diff --git a/include/linux/kexec.h b/include/linux/kexec.h
index a1f12e959bba..3c1deba496c9 100644
--- a/include/linux/kexec.h
+++ b/include/linux/kexec.h
@@ -380,8 +380,8 @@ extern note_buf_t __percpu *crash_notes;
 extern bool kexec_in_progress;
 
 int crash_shrink_memory(unsigned long new_size);
-size_t crash_get_memory_size(void);
 void crash_free_reserved_phys_range(unsigned long begin, unsigned long end);
+ssize_t crash_get_memory_size(void);
 
 void arch_kexec_protect_crashkres(void);
 void arch_kexec_unprotect_crashkres(void);
diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c
index c589c7a9562c..e47870f30728 100644
--- a/kernel/kexec_core.c
+++ b/kernel/kexec_core.c
@@ -989,13 +989,16 @@ void crash_kexec(struct pt_regs *regs)
 	}
 }
 
-size_t crash_get_memory_size(void)
+ssize_t crash_get_memory_size(void)
 {
-	size_t size = 0;
+	ssize_t size = 0;
+
+	if (!mutex_trylock(&kexec_mutex))
+		return -EBUSY;
 
-	mutex_lock(&kexec_mutex);
 	if (crashk_res.end != crashk_res.start)
 		size = resource_size(&crashk_res);
+
 	mutex_unlock(&kexec_mutex);
 	return size;
 }
@@ -1016,7 +1019,8 @@ int crash_shrink_memory(unsigned long new_size)
 	unsigned long old_size;
 	struct resource *ram_res;
 
-	mutex_lock(&kexec_mutex);
+	if (!mutex_trylock(&kexec_mutex))
+		return -EBUSY;
 
 	if (kexec_crash_image) {
 		ret = -ENOENT;
diff --git a/kernel/ksysfs.c b/kernel/ksysfs.c
index 35859da8bd4f..e20c19e3ba49 100644
--- a/kernel/ksysfs.c
+++ b/kernel/ksysfs.c
@@ -106,7 +106,12 @@ KERNEL_ATTR_RO(kexec_crash_loaded);
 static ssize_t kexec_crash_size_show(struct kobject *kobj,
 				       struct kobj_attribute *attr, char *buf)
 {
-	return sprintf(buf, "%zu\n", crash_get_memory_size());
+	ssize_t size = crash_get_memory_size();
+
+	if (size < 0)
+		return size;
+
+	return sprintf(buf, "%zd\n", size);
 }
 static ssize_t kexec_crash_size_store(struct kobject *kobj,
 				   struct kobj_attribute *attr,