Yii Yong Lee

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• Yii Yong Lee

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File Linux-2.6.6/drivers/pci/hotplug/shpchp_ctrl.
c 1497 rc p_slot-gthpc_ops-gtcheck_cmd_status(c
trl) 1498 if (rc) 1499 err("s Failed
to enable slot, error code(d)\n",
__FUNCTION__, rc) ..... 1501
up(ctrl-gtcrit_sect) 1502 return rc 1503
...... 1573 retval
p_slot-gthpc_ops-gtcheck_cmd_status(ctrl) 1574
if (retval) 1575 err("s Failed to disable
slot, error code(d)\n", __FUNCTION__,
rc) 1576 1577 up(ctrl-gtcrit_sect) 1578
return retval 1579
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Retval??????
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127 o_count v_count 128 o_var
variables 129 130 v_count STORE_INCR 131
variables (char ) malloc (v_countsizeof(char
)) 132 133 for (indx 3 indx lt o_count
indx) 134 variablesindx
o_varindx 135 136 for ( indx lt v_count
indx) 137 variablesindx NULL
...... 161 o_count a_count 162 o_ary
arrays 163 164 a_count STORE_INCR 165
arrays (char ) malloc (a_countsizeof(char
)) 166 167 for (indx 1 indx lt o_count
indx) 168 variablesindx
o_aryindx 169 170 for ( indx lt v_count
indx) 171 listsindx NULL
o_count


v_count

o_var
varse


STORE_INCR
v_count
(
char
)
(

varse

malloc
v_count

sizeof
(
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char

)

for
indx
(
)

1

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lt
o_count

indx

varse


indx

o_var


indx

for
(
)

indx
lt
v_count

indx

varse


indx

NULL

o_count


a_count

o_ary
arrays


STORE_INCR
a_count
(
char
)
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arrays

malloc
a_count

sizeof
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char

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for
indx
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lt
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lists


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varse arrays 2
varse lists 1
varse varse 1
v_count a_count 4
v_count v_count 1
o_count o_count 2
o_var o_ary 2
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• UnchangedRatio
• Conflict

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UnchangedRatio
NumOfUnchangedID Un
changedRatio
TotalNumOfID

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UnchangedRatio????
????1 ????2 ?? UnchangedRatio
v_count a_count 4 0.20
v_count v_count 1 0.20
varse arrays 2 0.25
varse lists 1 0.25
varse varse 1 0.25

• v_count?UnchangedRatio?0.20???
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Conflict

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????1 ????2 ?? UnchangedRatio Conflict
v_count a_count 4 0.20 False
v_count v_count 1 0.20 False
varse arrays 2 0.25 True
varse lists 1 0.25 True
varse varse 1 0.25 True
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????1 ????2 ?? UnchangedRatio Conflict
v_count a_count 4 0.20 False
v_count v_count 1 0.20 False
????????? ????????? ??? UnchangedRatio
????1 ????2 v_count 0.20
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• ???????? Java
• ????????????????????????CCFinder???
• ????????????????JFLEX??????
• ???????????????????GUI???

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????GUI
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• ??Linux kernel 2.6.6
• ????? 6,491
• LOC ?400?
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• ????????????30
• UnchangedRatio???0.4

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Linux-2.6.6/arch 2,355 724,858 87 1,615
Linux-2.6.6/drivers 2,323 2,344,594 120 3,637

• arch???????87??drivers???????120????????????
• ??????????????????????????0.25??

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arch 3 5 87

• ????Linux??????Linux-2.6.6???????????
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Module Before RNR Filtering Before RNR Filtering After RNR Filtering After RNR Filtering
Module With Overlapping Clone Without Overlapping Clone With Overlapping Clone Without Overlapping Clone
Linux-2.6.6/arch 16,740,180 14,977,660 23,599 19,273
Linux-2.6.6/drivers 8,325,367 7,888,115 60,706 56,260
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False Positive???
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