945af95f42
All system calls made from userspace which involve pointers to kernel objects (including device drivers) will need to have those pointers validated; userspace should never be able to crash the kernel by passing it garbage. The actual validation with _k_object_validate() will be in the system call receiver code, which doesn't exist yet. - CONFIG_USERSPACE introduced. We are somewhat far away from having an end-to-end implementation, but at least need a Kconfig symbol to guard the incoming code with. Formal documentation doesn't exist yet either, but will appear later down the road once the implementation is mostly finalized. - In the memory region for RAM, the data section has been moved last, past bss and noinit. This ensures that inserting generated tables with addresses of kernel objects does not change the addresses of those objects (which would make the table invalid) - The DWARF debug information in the generated ELF binary is parsed to fetch the locations of all kernel objects and pass this to gperf to create a perfect hash table of their memory addresses. - The generated gperf code doesn't know that we are exclusively working with memory addresses and uses memory inefficently. A post-processing script process_gperf.py adjusts the generated code before it is compiled to work with pointer values directly and not strings containing them. - _k_object_init() calls inserted into the init functions for the set of kernel object types we are going to support so far Issue: ZEP-2187 Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
137 lines
3 KiB
C
137 lines
3 KiB
C
/*
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* Copyright (c) 2016 Wind River Systems, Inc.
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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#include <kernel.h>
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#include <kernel_structs.h>
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#include <debug/object_tracing_common.h>
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#include <toolchain.h>
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#include <linker/sections.h>
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#include <wait_q.h>
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#include <misc/dlist.h>
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#include <ksched.h>
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#include <init.h>
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extern struct k_mem_slab _k_mem_slab_list_start[];
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extern struct k_mem_slab _k_mem_slab_list_end[];
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#ifdef CONFIG_OBJECT_TRACING
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struct k_mem_slab *_trace_list_k_mem_slab;
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#endif /* CONFIG_OBJECT_TRACING */
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/**
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* @brief Initialize kernel memory slab subsystem.
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*
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* Perform any initialization of memory slabs that wasn't done at build time.
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* Currently this just involves creating the list of free blocks for each slab.
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*
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* @return N/A
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*/
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static void create_free_list(struct k_mem_slab *slab)
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{
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u32_t j;
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char *p;
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slab->free_list = NULL;
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p = slab->buffer;
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for (j = 0; j < slab->num_blocks; j++) {
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*(char **)p = slab->free_list;
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slab->free_list = p;
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p += slab->block_size;
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}
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}
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/**
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* @brief Complete initialization of statically defined memory slabs.
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*
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* Perform any initialization that wasn't done at build time.
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*
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* @return N/A
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*/
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static int init_mem_slab_module(struct device *dev)
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{
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ARG_UNUSED(dev);
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struct k_mem_slab *slab;
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for (slab = _k_mem_slab_list_start;
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slab < _k_mem_slab_list_end;
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slab++) {
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create_free_list(slab);
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SYS_TRACING_OBJ_INIT(k_mem_slab, slab);
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}
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return 0;
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}
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SYS_INIT(init_mem_slab_module, PRE_KERNEL_1,
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CONFIG_KERNEL_INIT_PRIORITY_OBJECTS);
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void k_mem_slab_init(struct k_mem_slab *slab, void *buffer,
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size_t block_size, u32_t num_blocks)
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{
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slab->num_blocks = num_blocks;
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slab->block_size = block_size;
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slab->buffer = buffer;
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slab->num_used = 0;
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create_free_list(slab);
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sys_dlist_init(&slab->wait_q);
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SYS_TRACING_OBJ_INIT(k_mem_slab, slab);
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_k_object_init(slab);
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}
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int k_mem_slab_alloc(struct k_mem_slab *slab, void **mem, s32_t timeout)
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{
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unsigned int key = irq_lock();
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int result;
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if (slab->free_list != NULL) {
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/* take a free block */
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*mem = slab->free_list;
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slab->free_list = *(char **)(slab->free_list);
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slab->num_used++;
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result = 0;
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} else if (timeout == K_NO_WAIT) {
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/* don't wait for a free block to become available */
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*mem = NULL;
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result = -ENOMEM;
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} else {
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/* wait for a free block or timeout */
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_pend_current_thread(&slab->wait_q, timeout);
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result = _Swap(key);
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if (result == 0) {
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*mem = _current->base.swap_data;
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}
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return result;
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}
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irq_unlock(key);
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return result;
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}
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void k_mem_slab_free(struct k_mem_slab *slab, void **mem)
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{
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int key = irq_lock();
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struct k_thread *pending_thread = _unpend_first_thread(&slab->wait_q);
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if (pending_thread) {
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_set_thread_return_value_with_data(pending_thread, 0, *mem);
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_abort_thread_timeout(pending_thread);
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_ready_thread(pending_thread);
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if (_must_switch_threads()) {
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_Swap(key);
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return;
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}
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} else {
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**(char ***)mem = slab->free_list;
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slab->free_list = *(char **)mem;
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slab->num_used--;
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}
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irq_unlock(key);
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}
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