diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h
index 9143100ea3ea..3be6a98751f0 100644
--- a/arch/x86/include/asm/kexec.h
+++ b/arch/x86/include/asm/kexec.h
@@ -214,14 +214,17 @@ void arch_crash_handle_hotplug_event(struct kimage *image);
 #define arch_crash_handle_hotplug_event arch_crash_handle_hotplug_event
 
 #ifdef CONFIG_HOTPLUG_CPU
-static inline int crash_hotplug_cpu_support(void) { return 1; }
-#define crash_hotplug_cpu_support crash_hotplug_cpu_support
+int arch_crash_hotplug_cpu_support(void);
+#define crash_hotplug_cpu_support arch_crash_hotplug_cpu_support
 #endif
 
 #ifdef CONFIG_MEMORY_HOTPLUG
-static inline int crash_hotplug_memory_support(void) { return 1; }
-#define crash_hotplug_memory_support crash_hotplug_memory_support
+int arch_crash_hotplug_memory_support(void);
+#define crash_hotplug_memory_support arch_crash_hotplug_memory_support
 #endif
+
+unsigned int arch_crash_get_elfcorehdr_size(void);
+#define crash_get_elfcorehdr_size arch_crash_get_elfcorehdr_size
 #endif
 
 #endif /* __ASSEMBLY__ */
diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c
index c70a111c44fa..caf22bcb61af 100644
--- a/arch/x86/kernel/crash.c
+++ b/arch/x86/kernel/crash.c
@@ -427,6 +427,33 @@ int crash_load_segments(struct kimage *image)
 #undef pr_fmt
 #define pr_fmt(fmt) "crash hp: " fmt
 
+/* These functions provide the value for the sysfs crash_hotplug nodes */
+#ifdef CONFIG_HOTPLUG_CPU
+int arch_crash_hotplug_cpu_support(void)
+{
+	return crash_check_update_elfcorehdr();
+}
+#endif
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int arch_crash_hotplug_memory_support(void)
+{
+	return crash_check_update_elfcorehdr();
+}
+#endif
+
+unsigned int arch_crash_get_elfcorehdr_size(void)
+{
+	unsigned int sz;
+
+	/* kernel_map, VMCOREINFO and maximum CPUs */
+	sz = 2 + CONFIG_NR_CPUS_DEFAULT;
+	if (IS_ENABLED(CONFIG_MEMORY_HOTPLUG))
+		sz += CONFIG_CRASH_MAX_MEMORY_RANGES;
+	sz *= sizeof(Elf64_Phdr);
+	return sz;
+}
+
 /**
  * arch_crash_handle_hotplug_event() - Handle hotplug elfcorehdr changes
  * @image: a pointer to kexec_crash_image
diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index 6a8a724ac638..bb0e614f2a05 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -335,6 +335,10 @@ 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;
@@ -411,9 +415,9 @@ 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 */
@@ -501,6 +505,8 @@ static inline void arch_kexec_pre_free_pages(void *vaddr, unsigned int pages) {
 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
@@ -509,6 +515,10 @@ static inline int crash_hotplug_cpu_support(void) { return 0; }
 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/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
 
 /*
diff --git a/kernel/Kconfig.kexec b/kernel/Kconfig.kexec
index d0a9a5392035..6e5350d2d7a6 100644
--- a/kernel/Kconfig.kexec
+++ b/kernel/Kconfig.kexec
@@ -144,4 +144,8 @@ config CRASH_MAX_MEMORY_RANGES
 	  memory buffer/segment size under 1MiB. This represents a sane choice
 	  to accommodate both baremetal and virtual machine configurations.
 
+	  For the kexec_load() syscall path, CRASH_MAX_MEMORY_RANGES is part of
+	  the computation behind the value provided through the
+	  /sys/kernel/crash_elfcorehdr_size attribute.
+
 endmenu
diff --git a/kernel/crash_core.c b/kernel/crash_core.c
index 53d211c690a1..fa918176d46d 100644
--- a/kernel/crash_core.c
+++ b/kernel/crash_core.c
@@ -704,6 +704,33 @@ subsys_initcall(crash_save_vmcoreinfo_init);
 #ifdef CONFIG_CRASH_HOTPLUG
 #undef pr_fmt
 #define pr_fmt(fmt) "crash hp: " fmt
+
+/*
+ * This routine utilized when the crash_hotplug sysfs node is read.
+ * It reflects the kernel's ability/permission to update the crash
+ * elfcorehdr directly.
+ */
+int crash_check_update_elfcorehdr(void)
+{
+	int rc = 0;
+
+	/* Obtain lock while reading crash information */
+	if (!kexec_trylock()) {
+		pr_info("kexec_trylock() failed, elfcorehdr may be inaccurate\n");
+		return 0;
+	}
+	if (kexec_crash_image) {
+		if (kexec_crash_image->file_mode)
+			rc = 1;
+		else
+			rc = kexec_crash_image->update_elfcorehdr;
+	}
+	/* Release lock now that update complete */
+	kexec_unlock();
+
+	return rc;
+}
+
 /*
  * To accurately reflect hot un/plug changes of cpu and memory resources
  * (including onling and offlining of those resources), the elfcorehdr
@@ -734,6 +761,10 @@ static void crash_handle_hotplug_event(unsigned int hp_action, unsigned int cpu)
 
 	image = kexec_crash_image;
 
+	/* Check that updating elfcorehdr is permitted */
+	if (!(image->file_mode || image->update_elfcorehdr))
+		goto out;
+
 	if (hp_action == KEXEC_CRASH_HP_ADD_CPU ||
 		hp_action == KEXEC_CRASH_HP_REMOVE_CPU)
 		pr_debug("hp_action %u, cpu %u\n", hp_action, cpu);
diff --git a/kernel/kexec.c b/kernel/kexec.c
index 92d301f98776..107f355eac10 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -129,6 +129,11 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
 	if (flags & KEXEC_PRESERVE_CONTEXT)
 		image->preserve_context = 1;
 
+#ifdef CONFIG_CRASH_HOTPLUG
+	if (flags & KEXEC_UPDATE_ELFCOREHDR)
+		image->update_elfcorehdr = 1;
+#endif
+
 	ret = machine_kexec_prepare(image);
 	if (ret)
 		goto out;
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index aad7a3bfd846..1d4bc493b2f4 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -165,6 +165,18 @@ static ssize_t vmcoreinfo_show(struct kobject *kobj,
 }
 KERNEL_ATTR_RO(vmcoreinfo);
 
+#ifdef CONFIG_CRASH_HOTPLUG
+static ssize_t crash_elfcorehdr_size_show(struct kobject *kobj,
+			       struct kobj_attribute *attr, char *buf)
+{
+	unsigned int sz = crash_get_elfcorehdr_size();
+
+	return sysfs_emit(buf, "%u\n", sz);
+}
+KERNEL_ATTR_RO(crash_elfcorehdr_size);
+
+#endif
+
 #endif /* CONFIG_CRASH_CORE */
 
 /* whether file capabilities are enabled */
@@ -255,6 +267,9 @@ static struct attribute * kernel_attrs[] = {
 #endif
 #ifdef CONFIG_CRASH_CORE
 	&vmcoreinfo_attr.attr,
+#ifdef CONFIG_CRASH_HOTPLUG
+	&crash_elfcorehdr_size_attr.attr,
+#endif
 #endif
 #ifndef CONFIG_TINY_RCU
 	&rcu_expedited_attr.attr,
