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🐛 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

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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
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16
user/libs/libc/malloc.c
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@ -127,7 +127,7 @@ static malloc_mem_chunk_t *malloc_query_free_chunk_ff(uint64_t size)
*
* @param size 扩大的内存大小
*/
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);