[REGRESSION] 2.6.28-rc8: oldish top core dumps (in its meminfo()function)

From: Andreas Mohr
Date: Fri Dec 12 2008 - 13:49:18 EST



[f'up]

I just tried it on -rc8 and a (freshly rebooted) -rc7, both core
dumped, yet a 2.6.27.7 test does NOT do that.
Breakage may be older than -rc7, also might be caused by .config
changes (via make oldconfig), since a diff shows several changes.

This is a JFYI since I pretty much won't be able to debug this issue,
at least not now.

Oh, one important part, the crash in libproc.so happens at 0xb7f077b7:

0xb7f0770d <meminfo+413>: je 0xb7f07a61 <meminfo+1265>
0xb7f07713 <meminfo+419>: cld
0xb7f07714 <meminfo+420>: mov 0xffffffbc(%ebp),%esi
0xb7f07717 <meminfo+423>: mov $0xe,%ecx
0xb7f0771c <meminfo+428>: lea 0xfffff14e(%ebx),%edi
0xb7f07722 <meminfo+434>: repz cmpsb %es:(%edi),%ds:(%esi)
0xb7f07724 <meminfo+436>: je 0xb7f07a10 <meminfo+1184>
0xb7f0772a <meminfo+442>: cld
0xb7f0772b <meminfo+443>: mov 0xffffffbc(%ebp),%esi
0xb7f0772e <meminfo+446>: mov $0xa,%ecx
0xb7f07733 <meminfo+451>: lea 0xfffff15c(%ebx),%edi
0xb7f07739 <meminfo+457>: repz cmpsb %es:(%edi),%ds:(%esi)
0xb7f0773b <meminfo+459>: je 0xb7f079c5 <meminfo+1109>
0xb7f07741 <meminfo+465>: cld
0xb7f07742 <meminfo+466>: mov 0xffffffbc(%ebp),%esi
0xb7f07745 <meminfo+469>: mov $0x9,%ecx
0xb7f0774a <meminfo+474>: lea 0xfffff166(%ebx),%edi
0xb7f07750 <meminfo+480>: repz cmpsb %es:(%edi),%ds:(%esi)
0xb7f07752 <meminfo+482>: je 0xb7f0797a <meminfo+1034>
0xb7f07758 <meminfo+488>: cld
0xb7f07759 <meminfo+489>: mov 0xffffffbc(%ebp),%esi
0xb7f0775c <meminfo+492>: mov $0xb,%ecx
0xb7f07761 <meminfo+497>: lea 0xfffff16f(%ebx),%edi
0xb7f07767 <meminfo+503>: repz cmpsb %es:(%edi),%ds:(%esi)
0xb7f07769 <meminfo+505>: je 0xb7f0792f <meminfo+959>
0xb7f0776f <meminfo+511>: cld
0xb7f07770 <meminfo+512>: mov 0xffffffbc(%ebp),%esi
0xb7f07773 <meminfo+515>: mov $0xa,%ecx
0xb7f07778 <meminfo+520>: lea 0xfffff17a(%ebx),%edi
0xb7f0777e <meminfo+526>: repz cmpsb %es:(%edi),%ds:(%esi)
0xb7f07780 <meminfo+528>: je 0xb7f078e4 <meminfo+884>
0xb7f07786 <meminfo+534>: cld
0xb7f07787 <meminfo+535>: mov 0xffffffbc(%ebp),%esi
0xb7f0778a <meminfo+538>: mov $0xb,%ecx
0xb7f0778f <meminfo+543>: lea 0xfffff184(%ebx),%edi
0xb7f07795 <meminfo+549>: repz cmpsb %es:(%edi),%ds:(%esi)
0xb7f07797 <meminfo+551>: je 0xb7f07893 <meminfo+803>
0xb7f0779d <meminfo+557>: cld
0xb7f0779e <meminfo+558>: mov 0xffffffbc(%ebp),%esi
0xb7f077a1 <meminfo+561>: mov $0xa,%ecx
0xb7f077a6 <meminfo+566>: lea 0xfffff18f(%ebx),%edi
0xb7f077ac <meminfo+572>: repz cmpsb %es:(%edi),%ds:(%esi)
0xb7f077ae <meminfo+574>: je 0xb7f07842 <meminfo+722>
0xb7f077b4 <meminfo+580>: mov 0xffffffc4(%ebp),%ecx
0xb7f077b7 <meminfo+583>: movzbl (%ecx),%eax
0xb7f077ba <meminfo+586>: inc %ecx
0xb7f077bb <meminfo+587>: mov %ecx,0xffffffc4(%ebp)
0xb7f077be <meminfo+590>: cmp $0xa,%al
0xb7f077c0 <meminfo+592>: jne 0xb7f077b4 <meminfo+580>
0xb7f077c2 <meminfo+594>: lea 0x0(%esi),%esi
0xb7f077c9 <meminfo+601>: lea 0x0(%edi),%edi
0xb7f077d0 <meminfo+608>: mov 0xffffffc4(%ebp),%eax
0xb7f077d3 <meminfo+611>: cmpb $0x0,(%eax)
0xb7f077d6 <meminfo+614>: jne 0xb7f07610 <meminfo+160>
0xb7f077dc <meminfo+620>: mov 0x8(%ebp),%ecx
0xb7f077df <meminfo+623>: mov 0x88(%ecx),%eax
0xb7f077e5 <meminfo+629>: mov 0x8c(%ecx),%edx
0xb7f077eb <meminfo+635>: sub 0x98(%ecx),%eax
0xb7f077f1 <meminfo+641>: sbb 0x9c(%ecx),%edx
0xb7f077f7 <meminfo+647>: mov %eax,0x90(%ecx)
0xb7f077fd <meminfo+653>: mov (%ecx),%eax
0xb7f077ff <meminfo+655>: sub 0x30(%ecx),%eax
0xb7f07802 <meminfo+658>: mov %edx,0x94(%ecx)
0xb7f07808 <meminfo+664>: mov 0x4(%ecx),%edx
0xb7f0780b <meminfo+667>: sbb 0x34(%ecx),%edx
0xb7f0780e <meminfo+670>: mov %eax,0x18(%ecx)
0xb7f07811 <meminfo+673>: mov 0x8(%ecx),%eax
0xb7f07814 <meminfo+676>: sub 0x38(%ecx),%eax
0xb7f07817 <meminfo+679>: mov %edx,0x1c(%ecx)
0xb7f0781a <meminfo+682>: mov 0xc(%ecx),%edx
0xb7f0781d <meminfo+685>: sbb 0x3c(%ecx),%edx
0xb7f07820 <meminfo+688>: mov %eax,0x20(%ecx)
0xb7f07823 <meminfo+691>: mov 0x10(%ecx),%eax
0xb7f07826 <meminfo+694>: sub 0x40(%ecx),%eax
0xb7f07829 <meminfo+697>: mov %edx,0x24(%ecx)
0xb7f0782c <meminfo+700>: mov 0x14(%ecx),%edx
0xb7f0782f <meminfo+703>: sbb 0x44(%ecx),%edx
0xb7f07832 <meminfo+706>: mov %eax,0x28(%ecx)
0xb7f07835 <meminfo+709>: mov %edx,0x2c(%ecx)
0xb7f07838 <meminfo+712>: add $0x5c,%esp
0xb7f0783b <meminfo+715>: xor %eax,%eax
0xb7f0783d <meminfo+717>: pop %ebx
0xb7f0783e <meminfo+718>: pop %esi
0xb7f0783f <meminfo+719>: pop %edi
0xb7f07840 <meminfo+720>: pop %ebp
0xb7f07841 <meminfo+721>: ret

(gdb) inf reg
eax 0x0 0
ecx 0xb7f0e000 -1208950784
edx 0x1 1
ebx 0xb7f0a264 -1208966556
esp 0xbfc40220 0xbfc40220
ebp 0xbfc40288 0xbfc40288
esi 0xbfc40261 -1077673375
edi 0xb7f093f4 -1208970252
eip 0xb7f077b7 0xb7f077b7
eflags 0x210297 2163351
cs 0x73 115
ss 0x7b 123
ds 0x7b 123
es 0x7b 123
fs 0x0 0
gs 0x33 51


(gdb) x 0xb7f0e000
0xb7f0e000: Cannot access memory at address 0xb7f0e000


Thanks,

Andreas Mohr
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