Merge tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - An extensive rework of kexec and crash Kconfig from Eric DeVolder
   ("refactor Kconfig to consolidate KEXEC and CRASH options")

 - kernel.h slimming work from Andy Shevchenko ("kernel.h: Split out a
   couple of macros to args.h")

 - gdb feature work from Kuan-Ying Lee ("Add GDB memory helper
   commands")

 - vsprintf inclusion rationalization from Andy Shevchenko
   ("lib/vsprintf: Rework header inclusions")

 - Switch the handling of kdump from a udev scheme to in-kernel
   handling, by Eric DeVolder ("crash: Kernel handling of CPU and memory
   hot un/plug")

 - Many singleton patches to various parts of the tree

* tag 'mm-nonmm-stable-2023-08-28-22-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (81 commits)
  document while_each_thread(), change first_tid() to use for_each_thread()
  drivers/char/mem.c: shrink character device's devlist[] array
  x86/crash: optimize CPU changes
  crash: change crash_prepare_elf64_headers() to for_each_possible_cpu()
  crash: hotplug support for kexec_load()
  x86/crash: add x86 crash hotplug support
  crash: memory and CPU hotplug sysfs attributes
  kexec: exclude elfcorehdr from the segment digest
  crash: add generic infrastructure for crash hotplug support
  crash: move a few code bits to setup support of crash hotplug
  kstrtox: consistently use _tolower()
  kill do_each_thread()
  nilfs2: fix WARNING in mark_buffer_dirty due to discarded buffer reuse
  scripts/bloat-o-meter: count weak symbol sizes
  treewide: drop CONFIG_EMBEDDED
  lockdep: fix static memory detection even more
  lib/vsprintf: declare no_hash_pointers in sprintf.h
  lib/vsprintf: split out sprintf() and friends
  kernel/fork: stop playing lockless games for exe_file replacement
  adfs: delete unused "union adfs_dirtail" definition
  ...

18 files changed, 198 insertions, 130 deletions

diff --git a/include/kunit/test.h b/include/kunit/test.h
index d33114097d0d..68ff01aee244 100644
--- a/include/kunit/test.h
+++ b/include/kunit/test.h
@@ -12,6 +12,7 @@
 #include <kunit/assert.h>
 #include <kunit/try-catch.h>
 
+#include <linux/args.h>
 #include <linux/compiler.h>
 #include <linux/container_of.h>
 #include <linux/err.h>
diff --git a/include/linux/args.h b/include/linux/args.h
new file mode 100644
index 000000000000..8ff60a54eb7d
--- /dev/null
+++ b/include/linux/args.h
@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef _LINUX_ARGS_H
+#define _LINUX_ARGS_H
+
+/*
+ * How do these macros work?
+ *
+ * In __COUNT_ARGS() _0 to _12 are just placeholders from the start
+ * in order to make sure _n is positioned over the correct number
+ * from 12 to 0 (depending on X, which is a variadic argument list).
+ * They serve no purpose other than occupying a position. Since each
+ * macro parameter must have a distinct identifier, those identifiers
+ * are as good as any.
+ *
+ * In COUNT_ARGS() we use actual integers, so __COUNT_ARGS() returns
+ * that as _n.
+ */
+
+/* This counts to 12. Any more, it will return 13th argument. */
+#define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
+#define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
+
+/* Concatenate two parameters, but allow them to be expanded beforehand. */
+#define __CONCAT(a, b) a ## b
+#define CONCATENATE(a, b) __CONCAT(a, b)
+
+#endif	/* _LINUX_ARGS_H */
diff --git a/include/linux/arm-smccc.h b/include/linux/arm-smccc.h
index f196c19f8e55..7c67c17321d4 100644
--- a/include/linux/arm-smccc.h
+++ b/include/linux/arm-smccc.h
@@ -5,6 +5,7 @@
 #ifndef __LINUX_ARM_SMCCC_H
 #define __LINUX_ARM_SMCCC_H
 
+#include <linux/args.h>
 #include <linux/init.h>
 #include <uapi/linux/const.h>
 
@@ -413,31 +414,26 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
 
 #endif
 
-#define ___count_args(_0, _1, _2, _3, _4, _5, _6, _7, _8, x, ...) x
+#define __constraint_read_2	"r" (arg0)
+#define __constraint_read_3	__constraint_read_2, "r" (arg1)
+#define __constraint_read_4	__constraint_read_3, "r" (arg2)
+#define __constraint_read_5	__constraint_read_4, "r" (arg3)
+#define __constraint_read_6	__constraint_read_5, "r" (arg4)
+#define __constraint_read_7	__constraint_read_6, "r" (arg5)
+#define __constraint_read_8	__constraint_read_7, "r" (arg6)
+#define __constraint_read_9	__constraint_read_8, "r" (arg7)
 
-#define __count_args(...)						\
-	___count_args(__VA_ARGS__, 7, 6, 5, 4, 3, 2, 1, 0)
-
-#define __constraint_read_0	"r" (arg0)
-#define __constraint_read_1	__constraint_read_0, "r" (arg1)
-#define __constraint_read_2	__constraint_read_1, "r" (arg2)
-#define __constraint_read_3	__constraint_read_2, "r" (arg3)
-#define __constraint_read_4	__constraint_read_3, "r" (arg4)
-#define __constraint_read_5	__constraint_read_4, "r" (arg5)
-#define __constraint_read_6	__constraint_read_5, "r" (arg6)
-#define __constraint_read_7	__constraint_read_6, "r" (arg7)
-
-#define __declare_arg_0(a0, res)					\
+#define __declare_arg_2(a0, res)					\
 	struct arm_smccc_res   *___res = res;				\
 	register unsigned long arg0 asm("r0") = (u32)a0
 
-#define __declare_arg_1(a0, a1, res)					\
+#define __declare_arg_3(a0, a1, res)					\
 	typeof(a1) __a1 = a1;						\
 	struct arm_smccc_res   *___res = res;				\
 	register unsigned long arg0 asm("r0") = (u32)a0;			\
 	register typeof(a1) arg1 asm("r1") = __a1
 
-#define __declare_arg_2(a0, a1, a2, res)				\
+#define __declare_arg_4(a0, a1, a2, res)				\
 	typeof(a1) __a1 = a1;						\
 	typeof(a2) __a2 = a2;						\
 	struct arm_smccc_res   *___res = res;				\
@@ -445,7 +441,7 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
 	register typeof(a1) arg1 asm("r1") = __a1;			\
 	register typeof(a2) arg2 asm("r2") = __a2
 
-#define __declare_arg_3(a0, a1, a2, a3, res)				\
+#define __declare_arg_5(a0, a1, a2, a3, res)				\
 	typeof(a1) __a1 = a1;						\
 	typeof(a2) __a2 = a2;						\
 	typeof(a3) __a3 = a3;						\
@@ -455,34 +451,26 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
 	register typeof(a2) arg2 asm("r2") = __a2;			\
 	register typeof(a3) arg3 asm("r3") = __a3
 
-#define __declare_arg_4(a0, a1, a2, a3, a4, res)			\
+#define __declare_arg_6(a0, a1, a2, a3, a4, res)			\
 	typeof(a4) __a4 = a4;						\
-	__declare_arg_3(a0, a1, a2, a3, res);				\
+	__declare_arg_5(a0, a1, a2, a3, res);				\
 	register typeof(a4) arg4 asm("r4") = __a4
 
-#define __declare_arg_5(a0, a1, a2, a3, a4, a5, res)			\
+#define __declare_arg_7(a0, a1, a2, a3, a4, a5, res)			\
 	typeof(a5) __a5 = a5;						\
-	__declare_arg_4(a0, a1, a2, a3, a4, res);			\
+	__declare_arg_6(a0, a1, a2, a3, a4, res);			\
 	register typeof(a5) arg5 asm("r5") = __a5
 
-#define __declare_arg_6(a0, a1, a2, a3, a4, a5, a6, res)		\
+#define __declare_arg_8(a0, a1, a2, a3, a4, a5, a6, res)		\
 	typeof(a6) __a6 = a6;						\
-	__declare_arg_5(a0, a1, a2, a3, a4, a5, res);			\
+	__declare_arg_7(a0, a1, a2, a3, a4, a5, res);			\
 	register typeof(a6) arg6 asm("r6") = __a6
 
-#define __declare_arg_7(a0, a1, a2, a3, a4, a5, a6, a7, res)		\
+#define __declare_arg_9(a0, a1, a2, a3, a4, a5, a6, a7, res)		\
 	typeof(a7) __a7 = a7;						\
-	__declare_arg_6(a0, a1, a2, a3, a4, a5, a6, res);		\
+	__declare_arg_8(a0, a1, a2, a3, a4, a5, a6, res);		\
 	register typeof(a7) arg7 asm("r7") = __a7
 
-#define ___declare_args(count, ...) __declare_arg_ ## count(__VA_ARGS__)
-#define __declare_args(count, ...)  ___declare_args(count, __VA_ARGS__)
-
-#define ___constraints(count)						\
-	: __constraint_read_ ## count					\
-	: smccc_sve_clobbers "memory"
-#define __constraints(count)	___constraints(count)
-
 /*
  * We have an output list that is not necessarily used, and GCC feels
  * entitled to optimise the whole sequence away. "volatile" is what
@@ -494,11 +482,14 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
 		register unsigned long r1 asm("r1");			\
 		register unsigned long r2 asm("r2");			\
 		register unsigned long r3 asm("r3"); 			\
-		__declare_args(__count_args(__VA_ARGS__), __VA_ARGS__);	\
+		CONCATENATE(__declare_arg_,				\
+			    COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__);	\
 		asm volatile(SMCCC_SVE_CHECK				\
 			     inst "\n" :				\
 			     "=r" (r0), "=r" (r1), "=r" (r2), "=r" (r3)	\
-			     __constraints(__count_args(__VA_ARGS__)));	\
+			     : CONCATENATE(__constraint_read_,		\
+					   COUNT_ARGS(__VA_ARGS__))	\
+			     : smccc_sve_clobbers "memory");		\
 		if (___res)						\
 			*___res = (typeof(*___res)){r0, r1, r2, r3};	\
 	} while (0)
@@ -542,8 +533,12 @@ asmlinkage void __arm_smccc_hvc(unsigned long a0, unsigned long a1,
  */
 #define __fail_smccc_1_1(...)						\
 	do {								\
-		__declare_args(__count_args(__VA_ARGS__), __VA_ARGS__);	\
-		asm ("" : __constraints(__count_args(__VA_ARGS__)));	\
+		CONCATENATE(__declare_arg_,				\
+			    COUNT_ARGS(__VA_ARGS__))(__VA_ARGS__);	\
+		asm ("" :						\
+		     : CONCATENATE(__constraint_read_,			\
+				   COUNT_ARGS(__VA_ARGS__))		\
+		     : smccc_sve_clobbers "memory");			\
 		if (___res)						\
 			___res->a0 = SMCCC_RET_NOT_SUPPORTED;		\
 	} while (0)
diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h
index de62a722431e..0c06561bf5ff 100644
--- a/include/linux/crash_core.h
+++ b/include/linux/crash_core.h
@@ -28,6 +28,8 @@
 				     VMCOREINFO_BYTES)
 
 typedef u32 note_buf_t[CRASH_CORE_NOTE_BYTES/4];
+/* Per cpu memory for storing cpu states in case of system crash. */
+extern note_buf_t __percpu *crash_notes;
 
 void crash_update_vmcoreinfo_safecopy(void *ptr);
 void crash_save_vmcoreinfo(void);
@@ -84,4 +86,29 @@ int parse_crashkernel_high(char *cmdline, unsigned long long system_ram,
 int parse_crashkernel_low(char *cmdline, unsigned long long system_ram,
 		unsigned long long *crash_size, unsigned long long *crash_base);
 
+/* Alignment required for elf header segment */
+#define ELF_CORE_HEADER_ALIGN   4096
+
+struct crash_mem {
+	unsigned int max_nr_ranges;
+	unsigned int nr_ranges;
+	struct range ranges[];
+};
+
+extern int crash_exclude_mem_range(struct crash_mem *mem,
+				   unsigned long long mstart,
+				   unsigned long long mend);
+extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
+				       void **addr, unsigned long *sz);
+
+struct kimage;
+struct kexec_segment;
+
+#define KEXEC_CRASH_HP_NONE			0
+#define KEXEC_CRASH_HP_ADD_CPU			1
+#define KEXEC_CRASH_HP_REMOVE_CPU		2
+#define KEXEC_CRASH_HP_ADD_MEMORY		3
+#define KEXEC_CRASH_HP_REMOVE_MEMORY		4
+#define KEXEC_CRASH_HP_INVALID_CPU		-1U
+
 #endif /* LINUX_CRASH_CORE_H */
diff --git a/include/linux/genl_magic_func.h b/include/linux/genl_magic_func.h
index 2984b0cb24b1..d4da060b7532 100644
--- a/include/linux/genl_magic_func.h
+++ b/include/linux/genl_magic_func.h
@@ -2,6 +2,7 @@
 #ifndef GENL_MAGIC_FUNC_H
 #define GENL_MAGIC_FUNC_H
 
+#include <linux/args.h>
 #include <linux/build_bug.h>
 #include <linux/genl_magic_struct.h>
 
@@ -23,7 +24,7 @@
 #define GENL_struct(tag_name, tag_number, s_name, s_fields)		\
 	[tag_name] = { .type = NLA_NESTED },
 
-static struct nla_policy CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy)[] = {
+static struct nla_policy CONCATENATE(GENL_MAGIC_FAMILY, _tla_nl_policy)[] = {
 #include GENL_MAGIC_INCLUDE_FILE
 };
 
@@ -209,7 +210,7 @@ static int s_name ## _from_attrs_for_change(struct s_name *s,		\
  * Magic: define op number to op name mapping				{{{1
  *									{{{2
  */
-static const char *CONCAT_(GENL_MAGIC_FAMILY, _genl_cmd_to_str)(__u8 cmd)
+static const char *CONCATENATE(GENL_MAGIC_FAMILY, _genl_cmd_to_str)(__u8 cmd)
 {
 	switch (cmd) {
 #undef GENL_op
@@ -235,7 +236,7 @@ static const char *CONCAT_(GENL_MAGIC_FAMILY, _genl_cmd_to_str)(__u8 cmd)
 	.cmd = op_name,						\
 },
 
-#define ZZZ_genl_ops		CONCAT_(GENL_MAGIC_FAMILY, _genl_ops)
+#define ZZZ_genl_ops		CONCATENATE(GENL_MAGIC_FAMILY, _genl_ops)
 static struct genl_ops ZZZ_genl_ops[] __read_mostly = {
 #include GENL_MAGIC_INCLUDE_FILE
 };
@@ -248,32 +249,32 @@ static struct genl_ops ZZZ_genl_ops[] __read_mostly = {
  * and provide register/unregister functions.
  *									{{{2
  */
-#define ZZZ_genl_family		CONCAT_(GENL_MAGIC_FAMILY, _genl_family)
+#define ZZZ_genl_family		CONCATENATE(GENL_MAGIC_FAMILY, _genl_family)
 static struct genl_family ZZZ_genl_family;
 /*
  * Magic: define multicast groups
  * Magic: define multicast group registration helper
  */
-#define ZZZ_genl_mcgrps		CONCAT_(GENL_MAGIC_FAMILY, _genl_mcgrps)
+#define ZZZ_genl_mcgrps		CONCATENATE(GENL_MAGIC_FAMILY, _genl_mcgrps)
 static const struct genl_multicast_group ZZZ_genl_mcgrps[] = {
 #undef GENL_mc_group
 #define GENL_mc_group(group) { .name = #group, },
 #include GENL_MAGIC_INCLUDE_FILE
 };
 
-enum CONCAT_(GENL_MAGIC_FAMILY, group_ids) {
+enum CONCATENATE(GENL_MAGIC_FAMILY, group_ids) {
 #undef GENL_mc_group
-#define GENL_mc_group(group) CONCAT_(GENL_MAGIC_FAMILY, _group_ ## group),
+#define GENL_mc_group(group) CONCATENATE(GENL_MAGIC_FAMILY, _group_ ## group),
 #include GENL_MAGIC_INCLUDE_FILE
 };
 
 #undef GENL_mc_group
 #define GENL_mc_group(group)						\
-static int CONCAT_(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)(	\
+static int CONCATENATE(GENL_MAGIC_FAMILY, _genl_multicast_ ## group)(	\
 	struct sk_buff *skb, gfp_t flags)				\
 {									\
 	unsigned int group_id =						\
-		CONCAT_(GENL_MAGIC_FAMILY, _group_ ## group);		\
+		CONCATENATE(GENL_MAGIC_FAMILY, _group_ ## group);		\
 	return genlmsg_multicast(&ZZZ_genl_family, skb, 0,		\
 				 group_id, flags);			\
 }
@@ -289,8 +290,8 @@ static struct genl_family ZZZ_genl_family __ro_after_init = {
 #ifdef GENL_MAGIC_FAMILY_HDRSZ
 	.hdrsize = NLA_ALIGN(GENL_MAGIC_FAMILY_HDRSZ),
 #endif
-	.maxattr = ARRAY_SIZE(CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy))-1,
-	.policy	= CONCAT_(GENL_MAGIC_FAMILY, _tla_nl_policy),
+	.maxattr = ARRAY_SIZE(CONCATENATE(GENL_MAGIC_FAMILY, _tla_nl_policy))-1,
+	.policy	= CONCATENATE(GENL_MAGIC_FAMILY, _tla_nl_policy),
 	.ops = ZZZ_genl_ops,
 	.n_ops = ARRAY_SIZE(ZZZ_genl_ops),
 	.mcgrps = ZZZ_genl_mcgrps,
@@ -299,12 +300,12 @@ static struct genl_family ZZZ_genl_family __ro_after_init = {
 	.module = THIS_MODULE,
 };
 
-int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void)
+int CONCATENATE(GENL_MAGIC_FAMILY, _genl_register)(void)
 {
 	return genl_register_family(&ZZZ_genl_family);
 }
 
-void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void)
+void CONCATENATE(GENL_MAGIC_FAMILY, _genl_unregister)(void)
 {
 	genl_unregister_family(&ZZZ_genl_family);
 }
diff --git a/include/linux/genl_magic_struct.h b/include/linux/genl_magic_struct.h
index f81d48987528..a419d93789ff 100644
--- a/include/linux/genl_magic_struct.h
+++ b/include/linux/genl_magic_struct.h
@@ -14,14 +14,12 @@
 # error "you need to define GENL_MAGIC_INCLUDE_FILE before inclusion"
 #endif
 
+#include <linux/args.h>
 #include <linux/genetlink.h>
 #include <linux/types.h>
 
-#define CONCAT__(a,b)	a ## b
-#define CONCAT_(a,b)	CONCAT__(a,b)
-
-extern int CONCAT_(GENL_MAGIC_FAMILY, _genl_register)(void);
-extern void CONCAT_(GENL_MAGIC_FAMILY, _genl_unregister)(void);
+extern int CONCATENATE(GENL_MAGIC_FAMILY, _genl_register)(void);
+extern void CONCATENATE(GENL_MAGIC_FAMILY, _genl_unregister)(void);
 
 /*
  * Extension of genl attribute validation policies			{{{2
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 0d91e0af0125..cee8fe87e9f4 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -29,6 +29,7 @@
 #include <linux/panic.h>
 #include <linux/printk.h>
 #include <linux/build_bug.h>
+#include <linux/sprintf.h>
 #include <linux/static_call_types.h>
 #include <linux/instruction_pointer.h>
 #include <asm/byteorder.h>
@@ -203,35 +204,6 @@ static inline void might_fault(void) { }
 
 void do_exit(long error_code) __noreturn;
 
-extern int num_to_str(char *buf, int size,
-		      unsigned long long num, unsigned int width);
-
-/* lib/printf utilities */
-
-extern __printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
-extern __printf(2, 0) int vsprintf(char *buf, const char *, va_list);
-extern __printf(3, 4)
-int snprintf(char *buf, size_t size, const char *fmt, ...);
-extern __printf(3, 0)
-int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
-extern __printf(3, 4)
-int scnprintf(char *buf, size_t size, const char *fmt, ...);
-extern __printf(3, 0)
-int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
-extern __printf(2, 3) __malloc
-char *kasprintf(gfp_t gfp, const char *fmt, ...);
-extern __printf(2, 0) __malloc
-char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
-extern __printf(2, 0)
-const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
-
-extern __scanf(2, 3)
-int sscanf(const char *, const char *, ...);
-extern __scanf(2, 0)
-int vsscanf(const char *, const char *, va_list);
-
-extern int no_hash_pointers_enable(char *str);
-
 extern int get_option(char **str, int *pint);
 extern char *get_options(const char *str, int nints, int *ints);
 extern unsigned long long memparse(const char *ptr, char **retptr);
@@ -457,13 +429,6 @@ ftrace_vprintk(const char *fmt, va_list ap)
 static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { }
 #endif /* CONFIG_TRACING */
 
-/* This counts to 12. Any more, it will return 13th argument. */
-#define __COUNT_ARGS(_0, _1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _n, X...) _n
-#define COUNT_ARGS(X...) __COUNT_ARGS(, ##X, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0)
-
-#define __CONCAT(a, b) a ## b
-#define CONCATENATE(a, b) __CONCAT(a, b)
-
 /* Rebuild everything on CONFIG_FTRACE_MCOUNT_RECORD */
 #ifdef CONFIG_FTRACE_MCOUNT_RECORD
 # define REBUILD_DUE_TO_FTRACE_MCOUNT_RECORD
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 22b5cd24f581..32c78078552c 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -33,6 +33,7 @@ extern note_buf_t __percpu *crash_notes;
 #include <linux/compat.h>
 #include <linux/ioport.h>
 #include <linux/module.h>
+#include <linux/highmem.h>
 #include <asm/kexec.h>
 
 /* Verify architecture specific macros are defined */
@@ -230,21 +231,6 @@ static inline int arch_kexec_locate_mem_hole(struct kexec_buf *kbuf)
 }
 #endif
 
-/* Alignment required for elf header segment */
-#define ELF_CORE_HEADER_ALIGN   4096
-
-struct crash_mem {
-	unsigned int max_nr_ranges;
-	unsigned int nr_ranges;
-	struct range ranges[];
-};
-
-extern int crash_exclude_mem_range(struct crash_mem *mem,
-				   unsigned long long mstart,
-				   unsigned long long mend);
-extern int crash_prepare_elf64_headers(struct crash_mem *mem, int need_kernel_map,
-				       void **addr, unsigned long *sz);
-
 #ifndef arch_kexec_apply_relocations_add
 /*
  * arch_kexec_apply_relocations_add - apply relocations of type RELA
@@ -334,6 +320,10 @@ struct kimage {
 	unsigned int preserve_context : 1;
 	/* If set, we are using file mode kexec syscall */
 	unsigned int file_mode:1;
+#ifdef CONFIG_CRASH_HOTPLUG
+	/* If set, allow changes to elfcorehdr of kexec_load'd image */
+	unsigned int update_elfcorehdr:1;
+#endif
 
 #ifdef ARCH_HAS_KIMAGE_ARCH
 	struct kimage_arch arch;
@@ -360,6 +350,12 @@ struct kimage {
 	struct purgatory_info purgatory_info;
 #endif
 
+#ifdef CONFIG_CRASH_HOTPLUG
+	int hp_action;
+	int elfcorehdr_index;
+	bool elfcorehdr_updated;
+#endif
+
 #ifdef CONFIG_IMA_KEXEC
 	/* Virtual address of IMA measurement buffer for kexec syscall */
 	void *ima_buffer;
@@ -404,9 +400,9 @@ bool kexec_load_permitted(int kexec_image_type);
 
 /* List of defined/legal kexec flags */
 #ifndef CONFIG_KEXEC_JUMP
-#define KEXEC_FLAGS    KEXEC_ON_CRASH
+#define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_UPDATE_ELFCOREHDR)
 #else
-#define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT)
+#define KEXEC_FLAGS    (KEXEC_ON_CRASH | KEXEC_PRESERVE_CONTEXT | KEXEC_UPDATE_ELFCOREHDR)
 #endif
 
 /* List of defined/legal kexec file flags */
@@ -490,6 +486,24 @@ static inline int arch_kexec_post_alloc_pages(void *vaddr, unsigned int pages, g
 static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) { }
 #endif
 
+#ifndef arch_crash_handle_hotplug_event
+static inline void arch_crash_handle_hotplug_event(struct kimage *image) { }
+#endif
+
+int crash_check_update_elfcorehdr(void);
+
+#ifndef crash_hotplug_cpu_support
+static inline int crash_hotplug_cpu_support(void) { return 0; }
+#endif
+
+#ifndef crash_hotplug_memory_support
+static inline int crash_hotplug_memory_support(void) { return 0; }
+#endif
+
+#ifndef crash_get_elfcorehdr_size
+static inline unsigned int crash_get_elfcorehdr_size(void) { return 0; }
+#endif
+
 #else /* !CONFIG_KEXEC_CORE */
 struct pt_regs;
 struct task_struct;
diff --git a/include/linux/kthread.h b/include/linux/kthread.h
index f1f95a71a4bc..2c30ade43bc8 100644
--- a/include/linux/kthread.h
+++ b/include/linux/kthread.h
@@ -88,7 +88,6 @@ void kthread_bind_mask(struct task_struct *k, const struct cpumask *mask);
 int kthread_stop(struct task_struct *k);
 bool kthread_should_stop(void);
 bool kthread_should_park(void);
-bool __kthread_should_park(struct task_struct *k);
 bool kthread_should_stop_or_park(void);
 bool kthread_freezable_should_stop(bool *was_frozen);
 void *kthread_func(struct task_struct *k);
diff --git a/include/linux/limits.h b/include/linux/limits.h
index f6bcc9369010..38eb7f6f7e88 100644
--- a/include/linux/limits.h
+++ b/include/linux/limits.h
@@ -10,6 +10,8 @@
 #define SSIZE_MAX	((ssize_t)(SIZE_MAX >> 1))
 #define PHYS_ADDR_MAX	(~(phys_addr_t)0)
 
+#define RESOURCE_SIZE_MAX	((resource_size_t)~0)
+
 #define U8_MAX		((u8)~0U)
 #define S8_MAX		((s8)(U8_MAX >> 1))
 #define S8_MIN		((s8)(-S8_MAX - 1))
diff --git a/include/linux/math.h b/include/linux/math.h
index 2d388650c556..dd4152711de7 100644
--- a/include/linux/math.h
+++ b/include/linux/math.h
@@ -156,6 +156,25 @@ __STRUCT_FRACT(u32)
 	({ signed type __x = (x); __x < 0 ? -__x : __x; }), other)
 
 /**
+ * abs_diff - return absolute value of the difference between the arguments
+ * @a: the first argument
+ * @b: the second argument
+ *
+ * @a and @b have to be of the same type. With this restriction we compare
+ * signed to signed and unsigned to unsigned. The result is the subtraction
+ * the smaller of the two from the bigger, hence result is always a positive
+ * value.
+ *
+ * Return: an absolute value of the difference between the @a and @b.
+ */
+#define abs_diff(a, b) ({			\
+	typeof(a) __a = (a);			\
+	typeof(b) __b = (b);			\
+	(void)(&__a == &__b);			\
+	__a > __b ? (__a - __b) : (__b - __a);	\
+})
+
+/**
  * reciprocal_scale - "scale" a value into range [0, ep_ro)
  * @val: value
  * @ep_ro: right open interval endpoint
diff --git a/include/linux/nmi.h b/include/linux/nmi.h
index e3e6a64b98e0..e92e378df000 100644
--- a/include/linux/nmi.h
+++ b/include/linux/nmi.h
@@ -157,31 +157,31 @@ static inline void touch_nmi_watchdog(void)
 #ifdef arch_trigger_cpumask_backtrace
 static inline bool trigger_all_cpu_backtrace(void)
 {
-	arch_trigger_cpumask_backtrace(cpu_online_mask, false);
+	arch_trigger_cpumask_backtrace(cpu_online_mask, -1);
 	return true;
 }
 
-static inline bool trigger_allbutself_cpu_backtrace(void)
+static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
 {
-	arch_trigger_cpumask_backtrace(cpu_online_mask, true);
+	arch_trigger_cpumask_backtrace(cpu_online_mask, exclude_cpu);
 	return true;
 }
 
 static inline bool trigger_cpumask_backtrace(struct cpumask *mask)
 {
-	arch_trigger_cpumask_backtrace(mask, false);
+	arch_trigger_cpumask_backtrace(mask, -1);
 	return true;
 }
 
 static inline bool trigger_single_cpu_backtrace(int cpu)
 {
-	arch_trigger_cpumask_backtrace(cpumask_of(cpu), false);
+	arch_trigger_cpumask_backtrace(cpumask_of(cpu), -1);
 	return true;
 }
 
 /* generic implementation */
 void nmi_trigger_cpumask_backtrace(const cpumask_t *mask,
-				   bool exclude_self,
+				   int exclude_cpu,
 				   void (*raise)(cpumask_t *mask));
 bool nmi_cpu_backtrace(struct pt_regs *regs);
 
@@ -190,7 +190,7 @@ static inline bool trigger_all_cpu_backtrace(void)
 {
 	return false;
 }
-static inline bool trigger_allbutself_cpu_backtrace(void)
+static inline bool trigger_allbutcpu_cpu_backtrace(int exclude_cpu)
 {
 	return false;
 }
diff --git a/include/linux/pci.h b/include/linux/pci.h
index c69a2cc1f412..9c856e9aada5 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -23,7 +23,7 @@
 #ifndef LINUX_PCI_H
 #define LINUX_PCI_H
 
-
+#include <linux/args.h>
 #include <linux/mod_devicetable.h>
 
 #include <linux/types.h>
diff --git a/include/linux/range.h b/include/linux/range.h
index 7efb6a9b069b..6ad0b73cb7ad 100644
--- a/include/linux/range.h
+++ b/include/linux/range.h
@@ -31,12 +31,4 @@ int clean_sort_range(struct range *range, int az);
 
 void sort_range(struct range *range, int nr_range);
 
-#define MAX_RESOURCE ((resource_size_t)~0)
-static inline resource_size_t cap_resource(u64 val)
-{
-	if (val > MAX_RESOURCE)
-		return MAX_RESOURCE;
-
-	return val;
-}
 #endif
diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h
index 669e8cff40c7..0014d3adaf84 100644
--- a/include/linux/sched/signal.h
+++ b/include/linux/sched/signal.h
@@ -649,12 +649,9 @@ extern void flush_itimer_signals(void);
 extern bool current_is_single_threaded(void);
 
 /*
- * Careful: do_each_thread/while_each_thread is a double loop so
- *          'break' will not work as expected - use goto instead.
+ * Without tasklist/siglock it is only rcu-safe if g can't exit/exec,
+ * otherwise next_thread(t) will never reach g after list_del_rcu(g).
  */
-#define do_each_thread(g, t) \
-	for (g = t = &init_task ; (g = t = next_task(g)) != &init_task ; ) do
-
 #define while_each_thread(g, t) \
 	while ((t = next_thread(t)) != g)
 
diff --git a/include/linux/sprintf.h b/include/linux/sprintf.h
new file mode 100644
index 000000000000..33dcbec71925
--- /dev/null
+++ b/include/linux/sprintf.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_KERNEL_SPRINTF_H_
+#define _LINUX_KERNEL_SPRINTF_H_
+
+#include <linux/compiler_attributes.h>
+#include <linux/types.h>
+
+int num_to_str(char *buf, int size, unsigned long long num, unsigned int width);
+
+__printf(2, 3) int sprintf(char *buf, const char * fmt, ...);
+__printf(2, 0) int vsprintf(char *buf, const char *, va_list);
+__printf(3, 4) int snprintf(char *buf, size_t size, const char *fmt, ...);
+__printf(3, 0) int vsnprintf(char *buf, size_t size, const char *fmt, va_list args);
+__printf(3, 4) int scnprintf(char *buf, size_t size, const char *fmt, ...);
+__printf(3, 0) int vscnprintf(char *buf, size_t size, const char *fmt, va_list args);
+__printf(2, 3) __malloc char *kasprintf(gfp_t gfp, const char *fmt, ...);
+__printf(2, 0) __malloc char *kvasprintf(gfp_t gfp, const char *fmt, va_list args);
+__printf(2, 0) const char *kvasprintf_const(gfp_t gfp, const char *fmt, va_list args);
+
+__scanf(2, 3) int sscanf(const char *, const char *, ...);
+__scanf(2, 0) int vsscanf(const char *, const char *, va_list);
+
+/* These are for specific cases, do not use without real need */
+extern bool no_hash_pointers;
+int no_hash_pointers_enable(char *str);
+
+#endif	/* _LINUX_KERNEL_SPRINTF_H */
diff --git a/include/trace/bpf_probe.h b/include/trace/bpf_probe.h
index 1f7fc1fc590c..e609cd7da47e 100644
--- a/include/trace/bpf_probe.h
+++ b/include/trace/bpf_probe.h
@@ -12,6 +12,8 @@
 #undef __perf_task
 #define __perf_task(t)	(t)
 
+#include <linux/args.h>
+
 /* cast any integer, pointer, or small struct to u64 */
 #define UINTTYPE(size) \
 	__typeof__(__builtin_choose_expr(size == 1,  (u8)1, \
diff --git a/include/uapi/linux/kexec.h b/include/uapi/linux/kexec.h
index 981016e05cfa..01766dd839b0 100644
--- a/include/uapi/linux/kexec.h
+++ b/include/uapi/linux/kexec.h
@@ -12,6 +12,7 @@
 /* kexec flags for different usage scenarios */
 #define KEXEC_ON_CRASH		0x00000001
 #define KEXEC_PRESERVE_CONTEXT	0x00000002
+#define KEXEC_UPDATE_ELFCOREHDR	0x00000004
 #define KEXEC_ARCH_MASK		0xffff0000
 
 /*