Engineering Report <dv> - Week 34, 2015¶
Highlights¶
- 回報問題
- Bug 344802 - disInstr(arm): unhandled instruction: 0xEC510F1E
- bug report 裡面也有人拿來跑 SurfaceFlinger
- 待修正 Bug List
- disInstr(arm)
- [#344802] 0xEC510F1E (cond=14(0xE) 27:20=197(0xC5) 4:4=1 3:0=14(0xE))
- mrrc 15, 1, r0, r1, cr14
- [#331178] 0xEE190F1D (cond=14(0xE) 27:20=225(0xE1) 4:4=1 3:0=13(0xD))
- mrc 15, 0, r0, cr9, cr13, {0}
- disInstr(thumb)
- 0xDEFF 0xF8DF
- mrcle 8, 7, APSR_nzcv, cr15, cr15, {6}
- 0xDEFF 0xF107
- nrmlee f7, f7
- 0xDEFF 0x461F
- mrcle 6, 7, r4, cr15, cr15, {0}
- 0xDEFF 0x4607
- cdple 6, 15, cr4, cr15, cr7, {0}
WARNING: linker: Unsupported flags DT_FLAGS_1=0x421
From Valgrind IRC (2015-05) (看起來前面提到的兩個 unhandled ARM instruction 可以先忽略 ?)
17:48 < jaeckel> disInstr(arm): unhandled instruction: 0xEE190F1D 17:48 < jaeckel> does that count as error? 17:49 < tomhughes> well that's a fatal, termingating your application now error 17:49 < tomhughes> that means your code is executing an instruction we don't know how to emulate 17:49 < tomhughes> I mean unless you catch the SIGILL and handle it somehow anyway 17:51 < jaeckel> yeah, that's handled 17:51 < jaeckel> so my application run afterwards 17:52 < jaeckel> btw. is there a chance this gets fixed someday? 17:52 < jaeckel> because it's marked as 'Probably WONTFIX or CANTFIX ' 17:53 < tomhughes> well how do you "handle" it? it's generally hard unless there's some other instruction you can use instead 17:53 < jaeckel> TBH I don't know 17:54 < tomhughes> according to https://bugs.kde.org/show_bug.cgi?id=331178 it's expected 17:54 < tomhughes> that instruction is priviliged so crypto libraries that use it in userspace just ignore the failure 17:56 < jaeckel> okay, that would explain why it continues 17:58 < jaeckel> so I suppose we can also ignore that this happens? 17:58 < tomhughes> sounds like it
Plan¶
補上 Elf32_Nhdr 的 condition 判斷，讓 issue #339861 可以 close
發現原來有 for Android Emulator 的 README ，之前眼殘沒看到，接下來嘗試它能不能 work
- Build 現在新版的 Android (開 Debug 相關 info)，而不是使用現在我手機上的 Android 5.1
- 至少要有的 compile 參數 :
-g -fno-omit-frame-pointer -fno-stack-check(for better stack trace information)
- 至少要有的 compile 參數 :
Issues¶
- 有些 stack trace 只顯示了
??? 根據 FAQ 裡的敘述，share objects 如果被 unloaded 的話會讓 Valgrind 的 error message 變成
???，workaround 為避免這些 share objects 去呼叫dlclose- 範例
有 debug info 而且 unstripped (最好的情況)
Invalid write of size 1 at 0x80483BF: really (malloc1.c:20) by 0x8048370: main (malloc1.c:9)沒有 debug info 而且 unstripped
Invalid write of size 1 at 0x80483BF: really (in /auto/homes/njn25/grind/head5/a.out) by 0x8048370: main (in /auto/homes/njn25/grind/head5/a.out)沒有 debug info 而且 stripped
Invalid write of size 1 at 0x80483BF: (within /auto/homes/njn25/grind/head5/a.out) by 0x8048370: (within /auto/homes/njn25/grind/head5/a.out) by 0x42015703: __libc_start_main (in /lib/tls/libc-2.3.2.so) by 0x80482CC: (within /auto/homes/njn25/grind/head5/a.out)有 debug info 而且加了
-fomit-frame-pointerInvalid write of size 1 at 0x80483C4: really (malloc1.c:20) by 0x42015703: __libc_start_main (in /lib/tls/libc-2.3.2.so) by 0x80482CC: ??? (start.S:81)unloaded shared object
84 bytes in 1 blocks are possibly lost in loss record 488 of 713 at 0x1B9036DA: operator new(unsigned) (vg_replace_malloc.c:132) by 0x1DB63EEB: ??? by 0x1DB4B800: ??? by 0x1D65E007: ??? by 0x8049EE6: main (main.cpp:24)
- 有些 stack trace 只顯示了