You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
109 lines
3.6 KiB
109 lines
3.6 KiB
This is a KDE tool to assist with malloc debugging using glibc's "mtrace"
|
|
functionality. Unfortunately the mtrace that is part of current (9/9/2000)
|
|
glibc versions only logs the return-address of the malloc/free call.
|
|
|
|
THIS PROGRAM DEPENDS ON GLIBC! It does not pretend to be portable.
|
|
|
|
Howto use:
|
|
|
|
Install the libktrace.so shared library, the ktrace.h header file, the
|
|
and kde.excludes file and the kmtrace processing tool with:
|
|
|
|
make install
|
|
|
|
There are two ways to activate memory usage loggings by ktrace :
|
|
|
|
1) The LD_PRELOAD way
|
|
|
|
This way, you can debug any application without having to recompile it,
|
|
but you'll have to debug also the memory allocated by TDEApplication and
|
|
friends.
|
|
|
|
You can activate malloc logging by starting yourApplication as:
|
|
|
|
MALLOC_TRACE=/tmp/ktrace.out LD_PRELOAD=/usr/lib/kmtrace/libktrace.so yourApplication
|
|
|
|
2) The manual way
|
|
|
|
Take the KDE application that you want to investigate and add
|
|
|
|
#include <ktrace.h>
|
|
|
|
Add as first statement in main():
|
|
|
|
ktrace();
|
|
|
|
Add ktrace_s.a to the LDADD line in your Makefile.am like:
|
|
|
|
kicker_LDADD = kicker.la /usr/lib/kmtrace/libktrace_s.a
|
|
|
|
Note that the static library is used.
|
|
You can now activate malloc logging by starting yourApplication as:
|
|
|
|
MALLOC_TRACE=/tmp/ktrace.out yourApplication
|
|
|
|
This will generate a huge log in /tmp/ktrace.out.
|
|
|
|
You can process this log with:
|
|
|
|
kmtrace /tmp/ktrace.out > ktrace.parsed
|
|
|
|
By default the trace-output is stored in the current directory
|
|
as "ktrace.out". kmtrace also searches it there, so you don't need
|
|
to add any commandline options.
|
|
|
|
TIPS
|
|
====
|
|
|
|
* If you can't be bothered with the stuff that TDEApplication allocates for you
|
|
you might want to put the ktrace() call after the TDEApplication constructor.
|
|
This will lead to a lot of warnings like:
|
|
|
|
Freeing unalloacted memory: 0x08056108
|
|
|
|
Which are harmless, it just means that the memory was allocated before you
|
|
turned the tracing on. Note that you cannot use this if you're using
|
|
LD_PRELOAD to use ktrace.
|
|
|
|
* To filter out harmless allocations out of the output file you can specify
|
|
with the --exclude option a file with symbols to exclude from output. If a
|
|
backtrace contains a symbol that starts with any of the symbols in this file,
|
|
this backtrace / leaked block is not shown in the output.
|
|
|
|
In the file kde.exclude some example symbols are listed. Usage example:
|
|
|
|
kmtrace /tmp/malloc.trace > /tmp/malloc.parsed
|
|
|
|
* Be aware that the reported symbols may not be accurate under all
|
|
circumstances. E.g. consider the following backtrace:
|
|
|
|
0x405879c1 /lib/libdl.so.2(dlerror+0x1b1)
|
|
0x405873b3 /lib/libdl.so.2(dlopen+0x33)
|
|
0x4053c0b2 /ext/kde2.0/lib/libtdecore.so.3(QXmlSimpleReader::reportParseErro
|
|
0x4053c74b /ext/kde2.0/lib/libtdecore.so.3(lt_dlexit+0x24b)
|
|
0x4053c894 /ext/kde2.0/lib/libtdecore.so.3(lt_dlexit+0x394)
|
|
0x4053dd49 /ext/kde2.0/lib/libtdecore.so.3(lt_dlopen+0x899)
|
|
|
|
The QXmlSimpleReader is obviously wrong here.
|
|
|
|
* You can use the --tree option to kmtrace to specify a file to print a tree
|
|
of the allocations. You can also use --treedepth and --treethreshold options
|
|
to hide subtrees that are deeper than the specified depth or allocated less
|
|
than the given memory amount.
|
|
|
|
* The advantage of using libktrace_s.a (the static library) is that you can
|
|
put calls to ktrace() and kuntrace() around a block of code that
|
|
interests you. Only allocations and deallocations between the first call
|
|
to ktrace() and the first call to kuntrace() will be logged.
|
|
|
|
|
|
Have fun.
|
|
|
|
Waldo Bastian
|
|
bastian@kde.org
|
|
|
|
kmtrace.cpp by Waldo Bastian <bastian@kde.org>
|
|
ktrace.c by Waldo Bastian <bastian@kde.org> based on mtrace.c
|
|
mtrace.c by Mike Haertel <mike@ai.mit.edu>
|
|
mtrace.c patched by Andi Kleen <ak@suse.de>
|