llext: add option to keep section data after llext_load (325d6b7d) · Commits · Wenxi XU / zephyr

include/zephyr/llext/llext.h

+24 −0

Original line number	Diff line number	Diff line
		@@ -146,6 +146,7 @@ static inline unsigned int llext_section_count(const struct llext *ext)
		struct llext_load_param {
		/** Perform local relocation */
		bool relocate_local;

		/**
		* Use the virtual symbol addresses from the ELF, not addresses within
		* the memory buffer, when calculating relocation targets. It also
		@@ -154,12 +155,22 @@ struct llext_load_param {
		* allocation and copying internally.
		*/
		bool pre_located;

		/**
		* Extensions can implement custom ELF sections to be loaded in specific
		* memory regions, detached from other sections of compatible types.
		* This optional callback checks whether a section should be detached.
		*/
		bool (section_detached)(const elf_shdr_t shdr);

		/**
		* Keep the ELF section data in memory after loading the extension. This
		* is needed to use some of the functions in @ref llext_inspect_apis.
		*
		* @note Related memory must be freed by @ref llext_free_inspection_data
		* before the extension can be unloaded via @ref llext_unload.
		*/
		bool keep_section_info;
		};

		/** Default initializer for @ref llext_load_param */
		@@ -211,6 +222,19 @@ int llext_load(struct llext_loader loader, const char name, struct llext **ext
		*/
		int llext_unload(struct llext **ext);

		/**
		* @brief Free any inspection-related memory for the specified loader and extension.
		*
		* This is only required if inspection data was requested at load time by
		* setting @ref llext_load_param.keep_section_info; otherwise, this call will
		* be a no-op.
		*
		* @param[in] ldr Extension loader
		* @param[in] ext Extension
		* @returns 0 on success, or a negative error code.
		*/
		int llext_free_inspection_data(struct llext_loader ldr, struct llext ext);

		/** @brief Entry point function signature for an extension. */
		typedef void (llext_entry_fn_t)(void user_data);

subsys/llext/llext_load.c

+17 −4

Original line number	Diff line number	Diff line
		@@ -112,6 +112,7 @@ static int llext_load_elf_data(struct llext_loader ldr, struct llext ext)
		LOG_ERR("Failed to allocate section map, size %zu", sect_map_sz);
		return -ENOMEM;
		}
		ext->alloc_size += sect_map_sz;
		for (int i = 0; i < ext->sect_cnt; i++) {
		ldr->sect_map[i].mem_idx = LLEXT_MEM_COUNT;
		ldr->sect_map[i].offset = 0;
		@@ -759,12 +760,13 @@ int do_llext_load(struct llext_loader ldr, struct llext ext,

		out:
		/*
		* Free resources only used during loading. Note that this exploits
		* the fact that freeing a NULL pointer has no effect.
		* Free resources only used during loading, unless explicitly requested.
		* Note that this exploits the fact that freeing a NULL pointer has no effect.
		*/

		llext_free(ldr->sect_map);
		ldr->sect_map = NULL;
		if (ret != 0 \|\| !ldr_parm \|\| !ldr_parm->keep_section_info) {
		llext_free_inspection_data(ldr, ext);
		}

		/* Until proper inter-llext linking is implemented, the symbol table is
		* not useful outside of the loading process; keep it only if debugging
		@@ -796,3 +798,14 @@ out:

		return ret;
		}

		int llext_free_inspection_data(struct llext_loader ldr, struct llext ext)
		{
		if (ldr->sect_map) {
		ext->alloc_size -= ext->sect_cnt * sizeof(ldr->sect_map[0]);
		llext_free(ldr->sect_map);
		ldr->sect_map = NULL;
		}

		return 0;
		}

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