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我正在尝试在 FreeBSD 上使用 Valgrind 并遇到一些问题。这是输出

==4764== Memcheck, a memory error detector
==4764== Copyright (C) 2002-2012, and GNU GPL'd, by Julian Seward et al.
==4764== Using Valgrind-3.8.0 and LibVEX; rerun with -h for copyright info
==4764== Command: driver -i
==4764== 
==4764== 
==4764== HEAP SUMMARY:
==4764==     in use at exit: 33,852 bytes in 4 blocks
==4764==   total heap usage: 12 allocs, 8 frees, 171,894 bytes allocated
==4764== 
==4764== LEAK SUMMARY:
==4764==    definitely lost: 0 bytes in 0 blocks
==4764==    indirectly lost: 0 bytes in 0 blocks
==4764==      possibly lost: 0 bytes in 0 blocks
==4764==    still reachable: 33,852 bytes in 4 blocks
==4764==         suppressed: 0 bytes in 0 blocks
==4764== Rerun with --leak-check=full to see details of leaked memory
==4764== 
==4764== For counts of detected and suppressed errors, rerun with: -v
==4764== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
==4765== Syscall param ioctl(generic) points to uninitialised byte(s)
==4765==    at 0x3196CBC: __sys_ioctl (in /lib/libc.so.7)
==4765==    by 0x1A40469: ??? (in /lib/libpcap.so.8)
==4765==    by 0x1A3ED18: pcap_activate (in /lib/libpcap.so.8)
==4765==    by 0x1A3F43A: pcap_open_live (in /lib/libpcap.so.8)
==4765==    by 0x1822DB7: pcap_init (pcaputil.c:77)
==4765==    by 0x120FE6A: driver_init (recfm.c:387)
==4765==    by 0x402633: main (driver.c:224)
==4765==  Address 0x7ff000270 is on thread 1's stack
==4765==  Uninitialised value was created by a stack allocation
==4765==    at 0x1A3FED0: ??? (in /lib/libpcap.so.8)
==4765== 
==4765== Conditional jump or move depends on uninitialised value(s)
==4765==    at 0x1A408DD: ??? (in /lib/libpcap.so.8)
==4765==    by 0x1A3ED18: pcap_activate (in /lib/libpcap.so.8)
==4765==    by 0x1A3F43A: pcap_open_live (in /lib/libpcap.so.8)
==4765==    by 0x1822DB7: pcap_init (pcaputil.c:77)
==4765==    by 0x120FE6A: driver_init (recfm.c:387)
==4765==    by 0x402633: main (driver.c:224)
==4765==  Uninitialised value was created by a heap allocation
==4765==    at 0x1008DAB: malloc (vg_replace_malloc.c:274)
==4765==    by 0x1A4013E: ??? (in /lib/libpcap.so.8)
==4765==    by 0x1A3ED18: pcap_activate (in /lib/libpcap.so.8)
==4765==    by 0x1A3F43A: pcap_open_live (in /lib/libpcap.so.8)
==4765==    by 0x1822DB7: pcap_init (pcaputil.c:77)
==4765==    by 0x120FE6A: driver_init (recfm.c:387)
==4765==    by 0x402633: main (driver.c:224)
==4765== 
==4765== Warning: noted but unhandled ioctl 0x20004269 with no size/direction hints   This could cause spurious value errors to appear.   See README_MISSING_SYSCALL_OR_IOCTL for guidance on writing a proper wrapper.Syscall param ioctl(generic) points to uninitialised byte(s)
==4765==    at 0x3196CBC: __sys_ioctl (in /lib/libc.so.7)
==4765==    by 0x1A40291: ??? (in /lib/libpcap.so.8)
==4765==    by 0x1A3ED18: pcap_activate (in /lib/libpcap.so.8)
==4765==    by 0x1A3F43A: pcap_open_live (in /lib/libpcap.so.8)
==4765==    by 0x1822DB7: pcap_init (pcaputil.c:77)
==4765==    by 0x120FE6A: driver_init (recfm.c:387)
==4765==    by 0x402633: main (driver.c:224)
==4765==  Address 0x7fefffd14 is on thread 1's stack
==4765==  Uninitialised value was created by a stack allocation
==4765==    at 0x1A3FEF8: ??? (in /lib/libpcap.so.8)
==4765== 
==4765== Syscall param ioctl(generic) points to uninitialised byte(s)
==4765==    at 0x3196CBC: __sys_ioctl (in /lib/libc.so.7)
==4765==    by 0x1A40C98: ??? (in /lib/libpcap.so.8)
==4765==    by 0x1823277: pcap_init (pcaputil.c:98)
==4765==    by 0x120FE6A: driver_init (recfm.c:387)
==4765==    by 0x402633: main (driver.c:224)
==4765==  Address 0x7ff000454 is on thread 1's stack
==4765==  Uninitialised value was created by a stack allocation
==4765==    at 0x1822C10: pcap_init (pcaputil.c:61)
==4765== 
--4765-- WARNING: unhandled syscall: 522
--4765-- You may be able to write your own handler.
--4765-- Read the file README_MISSING_SYSCALL_OR_IOCTL.
--4765-- Nevertheless we consider this a bug.  Please report
--4765-- it at http://valgrind.org/support/bug_reports.html.

...repeated a bunch of times

最后一个警告，一遍又一遍地重复，但我认为这不一定是问题，对吧？更令人担忧的是我认为的另一个问题。

看起来我的程序仍在后台运行，但我显然没有从 valgrind 得到好的报告。它提到的违规行之一是 pcaputil:77

如下：

pd=pcap_open_live(__intf, snaplen, 1, 512, ebuf)

哪里_intf是 a char *，snaplen是一个int，并且ebuf是一个char ebuf[SIZE] = {0};数组

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2 回答 2

1

实际上，这只是 Valgrind-for-FreeBSD 并没有真正理解一些 ioctl。OS X 上存在同样的问题（并且可能存在于所有其他 *BSD 上）；请参阅Valgrind 错误 312989（他们使用 KDE 的错误数据库；他们实际上并没有超过 300,000 个错误 :-)）。

FreeBSD 的修复将是类似的，尽管出于某种原因，他们决定遵循“将所有内容从包含文件复制到 Valgrind 源”的 Linux 约定，而不是“只包含系统头文件”的达尔文约定; 这意味着头文件需要做更多的工作。我会询问 FreeBSD Valgrind 的维护者，达尔文方法是否更好。

于 2013-01-10T04:27:26.007 回答
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好吧，Valgrind 有一个错误。FreeBSD 中有一个系统调用无法处理。可能是 pcap 调用的东西。这有可能正在传播并导致 Valgrind 说 pcap 正在跳过未初始化的数据。甚至有可能您的程序运行良好，只是 Valgrind 有问题。最好的方法是添加你自己的 ioctl 包装器，修补 valgrind，看看它是否仍然很糟糕。或者您可以使用 pcap 的替代方案，它不使用它正在使用的任何系统调用。

抱歉，如果这不是一个简单的解决方案。

于 2013-01-09T16:00:39.980 回答