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Date: Thu, 5 Jan 2012 18:57:56 +0800
Message-ID: <CABBJUpeiLsvCQwjSczN00Rp_6JoGKS39LnD9auhVcgHXfnhymw@mail.gmail.com>
To: PHP Internals <internals@lists.php.net>
Cc: Rasmus Lerdorf <rasmus@lerdorf.com>, Stas Malyshev <smalyshev@sugarcrm.com>, 
	Pierre Joye <pierre.php@gmail.com>, =?UTF-8?Q?Johannes_Schl=C3=BCter?= <johannes@schlueters.de>, 
	Dmitry Stogov <dmitry@php.net>
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Subject: Re: Yet another fix for max_input_vars
From: laruence@php.net (Laruence)

Hi:

run bench.php:

*before patched:

$ sapi/cli/php Zend/bench.php
simple             0.374
simplecall         0.720
simpleucall        0.600
simpleudcall       0.633
mandel             1.161
mandel2            1.632
ackermann(7)       0.810
ary(50000)         0.108
ary2(50000)        0.098
ary3(2000)         0.699
fibo(30)           2.180
hash1(50000)       0.168
hash2(500)         0.171
heapsort(20000)    0.395
matrix(20)         0.354
nestedloop(12)     0.656
sieve(30)          0.441
strcat(200000)     0.073
------------------------
Total             11.276


*after patched:
sapi/cli/php Zend/bench.php
 simple             0.520
simplecall         0.723
simpleucall        0.622
simpleudcall       0.639
mandel             1.168
mandel2            1.711
ackermann(7)       0.784
ary(50000)         0.116
ary2(50000)        0.100
ary3(2000)         0.749
fibo(30)           2.188
hash1(50000)       0.177
hash2(500)         0.184
heapsort(20000)    0.421
matrix(20)         0.420
nestedloop(12)     0.836
sieve(30)          0.458
strcat(200000)     0.073
------------------------
Total             11.888



thanks


On Thu, Jan 5, 2012 at 4:53 PM, Laruence <laruence@php.net> wrote:
> Hi:
> =C2=A0 =C2=A0the origin thread is too long, so I open a new thread for th=
is.
>
> =C2=A0 =C2=A0I have made another patch try to fix this issue.
>
> =C2=A0 =C2=A0the key point is, randomizing the table size(tableMask).
>
> =C2=A0 =C2=A0instead of double the the table size in zend_hash_do_resize,=
 =C2=A0I
> increase the table size with a random delta ( the value now is just a
> try, =C2=A0we can change it to a more appropriate value),
> =C2=A0that is: =C2=A0new_table_size =3D old_table_size * 2 + random_num.
>
> =C2=A0 =C2=A0then, =C2=A0the collision can not be predicatible, which fix=
 the
> problem, =C2=A0and also fixed the issue in json/soap/serialize etc.
>
> =C2=A0 =C2=A0here is the patch(draft now):
> https://bugs.php.net/patch-display.php?bug_id=3D60655&patch=3Drand_hash_r=
esize.patch&revision=3Dlatest
>
> =C2=A0 =C2=A0after this fix , may slow down the php, but compared to the
> security threat I thinks the cost could be ignored.
>
> =C2=A0 =C2=A0for the test script list in
> http://nikic.github.com/2011/12/28/Supercolliding-a-PHP-array.html:
>
> =C2=A0 =C2=A0*before patched:
> =C2=A0 =C2=A0 =C2=A0 =C2=A0Inserting 65536 evil elements took 162.6594028=
4729 seconds
> =C2=A0 =C2=A0 =C2=A0 =C2=A0Inserting 65536 good elements took 0.075557947=
158813 seconds
>
> =C2=A0 =C2=A0*after =C2=A0patched:
> =C2=A0 =C2=A0 =C2=A0 =C2=A0Inserting 65536 evil elements took 0.074128866=
195679 seconds
> =C2=A0 =C2=A0 =C2=A0 =C2=A0Inserting 65536 good elements took 0.091044902=
801514 seconds
>
> =C2=A0 =C2=A0what do you think ?
>
> thanks
>
> --
> Laruence =C2=A0Xinchen Hui
> http://www.laruence.com/



--=20
Laruence =C2=A0Xinchen Hui
http://www.laruence.com/