fs/proc/vmcore: factor out allocating a vmcore range and adding it to a list

Let's factor it out into include/linux/crash_dump.h, from where we can
use it also outside of vmcore.c later.

Acked-by: Baoquan He <bhe@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20241204125444.1734652-7-david@redhat.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Author: davidhildenbrand

fs/proc/vmcore.c

@@ -709,11 +709,6 @@ static const struct proc_ops vmcore_proc_ops = {
 	.proc_mmap	= mmap_vmcore,
 };
 
-static struct vmcore_range * __init get_new_element(void)
-{
-	return kzalloc(sizeof(struct vmcore_range), GFP_KERNEL);
-}
-
 static u64 get_vmcore_size(size_t elfsz, size_t elfnotesegsz,
 			   struct list_head *vc_list)
 {
@@ -1116,7 +1111,6 @@ static int __init process_ptload_program_headers_elf64(char *elfptr,
 						size_t elfnotes_sz,
 						struct list_head *vc_list)
 {
-	struct vmcore_range *new;
 	int i;
 	Elf64_Ehdr *ehdr_ptr;
 	Elf64_Phdr *phdr_ptr;
@@ -1139,13 +1133,8 @@ static int __init process_ptload_program_headers_elf64(char *elfptr,
 		end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
 		size = end - start;
 
-		/* Add this contiguous chunk of memory to vmcore list.*/
-		new = get_new_element();
-		if (!new)
+		if (vmcore_alloc_add_range(vc_list, start, size))
 			return -ENOMEM;
-		new->paddr = start;
-		new->size = size;
-		list_add_tail(&new->list, vc_list);
 
 		/* Update the program header offset. */
 		phdr_ptr->p_offset = vmcore_off + (paddr - start);
@@ -1159,7 +1148,6 @@ static int __init process_ptload_program_headers_elf32(char *elfptr,
 						size_t elfnotes_sz,
 						struct list_head *vc_list)
 {
-	struct vmcore_range *new;
 	int i;
 	Elf32_Ehdr *ehdr_ptr;
 	Elf32_Phdr *phdr_ptr;
@@ -1182,13 +1170,8 @@ static int __init process_ptload_program_headers_elf32(char *elfptr,
 		end = roundup(paddr + phdr_ptr->p_memsz, PAGE_SIZE);
 		size = end - start;
 
-		/* Add this contiguous chunk of memory to vmcore list.*/
-		new = get_new_element();
-		if (!new)
+		if (vmcore_alloc_add_range(vc_list, start, size))
 			return -ENOMEM;
-		new->paddr = start;
-		new->size = size;
-		list_add_tail(&new->list, vc_list);
 
 		/* Update the program header offset */
 		phdr_ptr->p_offset = vmcore_off + (paddr - start);

include/linux/crash_dump.h

@@ -121,6 +121,20 @@ struct vmcore_range {
 	loff_t offset;
 };
 
+/* Allocate a vmcore range and add it to the list. */
+static inline int vmcore_alloc_add_range(struct list_head *list,
+		unsigned long long paddr, unsigned long long size)
+{
+	struct vmcore_range *m = kzalloc(sizeof(*m), GFP_KERNEL);
+
+	if (!m)
+		return -ENOMEM;
+	m->paddr = paddr;
+	m->size = size;
+	list_add_tail(&m->list, list);
+	return 0;
+}
+
 #else /* !CONFIG_CRASH_DUMP */
 static inline bool is_kdump_kernel(void) { return false; }
 #endif /* CONFIG_CRASH_DUMP */