./match_pattern.out: malloc(): memory corruption: 0x0000000013a11600 *** Post: 302553849

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Top Forums Programming ./match_pattern.out: malloc(): memory corruption: 0x0000000013a11600 *** Post 302553849 by JohnGraham on Friday 9th of September 2011 02:56:10 AM

09-09-2011

Registered User

Quote:

Originally Posted by shoaibjameel123

I reckon its the problem with malloc(), free() pair.

Memory corruption is normally due to you straying outside the bounds of an array - not with malloc()/free() statements matching up. You've probably overwritten some of the space next to a malloc()'d portion of memory that glibc expects to be able to use for keeping track of the memory region - go through with a debugger and have a look for bounds errors.

As an aside, here's the sort of thing you can expect if you did have a problem with malloc()/free() pairs:

Code:

[john@john-laptop tmp.u6Q7IbZntd]$ cat prog.c
#include <stdlib.h>

int main(void)
{
    void *p = malloc(1);
    free(p);
    free(p);
    return 0;
}
[john@john-laptop tmp.u6Q7IbZntd]$ gcc prog.c -o prog
[john@john-laptop tmp.u6Q7IbZntd]$ ./prog
*** glibc detected *** ./prog: double free or corruption (fasttop): 0x09ba3008 ***
======= Backtrace: =========
/lib/libc.so.6(+0x6c501)[0x58b501]
/lib/libc.so.6(+0x6dd70)[0x58cd70]
/lib/libc.so.6(cfree+0x6d)[0x58fe5d]
./prog[0x8048425]
/lib/libc.so.6(__libc_start_main+0xe7)[0x535ce7]
./prog[0x8048361]
======= Memory map: ========
0051f000-00676000 r-xp 00000000 08:04 2793795    /lib/libc-2.12.1.so
00676000-00678000 r--p 00157000 08:04 2793795    /lib/libc-2.12.1.so
00678000-00679000 rw-p 00159000 08:04 2793795    /lib/libc-2.12.1.so
00679000-0067c000 rw-p 00000000 00:00 0 
0091c000-0091d000 r-xp 00000000 00:00 0          [vdso]
00ab9000-00ad3000 r-xp 00000000 08:04 2793551    /lib/libgcc_s.so.1
00ad3000-00ad4000 r--p 00019000 08:04 2793551    /lib/libgcc_s.so.1
00ad4000-00ad5000 rw-p 0001a000 08:04 2793551    /lib/libgcc_s.so.1
00dd4000-00df0000 r-xp 00000000 08:04 2793792    /lib/ld-2.12.1.so
00df0000-00df1000 r--p 0001b000 08:04 2793792    /lib/ld-2.12.1.so
00df1000-00df2000 rw-p 0001c000 08:04 2793792    /lib/ld-2.12.1.so
08048000-08049000 r-xp 00000000 08:04 1220779    /tmp/tmp.u6Q7IbZntd/prog
08049000-0804a000 r--p 00000000 08:04 1220779    /tmp/tmp.u6Q7IbZntd/prog
0804a000-0804b000 rw-p 00001000 08:04 1220779    /tmp/tmp.u6Q7IbZntd/prog
09ba3000-09bc4000 rw-p 00000000 00:00 0          [heap]
b7500000-b7521000 rw-p 00000000 00:00 0 
b7521000-b7600000 ---p 00000000 00:00 0 
b76fc000-b76fd000 rw-p 00000000 00:00 0 
b7714000-b7716000 rw-p 00000000 00:00 0 
bffdf000-c0000000 rw-p 00000000 00:00 0          [stack]
Aborted

JohnGraham

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LEARN ABOUT DEBIAN

unicoverage

UNICOVERAGE(1)						      General Commands Manual						    UNICOVERAGE(1)

NAME

       unicoverage - Print coverage of each Unicode BMP Script.

SYNOPSIS

       unicoverage [-iinput_file] [-ooutput_file]

DESCRIPTION

       unicoverage  reads  a  GNU Unifont .hex font and uses data in coverage.dat (which must reside in the current directory).  The output is the
       percent coverage of each script in the Unicode Basic Multilingual Plane.

OPTIONS

       -i	   Specify the input file. The default is stdin.

       -o	   Specify the output file. The default is stdout.  Sample usage:

       unicoverage < unifont.hex >coverage.txt

FILES

       coverage.dat, *.hex GNU Unifont files.

SEE ALSO

       bdfimplode(1), hex2bdf(1), hex2bdf-split(1), hex2sfd(1), hexbraille(1), hexdraw(1), hexmerge(1), johab2ucs2(1),	unibmp2hex(1),	unidup(1),
       unihex2bmp(1), unipagecount(1), uniunmask(1)

AUTHOR

       unicoverage was written by Paul Hardy.

LICENSE

       unicoverage  is Copyright (C) 2007, 2008 Paul Hardy, and is released under version 2 of the GNU General Public License, or (at your option)
       a later version.

BUGS

       No known real bugs exist, except that this software does not perform extensive error checking on its input files.

								    2007 Dec 31 						    UNICOVERAGE(1)