[PATCH 4.7 138/184] efi/libstub: Use efi_exit_boot_services() in FDT

From: Greg Kroah-Hartman
Date: Thu Sep 22 2016 - 13:48:27 EST


4.7-stable review patch. If anyone has any objections, please let me know.

------------------

From: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx>

commit ed9cc156c42ff0c0bf9b1d09df48a12bf0873473 upstream.

The FDT code directly calls ExitBootServices. This is inadvisable as the
UEFI spec details a complex set of errors, race conditions, and API
interactions that the caller of ExitBootServices must get correct. The
FDT code does not handle EFI_INVALID_PARAMETER as required by the spec,
which causes intermittent boot failures on the Qualcomm Technologies
QDF2432. Call the efi_exit_boot_services() helper intead, which handles
the EFI_INVALID_PARAMETER scenario properly.

Signed-off-by: Jeffrey Hugo <jhugo@xxxxxxxxxxxxxx>
Cc: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Leif Lindholm <leif.lindholm@xxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/firmware/efi/libstub/fdt.c | 37 +++++++++++++++++++++++++++----------
1 file changed, 27 insertions(+), 10 deletions(-)

--- a/drivers/firmware/efi/libstub/fdt.c
+++ b/drivers/firmware/efi/libstub/fdt.c
@@ -152,6 +152,27 @@ fdt_set_fail:
#define EFI_FDT_ALIGN EFI_PAGE_SIZE
#endif

+struct exit_boot_struct {
+ efi_memory_desc_t *runtime_map;
+ int *runtime_entry_count;
+};
+
+static efi_status_t exit_boot_func(efi_system_table_t *sys_table_arg,
+ struct efi_boot_memmap *map,
+ void *priv)
+{
+ struct exit_boot_struct *p = priv;
+ /*
+ * Update the memory map with virtual addresses. The function will also
+ * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME
+ * entries so that we can pass it straight to SetVirtualAddressMap()
+ */
+ efi_get_virtmap(*map->map, *map->map_size, *map->desc_size,
+ p->runtime_map, p->runtime_entry_count);
+
+ return EFI_SUCCESS;
+}
+
/*
* Allocate memory for a new FDT, then add EFI, commandline, and
* initrd related fields to the FDT. This routine increases the
@@ -183,6 +204,7 @@ efi_status_t allocate_new_fdt_and_exit_b
efi_status_t status;
int runtime_entry_count = 0;
struct efi_boot_memmap map;
+ struct exit_boot_struct priv;

map.map = &runtime_map;
map.map_size = &map_size;
@@ -257,16 +279,11 @@ efi_status_t allocate_new_fdt_and_exit_b
}
}

- /*
- * Update the memory map with virtual addresses. The function will also
- * populate @runtime_map with copies of just the EFI_MEMORY_RUNTIME
- * entries so that we can pass it straight into SetVirtualAddressMap()
- */
- efi_get_virtmap(memory_map, map_size, desc_size, runtime_map,
- &runtime_entry_count);
-
- /* Now we are ready to exit_boot_services.*/
- status = sys_table->boottime->exit_boot_services(handle, mmap_key);
+ sys_table->boottime->free_pool(memory_map);
+ priv.runtime_map = runtime_map;
+ priv.runtime_entry_count = &runtime_entry_count;
+ status = efi_exit_boot_services(sys_table, handle, &map, &priv,
+ exit_boot_func);

if (status == EFI_SUCCESS) {
efi_set_virtual_address_map_t *svam;