diff options
Diffstat (limited to 'kernel/l0')
| -rw-r--r-- | kernel/l0/kmain.c | 27 | ||||
| -rw-r--r-- | kernel/l0/loader.s | 7 | ||||
| -rw-r--r-- | kernel/l0/paging.c | 28 |
3 files changed, 33 insertions, 29 deletions
diff --git a/kernel/l0/kmain.c b/kernel/l0/kmain.c index 97b5a97..53afb6b 100644 --- a/kernel/l0/kmain.c +++ b/kernel/l0/kmain.c @@ -31,31 +31,36 @@ void test_pf_handler(pagedir_t *pd, region_info_t *i, void* addr) { void* page_alloc_fun_for_kmalloc(size_t bytes) { void* addr = region_alloc(bytes, REGION_T_CORE_HEAP, test_pf_handler); - dbg_printf("Alloc %p bytes for kmalloc at: %p\n", bytes, addr); + dbg_printf("[alloc 0x%p for kmalloc : %p]\n", bytes, addr); return addr; } void page_free_fun_for_kmalloc(void* ptr) { + dbg_printf("[Free 0x%p", ptr); + region_info_t *i = find_region(ptr); ASSERT(i != 0 && i->type == REGION_T_CORE_HEAP); for (void* x = i->addr; x < i->addr + i->size; x += PAGE_SIZE) { uint32_t f = pd_get_frame(x); + dbg_printf(" %i", f); if (f != 0) { pd_unmap_page(x); frame_free(f, 1); } } + dbg_printf(" : "); region_free(ptr); + dbg_printf("ok]\n"); } slab_type_t slab_sizes[] = { - { "8B obj", 8, 1 }, + { "8B obj", 8, 2 }, { "16B obj", 16, 2 }, { "32B obj", 32, 2 }, - { "64B obj", 64, 2 }, - { "128B obj", 128, 2 }, + { "64B obj", 64, 4 }, + { "128B obj", 128, 4 }, { "256B obj", 256, 4 }, - { "512B obj", 512, 4 }, + { "512B obj", 512, 8 }, { "1KB obj", 1024, 8 }, - { "2KB obj", 2048, 8 }, + { "2KB obj", 2048, 16 }, { "4KB obj", 4096, 16 }, { 0, 0, 0 } }; @@ -149,16 +154,16 @@ void kmain(struct multiboot_info_t *mbd, int32_t mb_magic) { region_free(s); BOCHS_BREAKPOINT; - // TEST SLAB ALLOCATOR!!! + // Test slab allocator ! mem_allocator_t *a = create_slab_allocator(slab_sizes, page_alloc_fun_for_kmalloc, page_free_fun_for_kmalloc); dbg_printf("Created slab allocator at 0x%p\n", a); dbg_print_region_stats(); - const int m = 10000; - uint16_t* ptr[m]; + const int m = 200; + uint16_t** ptr = slab_alloc(a, m * sizeof(uint32_t)); for (int i = 0; i < m; i++) { - size_t s = 1 << ((i * 7) % 12 + 2); + size_t s = 1 << ((i * 7) % 11 + 2); ptr[i] = (uint16_t*)slab_alloc(a, s); ASSERT((void*)ptr[i] >= kernel_data_end && (size_t)ptr[i] < 0xFFC00000); *ptr[i] = ((i * 211) % 1024); @@ -172,7 +177,7 @@ void kmain(struct multiboot_info_t *mbd, int32_t mb_magic) { slab_free(a, ptr[i]); } dbg_print_region_stats(); - dbg_printf("Destroying slab allocator.\n"); + dbg_printf("Destroying slab allocator...\n"); destroy_slab_allocator(a); dbg_print_region_stats(); diff --git a/kernel/l0/loader.s b/kernel/l0/loader.s index 6ad4ff0..5d0a2b8 100644 --- a/kernel/l0/loader.s +++ b/kernel/l0/loader.s @@ -1,6 +1,7 @@ [EXTERN kmain] ; kmain is defined in kmain.c [GLOBAL loader] ; making entry point visible to linker -[GLOBAL kernel_pd] ; make kernel page directory visible +[GLOBAL kernel_pd] ; make kernel page directory visible +[GLOBAL kernel_stack_protector] ; used to detect kernel stack overflow ; higher-half kernel setup K_HIGHHALF_ADDR equ 0xC0000000 @@ -74,7 +75,9 @@ hang: jmp hang [section .bss] -align 4 +align 0x1000 +kernel_stack_protector: + resb 0x1000 ; as soon as we have efficient paging, we WON'T map this page stack_bottom: resb LOADER_STACK_SIZE stack_top: diff --git a/kernel/l0/paging.c b/kernel/l0/paging.c index 5000c71..d289712 100644 --- a/kernel/l0/paging.c +++ b/kernel/l0/paging.c @@ -39,6 +39,8 @@ extern pagetable_t kernel_pd; // pre-allocate a page table so that we can map the first 4M of kernel memory static pagetable_t __attribute__((aligned(PAGE_SIZE))) kernel_pt0; +extern char kernel_stack_protector; + static pagedir_t kernel_pd_d; static pagedir_t *current_pd_d; @@ -58,19 +60,13 @@ void page_fault_handler(registers_t *regs) { return; } + if (vaddr >= (void*)&kernel_stack_protector && vaddr < (void*)&kernel_stack_protector + PAGE_SIZE) { + dbg_printf("Kernel stack overflow at 0x%p\n", vaddr); + PANIC("Kernel stack overflow."); + } + if ((size_t)vaddr >= PD_MIRROR_ADDR) { dbg_printf("Fault on access to mirrorred PD at 0x%p\n", vaddr); - - uint32_t x = (size_t)vaddr - PD_MIRROR_ADDR; - uint32_t page = (x % PAGE_SIZE) / 4; - uint32_t pt = x / PAGE_SIZE; - dbg_printf("For pt 0x%p, page 0x%p -> addr 0x%p\n", pt, page, ((pt * 1024) + page) * PAGE_SIZE); - - for (int i = 0; i < N_PAGES_IN_PT; i++) { - //dbg_printf("%i. 0x%p\n", i, kernel_pd.page[i]); - } - - dbg_dump_registers(regs); dbg_print_region_stats(); PANIC("Unhandled kernel space page fault"); } @@ -108,7 +104,11 @@ void paging_setup(void* kernel_data_end) { ASSERT(PAGE_OF_ADDR(K_HIGHHALF_ADDR) == 0); // kernel is 4M-aligned ASSERT(FIRST_KERNEL_PT == 768); for (size_t i = 0; i < n_kernel_pages; i++) { - kernel_pt0.page[i] = (i << PTE_FRAME_SHIFT) | PTE_PRESENT | PTE_RW | PTE_GLOBAL; + if ((i * PAGE_SIZE) + K_HIGHHALF_ADDR == (size_t)&kernel_stack_protector) { + frame_free(i, 1); // don't map kernel stack protector page + } else { + kernel_pt0.page[i] = (i << PTE_FRAME_SHIFT) | PTE_PRESENT | PTE_RW | PTE_GLOBAL; + } } for (size_t i = n_kernel_pages; i < 1024; i++){ kernel_pt0.page[i] = 0; @@ -180,8 +180,6 @@ int pd_map_page(void* vaddr, uint32_t frame_id, bool rw) { (new_pt_frame << PTE_FRAME_SHIFT) | PTE_PRESENT | PTE_RW; invlpg(¤t_pt[pt]); } - dbg_printf("[%p,%i,%i,", vaddr, pt, page); - current_pt[pt].page[page] = (frame_id << PTE_FRAME_SHIFT) | PTE_PRESENT @@ -189,8 +187,6 @@ int pd_map_page(void* vaddr, uint32_t frame_id, bool rw) { | (rw ? PTE_RW : 0); invlpg(vaddr); - dbg_printf("]"); - return 0; } |