On Thu, Jan 05, 2023 at 09:25:35PM +0100, Heinrich Schuchardt wrote:
> Carve out code from efidebug command used to read the memory map.
>
> Signed-off-by: Heinrich Schuchardt <heinrich.schucha...@canonical.com>
> ---
> v2:
> new patch
> ---
> cmd/efidebug.c | 18 ++++--------------
> include/efi_loader.h | 3 +++
> lib/efi_loader/efi_memory.c | 34 ++++++++++++++++++++++++++++++++++
> 3 files changed, 41 insertions(+), 14 deletions(-)
>
> diff --git a/cmd/efidebug.c b/cmd/efidebug.c
> index 569003ae2e..e6959ede93 100644
> --- a/cmd/efidebug.c
> +++ b/cmd/efidebug.c
> @@ -591,25 +591,15 @@ static void print_memory_attributes(u64 attributes)
> static int do_efi_show_memmap(struct cmd_tbl *cmdtp, int flag,
> int argc, char *const argv[])
> {
> - struct efi_mem_desc *memmap = NULL, *map;
> - efi_uintn_t map_size = 0;
> + struct efi_mem_desc *memmap, *map;
> + efi_uintn_t map_size;
> const char *type;
> int i;
> efi_status_t ret;
>
> - ret = efi_get_memory_map(&map_size, memmap, NULL, NULL, NULL);
> - if (ret == EFI_BUFFER_TOO_SMALL) {
> - map_size += sizeof(struct efi_mem_desc); /* for my own */
> - ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, map_size,
> - (void *)&memmap);
> - if (ret != EFI_SUCCESS)
> - return CMD_RET_FAILURE;
> - ret = efi_get_memory_map(&map_size, memmap, NULL, NULL, NULL);
> - }
> - if (ret != EFI_SUCCESS) {
> - efi_free_pool(memmap);
> + ret = efi_get_memory_map_alloc(&map_size, &memmap);
> + if (ret != EFI_SUCCESS)
> return CMD_RET_FAILURE;
> - }
>
> printf("Type Start%.*s End%.*s Attributes\n",
> EFI_PHYS_ADDR_WIDTH - 5, spc, EFI_PHYS_ADDR_WIDTH - 3, spc);
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 0899e293e5..02d151b715 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -734,6 +734,9 @@ efi_status_t efi_allocate_pool(enum efi_memory_type
> pool_type,
> efi_uintn_t size, void **buffer);
> /* EFI pool memory free function. */
> efi_status_t efi_free_pool(void *buffer);
> +/* Allocate and retrieve EFI memory map */
> +efi_status_t efi_get_memory_map_alloc(efi_uintn_t *map_size,
> + struct efi_mem_desc **memory_map);
> /* Returns the EFI memory map */
> efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
> struct efi_mem_desc *memory_map,
> diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
> index 8d347f101f..32254d2433 100644
> --- a/lib/efi_loader/efi_memory.c
> +++ b/lib/efi_loader/efi_memory.c
> @@ -736,6 +736,40 @@ efi_status_t efi_get_memory_map(efi_uintn_t
> *memory_map_size,
> return EFI_SUCCESS;
> }
>
> +/**
> + * efi_get_memory_map_alloc() - allocate map describing memory usage
> + *
> + * The caller is responsible for calling FreePool() if the call succeeds.
> + *
> + * @memory_map buffer to which the memory map is written
> + * @map_size size of the memory map
> + * Return: status code
> + */
> +efi_status_t efi_get_memory_map_alloc(efi_uintn_t *map_size,
> + struct efi_mem_desc **memory_map)
> +{
> + efi_status_t ret;
> +
> + *memory_map = NULL;
> + *map_size = 0;
> + ret = efi_get_memory_map(map_size, *memory_map, NULL, NULL, NULL);
Although this is correct and efi_get_memory_map() will only return
EFI_BUFFER_TOO_SMALL, since we initialize the map_size to 0, I don't know
if code analysis tools are smart enough to understand this. Perhaps we
should initialize ret?
> + if (ret == EFI_BUFFER_TOO_SMALL) {
> + *map_size += sizeof(struct efi_mem_desc); /* for the map */
> + ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, *map_size,
> + (void **)memory_map);
> + if (ret != EFI_SUCCESS)
> + return ret;
> + ret = efi_get_memory_map(map_size, *memory_map,
> + NULL, NULL, NULL);
> + if (ret != EFI_SUCCESS) {
> + efi_free_pool(*memory_map);
> + *memory_map = NULL;
> + }
> + }
> +
> + return ret;
> +}
> +
> /**
> * efi_add_conventional_memory_map() - add a RAM memory area to the map
> *
> --
> 2.37.2
>
Reviewed-by: Ilias Apalodimas <ilias.apalodi...@linaro.org>
