http://wengshanjin.javaeye.com/blog/557940
C++代碼 ![複製代碼]()
- //mytest.cpp
- int main(int argc, char * argv[])
- { //line 120
- const int N=10; // # of elements in array
- const int g_nLargeRange = 500 * 1024 * 1024;
- cout << "Start of tests" << endl;
- int *p1 = new int(1); // use to cause leak
- int *p2 = new int[N]; // allocate an int array
- int *p3 = new int(2); // used to test wrong delete
- char *cp = 0; // cp is null pointer
- char ca[3]; // unintialized array
- char * pLarge = NULL; // used to test set address range perms: large range
- cout << "Test 1: off by one" << endl;
- for (int i=1; i<N+1; i++) // one-off in loop
- p2[i] = i; // err - initialize element p[N]
- cout << "Test 2: access freed storage" << endl;
- delete p1;
- *p1 = 3; // err - accessing freed storage
- cout << "Test 3: using uninitialized storage" << endl;
- if (p2[0]) cout << "Junk" << endl;// err - used uninit data
- cout << "Test 4: delete array using scalar delete" << endl;
- delete p2; // err - delete array with scalar delete
- cout << "Test 5: array delete of scalar" << endl;
- delete [] p3; // err - array delete of scalar
- cout << "Test 6: overlapping storage blocks" << endl;
- memcpy( ca, &ca[1],2 ); // err - overlapping storage blocks
- cout << "Test 7: system call using uninitialize data" << endl;
- sleep( 1 & ca[0] ); // err - uninit data in system call
- cout << "Test 8: set address range perms: large range" << endl;
- pLarge = new char[g_nLargeRange];
- cout << "Test 9: assign to null pointer - seg faults" << endl;
- *cp = 'a'; // err - used null pointer (Seg fauilts)
- cout << "End of tests" << endl;
- return 0;
- }
Using the command
valgrind --tool=memcheck --num-callers=50 --leak-check=full --log-file=memcheck ./mytest
cat memcheck
==29440== Memcheck, a memory error detector.
==29440== Copyright (C) 2002-2007, and GNU GPL'd, by Julian Seward et al.
==29440== Using LibVEX rev 1804, a library for dynamic binary translation.
==29440== Copyright (C) 2004-2007, and GNU GPL'd, by OpenWorks LLP.
==29440== Using valgrind-3.3.0, a dynamic binary instrumentation framework.
==29440== Copyright (C) 2000-2007, and GNU GPL'd, by Julian Seward et al.
==29440== For more details, rerun with: -v
==29440==
==29440== My PID = 29440, parent PID = 21240. Prog and args are:
==29440== ./mytest
==29440==
==29440== Invalid write of size 4
==29440== at 0x804C2DB: main (mytest.cpp:133)
==29440== Address 0x40f5408 is 0 bytes after a block of size 40 alloc'd
==29440== at 0x40050B9: operator new[](unsigned) (vg_replace_malloc.c:268)
==29440== by 0x804C26D: main (mytest.cpp:126)
==29440==
==29440== Invalid write of size 4
==29440== at 0x804C31C: main (mytest.cpp:136)
==29440== Address 0x40f53a8 is 0 bytes inside a block of size 4 free'd
==29440== at 0x400576D: operator delete(void*) (vg_replace_malloc.c:342)
==29440== by 0x804C315: main (mytest.cpp:135)
==29440==
==29440== Conditional jump or move depends on uninitialised value(s)
==29440== at 0x804C34E: main (mytest.cpp:138)
==29440==
==29440== Mismatched free() / delete / delete []
==29440== at 0x400576D: operator delete(void*) (vg_replace_malloc.c:342)
==29440== by 0x804C3A6: main (mytest.cpp:140)
==29440== Address 0x40f53e0 is 0 bytes inside a block of size 40 alloc'd
==29440== at 0x40050B9: operator new[](unsigned) (vg_replace_malloc.c:268)
==29440== by 0x804C26D: main (mytest.cpp:126)
==29440==
==29440== Mismatched free() / delete / delete []
==29440== at 0x4005AFD: operator delete[](void*) (vg_replace_malloc.c:364)
==29440== by 0x804C3E0: main (mytest.cpp:142)
==29440== Address 0x40f5438 is 0 bytes inside a block of size 4 alloc'd
==29440== at 0x4004BF9: operator new(unsigned) (vg_replace_malloc.c:224)
==29440== by 0x804C27D: main (mytest.cpp:127)
==29440==
==29440== Source and destination overlap in memcpy(0xBEEEF860, 0xBEEEF861, 2)
==29440== at 0x4006949: memcpy (mc_replace_strmem.c:402)
==29440== by 0x804C41C: main (mytest.cpp:144)
==29440==
==29440== Conditional jump or move depends on uninitialised value(s)
==29440== at 0xC2A84C: sleep (in /lib/tls/libc-2.3.4.so)
==29440== by 0x804C455: main (mytest.cpp:146)
==29440==
==29440== Syscall param nanosleep(req) points to uninitialised byte(s)
==29440== at 0xC2AB60: __nanosleep_nocancel (in /lib/tls/libc-2.3.4.so)
==29440== by 0x804C455: main (mytest.cpp:146)
==29440== Address 0xbeeef684 is on thread 1's stack
==29440==
==29440== Conditional jump or move depends on uninitialised value(s)
==29440== at 0xC2A99C: sleep (in /lib/tls/libc-2.3.4.so)
==29440== by 0x804C455: main (mytest.cpp:146)
==29440== Warning: set address range perms: large range 524288000 (undefined)
==29440==
==29440== Invalid write of size 1
==29440== at 0x804C4BB: main (mytest.cpp:150)
==29440== Address 0x0 is not stack'd, malloc'd or (recently) free'd
==29440==
==29440== Process terminating with default action of signal 11 (SIGSEGV): dumping core
==29440== Access not within mapped region at address 0x0
==29440== at 0x804C4BB: main (mytest.cpp:150)
==29440==
==29440== ERROR SUMMARY: 10 errors from 10 contexts (suppressed: 19 from 1)
==29440== malloc/free: in use at exit: 524,288,016 bytes in 2 blocks.
==29440== malloc/free: 11 allocs, 9 frees, 524,288,591 bytes allocated.
==29440== For counts of detected errors, rerun with: -v
==29440== searching for pointers to 2 not-freed blocks.
==29440== checked 149,404 bytes.
==29440==
==29440==
==29440== 16 bytes in 1 blocks are possibly lost in loss record 1 of 2
==29440== at 0x4004BF9: operator new(unsigned) (vg_replace_malloc.c:224)
==29440== by 0x260901: std::string::_Rep::_S_create(unsigned, unsigned, std::allocator<char> const&) (in /usr/lib/libstdc++.so.6.0.3)
==29440== by 0x261049: std::string::_M_mutate(unsigned, unsigned, unsigned) (in /usr/lib/libstdc++.so.6.0.3)
==29440== by 0x261348: std::string::assign(char const*, unsigned) (in /usr/lib/libstdc++.so.6.0.3)
==29440== by 0x805BC8C: _GLOBAL__I__ZN3cmx29convertYearMonthDayToLongLongEiiiRy (char_traits.h:258)
==29440== by 0x805BE1C: (within /home/welkin/svn/cm30/coremail/bin/mytest/mytest)
==29440== by 0x804A8F4: (within /home/welkin/svn/cm30/coremail/bin/mytest/mytest)
==29440== by 0x805BD85: __libc_csu_init (in /home/welkin/svn/cm30/coremail/bin/mytest/mytest)
==29440== by 0xBB4D90: (below main) (in /lib/tls/libc-2.3.4.so)
==29440==
==29440== LEAK SUMMARY:
==29440== definitely lost: 0 bytes in 0 blocks.
==29440== possibly lost: 16 bytes in 1 blocks.
==29440== still reachable: 524,288,000 bytes in 1 blocks.
==29440== suppressed: 0 bytes in 0 blocks.
==29440== Reachable blocks (those to which a pointer was found) are not shown.
==29440== To see them, rerun with: --leak-check=full --show-reachable=yes