xref: /aosp_15_r20/art/tools/runtime_memusage/README (revision 795d594fd825385562da6b089ea9b2033f3abf5a)

Dex File Poisoning Access
=========================

These set of executables are useful for condensing large amounts of memory reads
of Dex Files into smaller, split pieces of information. Two kinds of information
are provided:
	1. Visualizing what part of a Dex File is being accessed at what time
	as a graph
	2. Ordering stack traces by most commonly occurring
Both of these kinds of information can be split up further by providing category
names as arguments. A trace is put into a category if the category name is a
substring of the symbolized trace.

How:
======
These set of tools  work in conjunction with the class
DexFileTrackingRegistrar, which marks sections of Dex Files as poisoned. As Dex
Files are marked for poisoning, their starting addresses are logged in logcat.
In addition, when poisoned sections of memory are accesses, their stack trace is
also outputted to logcat.

sanitizer_logcat_analysis.sh is the main executable that will use the other two
in order to give both types of information. The other two are used in some of
the intermediary steps which are described in sanitizer_logcat_analysis.sh,
though they can also be executed individually if provided the necessary input.

Why:
======

The main reason for splitting the functionality across multiple files is because
sanitizer_logcat_analysis.sh uses external executable development/scripts/stack.
This is necessary  in order to get symbolized traces from the output given by
Address Sanitizer.

How to Use:

sanitizer_logcat_analysis.sh at minimum requires all logcat output in the form
of a file. Additional options specified below are useful for removing
unnecessary trace information.

===========================================================================
Usage: sanitizer_logcat_analysis.sh [options] [LOGCAT_FILE] [CATEGORIES...]
    -a
        Forces all pids associated with registered dex
        files in the logcat to be processed.
        default: only the last pid is processed

    -b  [DEX_FILE_NUMBER]
        Outputs data for the specified baksmali
        dump if -p is provided.
        default: first baksmali dump in order of dex
          file registration

    -d  OUT_DIRECTORY
        Puts all output in specified directory.
        If not given, output will be put in a local
        temp folder which will be deleted after
        execution.

    -e
        All traces will have exactly the same number
        of categories which is specified by either
        the -m argument or by prune_sanitizer_output.py

    -f
        Forces redo of all commands even if output
        files exist. Steps are skipped if their output
        exist already and this is not enabled.

    -m  [MINIMUM_CALLS_PER_TRACE]
        Filters out all traces that do not have
        at least MINIMUM_CALLS_PER_TRACE lines.
        default: specified by prune_sanitizer_output.py

    -o  [OFFSET],[OFFSET]
        Filters out all Dex File offsets outside the
        range between provided offsets. 'inf' can be
        provided for infinity.
        default: 0,inf

    -p  [PACKAGE_NAME]
        Using the package name, uses baksmali to get
        a dump of the Dex File format for the package.

    -t  [TIME_OFFSET],[TIME_OFFSET]
        Filters out all time offsets outside the
        range between provided offsets. 'inf' can be
        provided for infinity.
        default: 0,inf

    CATEGORIES are words that are expected to show in
       a large subset of symbolized traces. Splits
       output based on each word.

    LOGCAT_FILE is the piped output from adb logcat.
===========================================================================