[PATCH v4 3/4] kexec_file: Don't place kexec images on IORESOURCE_MEM_DRIVER_MANAGED

From: David Hildenbrand
Date: Fri May 08 2020 - 04:42:48 EST


Memory flagged with IORESOURCE_MEM_DRIVER_MANAGED is special - it won't be
part of the initial memmap of the kexec kernel and not all memory might be
accessible. Don't place any kexec images onto it.

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Pankaj Gupta <pankaj.gupta.linux@xxxxxxxxx>
Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
Cc: Baoquan He <bhe@xxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Eric Biederman <ebiederm@xxxxxxxxxxxx>
Cc: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>
Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
---
kernel/kexec_file.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index faa74d5f6941..bb05fd52de85 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c
@@ -540,6 +540,11 @@ static int locate_mem_hole_callback(struct resource *res, void *arg)
unsigned long sz = end - start + 1;

/* Returning 0 will take to next memory range */
+
+ /* Don't use memory that will be detected and handled by a driver. */
+ if (res->flags & IORESOURCE_MEM_DRIVER_MANAGED)
+ return 0;
+
if (sz < kbuf->memsz)
return 0;

--
2.25.4