[PATCH v5 4/7] mm/vmalloc: explicitly identify vm_map_ram area when shown in /proc/vmcoreinfo

From: Baoquan He
Date: Mon Feb 06 2023 - 03:41:51 EST


Now, by marking VMAP_RAM in vmap_area->flags for vm_map_ram area, we can
clearly differentiate it with other vmalloc areas. So identify
vm_map_area area by checking VMAP_RAM of vmap_area->flags when shown
in /proc/vmcoreinfo.

Meanwhile, the code comment above vm_map_ram area checking in s_show()
is not needed any more, remove it here.

Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
Reviewed-by: Lorenzo Stoakes <lstoakes@xxxxxxxxx>
---
mm/vmalloc.c | 11 ++++-------
1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 4bb78ebd70f6..dea76e73e57c 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -4233,14 +4233,11 @@ static int s_show(struct seq_file *m, void *p)

va = list_entry(p, struct vmap_area, list);

- /*
- * s_show can encounter race with remove_vm_area, !vm on behalf
- * of vmap area is being tear down or vm_map_ram allocation.
- */
if (!va->vm) {
- seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
- (void *)va->va_start, (void *)va->va_end,
- va->va_end - va->va_start);
+ if (va->flags & VMAP_RAM)
+ seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
+ (void *)va->va_start, (void *)va->va_end,
+ va->va_end - va->va_start);

goto final;
}
--
2.34.1