Rather than only updating the maps when a pc can't be found, always update
the maps before using them. This avoids issues where the maps change
and it could cause a crash reading from a map that has been modified.
This assumes that executed code never gets unloaded, or that the
code is unloaded so infrequently that it doesn't matter. This happens
because the pcs for the backtraces are gathered as the program runs
and those pcs are symbolized and made into relative pcs at a later time.
Also, add safe reading of the elf data when necessary to avoid any
crashes if maps are changing while this is running.
Since the MapEntry objects can be deleted, copy the values for
the current map in the backtrace code to detect when in our own code
instead of keeping a pointer.
Bug: 340988785
Test: malloc_debug unit/system tests pass.
Test: libmemunreachable tests pass.
Change-Id: Ica2ba50a5bcf9e19c7e4033e29a5a67a1847d1a6
malloc_debug can use libunwind and libunwindstck to unwind backtrace,
if libc.debug.malloc.options contains the string of "backtrace_full",
malloc_debug will use libunwindstck, and if libc.debug.malloc.options
contains the string of "backtrace=*", malloc_debug will use libunwind.
The result of libunwindstck is normal, but the result of libuniwnd
is abnormal, there is a offset between the rel_cp and the correct value,
so addr2line can't decode the right line number.
Libunwind and libunbiwndpack calculate load_bias is different, so malloc_debug
get load_bias alignment with libunwindstack.
Bug: 169539402
Change-Id: I640fb5db39af622a0bb52abf2c107984065a89d5
When the linker was changed so that it put a read-only map and
read-execute map, this code incorrectly computed the relative pc and
offset. Modify to look for the actual start map in this case.
Also, change the load_base name to load_bias.
Bug: 120613266
Test: Dumped logcat while dumping backtraces.
Change-Id: I6628694c5222ea34d63217af3d138707d4900004
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
When using sscanf and "%4s", the array passed in must include space for
a nul terminator.
Bug: 26739265
Change-Id: I0140a6100ca370666ae61689087ba41b4914789d
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
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
Renamed from libc/bionic/debug_mapinfo.cpp (Browse further)
