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path: root/drivers/firmware/efi/libstub/efi-stub-helper.c
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Diffstat (limited to 'drivers/firmware/efi/libstub/efi-stub-helper.c')
-rw-r--r--drivers/firmware/efi/libstub/efi-stub-helper.c169
1 files changed, 139 insertions, 30 deletions
diff --git a/drivers/firmware/efi/libstub/efi-stub-helper.c b/drivers/firmware/efi/libstub/efi-stub-helper.c
index 3bd127f95315..aded10662020 100644
--- a/drivers/firmware/efi/libstub/efi-stub-helper.c
+++ b/drivers/firmware/efi/libstub/efi-stub-helper.c
@@ -41,6 +41,8 @@ static unsigned long __chunk_size = EFI_READ_CHUNK_SIZE;
#define EFI_ALLOC_ALIGN EFI_PAGE_SIZE
#endif
+#define EFI_MMAP_NR_SLACK_SLOTS 8
+
struct file_info {
efi_file_handle_t *handle;
u64 size;
@@ -63,49 +65,62 @@ void efi_printk(efi_system_table_t *sys_table_arg, char *str)
}
}
+static inline bool mmap_has_headroom(unsigned long buff_size,
+ unsigned long map_size,
+ unsigned long desc_size)
+{
+ unsigned long slack = buff_size - map_size;
+
+ return slack / desc_size >= EFI_MMAP_NR_SLACK_SLOTS;
+}
+
efi_status_t efi_get_memory_map(efi_system_table_t *sys_table_arg,
- efi_memory_desc_t **map,
- unsigned long *map_size,
- unsigned long *desc_size,
- u32 *desc_ver,
- unsigned long *key_ptr)
+ struct efi_boot_memmap *map)
{
efi_memory_desc_t *m = NULL;
efi_status_t status;
unsigned long key;
u32 desc_version;
- *map_size = sizeof(*m) * 32;
+ *map->desc_size = sizeof(*m);
+ *map->map_size = *map->desc_size * 32;
+ *map->buff_size = *map->map_size;
again:
- /*
- * Add an additional efi_memory_desc_t because we're doing an
- * allocation which may be in a new descriptor region.
- */
- *map_size += sizeof(*m);
status = efi_call_early(allocate_pool, EFI_LOADER_DATA,
- *map_size, (void **)&m);
+ *map->map_size, (void **)&m);
if (status != EFI_SUCCESS)
goto fail;
- *desc_size = 0;
+ *map->desc_size = 0;
key = 0;
- status = efi_call_early(get_memory_map, map_size, m,
- &key, desc_size, &desc_version);
- if (status == EFI_BUFFER_TOO_SMALL) {
+ status = efi_call_early(get_memory_map, map->map_size, m,
+ &key, map->desc_size, &desc_version);
+ if (status == EFI_BUFFER_TOO_SMALL ||
+ !mmap_has_headroom(*map->buff_size, *map->map_size,
+ *map->desc_size)) {
efi_call_early(free_pool, m);
+ /*
+ * Make sure there is some entries of headroom so that the
+ * buffer can be reused for a new map after allocations are
+ * no longer permitted. Its unlikely that the map will grow to
+ * exceed this headroom once we are ready to trigger
+ * ExitBootServices()
+ */
+ *map->map_size += *map->desc_size * EFI_MMAP_NR_SLACK_SLOTS;
+ *map->buff_size = *map->map_size;
goto again;
}
if (status != EFI_SUCCESS)
efi_call_early(free_pool, m);
- if (key_ptr && status == EFI_SUCCESS)
- *key_ptr = key;
- if (desc_ver && status == EFI_SUCCESS)
- *desc_ver = desc_version;
+ if (map->key_ptr && status == EFI_SUCCESS)
+ *map->key_ptr = key;
+ if (map->desc_ver && status == EFI_SUCCESS)
+ *map->desc_ver = desc_version;
fail:
- *map = m;
+ *map->map = m;
return status;
}
@@ -113,13 +128,20 @@ fail:
unsigned long get_dram_base(efi_system_table_t *sys_table_arg)
{
efi_status_t status;
- unsigned long map_size;
+ unsigned long map_size, buff_size;
unsigned long membase = EFI_ERROR;
struct efi_memory_map map;
efi_memory_desc_t *md;
+ struct efi_boot_memmap boot_map;
- status = efi_get_memory_map(sys_table_arg, (efi_memory_desc_t **)&map.map,
- &map_size, &map.desc_size, NULL, NULL);
+ boot_map.map = (efi_memory_desc_t **)&map.map;
+ boot_map.map_size = &map_size;
+ boot_map.desc_size = &map.desc_size;
+ boot_map.desc_ver = NULL;
+ boot_map.key_ptr = NULL;
+ boot_map.buff_size = &buff_size;
+
+ status = efi_get_memory_map(sys_table_arg, &boot_map);
if (status != EFI_SUCCESS)
return membase;
@@ -144,15 +166,22 @@ efi_status_t efi_high_alloc(efi_system_table_t *sys_table_arg,
unsigned long size, unsigned long align,
unsigned long *addr, unsigned long max)
{
- unsigned long map_size, desc_size;
+ unsigned long map_size, desc_size, buff_size;
efi_memory_desc_t *map;
efi_status_t status;
unsigned long nr_pages;
u64 max_addr = 0;
int i;
+ struct efi_boot_memmap boot_map;
+
+ 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;
- status = efi_get_memory_map(sys_table_arg, &map, &map_size, &desc_size,
- NULL, NULL);
+ status = efi_get_memory_map(sys_table_arg, &boot_map);
if (status != EFI_SUCCESS)
goto fail;
@@ -230,14 +259,21 @@ efi_status_t efi_low_alloc(efi_system_table_t *sys_table_arg,
unsigned long size, unsigned long align,
unsigned long *addr)
{
- unsigned long map_size, desc_size;
+ unsigned long map_size, desc_size, buff_size;
efi_memory_desc_t *map;
efi_status_t status;
unsigned long nr_pages;
int i;
+ struct efi_boot_memmap boot_map;
- status = efi_get_memory_map(sys_table_arg, &map, &map_size, &desc_size,
- NULL, NULL);
+ 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;
+
+ status = efi_get_memory_map(sys_table_arg, &boot_map);
if (status != EFI_SUCCESS)
goto fail;
@@ -704,3 +740,76 @@ char *efi_convert_cmdline(efi_system_table_t *sys_table_arg,
*cmd_line_len = options_bytes;
return (char *)cmdline_addr;
}
+
+/*
+ * Handle calling ExitBootServices according to the requirements set out by the
+ * spec. Obtains the current memory map, and returns that info after calling
+ * ExitBootServices. The client must specify a function to perform any
+ * processing of the memory map data prior to ExitBootServices. A client
+ * specific structure may be passed to the function via priv. The client
+ * function may be called multiple times.
+ */
+efi_status_t efi_exit_boot_services(efi_system_table_t *sys_table_arg,
+ void *handle,
+ struct efi_boot_memmap *map,
+ void *priv,
+ efi_exit_boot_map_processing priv_func)
+{
+ efi_status_t status;
+
+ status = efi_get_memory_map(sys_table_arg, map);
+
+ if (status != EFI_SUCCESS)
+ goto fail;
+
+ status = priv_func(sys_table_arg, map, priv);
+ if (status != EFI_SUCCESS)
+ goto free_map;
+
+ status = efi_call_early(exit_boot_services, handle, *map->key_ptr);
+
+ if (status == EFI_INVALID_PARAMETER) {
+ /*
+ * The memory map changed between efi_get_memory_map() and
+ * exit_boot_services(). Per the UEFI Spec v2.6, Section 6.4:
+ * EFI_BOOT_SERVICES.ExitBootServices we need to get the
+ * updated map, and try again. The spec implies one retry
+ * should be sufficent, which is confirmed against the EDK2
+ * implementation. Per the spec, we can only invoke
+ * get_memory_map() and exit_boot_services() - we cannot alloc
+ * so efi_get_memory_map() cannot be used, and we must reuse
+ * the buffer. For all practical purposes, the headroom in the
+ * buffer should account for any changes in the map so the call
+ * to get_memory_map() is expected to succeed here.
+ */
+ *map->map_size = *map->buff_size;
+ status = efi_call_early(get_memory_map,
+ map->map_size,
+ *map->map,
+ map->key_ptr,
+ map->desc_size,
+ map->desc_ver);
+
+ /* exit_boot_services() was called, thus cannot free */
+ if (status != EFI_SUCCESS)
+ goto fail;
+
+ status = priv_func(sys_table_arg, map, priv);
+ /* exit_boot_services() was called, thus cannot free */
+ if (status != EFI_SUCCESS)
+ goto fail;
+
+ status = efi_call_early(exit_boot_services, handle, *map->key_ptr);
+ }
+
+ /* exit_boot_services() was called, thus cannot free */
+ if (status != EFI_SUCCESS)
+ goto fail;
+
+ return EFI_SUCCESS;
+
+free_map:
+ efi_call_early(free_pool, *map->map);
+fail:
+ return status;
+}