When allocating memory for the copy of the FDT that the stub
modifies and passes to the kernel, it uses the current size as
an estimate of how much memory to allocate, and increases it page
by page if it turns out to be too small. However, when loading
the FDT from a UEFI configuration table, the estimated size is
left at its default value of zero, and the allocation loop runs
starting from zero all the way up to the allocation size that
finally fits the updated FDT.
Instead, retrieve the size of the FDT when loading it from the
UEFI config table.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
---
drivers/firmware/efi/libstub/arm-stub.c | 4 ++--
drivers/firmware/efi/libstub/efistub.h | 2 +-
drivers/firmware/efi/libstub/fdt.c | 4 +++-
3 files changed, 6 insertions(+), 4 deletions(-)
diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index b98f0fcb4c6a..84d0a0b4ac4f 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -175,7 +175,7 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
unsigned long initrd_addr;
u64 initrd_size = 0;
unsigned long fdt_addr = 0; /* Original DTB */
- u64 fdt_size = 0; /* We don't get size from configuration table */
+ unsigned long fdt_size = 0;
char *cmdline_ptr = NULL;
int cmdline_size = 0;
unsigned long new_fdt_addr;
@@ -252,7 +252,7 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
pr_efi(sys_table, "Using DTB from command line\n");
} else {
/* Look for a device tree configuration table entry. */
- fdt_addr = (uintptr_t)get_fdt(sys_table);
+ fdt_addr = (uintptr_t)get_fdt(sys_table, &fdt_size);
if (fdt_addr)
pr_efi(sys_table, "Using DTB from configuration table\n");
}
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 47437b16b186..e334a01cf92f 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -41,7 +41,7 @@ efi_status_t allocate_new_fdt_and_exit_boot(efi_system_table_t *sys_table,
unsigned long fdt_addr,
unsigned long fdt_size);
-void *get_fdt(efi_system_table_t *sys_table);
+void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size);
void efi_get_virtmap(efi_memory_desc_t *memory_map, unsigned long map_size,
unsigned long desc_size, efi_memory_desc_t *runtime_map,
diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index 378196944e66..21aca05448d4 100644
--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -320,7 +320,7 @@ fail:
return EFI_LOAD_ERROR;
}
-void *get_fdt(efi_system_table_t *sys_table)
+void *get_fdt(efi_system_table_t *sys_table, unsigned long *fdt_size)
{
efi_guid_t fdt_guid = DEVICE_TREE_GUID;
efi_config_table_t *tables;
@@ -333,6 +333,8 @@ void *get_fdt(efi_system_table_t *sys_table)
for (i = 0; i < sys_table->nr_tables; i++)
if (efi_guidcmp(tables[i].guid, fdt_guid) == 0) {
fdt = (void *) tables[i].table;
+ if (!fdt_check_header(fdt))
+ *fdt_size = fdt_totalsize(fdt);
break;
}
--
1.8.3.2
--
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