ b/include/linux/xxhash.h
@@ -178,32 +178,6 @@ struct xxh64_state {
 void xxh32_reset(struct xxh32_state *state, uint32_t seed);
 
 /**
- * xxh32_update() - hash the data given and update the xxh32 state
- *
- * @state:  The xxh32 state to update.
- * @input:  The data to hash.
- * @length: The length of the data to hash.
- *
- * After calling xxh32_reset() call xxh32_update() as many times as necessary.
- *
- * Return:  Zero on success, otherwise an error code.
- */
-int xxh32_update(struct xxh32_state *state, const void *input, size_t length);
-
-/**
- * xxh32_digest() - produce the current xxh32 hash
- *
- * @state: Produce the current xxh32 hash of this state.
- *
- * A hash value can be produced at any time. It is still possible to continue
- * inserting input into the hash state after a call to xxh32_digest(), and
- * generate new hashes later on, by calling xxh32_digest() again.
- *
- * Return: The xxh32 hash stored in the state.
- */
-uint32_t xxh32_digest(const struct xxh32_state *state);
-
-/**
  * xxh64_reset() - reset the xxh64 state to start a new hashing operation
  *
  * @state: The xxh64 state to reset.