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path: root/drivers/firmware/efi/efi.c
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Diffstat (limited to 'drivers/firmware/efi/efi.c')
-rw-r--r--drivers/firmware/efi/efi.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 55b77c576c42..4b7cf7bc0ded 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0-only
/*
* efi.c - EFI subsystem
*
@@ -9,8 +10,6 @@
* allowing the efivarfs to be mounted or the efivars module to be loaded.
* The existance of /sys/firmware/efi may also be used by userspace to
* determine that the system supports EFI.
- *
- * This file is released under the GPLv2.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
@@ -636,6 +635,9 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables)
void *config_tables;
int sz, ret;
+ if (efi.systab->nr_tables == 0)
+ return 0;
+
if (efi_enabled(EFI_64BIT))
sz = sizeof(efi_config_table_64_t);
else
@@ -1007,14 +1009,16 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
/* first try to find a slot in an existing linked list entry */
for (prsv = efi_memreserve_root->next; prsv; prsv = rsv->next) {
- rsv = __va(prsv);
+ rsv = memremap(prsv, sizeof(*rsv), MEMREMAP_WB);
index = atomic_fetch_add_unless(&rsv->count, 1, rsv->size);
if (index < rsv->size) {
rsv->entry[index].base = addr;
rsv->entry[index].size = size;
+ memunmap(rsv);
return 0;
}
+ memunmap(rsv);
}
/* no slot found - allocate a new linked list entry */
@@ -1022,7 +1026,13 @@ int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
if (!rsv)
return -ENOMEM;
- rsv->size = EFI_MEMRESERVE_COUNT(PAGE_SIZE);
+ /*
+ * The memremap() call above assumes that a linux_efi_memreserve entry
+ * never crosses a page boundary, so let's ensure that this remains true
+ * even when kexec'ing a 4k pages kernel from a >4k pages kernel, by
+ * using SZ_4K explicitly in the size calculation below.
+ */
+ rsv->size = EFI_MEMRESERVE_COUNT(SZ_4K);
atomic_set(&rsv->count, 1);
rsv->entry[0].base = addr;
rsv->entry[0].size = size;