为什么我会遇到 C malloc 断言失败? [英] Why do I get a C malloc assertion failure?

问题描述

我正在实现一个分而治之的多项式算法，因此我可以针对 OpenCL 实现对其进行基准测试，但是我无法让 malloc 工作.当我运行程序时，它会分配一堆东西，检查一些东西，然后将 size/2 发送给算法.然后，当我再次点击 malloc 行时，它会吐出:

I am implementing a divide and conquer polynomial algorithm so I can benchmark it against an OpenCL implementation, but I can't get malloc to work. When I run the program, it allocates a bunch of stuff, checks some things, then sends the size/2 to the algorithm. Then when I hit the malloc line again it spits out this:

malloc.c:3096: sYSMALLOc: Assertion `(old_top == (((mbinptr) (((char *) &((av)->bins[((1) - 1) * 2])) - __builtin_offsetof (struct malloc_chunk, fd)))) && old_size == 0) || ((unsigned long) (old_size) >= (unsigned long)((((__builtin_offsetof (struct malloc_chunk, fd_nextsize))+((2 * (sizeof(size_t))) - 1)) & ~((2 * (sizeof(size_t))) - 1))) && ((old_top)->size & 0x1) && ((unsigned long)old_end & pagemask) == 0)' failed.
Aborted

有问题的行是:

int *mult(int size, int *a, int *b) {
    int *out,i, j, *tmp1, *tmp2, *tmp3, *tmpa1, *tmpa2, *tmpb1, *tmpb2,d, *res1, *res2;
    fprintf(stdout, "size: %d
", size);

    out = (int *)malloc(sizeof(int) * size * 2);
}

我用 fprintf 检查了大小，它是一个正整数(通常是 50).我也尝试使用普通数字调用 malloc ，但仍然出现错误.我只是被正在发生的事情难住了，到目前为止我从 Google 发现的任何东西都没有帮助.

I checked size with a fprintf, and it is a positive integer (usually 50 at that point). I tried calling malloc with a plain number as well and I still get the error. I'm just stumped at what's going on, and nothing from Google I have found so far is helpful.

有什么想法吗?我正试图弄清楚如何编译一个更新的 GCC，以防它是一个编译器错误，但我真的很怀疑.

Any ideas what's going on? I'm trying to figure out how to compile a newer GCC in case it's a compiler error, but I really doubt it.

推荐答案

99.9% 的可能性是您的内存已损坏(缓冲区溢出或下溢，在释放后写入指针，在同一个指针上调用两次 free指针等)

99.9% likely that you have corrupted memory (over- or under-flowed a buffer, wrote to a pointer after it was freed, called free twice on the same pointer, etc.)

在 Valgrind 下运行您的代码，以查看您的程序哪里出错了.

Run your code under Valgrind to see where your program did something incorrect.

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