How to decode the address from the ???来自 valgrind 日志

Question

`下面是 Valgrind 运行后生成的堆栈跟踪，但无法找出代码中的可疑行，因为 ???符号。

==703294== Invalid free() / delete / delete[] / realloc()
==703294==    at 0x4C3AE59: operator delete[](void*) (vg_replace_malloc.c:1115)
==703294==    by 0x1676C7C6: __cxa_finalize (in /usr/lib64/libc-2.28.so)
==703294==    by 0xDBE8F36: ??? (in /xyz/bin/libxyz.so)
==703294==    by 0x4008E0D: _dl_fini (dl-fini.c:142)
==703294==    by 0x1676C29B: __run_exit_handlers (in /usr/lib64/libc-2.28.so)
==703294==    by 0x1676C3CF: exit (in /usr/lib64/libc-2.28.so)
==703294==    by 0x16755D8B: (below main) (in /usr/lib64/libc-2.28.so)
(...)

在 valgrind 运行期间是否需要添加任何方式或标志以解码地址或代码行而不是获取 ???在日志中。`

Answer 1

有关构建共享库的详细信息，请查看此处。

如果我的图书馆包含这个

#include "lib.h"

class InvalidFree
{
public:
  InvalidFree() : mem(new int[1]) {}
  ~InvalidFree() { delete mem; }
private:
  int *mem;
};

InvalidFree invalidFree;

int foo()
{
  return 42; 
}

注意在上面我混淆了使用

new []

和

delete

。我应该用

delete []

.

然后我用

g++ -o liblib.so -shared -O3 lib.cpp -fPIC

编译库

然后 Valgrind 给我

==25378== Mismatched free() / delete / delete []
==25378==    at 0x402E0FB: operator delete(void*, unsigned long) (vg_replace_malloc.c:593)
==25378==    by 0x5B7DED9: __cxa_finalize (in /usr/lib64/libc-2.17.so)
==25378==    by 0x403C132: ??? (in /example/path/liblib.so)
==25378==    by 0x400FFC9: _dl_fini (in /usr/lib64/ld-2.17.so)
==25378==    by 0x5B7DB68: __run_exit_handlers (in /usr/lib64/libc-2.17.so)
==25378==    by 0x5B7DBB6: exit (in /usr/lib64/libc-2.17.so)
==25378==    by 0x5B663DB: (below main) (in /usr/lib64/libc-2.17.so)
==25378==  Address 0x5f22c80 is 0 bytes inside a block of size 4 alloc'd
==25378==    at 0x402D57F: operator new[](unsigned long) (vg_replace_malloc.c:431)
==25378==    by 0x403C07D: _GLOBAL__sub_I_lib.cpp (in /example/path/liblib.so)
==25378==    by 0x400F902: _dl_init (in /usr/lib64/ld-2.17.so)
==25378==    by 0x4001159: ??? (in /usr/lib64/ld-2.17.so)

如果我在库的编译器选项中将

-O3

更改为

-g

然后我得到

==14347== Mismatched free() / delete / delete []
==14347==    at 0x402DF1B: operator delete(void*) (vg_replace_malloc.c:584)
==14347==    by 0x522495E: InvalidFree::~InvalidFree() (lib.cpp:7)
==14347==    by 0x5C7EED9: __cxa_finalize (in /usr/lib64/libc-2.17.so)
==14347==    by 0x5224862: ??? (in /example/path/liblib.so)
==14347==    by 0x400FFC9: _dl_fini (in /usr/lib64/ld-2.17.so)
==14347==    by 0x5C7EB68: __run_exit_handlers (in /usr/lib64/libc-2.17.so)
==14347==    by 0x5C7EBB6: exit (in /usr/lib64/libc-2.17.so)
==14347==    by 0x5C673DB: (below main) (in /usr/lib64/libc-2.17.so)
==14347==  Address 0x6012040 is 0 bytes inside a block of size 4 alloc'd
==14347==    at 0x402D57F: operator new[](unsigned long) (vg_replace_malloc.c:431)
==14347==    by 0x5224939: InvalidFree::InvalidFree() (lib.cpp:6)
==14347==    by 0x52248EB: __static_initialization_and_destruction_0(int, int) (lib.cpp:12)
==14347==    by 0x5224920: _GLOBAL__sub_I_lib.cpp (lib.cpp:17)
==14347==    by 0x400F902: _dl_init (in /usr/lib64/ld-2.17.so)
==14347==    by 0x4001159: ??? (in /usr/lib64/ld-2.17.so)