diff mbox series

[v3,4/7] mm/vmalloc: explicitly identify vm_map_ram area when shown in /proc/vmcoreinfo

Message ID 20230113031921.64716-5-bhe@redhat.com
State New
Headers
Series mm/vmalloc.c: allow vread() to read out vm_map_ram areas |

Commit Message

Baoquan He Jan. 13, 2023, 3:19 a.m. UTC 
  Now, by marking VMAP_RAM in vmap_area->flags for vm_map_ram, 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@redhat.com>
---
 mm/vmalloc.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

Comments

Uladzislau Rezki Jan. 16, 2023, 11:43 a.m. UTC | #1 
On Fri, Jan 13, 2023 at 11:19:18AM +0800, Baoquan He wrote:
> Now, by marking VMAP_RAM in vmap_area->flags for vm_map_ram, 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@redhat.com>
> ---
>  mm/vmalloc.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
> 
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 13875bc41e27..4a10b3b692fa 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -4225,11 +4225,7 @@ 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) {
> +	if (!va->vm && (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);
> -- 
> 2.34.1
> 
Reviewed-by: Uladzislau Rezki (Sony) <urezki@gmail.com>

--
Uladzislau Rezki
Lorenzo Stoakes Jan. 16, 2023, 12:24 p.m. UTC | #2 
On Fri, Jan 13, 2023 at 11:19:18AM +0800, Baoquan He wrote:
> Now, by marking VMAP_RAM in vmap_area->flags for vm_map_ram, 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@redhat.com>
> ---
>  mm/vmalloc.c | 6 +-----
>  1 file changed, 1 insertion(+), 5 deletions(-)
>
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 13875bc41e27..4a10b3b692fa 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -4225,11 +4225,7 @@ 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) {
> +	if (!va->vm && (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);
> --
> 2.34.1
>

Reviewed-by: Lorenzo Stoakes <lstoakes@gmail.com>
diff mbox series

Patch

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 13875bc41e27..4a10b3b692fa 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -4225,11 +4225,7 @@  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) {
+	if (!va->vm && (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);