在 Linux 上使用 gbd/valgrind 调试 C 扩展。

安装工具

除了构建 Pillow 的基本工具之外，你还需要一些基本知识。以下是 Ubuntu 上所需的工具，其他发行版可能有所不同。

• python3-dbg 包用于 gdb 扩展和 Python 符号

• gdb 和 valgrind

• 可能需要库的调试符号。在 Ubuntu 上，你可以按照以下说明安装相应的包：调试符号包

然后 sudo apt-get install libtiff5-dbgsym

• 至少在 Ubuntu 20.04 上，Python 3.8 的 python3-dbg 包存在一个错误，你需要添加一个或两个新的链接，以便在运行 Python 时自动加载它。

cd /usr/share/gdb/auto-load/usr/bin
ln -s python3.8m-gdb.py python3.8d-gdb.py

• 在 Ubuntu 18.04 中，它实际上将虚拟环境的路径包含在搜索 python3.*-gdb.py 文件中，但你可以在与二进制文件相同的目录中放置它。

• 我还发现历史记录对于 gdb 非常有用，因此我在我的 ~/.gdbinit 文件中添加了以下内容。

set history filename ~/.gdb_history
set history save on

• 如果 Python 堆栈在 gdb 中不起作用，那么在 .gdbinit 中使用 set debug auto-load 也很有用。

• 使用调试 Python 创建一个虚拟环境并激活它，然后安装所需的任何依赖项并构建。你应该使用调试 Python 构建，以便为你的扩展获得符号。

virtualenv -p python3.8-dbg ~/vpy38-dbg
source ~/vpy38-dbg/bin/activate
cd ~/Pillow && make install

测试用例

使用你的测试图像，创建一个非常简单的测试程序。

from PIL import Image

with Image.open(path) as im:
    im.load()

• 使用 valgrind 运行它，但请注意 Python 本身会引发一些问题，因此你应该查找 Pillow 层次结构中不像是仅仅在 Python 调用链中的条目。在本例中，我们感兴趣的条目在警告之后，并在调用堆栈中包含 decode.c 和 TiffDecode.c

(vpy38-dbg) ubuntu@primary:~/Home/tests$ valgrind python test_tiff.py
==51890== Memcheck, a memory error detector
==51890== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==51890== Using Valgrind-3.15.0 and LibVEX; rerun with -h for copyright info
==51890== Command: python test_tiff.py
==51890==
==51890== Invalid read of size 4
==51890==    at 0x472E3D: address_in_range (obmalloc.c:1401)
==51890==    by 0x472EEA: pymalloc_free (obmalloc.c:1677)
==51890==    by 0x474960: _PyObject_Free (obmalloc.c:1896)
==51890==    by 0x473BAC: _PyMem_DebugRawFree (obmalloc.c:2187)
==51890==    by 0x473BD4: _PyMem_DebugFree (obmalloc.c:2318)
==51890==    by 0x474C08: PyObject_Free (obmalloc.c:709)
==51890==    by 0x45DD60: dictresize (dictobject.c:1259)
==51890==    by 0x45DD76: insertion_resize (dictobject.c:1019)
==51890==    by 0x464F30: PyDict_SetDefault (dictobject.c:2924)
==51890==    by 0x4D03BE: PyUnicode_InternInPlace (unicodeobject.c:15289)
==51890==    by 0x4D0700: PyUnicode_InternFromString (unicodeobject.c:15322)
==51890==    by 0x64D2FC: descr_new (descrobject.c:857)
==51890==  Address 0x4c1b020 is 384 bytes inside a block of size 1,160 free'd
==51890==    at 0x483CA3F: free (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==51890==    by 0x4735D3: _PyMem_RawFree (obmalloc.c:127)
==51890==    by 0x473BAC: _PyMem_DebugRawFree (obmalloc.c:2187)
==51890==    by 0x474941: PyMem_RawFree (obmalloc.c:595)
==51890==    by 0x47496E: _PyObject_Free (obmalloc.c:1898)
==51890==    by 0x473BAC: _PyMem_DebugRawFree (obmalloc.c:2187)
==51890==    by 0x473BD4: _PyMem_DebugFree (obmalloc.c:2318)
==51890==    by 0x474C08: PyObject_Free (obmalloc.c:709)
==51890==    by 0x45DD60: dictresize (dictobject.c:1259)
==51890==    by 0x45DD76: insertion_resize (dictobject.c:1019)
==51890==    by 0x464F30: PyDict_SetDefault (dictobject.c:2924)
==51890==    by 0x4D03BE: PyUnicode_InternInPlace (unicodeobject.c:15289)
==51890==  Block was alloc'd at
==51890==    at 0x483B7F3: malloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==51890==    by 0x473646: _PyMem_RawMalloc (obmalloc.c:99)
==51890==    by 0x473529: _PyMem_DebugRawAlloc (obmalloc.c:2120)
==51890==    by 0x473565: _PyMem_DebugRawMalloc (obmalloc.c:2153)
==51890==    by 0x4748B1: PyMem_RawMalloc (obmalloc.c:572)
==51890==    by 0x475909: _PyObject_Malloc (obmalloc.c:1628)
==51890==    by 0x473529: _PyMem_DebugRawAlloc (obmalloc.c:2120)
==51890==    by 0x473565: _PyMem_DebugRawMalloc (obmalloc.c:2153)
==51890==    by 0x4736B0: _PyMem_DebugMalloc (obmalloc.c:2303)
==51890==    by 0x474B78: PyObject_Malloc (obmalloc.c:685)
==51890==    by 0x45C435: new_keys_object (dictobject.c:558)
==51890==    by 0x45DA95: dictresize (dictobject.c:1202)
==51890==
==51890== Invalid read of size 4
==51890==    at 0x472E3D: address_in_range (obmalloc.c:1401)
==51890==    by 0x47594A: pymalloc_realloc (obmalloc.c:1929)
==51890==    by 0x475A02: _PyObject_Realloc (obmalloc.c:1982)
==51890==    by 0x473DCA: _PyMem_DebugRawRealloc (obmalloc.c:2240)
==51890==    by 0x473FF8: _PyMem_DebugRealloc (obmalloc.c:2326)
==51890==    by 0x4749FB: PyMem_Realloc (obmalloc.c:623)
==51890==    by 0x44A6FC: list_resize (listobject.c:70)
==51890==    by 0x44A872: app1 (listobject.c:340)
==51890==    by 0x44FD65: PyList_Append (listobject.c:352)
==51890==    by 0x514315: r_ref (marshal.c:945)
==51890==    by 0x516034: r_object (marshal.c:1139)
==51890==    by 0x516C70: r_object (marshal.c:1389)
==51890==  Address 0x4c41020 is 32 bytes before a block of size 1,600 in arena "client"
==51890==
==51890== Conditional jump or move depends on uninitialised value(s)
==51890==    at 0x472E46: address_in_range (obmalloc.c:1403)
==51890==    by 0x47594A: pymalloc_realloc (obmalloc.c:1929)
==51890==    by 0x475A02: _PyObject_Realloc (obmalloc.c:1982)
==51890==    by 0x473DCA: _PyMem_DebugRawRealloc (obmalloc.c:2240)
==51890==    by 0x473FF8: _PyMem_DebugRealloc (obmalloc.c:2326)
==51890==    by 0x4749FB: PyMem_Realloc (obmalloc.c:623)
==51890==    by 0x44A6FC: list_resize (listobject.c:70)
==51890==    by 0x44A872: app1 (listobject.c:340)
==51890==    by 0x44FD65: PyList_Append (listobject.c:352)
==51890==    by 0x5E3321: _posix_listdir (posixmodule.c:3823)
==51890==    by 0x5E33A8: os_listdir_impl (posixmodule.c:3879)
==51890==    by 0x5E4D77: os_listdir (posixmodule.c.h:1197)
==51890==
==51890== Use of uninitialised value of size 8
==51890==    at 0x472E59: address_in_range (obmalloc.c:1403)
==51890==    by 0x47594A: pymalloc_realloc (obmalloc.c:1929)
==51890==    by 0x475A02: _PyObject_Realloc (obmalloc.c:1982)
==51890==    by 0x473DCA: _PyMem_DebugRawRealloc (obmalloc.c:2240)
==51890==    by 0x473FF8: _PyMem_DebugRealloc (obmalloc.c:2326)
==51890==    by 0x4749FB: PyMem_Realloc (obmalloc.c:623)
==51890==    by 0x44A6FC: list_resize (listobject.c:70)
==51890==    by 0x44A872: app1 (listobject.c:340)
==51890==    by 0x44FD65: PyList_Append (listobject.c:352)
==51890==    by 0x5E3321: _posix_listdir (posixmodule.c:3823)
==51890==    by 0x5E33A8: os_listdir_impl (posixmodule.c:3879)
==51890==    by 0x5E4D77: os_listdir (posixmodule.c.h:1197)
==51890==
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 16908288 bytes but only got 0. Skipping tag 0
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 67895296 bytes but only got 0. Skipping tag 0
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 1572864 bytes but only got 0. Skipping tag 42
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 116647 bytes but only got 4867. Skipping tag 42738
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 3468830728 bytes but only got 4851. Skipping tag 279
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 2198732800 bytes but only got 0. Skipping tag 0
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 67239937 bytes but only got 4125. Skipping tag 0
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 33947764 bytes but only got 0. Skipping tag 139
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 17170432 bytes but only got 0. Skipping tag 0
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 80478208 bytes but only got 0. Skipping tag 1
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 787460 bytes but only got 4882. Skipping tag 20
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 1075 bytes but only got 0. Skipping tag 256
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 120586240 bytes but only got 0. Skipping tag 194
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 65536 bytes but only got 0. Skipping tag 3
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 198656 bytes but only got 0. Skipping tag 279
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 206848 bytes but only got 0. Skipping tag 64512
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 130968 bytes but only got 4882. Skipping tag 256
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 77848 bytes but only got 4689. Skipping tag 64270
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 262156 bytes but only got 0. Skipping tag 257
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 33624064 bytes but only got 0. Skipping tag 49152
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 67178752 bytes but only got 4627. Skipping tag 50688
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 33632768 bytes but only got 0. Skipping tag 56320
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 134386688 bytes but only got 4115. Skipping tag 2048
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 33912832 bytes but only got 0. Skipping tag 7168
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 151966208 bytes but only got 4627. Skipping tag 10240
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 119032832 bytes but only got 3859. Skipping tag 256
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 46535680 bytes but only got 0. Skipping tag 256
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 35651584 bytes but only got 0. Skipping tag 42
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 524288 bytes but only got 0. Skipping tag 0
  warnings.warn(
_TIFFVSetField: tempfile.tif: Null count for "Tag 769" (type 1, writecount -3, passcount 1).
_TIFFVSetField: tempfile.tif: Null count for "Tag 42754" (type 1, writecount -3, passcount 1).
_TIFFVSetField: tempfile.tif: Null count for "Tag 769" (type 1, writecount -3, passcount 1).
_TIFFVSetField: tempfile.tif: Null count for "Tag 42754" (type 1, writecount -3, passcount 1).
ZIPDecode: Decoding error at scanline 0, incorrect header check.
==51890== Invalid write of size 4
==51890==    at 0x61C39E6: putcontig8bitYCbCr22tile (tif_getimage.c:2146)
==51890==    by 0x61C5865: gtStripContig (tif_getimage.c:977)
==51890==    by 0x6094317: ReadStrip (TiffDecode.c:269)
==51890==    by 0x6094749: ImagingLibTiffDecode (TiffDecode.c:479)
==51890==    by 0x60615D1: _decode (decode.c:136)
==51890==    by 0x64BF47: method_vectorcall_VARARGS (descrobject.c:300)
==51890==    by 0x4EB73C: _PyObject_Vectorcall (abstract.h:127)
==51890==    by 0x4EB73C: call_function (ceval.c:4963)
==51890==    by 0x4EB73C: _PyEval_EvalFrameDefault (ceval.c:3486)
==51890==    by 0x4DF2EE: PyEval_EvalFrameEx (ceval.c:741)
==51890==    by 0x43627B: function_code_fastcall (call.c:283)
==51890==    by 0x436D21: _PyFunction_Vectorcall (call.c:410)
==51890==    by 0x4EB73C: _PyObject_Vectorcall (abstract.h:127)
==51890==    by 0x4EB73C: call_function (ceval.c:4963)
==51890==    by 0x4EB73C: _PyEval_EvalFrameDefault (ceval.c:3486)
==51890==    by 0x4DF2EE: PyEval_EvalFrameEx (ceval.c:741)
==51890==  Address 0x6f456d4 is 0 bytes after a block of size 68 alloc'd
==51890==    at 0x483DFAF: realloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==51890==    by 0x60946D0: ImagingLibTiffDecode (TiffDecode.c:469)
==51890==    by 0x60615D1: _decode (decode.c:136)
==51890==    by 0x64BF47: method_vectorcall_VARARGS (descrobject.c:300)
==51890==    by 0x4EB73C: _PyObject_Vectorcall (abstract.h:127)
==51890==    by 0x4EB73C: call_function (ceval.c:4963)
==51890==    by 0x4EB73C: _PyEval_EvalFrameDefault (ceval.c:3486)
==51890==    by 0x4DF2EE: PyEval_EvalFrameEx (ceval.c:741)
==51890==    by 0x43627B: function_code_fastcall (call.c:283)
==51890==    by 0x436D21: _PyFunction_Vectorcall (call.c:410)
==51890==    by 0x4EB73C: _PyObject_Vectorcall (abstract.h:127)
==51890==    by 0x4EB73C: call_function (ceval.c:4963)
==51890==    by 0x4EB73C: _PyEval_EvalFrameDefault (ceval.c:3486)
==51890==    by 0x4DF2EE: PyEval_EvalFrameEx (ceval.c:741)
==51890==    by 0x4DFDFB: _PyEval_EvalCodeWithName (ceval.c:4298)
==51890==    by 0x436C40: _PyFunction_Vectorcall (call.c:435)
==51890==
==51890== Invalid write of size 4
==51890==    at 0x61C39B5: putcontig8bitYCbCr22tile (tif_getimage.c:2145)
==51890==    by 0x61C5865: gtStripContig (tif_getimage.c:977)
==51890==    by 0x6094317: ReadStrip (TiffDecode.c:269)
==51890==    by 0x6094749: ImagingLibTiffDecode (TiffDecode.c:479)
==51890==    by 0x60615D1: _decode (decode.c:136)
==51890==    by 0x64BF47: method_vectorcall_VARARGS (descrobject.c:300)
==51890==    by 0x4EB73C: _PyObject_Vectorcall (abstract.h:127)
==51890==    by 0x4EB73C: call_function (ceval.c:4963)
==51890==    by 0x4EB73C: _PyEval_EvalFrameDefault (ceval.c:3486)
==51890==    by 0x4DF2EE: PyEval_EvalFrameEx (ceval.c:741)
==51890==    by 0x43627B: function_code_fastcall (call.c:283)
==51890==    by 0x436D21: _PyFunction_Vectorcall (call.c:410)
==51890==    by 0x4EB73C: _PyObject_Vectorcall (abstract.h:127)
==51890==    by 0x4EB73C: call_function (ceval.c:4963)
==51890==    by 0x4EB73C: _PyEval_EvalFrameDefault (ceval.c:3486)
==51890==    by 0x4DF2EE: PyEval_EvalFrameEx (ceval.c:741)
==51890==  Address 0x6f456d8 is 4 bytes after a block of size 68 alloc'd
==51890==    at 0x483DFAF: realloc (in /usr/lib/x86_64-linux-gnu/valgrind/vgpreload_memcheck-amd64-linux.so)
==51890==    by 0x60946D0: ImagingLibTiffDecode (TiffDecode.c:469)
==51890==    by 0x60615D1: _decode (decode.c:136)
==51890==    by 0x64BF47: method_vectorcall_VARARGS (descrobject.c:300)
==51890==    by 0x4EB73C: _PyObject_Vectorcall (abstract.h:127)
==51890==    by 0x4EB73C: call_function (ceval.c:4963)
==51890==    by 0x4EB73C: _PyEval_EvalFrameDefault (ceval.c:3486)
==51890==    by 0x4DF2EE: PyEval_EvalFrameEx (ceval.c:741)
==51890==    by 0x43627B: function_code_fastcall (call.c:283)
==51890==    by 0x436D21: _PyFunction_Vectorcall (call.c:410)
==51890==    by 0x4EB73C: _PyObject_Vectorcall (abstract.h:127)
==51890==    by 0x4EB73C: call_function (ceval.c:4963)
==51890==    by 0x4EB73C: _PyEval_EvalFrameDefault (ceval.c:3486)
==51890==    by 0x4DF2EE: PyEval_EvalFrameEx (ceval.c:741)
==51890==    by 0x4DFDFB: _PyEval_EvalCodeWithName (ceval.c:4298)
==51890==    by 0x436C40: _PyFunction_Vectorcall (call.c:435)
==51890==
TIFFFillStrip: Invalid strip byte count 0, strip 1.
Traceback (most recent call last):
  File "test_tiff.py", line 8, in <module>
    im.load()
  File "/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py", line 1087, in load
    return self._load_libtiff()
  File "/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py", line 1191, in _load_libtiff
    raise OSError(err)
OSError: -2
sys:1: ResourceWarning: unclosed file <_io.BufferedReader name='crash-2020-10-test.tiff'>
==51890==
==51890== HEAP SUMMARY:
==51890==     in use at exit: 748,734 bytes in 444 blocks
==51890==   total heap usage: 6,320 allocs, 5,876 frees, 69,142,969 bytes allocated
==51890==
==51890== LEAK SUMMARY:
==51890==    definitely lost: 0 bytes in 0 blocks
==51890==    indirectly lost: 0 bytes in 0 blocks
==51890==      possibly lost: 721,538 bytes in 372 blocks
==51890==    still reachable: 27,196 bytes in 72 blocks
==51890==         suppressed: 0 bytes in 0 blocks
==51890== Rerun with --leak-check=full to see details of leaked memory
==51890==
==51890== Use --track-origins=yes to see where uninitialised values come from
==51890== For lists of detected and suppressed errors, rerun with: -s
==51890== ERROR SUMMARY: 2556 errors from 6 contexts (suppressed: 0 from 0)
(vpy38-dbg) ubuntu@primary:~/Home/tests$

• 现在我们已经确认存在一些奇怪/错误的情况，是时候使用 gdb 了。

• 使用 gdb python 启动。

• 从 valgrind 调用堆栈跟踪开始设置一个断点。 b TiffDecode.c:269

• 使用 r test_tiff.py 运行脚本。

• 当断点命中时，使用 info locals、bt、py-bt 或 p [variable] 探索状态。对于指针，p *[variable] 很有用。

(vpy38-dbg) ubuntu@primary:~/Home/tests$ gdb python
GNU gdb (Ubuntu 9.2-0ubuntu1~20.04) 9.2
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Type "show copying" and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
Type "show configuration" for configuration details.
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
    <https://www.gnu.org/software/gdb/documentation/>.

For help, type "help".
Type "apropos word" to search for commands related to "word"...
Reading symbols from python...
(gdb) b TiffDecode.c:269
No source file named TiffDecode.c.
Make breakpoint pending on future shared library load? (y or [n]) y
Breakpoint 1 (TiffDecode.c:269) pending.
(gdb) r test_tiff.py
Starting program: /home/ubuntu/vpy38-dbg/bin/python test_tiff.py
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1".
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 16908288 bytes but only got 0. Skipping tag 0
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 67895296 bytes but only got 0. Skipping tag 0
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 1572864 bytes but only got 0. Skipping tag 42
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 116647 bytes but only got 4867. Skipping tag 42738
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 3468830728 bytes but only got 4851. Skipping tag 279
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 2198732800 bytes but only got 0. Skipping tag 0
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 67239937 bytes but only got 4125. Skipping tag 0
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 33947764 bytes but only got 0. Skipping tag 139
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 17170432 bytes but only got 0. Skipping tag 0
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 80478208 bytes but only got 0. Skipping tag 1
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 787460 bytes but only got 4882. Skipping tag 20
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 1075 bytes but only got 0. Skipping tag 256
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 120586240 bytes but only got 0. Skipping tag 194
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 65536 bytes but only got 0. Skipping tag 3
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 198656 bytes but only got 0. Skipping tag 279
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 206848 bytes but only got 0. Skipping tag 64512
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 130968 bytes but only got 4882. Skipping tag 256
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 77848 bytes but only got 4689. Skipping tag 64270
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 262156 bytes but only got 0. Skipping tag 257
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 33624064 bytes but only got 0. Skipping tag 49152
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 67178752 bytes but only got 4627. Skipping tag 50688
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 33632768 bytes but only got 0. Skipping tag 56320
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 134386688 bytes but only got 4115. Skipping tag 2048
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 33912832 bytes but only got 0. Skipping tag 7168
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 151966208 bytes but only got 4627. Skipping tag 10240
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 119032832 bytes but only got 3859. Skipping tag 256
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 46535680 bytes but only got 0. Skipping tag 256
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 35651584 bytes but only got 0. Skipping tag 42
  warnings.warn(
/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py:770: UserWarning: Possibly corrupt EXIF data.  Expecting to read 524288 bytes but only got 0. Skipping tag 0
  warnings.warn(
_TIFFVSetField: tempfile.tif: Null count for "Tag 769" (type 1, writecount -3, passcount 1).
_TIFFVSetField: tempfile.tif: Null count for "Tag 42754" (type 1, writecount -3, passcount 1).
_TIFFVSetField: tempfile.tif: Null count for "Tag 769" (type 1, writecount -3, passcount 1).
_TIFFVSetField: tempfile.tif: Null count for "Tag 42754" (type 1, writecount -3, passcount 1).

Breakpoint 1, ReadStrip (tiff=tiff@entry=0xae9b90, row=0, buffer=0xac2eb0) at src/libImaging/TiffDecode.c:269
269                 ok = TIFFRGBAImageGet(&img, buffer, img.width, rows_to_read);
(gdb) p img
$1 = {tif = 0xae9b90, stoponerr = 0, isContig = 1, alpha = 0, width = 20, height = 1536, bitspersample = 8, samplesperpixel = 3,
  orientation = 1, req_orientation = 1, photometric = 6, redcmap = 0x0, greencmap = 0x0, bluecmap = 0x0, get =
    0x7ffff71d0710 <gtStripContig>, put = {any = 0x7ffff71ce550 <putcontig8bitYCbCr22tile>,
    contig = 0x7ffff71ce550 <putcontig8bitYCbCr22tile>, separate = 0x7ffff71ce550 <putcontig8bitYCbCr22tile>}, Map = 0x0,
  BWmap = 0x0, PALmap = 0x0, ycbcr = 0xaf24b0, cielab = 0x0, UaToAa = 0x0, Bitdepth16To8 = 0x0, row_offset = 0, col_offset = 0}
(gdb) up
#1  0x00007ffff736174a in ImagingLibTiffDecode (im=0xac1f90, state=0x7ffff76767e0, buffer=<optimized out>, bytes=<optimized out>)
    at src/libImaging/TiffDecode.c:479
479                 if (ReadStrip(tiff, state->y, (UINT32 *)state->buffer) == -1) {
(gdb) p *state
$2 = {count = 0, state = 0, errcode = 0, x = 0, y = 0, ystep = 0, xsize = 17, ysize = 108, xoff = 0, yoff = 0,
  shuffle = 0x7ffff735f411 <copy4>, bits = 32, bytes = 68, buffer = 0xac2eb0 "P\354\336\367\377\177", context = 0xa75440, fd = 0x0}
(gdb) py-bt
Traceback (most recent call first):
  File "/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py", line 1428, in _load_libtiff

  File "/home/ubuntu/vpy38-dbg/lib/python3.8/site-packages/Pillow-8.0.1-py3.8-linux-x86_64.egg/PIL/TiffImagePlugin.py", line 1087, in load
    return self._load_libtiff()
  File "test_tiff.py", line 8, in <module>
    im.load()

• 四处查看，直到你了解发生了什么。在本例中，state->xsize 和 img.width 不同，这会导致越界写入，因为接收缓冲区的尺寸为两者中较小的那个。

注意事项

• 如果你的程序正在 Docker 容器中运行/挂起，并且你的主机具有相应的工具，你可以在主机上以超级用户身份运行 gdb，并且你可能能够跟踪进程挂起的位置。你可能无法在 Docker 容器中执行此操作，因为默认情况下不允许跟踪能力。

• 在 Mac/Windows 上，可能会出现这种方法的变体，但具体细节会有所不同。

• 据我所知，Fedora 默认情况下支持 gdb 的功能。Ubuntu 一直以来都是一个需要努力才能使其正常工作的系统。