History log of /bionic/libc/malloc_debug/tests/backtrace_fake.cpp
Revision Date Author Comments
7993b80f894db20af4d1d154221c42fea6171a3d 29-Jan-2016 Christopher Ferris <cferris@google.com> Add better free tracking.

Included in this change:

- Change the tag when a pointer is freed so it's easy to detect if
an already freed pointer is being used.
- Move the free backtrace out of the header. This backtrace is only
used under only some circumstances, so no need to allocate space
in all headers for it.
- Add new option free_track_backtrace_num_frames to specify how many
frames to record when the free occurs. This removes the dependency
on the backtrace option to get backtraces.

Bug: 26739265
Change-Id: I76f5209507dcf46af67ada162a7cb2bf282116f2
63860cb8fd1adf3f679b9b4ad876323a8d65cd9d 17-Nov-2015 Christopher Ferris <cferris@google.com> Malloc debug rewrite.

The major components of the rewrite:

- Completely remove the qemu shared library code. Nobody was using it
and it appears to have broken at some point.
- Adds the ability to enable/disable different options independently.
- Adds a new option that can enable the backtrace on alloc/free when
a process gets a specific signal.
- Adds a new way to enable malloc debug. If a special property is
set, and the process has an environment variable set, then debug
malloc will be enabled. This allows something that might be
a derivative of app_process to be started with an environment variable
being enabled.
- get_malloc_leak_info() used to return one element for each pointer that
had the exact same backtrace. The new version returns information for
every one of the pointers with same backtrace. It turns out ddms already
automatically coalesces these, so the old method simply hid the fact
that there where multiple pointers with the same amount of backtrace.
- Moved all of the malloc debug specific code into the library.
Nothing related to the malloc debug data structures remains in libc.
- Removed the calls to the debug malloc cleanup routine. Instead, I
added an atexit call with the debug malloc cleanup routine. This gets
around most problems related to the timing of doing the cleanup.

The new properties and environment variables:

libc.debug.malloc.options
Set by option name (such as "backtrace"). Setting this to a bad value
will cause a usage statement to be printed to the log.

libc.debug.malloc.program
Same as before. If this is set, then only the program named will
be launched with malloc debug enabled. This is not a complete match,
but if any part of the property is in the program name, malloc debug is
enabled.

libc.debug.malloc.env_enabled
If set, then malloc debug is only enabled if the running process has the
environment variable LIBC_DEBUG_MALLOC_ENABLE set.

Bug: 19145921

Change-Id: I7b0e58cc85cc6d4118173fe1f8627a391b64c0d7