diff options
Diffstat (limited to 'bl1')
| -rw-r--r-- | bl1/bl1_fwu.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/bl1/bl1_fwu.c b/bl1/bl1_fwu.c index ace364d4..43bb4d2b 100644 --- a/bl1/bl1_fwu.c +++ b/bl1/bl1_fwu.c @@ -91,6 +91,124 @@ register_t bl1_fwu_smc_handler(unsigned int smc_fid, } /******************************************************************************* + * Utility functions to keep track of the images that are loaded at any time. + ******************************************************************************/ + +#ifdef PLAT_FWU_MAX_SIMULTANEOUS_IMAGES +#define FWU_MAX_SIMULTANEOUS_IMAGES PLAT_FWU_MAX_SIMULTANEOUS_IMAGES +#else +#define FWU_MAX_SIMULTANEOUS_IMAGES 10 +#endif + +static int bl1_fwu_loaded_ids[FWU_MAX_SIMULTANEOUS_IMAGES] = { + [0 ... FWU_MAX_SIMULTANEOUS_IMAGES-1] = INVALID_IMAGE_ID +}; + +/* + * Adds an image_id to the bl1_fwu_loaded_ids array. + * Returns 0 on success, 1 on error. + */ +static int bl1_fwu_add_loaded_id(int image_id) +{ + int i; + + /* Check if the ID is already in the list */ + for (i = 0; i < FWU_MAX_SIMULTANEOUS_IMAGES; i++) { + if (bl1_fwu_loaded_ids[i] == image_id) + return 0; + } + + /* Find an empty slot */ + for (i = 0; i < FWU_MAX_SIMULTANEOUS_IMAGES; i++) { + if (bl1_fwu_loaded_ids[i] == INVALID_IMAGE_ID) { + bl1_fwu_loaded_ids[i] = image_id; + return 0; + } + } + + return 1; +} + +/* + * Removes an image_id from the bl1_fwu_loaded_ids array. + * Returns 0 on success, 1 on error. + */ +static int bl1_fwu_remove_loaded_id(int image_id) +{ + int i; + + /* Find the ID */ + for (i = 0; i < FWU_MAX_SIMULTANEOUS_IMAGES; i++) { + if (bl1_fwu_loaded_ids[i] == image_id) { + bl1_fwu_loaded_ids[i] = INVALID_IMAGE_ID; + return 0; + } + } + + return 1; +} + +/******************************************************************************* + * This function checks if the specified image overlaps another image already + * loaded. It returns 0 if there is no overlap, a negative error code otherwise. + ******************************************************************************/ +static int bl1_fwu_image_check_overlaps(int image_id) +{ + const image_desc_t *image_desc, *checked_image_desc; + const image_info_t *info, *checked_info; + + uintptr_t image_base, image_end; + uintptr_t checked_image_base, checked_image_end; + + checked_image_desc = bl1_plat_get_image_desc(image_id); + checked_info = &checked_image_desc->image_info; + + /* Image being checked mustn't be empty. */ + assert(checked_info->image_size != 0); + + checked_image_base = checked_info->image_base; + checked_image_end = checked_image_base + checked_info->image_size - 1; + /* No need to check for overlaps, it's done in bl1_fwu_image_copy(). */ + + for (int i = 0; i < FWU_MAX_SIMULTANEOUS_IMAGES; i++) { + + /* Don't check image against itself. */ + if (bl1_fwu_loaded_ids[i] == image_id) + continue; + + image_desc = bl1_plat_get_image_desc(bl1_fwu_loaded_ids[i]); + + /* Only check images that are loaded or being loaded. */ + assert (image_desc->state != IMAGE_STATE_RESET); + + info = &image_desc->image_info; + + /* There cannot be overlaps with an empty image. */ + if (info->image_size == 0) + continue; + + image_base = info->image_base; + image_end = image_base + info->image_size - 1; + /* + * Overflows cannot happen. It is checked in + * bl1_fwu_image_copy() when the image goes from RESET to + * COPYING or COPIED. + */ + assert (image_end > image_base); + + /* Check if there are overlaps. */ + if (!(image_end < checked_image_base || + checked_image_end < image_base)) { + VERBOSE("Image with ID %d overlaps existing image with ID %d", + checked_image_desc->image_id, image_desc->image_id); + return -EPERM; + } + } + + return 0; +} + +/******************************************************************************* * This function is responsible for copying secure images in AP Secure RAM. ******************************************************************************/ static int bl1_fwu_image_copy(unsigned int image_id, @@ -189,6 +307,13 @@ static int bl1_fwu_image_copy(unsigned int image_id, /* Save the given image size. */ image_desc->image_info.image_size = image_size; + /* Make sure the image doesn't overlap other images. */ + if (bl1_fwu_image_check_overlaps(image_id)) { + image_desc->image_info.image_size = 0; + WARN("BL1-FWU: This image overlaps another one\n"); + return -EPERM; + } + /* * copied_size must be explicitly initialized here because the * FWU code doesn't necessarily do it when it resets the state @@ -213,6 +338,11 @@ static int bl1_fwu_image_copy(unsigned int image_id, return -ENOMEM; } + if (bl1_fwu_add_loaded_id(image_id)) { + WARN("BL1-FWU: Too many images loaded at the same time.\n"); + return -ENOMEM; + } + /* Everything looks sane. Go ahead and copy the block of data. */ dest_addr = image_desc->image_info.image_base + image_desc->copied_size; memcpy((void *) dest_addr, (const void *) image_src, block_size); @@ -290,6 +420,11 @@ static int bl1_fwu_image_auth(unsigned int image_id, return -ENOMEM; } + if (bl1_fwu_add_loaded_id(image_id)) { + WARN("BL1-FWU: Too many images loaded at the same time.\n"); + return -ENOMEM; + } + base_addr = image_src; total_size = image_size; @@ -319,6 +454,13 @@ static int bl1_fwu_image_auth(unsigned int image_id, /* Indicate that image can be copied again*/ image_desc->state = IMAGE_STATE_RESET; } + + /* + * Even if this fails it's ok because the ID isn't in the array. + * The image cannot be in RESET state here, it is checked at the + * beginning of the function. + */ + bl1_fwu_remove_loaded_id(image_id); return -EAUTH; } @@ -475,6 +617,13 @@ static int bl1_fwu_sec_image_done(void **handle, unsigned int flags) assert(EP_GET_EXE(image_desc->ep_info.h.attr) == EXECUTABLE); assert(image_desc->state == IMAGE_STATE_EXECUTED); +#if ENABLE_ASSERTIONS + int rc = bl1_fwu_remove_loaded_id(sec_exec_image_id); + assert(rc == 0); +#else + bl1_fwu_remove_loaded_id(sec_exec_image_id); +#endif + /* Update the flags. */ image_desc->state = IMAGE_STATE_RESET; sec_exec_image_id = INVALID_IMAGE_ID; |