efi/libstub: Use efi_exit_boot_services() in FDT

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@codeaurora.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>

1 files changed, 27 insertions, 10 deletions

diff --git a/drivers/firmware/efi/libstub/fdt.c b/drivers/firmware/efi/libstub/fdt.c
index bec0fa8d8746..a6a93116a8f0 100644
--- 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_boot(efi_system_table_t *sys_table,
         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_boot(efi_system_table_t *sys_table,
                 }
         }
 
-        /*
-         * 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;