🐛 修复malloc扩容时int32溢出的bug,以及扩容堆内存后,由于未执行合并从而导致产生大量碎片的bug

This commit is contained in:
fslongjin 2022-05-21 00:47:30 +08:00
parent 832c0c7e5c
commit 46ee327742
3 changed files with 25 additions and 16 deletions

View File

@ -177,6 +177,7 @@ void mm_init()
}
}
// 初始化0~2MB的物理页
// 由于这个区间的内存由多个内存段组成因此不会被以上代码初始化需要我们手动配置page[0]。
@ -195,6 +196,7 @@ void mm_init()
ZONE_NORMAL_INDEX = 0;
ZONE_UNMAPPED_INDEX = 0;
/*
for (int i = 0; i < memory_management_struct.count_zones; ++i)
{
struct Zone *z = memory_management_struct.zones_struct + i;
@ -202,9 +204,10 @@ void mm_init()
// z->zone_addr_start, z->zone_addr_end, z->zone_length, z->pages_group, z->count_pages);
// 1GB以上的内存空间不做映射
if (z->zone_addr_start >= 0x100000000 && (!ZONE_UNMAPPED_INDEX))
ZONE_UNMAPPED_INDEX = i;
// if (z->zone_addr_start >= 0x100000000 && (!ZONE_UNMAPPED_INDEX))
// ZONE_UNMAPPED_INDEX = i;
}
*/
// kdebug("ZONE_DMA_INDEX=%d\tZONE_NORMAL_INDEX=%d\tZONE_UNMAPPED_INDEX=%d", ZONE_DMA_INDEX, ZONE_NORMAL_INDEX, ZONE_UNMAPPED_INDEX);
// 设置内存页管理结构的地址,预留了一段空间,防止内存越界。
memory_management_struct.end_of_struct = (ul)((ul)memory_management_struct.zones_struct + memory_management_struct.zones_struct_len + sizeof(long) * 32) & (~(sizeof(long) - 1));
@ -230,7 +233,6 @@ void mm_init()
--tmp_page->zone->count_pages_free;
}
kinfo("Memory management unit initialize complete!");
flush_tlb();
@ -311,7 +313,6 @@ struct Page *alloc_pages(unsigned int zone_select, int num, ul flags)
continue;
struct Zone *z = memory_management_struct.zones_struct + i;
// 区域对应的起止页号
ul page_start = (z->zone_addr_start >> PAGE_2M_SHIFT);
ul page_end = (z->zone_addr_end >> PAGE_2M_SHIFT);
@ -350,6 +351,8 @@ struct Page *alloc_pages(unsigned int zone_select, int num, ul flags)
}
}
}
kBUG("Cannot alloc page, ZONE=%d\tnums=%d, total_2M_pages=%d", zone_select, num, total_2M_pages);
while(1);
return NULL;
}
@ -470,7 +473,7 @@ void page_table_init()
struct Zone *z = memory_management_struct.zones_struct + i;
struct Page *p = z->pages_group;
if (i == ZONE_UNMAPPED_INDEX)
if (i == ZONE_UNMAPPED_INDEX && ZONE_UNMAPPED_INDEX != 0)
break;
for (int j = 0; j < z->count_pages; ++j)
@ -484,8 +487,6 @@ void page_table_init()
kinfo("Page table Initialized.");
}
/**
* @brief
*

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@ -36,16 +36,16 @@ int main()
void *ptr[256] = {0};
for (int k = 0; k < 2; ++k)
{
printf("try to malloc 256*16K=4MB\n");
printf("try to malloc 256*1M=256MB\n");
uint64_t js = 0;
for (int i = 0; i < 256; ++i)
{
ptr[i] = malloc(4096 * 4);
ptr[i] = malloc(1024 * 1024);
js += *(uint64_t *)((uint64_t)(ptr[i]) - sizeof(uint64_t));
if (*(uint64_t *)((uint64_t)(ptr[i]) - sizeof(uint64_t)) > 0x4008)
printf("[%d] start_addr = %#018lx, len = %#010lx\n", (uint64_t)(ptr[i]) - 8, *(uint64_t *)((uint64_t)(ptr[i]) - sizeof(uint64_t)));
// if (*(uint64_t *)((uint64_t)(ptr[i]) - sizeof(uint64_t)) > 0x4008)
// printf("[%ld] start_addr = %#018lx, len = %#010lx\n", i, (uint64_t)(ptr[i]) - 8, *(uint64_t *)((uint64_t)(ptr[i]) - sizeof(uint64_t)));
}
// printf("ptr[0]->len=%lld\n", *(uint64_t *)((uint64_t)ptr[0] - sizeof(uint64_t)));
// printf("ptr[1]->len=%lld\n", *(uint64_t *)((uint64_t)ptr[1] - sizeof(uint64_t)));
// printf("ptr[24]->len=%lld\n", *(uint64_t*)((uint64_t)ptr[24] - sizeof(uint64_t)));

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@ -127,7 +127,7 @@ static malloc_mem_chunk_t *malloc_query_free_chunk_ff(uint64_t size)
*
* @param size
*/
static int malloc_enlarge(int32_t size)
static int malloc_enlarge(int64_t size)
{
if (brk_base_addr == 0) // 第一次调用,需要初始化
{
@ -292,6 +292,9 @@ void *malloc(ssize_t size)
if (malloc_enlarge(size) == -ENOMEM)
return (void *)-ENOMEM; // 内存不足
malloc_merge_free_chunk(); // 扩容后运行合并,否则会导致碎片
// 扩容后再次尝试获取
ck = malloc_query_free_chunk_bf(size);
@ -326,7 +329,6 @@ found:;
malloc_insert_free_list(new_ck);
}
// 此时链表结点的指针的空间被分配出去
return (void *)((uint64_t)ck + sizeof(uint64_t));
}
@ -340,11 +342,17 @@ static void release_brk()
// 先检测最顶上的块
// 由于块按照开始地址排列,因此找最后一个块
if (malloc_free_list_end == NULL)
{
printf("release(): free list end is null. \n");
return;
}
if ((uint64_t)malloc_free_list_end + malloc_free_list_end->length == brk_max_addr && (uint64_t)malloc_free_list_end <= brk_max_addr - (PAGE_2M_SIZE << 1))
{
int64_t delta = (brk_max_addr - (uint64_t)malloc_free_list_end) & PAGE_2M_MASK - PAGE_2M_SIZE;
int64_t delta = ((brk_max_addr - (uint64_t)malloc_free_list_end) & PAGE_2M_MASK) - PAGE_2M_SIZE;
// printf("(brk_max_addr - (uint64_t)malloc_free_list_end) & PAGE_2M_MASK=%#018lx\n ", (brk_max_addr - (uint64_t)malloc_free_list_end) & PAGE_2M_MASK);
// printf("PAGE_2M_SIZE=%#018lx\n", PAGE_2M_SIZE);
// printf("tdfghgbdfggkmfn=%#018lx\n ", (brk_max_addr - (uint64_t)malloc_free_list_end) & PAGE_2M_MASK - PAGE_2M_SIZE);
// printf("delta=%#018lx\n ", delta);
if (delta <= 0) // 不用释放内存
return;
sbrk(-delta);