Commit graph

15 commits

Author SHA1 Message Date
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
d0919623a2 Fix race in malloc debug option free_track.
The free track mechanism could fail if, at the same time a free occurs,
another thread is trying to free and verify the same allocation. This
doesn't work if the freed allocation is added to the list and we still
do work on it. The fix is to only add to the free list when we are done
with the allocation.

Also fix a problem where the usable size is computed incorrectly because
two of the arguments where reversed.

In addition, add a check that the allocation being verified has the correct
tag before trying to check the body of the allocation.

Add a test to catch the original failure.

Add a test for the tag being different.

Bug: 27601650
Change-Id: Ie9200677d066255b8e668a48422f23f909f4ddee
2016-03-16 17:38:08 -07:00
Colin Cross
7877df66c2 malloc_debug: fix multiplication overflow in debug_calloc
The over flow check for nmemb * bytes in debug_calloc is incorrect,
use the builtin overflow functions to check for multiplication and
addition overflow.

Change-Id: I3f1c13102621bc5380be1f69caa88dba2118f3cb
(cherry picked from commit 239838608d)
2016-03-10 14:53:02 -08:00
Colin Cross
9567c7b82c malloc_debug: round 0 byte allocations up to 1 byte
0 byte allocations can cause problems if they are immediately followed
by another allocation with no header, as both allocations will have the
same address.  Treat 0 byte allocations as 1 byte allocations so that
debug_iterate will return separate addresses for them.

Bug: 27578580
Change-Id: Ia8dc3481fa7062391e9b3ae58a36e8d47e7ee557
(cherry picked from commit 15af478080)
2016-03-10 14:53:02 -08:00
Colin Cross
baa7c6f307 malloc_debug: iterate: use usable_size
malloc_iterate with malloc debug enabled was returning allocation sizes
using the requested size instead of usable size.  If anything wrote
pointers above the requested size but below the usable size, those
pointers would be invisible to libmemunreachable and referenced
allocations could be reported as a leak.

Bug: 27107100
Change-Id: I6b19fd631f68ce93b3aee408cc3d296ec457bd01
(cherry picked from commit b23c6606d2)
2016-03-10 14:53:02 -08:00
Colin Cross
2c75991359 Add backtrace_string and export to libmemunreachable
Add backtrace_string to convert a malloc_debug backtrace to a string.
Also move the backtrace functions to libc_malloc_debug_backtrace so that
libmemunreachable can reuse them.

Change-Id: I5ad67001c0b4d184903c762863a8588181d4873b
2016-02-18 16:09:17 -08:00
Colin Cross
2d4721c0c5 Export malloc_backtrace
Change-Id: Ic1adb4dfd86b9ca698443a36263a3df2c91edda3
2016-02-18 16:09:16 -08:00
Colin Cross
869691c6f7 Export malloc_iterate and friends
Export malloc_iterate, malloc_enable, and malloc_disable to be used by
libmemunreachable.

Change-Id: I08a50349af82a95d096b6b4cbac37ababe4b9b06
2016-02-18 15:05:38 -08:00
Colin Cross
598cb89790 Merge "malloc_debug: reset TrackData mutex after fork" 2016-02-17 20:38:02 +00:00
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
Colin Cross
7a28a3cf1f malloc_debug: reset TrackData mutex after fork
Add a pthread_atfork handler to malloc_debug to lock the TrackData mutex
during fork and reset it in the child.  Ensures that the TrackData is
consistent when forking from a multi-threaded process, and that the
mutex is in a defined state in the child.

Change-Id: I0dfed30045a28551217ceac227d33b2e18894932
2016-02-12 16:41:14 -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