* [PATCH] memblock: Check memory add/cap ordering
@ 2021-08-11 8:55 Geert Uytterhoeven
2021-08-11 9:35 ` David Hildenbrand
2021-08-11 13:06 ` Mike Rapoport
0 siblings, 2 replies; 3+ messages in thread
From: Geert Uytterhoeven @ 2021-08-11 8:55 UTC (permalink / raw)
To: Mike Rapoport, Andrew Morton; +Cc: linux-mm, linux-kernel, Geert Uytterhoeven
For memblock_cap_memory_range() to work properly, it should be called
after memory is detected and added to memblock with memblock_add() or
memblock_add_node(). If memblock_cap_memory_range() would be called
before memory is registered, we may silently corrupt memory later
because the crash kernel will see all memory as available.
Print a warning and bail out if ordering is not satisfied.
Suggested-by: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
mm/memblock.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/mm/memblock.c b/mm/memblock.c
index 57a9849a5d820c34..e2ca8ddc8ebebf4e 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -1685,6 +1685,11 @@ void __init memblock_cap_memory_range(phys_addr_t base, phys_addr_t size)
if (!size)
return;
+ if (memblock.memory.cnt <= 1) {
+ pr_warn("%s: No memory registered yet\n", __func__);
+ return;
+ }
+
ret = memblock_isolate_range(&memblock.memory, base, size,
&start_rgn, &end_rgn);
if (ret)
--
2.25.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] memblock: Check memory add/cap ordering
2021-08-11 8:55 [PATCH] memblock: Check memory add/cap ordering Geert Uytterhoeven
@ 2021-08-11 9:35 ` David Hildenbrand
2021-08-11 13:06 ` Mike Rapoport
1 sibling, 0 replies; 3+ messages in thread
From: David Hildenbrand @ 2021-08-11 9:35 UTC (permalink / raw)
To: Geert Uytterhoeven, Mike Rapoport, Andrew Morton; +Cc: linux-mm, linux-kernel
On 11.08.21 10:55, Geert Uytterhoeven wrote:
> For memblock_cap_memory_range() to work properly, it should be called
> after memory is detected and added to memblock with memblock_add() or
> memblock_add_node(). If memblock_cap_memory_range() would be called
> before memory is registered, we may silently corrupt memory later
> because the crash kernel will see all memory as available.
>
> Print a warning and bail out if ordering is not satisfied.
>
> Suggested-by: Mike Rapoport <rppt@kernel.org>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> mm/memblock.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 57a9849a5d820c34..e2ca8ddc8ebebf4e 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -1685,6 +1685,11 @@ void __init memblock_cap_memory_range(phys_addr_t base, phys_addr_t size)
> if (!size)
> return;
>
> + if (memblock.memory.cnt <= 1) {
> + pr_warn("%s: No memory registered yet\n", __func__);
> + return;
> + }
> +
> ret = memblock_isolate_range(&memblock.memory, base, size,
> &start_rgn, &end_rgn);
> if (ret)
>
Reviewed-by: David Hildenbrand <david@redhat.com>
--
Thanks,
David / dhildenb
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] memblock: Check memory add/cap ordering
2021-08-11 8:55 [PATCH] memblock: Check memory add/cap ordering Geert Uytterhoeven
2021-08-11 9:35 ` David Hildenbrand
@ 2021-08-11 13:06 ` Mike Rapoport
1 sibling, 0 replies; 3+ messages in thread
From: Mike Rapoport @ 2021-08-11 13:06 UTC (permalink / raw)
To: Geert Uytterhoeven
Cc: Andrew Morton, David Hildenbrand, linux-mm, linux-kernel
On Wed, Aug 11, 2021 at 10:55:18AM +0200, Geert Uytterhoeven wrote:
> For memblock_cap_memory_range() to work properly, it should be called
> after memory is detected and added to memblock with memblock_add() or
> memblock_add_node(). If memblock_cap_memory_range() would be called
> before memory is registered, we may silently corrupt memory later
> because the crash kernel will see all memory as available.
>
> Print a warning and bail out if ordering is not satisfied.
>
> Suggested-by: Mike Rapoport <rppt@kernel.org>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Applied for 5.15,
Thanks!
--
Sincerely yours,
Mike.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2021-08-11 8:55 [PATCH] memblock: Check memory add/cap ordering Geert Uytterhoeven
2021-08-11 9:35 ` David Hildenbrand
2021-08-11 13:06 ` Mike Rapoport
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