在 Linux 上使用 gbd/valgrind 偵錯 C 擴充功能。¶
安裝工具¶
除了建置 Pillow 的基本工具外，您還需要一些基本工具。這些是在 Ubuntu 上所需的工具，其他發行版可能會有所不同。
python3-dbg套件，用於 gdb 擴充功能和 python 符號gdb和valgrind可能需要函式庫的偵錯符號。在 Ubuntu 上，您可以按照這些說明安裝對應的套件：偵錯符號套件
然後 sudo apt-get install libtiff5-dbgsym
至少在 Ubuntu 20.04 上使用 Python 3.8 的
python3-dbg套件存在一個錯誤，您需要新增一個或兩個連結，才能在執行 python 時自動載入
cd /usr/share/gdb/auto-load/usr/bin
ln -s python3.8m-gdb.py python3.8d-gdb.py
在 Ubuntu 18.04 中，它實際上會在搜尋
python3.*-gdb.py檔案時包含虛擬環境的路徑，但您可以將其放置在與二進位檔案相同的目錄中。我也發現歷史記錄對於 gdb 非常有用，因此我將此新增到我的
~/.gdbinit檔案中
set history filename ~/.gdb_history
set history save on
如果 python 堆疊在 gdb 中無法運作，則
set debug auto-load在.gdbinit中也可能會有所幫助。使用偵錯 python 建立並啟用虛擬環境，然後安裝所需的任何相依性並建置。您希望使用偵錯 python 建置，以便取得擴充功能的符號。
virtualenv -p python3.8-dbg ~/vpy38-dbg
source ~/vpy38-dbg/bin/activate
cd ~/Pillow && make install
測試案例¶
取得您的測試影像，並建立一個非常簡單的測試框架。
from PIL import Image
with Image.open(path) as im:
im.load()
透過 valgrind 執行此操作，但請注意 python 本身會觸發一些問題，因此您正在尋找 Pillow 階層中看起來不完全位於 python 呼叫鏈中的項目。在此範例中，我們感興趣的項目是在警告之後，且呼叫堆疊中有
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$
現在我們已確認有不尋常/不良的事情發生，是時候使用 gdb 了。
從
gdb python開始從 valgrind 堆疊追蹤設定一個中斷點。
b TiffDecode.c:269使用
r test_tiff.py執行指令碼當命中中斷點時，使用
info locals、bt、py-bt或p [變數]探索狀態。對於指標，p *[變數]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:
<https://gnu.dev.org.tw/software/gdb/bugs/>.
Find the GDB manual and other documentation resources online at:
<https://gnu.dev.org.tw/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()
四處探查，直到您了解發生什麼事。在此案例中，state->xsize 和 img.width 不同，這導致超出範圍的寫入，因為接收緩衝區的大小是針對兩者中較小的值。
注意事項¶
如果您的程式正在 docker 容器中執行/暫停，且您的主機具有適當的工具，則您可以在主機中以超級使用者身分執行 gdb，並且您可能會取得追蹤，了解程序暫停的位置。您可能無法從 docker 容器內執行此操作，因為依預設不允許追蹤功能。
在 mac/windows 上可能會出現此操作的變體，但詳細資訊會有所不同。
IIRC，Fedora 預設情況下會讓 gdb 位元正常運作。Ubuntu 一直都是要讓它運作的一場戰鬥。