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memblock: Check memory add/cap ordering

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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>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Link: https://lore.kernel.org/r/aabc5bad008d49f07d542815c6c8d28ec90bb09e.1628672091.git.geert+renesas@glider.be
This commit is contained in:
Geert Uytterhoeven 2021-08-11 10:55:18 +02:00 committed by Mike Rapoport
parent 00974b9a83
commit e888fa7bb8
1 changed files with 5 additions and 0 deletions
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5
mm/memblock.c
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@ -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)