Merge tag 'mm-nonmm-stable-2025-10-02-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - "ida: Remove the ida_simple_xxx() API" from Christophe Jaillet
   completes the removal of this legacy IDR API

 - "panic: introduce panic status function family" from Jinchao Wang
   provides a number of cleanups to the panic code and its various
   helpers, which were rather ad-hoc and scattered all over the place

 - "tools/delaytop: implement real-time keyboard interaction support"
   from Fan Yu adds a few nice user-facing usability changes to the
   delaytop monitoring tool

 - "efi: Fix EFI boot with kexec handover (KHO)" from Evangelos
   Petrongonas fixes a panic which was happening with the combination of
   EFI and KHO

 - "Squashfs: performance improvement and a sanity check" from Phillip
   Lougher teaches squashfs's lseek() about SEEK_DATA/SEEK_HOLE. A mere
   150x speedup was measured for a well-chosen microbenchmark

 - plus another 50-odd singleton patches all over the place

* tag 'mm-nonmm-stable-2025-10-02-15-29' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (75 commits)
  Squashfs: reject negative file sizes in squashfs_read_inode()
  kallsyms: use kmalloc_array() instead of kmalloc()
  MAINTAINERS: update Sibi Sankar's email address
  Squashfs: add SEEK_DATA/SEEK_HOLE support
  Squashfs: add additional inode sanity checking
  lib/genalloc: fix device leak in of_gen_pool_get()
  panic: remove CONFIG_PANIC_ON_OOPS_VALUE
  ocfs2: fix double free in user_cluster_connect()
  checkpatch: suppress strscpy warnings for userspace tools
  cramfs: fix incorrect physical page address calculation
  kernel: prevent prctl(PR_SET_PDEATHSIG) from racing with parent process exit
  Squashfs: fix uninit-value in squashfs_get_parent
  kho: only fill kimage if KHO is finalized
  ocfs2: avoid extra calls to strlen() after ocfs2_sprintf_system_inode_name()
  kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths
  sched/task.h: fix the wrong comment on task_lock() nesting with tasklist_lock
  coccinelle: platform_no_drv_owner: handle also built-in drivers
  coccinelle: of_table: handle SPI device ID tables
  lib/decompress: use designated initializers for struct compress_format
  efi: support booting with kexec handover (KHO)
  ...

1 files changed, 103 insertions, 26 deletions

diff --git a/kernel/panic.c b/kernel/panic.c
index 72fcbb5a071b..24cc3eec1805 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -53,7 +53,7 @@ static unsigned int __read_mostly sysctl_oops_all_cpu_backtrace;
 #define sysctl_oops_all_cpu_backtrace 0
 #endif /* CONFIG_SMP */
 
-int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
+int panic_on_oops = IS_ENABLED(CONFIG_PANIC_ON_OOPS);
 static unsigned long tainted_mask =
 	IS_ENABLED(CONFIG_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0;
 static int pause_on_oops;
@@ -67,6 +67,7 @@ static unsigned int warn_limit __read_mostly;
 static bool panic_console_replay;
 
 bool panic_triggering_all_cpu_backtrace;
+static bool panic_this_cpu_backtrace_printed;
 
 int panic_timeout = CONFIG_PANIC_TIMEOUT;
 EXPORT_SYMBOL_GPL(panic_timeout);
@@ -77,6 +78,11 @@ ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
 
 EXPORT_SYMBOL(panic_notifier_list);
 
+static void panic_print_deprecated(void)
+{
+	pr_info_once("Kernel: The 'panic_print' parameter is now deprecated. Please use 'panic_sys_info' and 'panic_console_replay' instead.\n");
+}
+
 #ifdef CONFIG_SYSCTL
 
 /*
@@ -125,7 +131,7 @@ static int proc_taint(const struct ctl_table *table, int write,
 static int sysctl_panic_print_handler(const struct ctl_table *table, int write,
 			   void *buffer, size_t *lenp, loff_t *ppos)
 {
-	pr_info_once("Kernel: 'panic_print' sysctl interface will be obsoleted by both 'panic_sys_info' and 'panic_console_replay'\n");
+	panic_print_deprecated();
 	return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
 }
 
@@ -294,6 +300,59 @@ void __weak crash_smp_send_stop(void)
 
 atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
 
+bool panic_try_start(void)
+{
+	int old_cpu, this_cpu;
+
+	/*
+	 * Only one CPU is allowed to execute the crash_kexec() code as with
+	 * panic().  Otherwise parallel calls of panic() and crash_kexec()
+	 * may stop each other.  To exclude them, we use panic_cpu here too.
+	 */
+	old_cpu = PANIC_CPU_INVALID;
+	this_cpu = raw_smp_processor_id();
+
+	return atomic_try_cmpxchg(&panic_cpu, &old_cpu, this_cpu);
+}
+EXPORT_SYMBOL(panic_try_start);
+
+void panic_reset(void)
+{
+	atomic_set(&panic_cpu, PANIC_CPU_INVALID);
+}
+EXPORT_SYMBOL(panic_reset);
+
+bool panic_in_progress(void)
+{
+	return unlikely(atomic_read(&panic_cpu) != PANIC_CPU_INVALID);
+}
+EXPORT_SYMBOL(panic_in_progress);
+
+/* Return true if a panic is in progress on the current CPU. */
+bool panic_on_this_cpu(void)
+{
+	/*
+	 * We can use raw_smp_processor_id() here because it is impossible for
+	 * the task to be migrated to the panic_cpu, or away from it. If
+	 * panic_cpu has already been set, and we're not currently executing on
+	 * that CPU, then we never will be.
+	 */
+	return unlikely(atomic_read(&panic_cpu) == raw_smp_processor_id());
+}
+EXPORT_SYMBOL(panic_on_this_cpu);
+
+/*
+ * Return true if a panic is in progress on a remote CPU.
+ *
+ * On true, the local CPU should immediately release any printing resources
+ * that may be needed by the panic CPU.
+ */
+bool panic_on_other_cpu(void)
+{
+	return (panic_in_progress() && !panic_on_this_cpu());
+}
+EXPORT_SYMBOL(panic_on_other_cpu);
+
 /*
  * A variant of panic() called from NMI context. We return if we've already
  * panicked on this CPU. If another CPU already panicked, loop in
@@ -302,15 +361,9 @@ atomic_t panic_cpu = ATOMIC_INIT(PANIC_CPU_INVALID);
  */
 void nmi_panic(struct pt_regs *regs, const char *msg)
 {
-	int old_cpu, this_cpu;
-
-	old_cpu = PANIC_CPU_INVALID;
-	this_cpu = raw_smp_processor_id();
-
-	/* atomic_try_cmpxchg updates old_cpu on failure */
-	if (atomic_try_cmpxchg(&panic_cpu, &old_cpu, this_cpu))
+	if (panic_try_start())
 		panic("%s", msg);
-	else if (old_cpu != this_cpu)
+	else if (panic_on_other_cpu())
 		nmi_panic_self_stop(regs);
 }
 EXPORT_SYMBOL(nmi_panic);
@@ -328,6 +381,19 @@ void check_panic_on_warn(const char *origin)
 		      origin, limit);
 }
 
+static void panic_trigger_all_cpu_backtrace(void)
+{
+	/* Temporary allow non-panic CPUs to write their backtraces. */
+	panic_triggering_all_cpu_backtrace = true;
+
+	if (panic_this_cpu_backtrace_printed)
+		trigger_allbutcpu_cpu_backtrace(raw_smp_processor_id());
+	else
+		trigger_all_cpu_backtrace();
+
+	panic_triggering_all_cpu_backtrace = false;
+}
+
 /*
  * Helper that triggers the NMI backtrace (if set in panic_print)
  * and then performs the secondary CPUs shutdown - we cannot have
@@ -335,12 +401,8 @@ void check_panic_on_warn(const char *origin)
  */
 static void panic_other_cpus_shutdown(bool crash_kexec)
 {
-	if (panic_print & SYS_INFO_ALL_CPU_BT) {
-		/* Temporary allow non-panic CPUs to write their backtraces. */
-		panic_triggering_all_cpu_backtrace = true;
-		trigger_all_cpu_backtrace();
-		panic_triggering_all_cpu_backtrace = false;
-	}
+	if (panic_print & SYS_INFO_ALL_CPU_BT)
+		panic_trigger_all_cpu_backtrace();
 
 	/*
 	 * Note that smp_send_stop() is the usual SMP shutdown function,
@@ -368,7 +430,6 @@ void vpanic(const char *fmt, va_list args)
 	static char buf[1024];
 	long i, i_next = 0, len;
 	int state = 0;
-	int old_cpu, this_cpu;
 	bool _crash_kexec_post_notifiers = crash_kexec_post_notifiers;
 
 	if (panic_on_warn) {
@@ -405,13 +466,10 @@ void vpanic(const char *fmt, va_list args)
 	 * `old_cpu == this_cpu' means we came from nmi_panic() which sets
 	 * panic_cpu to this CPU.  In this case, this is also the 1st CPU.
 	 */
-	old_cpu = PANIC_CPU_INVALID;
-	this_cpu = raw_smp_processor_id();
-
 	/* atomic_try_cmpxchg updates old_cpu on failure */
-	if (atomic_try_cmpxchg(&panic_cpu, &old_cpu, this_cpu)) {
+	if (panic_try_start()) {
 		/* go ahead */
-	} else if (old_cpu != this_cpu)
+	} else if (panic_on_other_cpu())
 		panic_smp_self_stop();
 
 	console_verbose();
@@ -422,13 +480,15 @@ void vpanic(const char *fmt, va_list args)
 		buf[len - 1] = '\0';
 
 	pr_emerg("Kernel panic - not syncing: %s\n", buf);
-#ifdef CONFIG_DEBUG_BUGVERBOSE
 	/*
 	 * Avoid nested stack-dumping if a panic occurs during oops processing
 	 */
-	if (!test_taint(TAINT_DIE) && oops_in_progress <= 1)
+	if (test_taint(TAINT_DIE) || oops_in_progress > 1) {
+		panic_this_cpu_backtrace_printed = true;
+	} else if (IS_ENABLED(CONFIG_DEBUG_BUGVERBOSE)) {
 		dump_stack();
-#endif
+		panic_this_cpu_backtrace_printed = true;
+	}
 
 	/*
 	 * If kgdb is enabled, give it a chance to run before we stop all
@@ -937,12 +997,29 @@ EXPORT_SYMBOL(__stack_chk_fail);
 #endif
 
 core_param(panic, panic_timeout, int, 0644);
-core_param(panic_print, panic_print, ulong, 0644);
 core_param(pause_on_oops, pause_on_oops, int, 0644);
 core_param(panic_on_warn, panic_on_warn, int, 0644);
 core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);
 core_param(panic_console_replay, panic_console_replay, bool, 0644);
 
+static int panic_print_set(const char *val, const struct kernel_param *kp)
+{
+	panic_print_deprecated();
+	return  param_set_ulong(val, kp);
+}
+
+static int panic_print_get(char *val, const struct kernel_param *kp)
+{
+	panic_print_deprecated();
+	return  param_get_ulong(val, kp);
+}
+
+static const struct kernel_param_ops panic_print_ops = {
+	.set	= panic_print_set,
+	.get	= panic_print_get,
+};
+__core_param_cb(panic_print, &panic_print_ops, &panic_print, 0644);
+
 static int __init oops_setup(char *s)
 {
 	if (!s)