From: Yu Chen <yu.ch...@zte.com.cn>
memblock reserved regions are not reported via /proc/iomem on ARM, kexec's
user-space doesn't know about memblock_reserve()d regions and thus
possible for kexec to overwrite with the new kernel or initrd.
[ 0.000000] Booting Linux on physical CPU 0xf00
[ 0.000000] Linux version 4.9.115-rt93-dirty (yuchen@localhost.localdomain)
(gcc version 6.2.0 (ZTE Embsys-TSP V3.07.2
0) ) #62 SMP PREEMPT Fri Sep 20 10:39:29 CST 2019
[ 0.000000] CPU: ARMv7 Processor [410fc075] revision 5 (ARMv7), cr=30c5387d
[ 0.000000] CPU: div instructions available: patching division code
[ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing
instruction cache
[ 0.000000] OF: fdt:Machine model: LS1021A TWR Board
[ 0.000000] INITRD: 0x80f7f000+0x03695e40 overlaps in-use memory region -
disabling initrd
Signed-off-by: Yu Chen <yu.ch...@zte.com.cn>
Reviewed-by: Junhua Huang <huang.jun...@zte.com.cn>
---
arch/arm/kernel/setup.c | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index d0a464e..606d1ac 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -911,6 +911,34 @@ static void __init request_standard_resources(const struct
machine_desc *mdesc)
request_resource(&ioport_resource, &lp2);
}
+static int __init reserve_memblock_reserved_regions(void)
+{
+ u64 i, j;
+
+ for (i = 0; i < num_standard_resources; ++i) {
+ struct resource *mem = &standard_resources[i];
+ phys_addr_t r_start, r_end, mem_size = resource_size(mem);
+
+ if (!memblock_is_region_reserved(mem->start, mem_size))
+ continue;
+
+ for_each_reserved_mem_region(j, &r_start, &r_end) {
+ resource_size_t start, end;
+
+ start = max(PFN_PHYS(PFN_DOWN(r_start)), mem->start);
+ end = min(PFN_PHYS(PFN_UP(r_end)) - 1, mem->end);
+
+ if (start > mem->end || end < mem->start)
+ continue;
+
+ reserve_region_with_split(mem, start, end, "reserved");
+ }
+ }
+
+ return 0;
+}
+arch_initcall(reserve_memblock_reserved_regions);
+
#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE) || \
defined(CONFIG_EFI)
struct screen_info screen_info = {
--
2.7.4
