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ktprime / emhash

Fast and memory efficient c++ flat hash map/set
MIT License
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[hash_table6 & hash_table7]core dump when rehash #13

Closed wangqiim closed 1 year ago

wangqiim commented 1 year ago

emhash7和emhash6 有同样的bug，当rehash扩容时，如下代码发生coredump

emhash7::HashMap<int64_t, Wrapper> mp; // Wrapper是原地封装char[128]的结构体
mp.reserve(5e7);

以emhash6为例 https://github.com/ktprime/emhash/blob/6f4a2c3ae25c6d4ed19935d78fe9e847be5a193d/hash_table6.hpp#L1273 https://github.com/ktprime/emhash/blob/6f4a2c3ae25c6d4ed19935d78fe9e847be5a193d/hash_table6.hpp#L457-L460 https://github.com/ktprime/emhash/blob/6f4a2c3ae25c6d4ed19935d78fe9e847be5a193d/hash_table6.hpp#L112-L118 如上，malloc时uint32溢出。导致后面的memset越界coredump。感觉把AllocSize的返回值修改一下比较好，比如返回uint64_t或者返回sizeof(int)对应的类型

wangqiim commented 1 year ago

修改了AllocSize的返回值为uint64_t之后，我之前的测试可以通过

ktprime commented 1 year ago

fix memory overflow，thanks report