5 files changed, 30 insertions, 20 deletions

diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index 99a5cde7c2d8..48161b1dd098 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -60,7 +60,11 @@ static struct screen_info *setup_graphics(void)
 		si = alloc_screen_info();
 		if (!si)
 			return NULL;
-		efi_setup_gop(si, &gop_proto, size);
+		status = efi_setup_gop(si, &gop_proto, size);
+		if (status != EFI_SUCCESS) {
+			free_screen_info(si);
+			return NULL;
+		}
 	}
 	return si;
 }
diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h
index 67d26949fd26..62943992f02f 100644
--- a/drivers/firmware/efi/libstub/efistub.h
+++ b/drivers/firmware/efi/libstub/efistub.h
@@ -92,6 +92,19 @@ extern __pure efi_system_table_t  *efi_system_table(void);
 #define EFI_LOCATE_BY_REGISTER_NOTIFY		1
 #define EFI_LOCATE_BY_PROTOCOL			2
 
+/*
+ * An efi_boot_memmap is used by efi_get_memory_map() to return the
+ * EFI memory map in a dynamically allocated buffer.
+ *
+ * The buffer allocated for the EFI memory map includes extra room for
+ * a minimum of EFI_MMAP_NR_SLACK_SLOTS additional EFI memory descriptors.
+ * This facilitates the reuse of the EFI memory map buffer when a second
+ * call to ExitBootServices() is needed because of intervening changes to
+ * the EFI memory map. Other related structures, e.g. x86 e820ext, need
+ * to factor in this headroom requirement as well.
+ */
+#define EFI_MMAP_NR_SLACK_SLOTS	8
+
 struct efi_boot_memmap {
 	efi_memory_desc_t	**map;
 	unsigned long		*map_size;
diff --git a/drivers/firmware/efi/libstub/mem.c b/drivers/firmware/efi/libstub/mem.c
index 869a79c8946f..09f4fa01914e 100644
--- a/drivers/firmware/efi/libstub/mem.c
+++ b/drivers/firmware/efi/libstub/mem.c
@@ -5,8 +5,6 @@
 
 #include "efistub.h"
 
-#define EFI_MMAP_NR_SLACK_SLOTS	8
-
 static inline bool mmap_has_headroom(unsigned long buff_size,
 				     unsigned long map_size,
 				     unsigned long desc_size)
diff --git a/drivers/firmware/efi/libstub/tpm.c b/drivers/firmware/efi/libstub/tpm.c
index 1d59e103a2e3..e9a684637b70 100644
--- a/drivers/firmware/efi/libstub/tpm.c
+++ b/drivers/firmware/efi/libstub/tpm.c
@@ -54,7 +54,7 @@ void efi_retrieve_tpm2_eventlog(void)
 	efi_status_t status;
 	efi_physical_addr_t log_location = 0, log_last_entry = 0;
 	struct linux_efi_tpm_eventlog *log_tbl = NULL;
-	struct efi_tcg2_final_events_table *final_events_table;
+	struct efi_tcg2_final_events_table *final_events_table = NULL;
 	unsigned long first_entry_addr, last_entry_addr;
 	size_t log_size, last_entry_size;
 	efi_bool_t truncated;
@@ -127,7 +127,8 @@ void efi_retrieve_tpm2_eventlog(void)
 	 * Figure out whether any events have already been logged to the
 	 * final events structure, and if so how much space they take up
 	 */
-	final_events_table = get_efi_config_table(LINUX_EFI_TPM_FINAL_LOG_GUID);
+	if (version == EFI_TCG2_EVENT_LOG_FORMAT_TCG_2)
+		final_events_table = get_efi_config_table(LINUX_EFI_TPM_FINAL_LOG_GUID);
 	if (final_events_table && final_events_table->nr_events) {
 		struct tcg_pcr_event2_head *header;
 		int offset;
diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 05ccb229fb45..f0339b5d3658 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -606,24 +606,18 @@ static efi_status_t allocate_e820(struct boot_params *params,
 				  struct setup_data **e820ext,
 				  u32 *e820ext_size)
 {
-	unsigned long map_size, desc_size, buff_size;
-	struct efi_boot_memmap boot_map;
-	efi_memory_desc_t *map;
+	unsigned long map_size, desc_size, map_key;
 	efi_status_t status;
-	__u32 nr_desc;
+	__u32 nr_desc, desc_version;
 
-	boot_map.map		= ↦
-	boot_map.map_size	= &map_size;
-	boot_map.desc_size	= &desc_size;
-	boot_map.desc_ver	= NULL;
-	boot_map.key_ptr	= NULL;
-	boot_map.buff_size	= &buff_size;
+	/* Only need the size of the mem map and size of each mem descriptor */
+	map_size = 0;
+	status = efi_bs_call(get_memory_map, &map_size, NULL, &map_key,
+			     &desc_size, &desc_version);
+	if (status != EFI_BUFFER_TOO_SMALL)
+		return (status != EFI_SUCCESS) ? status : EFI_UNSUPPORTED;
 
-	status = efi_get_memory_map(&boot_map);
-	if (status != EFI_SUCCESS)
-		return status;
-
-	nr_desc = buff_size / desc_size;
+	nr_desc = map_size / desc_size + EFI_MMAP_NR_SLACK_SLOTS;
 
 	if (nr_desc > ARRAY_SIZE(params->e820_table)) {
 		u32 nr_e820ext = nr_desc - ARRAY_SIZE(params->e820_table);