Commit graph

10 commits

Author SHA1 Message Date
Christopher Ferris
4da2503d70 Refactor malloc debug.
Changes
- Refactor the code so that only guards require creating a special header
  for every pointer allocated.
- Store only a single copy of every backtrace. This saves memory so that
  turning on the backtrace option doesn't result in 10X memory usage.
- Added new option track_allocs that only verifies pointers are valid for
  free/malloc_usable_size/realloc.
- Remove suffix from test names.
- Add the TRACK_ALLOCS options to all guard options.
- Add new option verify_pointers that is a lightweight way to verify
  pointers that are passed to allocation routines.
- Do auto-formatting of the code.
- Updated documentation for all of these changes.

Bug: 74361929

Test: Ran unit tests.
Test: Ran libmemunreachable unit tests.
Test: Ran an app with backtrace enabled.

Change-Id: I3246c48ae4f9811f64622d90d0a9b4d9d818702c
2018-04-02 18:59:23 -07:00
Elliott Hughes
cbc80ba9d8 Switch the rest of our internal headers to #pragma once.
We've been using #pragma once for new internal files, but let's be more bold.

Bug: N/A
Test: builds
Change-Id: I7e2ee2730043bd884f9571cdbd8b524043030c07
2018-02-13 14:27:17 -08:00
Christopher Ferris
602b88ccdd Provide method to dump backtrace heap data.
For non-zygote spawned processes, we might want to dump the backtrace
data. Provide a method to send a signal to a process and then dump the
data to a file.

Adds a method to dump the backtrace data on exit.

Update documentation and explain format of heap dump data.

Test: Ran unit tests, enabled new options and used them.
Change-Id: Ie2fa706694160731afe02c1382b037d06df1d069
2017-09-05 15:57:00 -07:00
Christopher Ferris
2b2b25b878 Refactor Config from a struct to a class.
This should make it easier to add new options, and to add options that
are complex. For example, I want to modify the behavior of
record_allocs_file so that it also enables record_allocs to a default
state.

Test: All unit tests pass.
Test: Enable the backtrace option and restart.
Change-Id: Idf5cdeed06ade3bc2c8ae39d228734bf65209b4f
2017-04-06 15:30:42 -07:00
Tamas Berghammer
ac81fe8657 Enable malloc debug using environment variables
Previously malloc debug can be enabled only using global settings
accessible to the root user only. This CL adds a new option to enable
it using environment variables making it possible to use it with pure
native (shell) applications on production builds (from shell user) and
prepares it for using it from logwrapper on production devices.

Remove the old environment variable and property since they are not
necessary.

Test: Enable malloc debug using environment variable and verify
Test: that it only affects the commands launched from the shell.
Test: Enable malloc debug using the property variable and verify
Test: that it affects all commands.
Test: Run all unit tests in 32 bit and 64 bit.
Change-Id: Iecb75a3471552f619f196ad550c5f41fcd9ce8e5
2016-11-17 13:13:27 -08:00
Christopher Ferris
7bd01783a8 Add the record alloc option.
This option adds the ability to record all of the allocation requests
and dump them to a file when a signal is sent to the process.

Included in this change, redo the option processing to add a new
string option.

Bug: 27747898

Change-Id: Ida043362e38b5eb1d459c99db9c2581015dab366
2016-07-08 14:05:17 -07:00
Christopher Ferris
55a89a48f4 Small refactor.
- Move all ScopedDisableDebugCalls into the debug_XXX calls. This avoids
any issues that might arise where every part of the code needs to properly
guard anything that might allocate. Instead everything is already guarded.
- Add a pointer to debug_data in all of the XXData classes. This avoids
calling individual functions passing in the debug_data pointer.
- Flip the NO_HEADER_OPTIONS to an explicit HEADER_OPTIONS list since fewer
options actually require a header.
- Move the extern of g_debug to the DebugData.h header.

Change-Id: Ia213a391b4a44d9ce122a709d09fe4f1b5426f36
2016-04-12 15:36:53 -07:00
Christopher Ferris
72df6708c8 Fix the default alignment of the allocations.
In order to enforce this constraint:

The pointer returned if the allocation succeeds shall be suitably
aligned so that it may be assigned to a pointer to any type of object
and then used to access such an object in the space allocated.

Force all allocations on 32 bit systems to have 8 byte alignment,
and all allocations on 64 bit systems to have 16 byte alignment.

Add a test to verify that the allocator returns the correct alignments.

Bug: 26739265
Change-Id: I9af53279617408676b94e4ec6481b3ed7ffafc6a
2016-02-12 17:30:30 -08:00
Christopher Ferris
7993b80f89 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
2016-01-29 15:19:22 -08:00
Christopher Ferris
63860cb8fd 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
2016-01-25 10:54:21 -08:00