History log of /system/core/libcorkscrew/arch-arm/backtrace-arm.c
Revision Date Author Comments (<<< Hide modified files) (Show modified files >>>)
b4ef91b97513434a13d6d84a810512315ecf4768 10-Jul-2012 David 'Digit' Turner <digit@google.com> libcorkscrew: avoid future name collisions.

This is a forward-compatibility patch used to avoid two problems:

1/ The C library <signal.h> is going to be updated to define 'struct sigcontext'
properly soon. Avoid redefining this structure here when it's not really needed
to prevent a type conflict.

2/ Similarly, proper ucontext_t support is going to be added, prevent conflict by
using a macro renaming trick. Mainly because there is a slight chance that the
C library definition will follow a slightly different layout/naming.

For context, see details at:


Change-Id: Ie94eb5d77297f8e0bafd146b65a648bd8805a551
19b39f371be5250e7b9e88016be1e5e665367b3f 22-Nov-2011 Jeff Brown <jeffbrown@google.com> Improve backtrace formatting.

Show the symbol offset, when available.

Centralized formatting of native stack traces in libcorkscrew.
It's handy for automated tools if all stacks look the same.
Since we already made them all look them same, we might as well
do the formatting in just one place.

Do not strip the Thumb bit on ARM. This fixes an off-by-one
issue that could happen when resolving a PC that was at the
very beginning of a Thumb function, since the symbol table would
have the Thumb bit set but since we stripped the bit from our
PC, we would be looking for an address one byte before the
one listed in the symbol table. It's also quite useful to see
whether a given function is executing in Thumb mode just by glancing
at the PC.

Change-Id: Icaa29add85ce0bcafe24d5ce2098e138d809e2ab
f0c5872637a63e28e3cd314cfc915c07f76df9c6 04-Nov-2011 Jeff Brown <jeffbrown@google.com> Improve stack unwinder robustness.

Keep track of whether memory maps are readable. Use the information
in try_get_word to try to avoid accidentally dereferencing an invalid
pointer within the current process. (Note that I haven't ever
seen that happen during normal unwinding, but it pays to be
a little more careful.)

Refactored try_get_word a little to make it easier to pass it the
needed state for validation checks by way of a little memory_t struct.

Improved how the memory map for the current process is cached. This is
important because we need up to date information about readable maps.
Use a 5 second cache expiration.

Improved the PC -> LR fallback logic in the unwinder so we can
eke out an extra frame sometimes.

Fixed a bug reading ELF program headers. The phnum & phentsize
fields are half-words. We were incorrectly interpreting
phnum as a whole word.

Used android_atomic_* operations carefully in the unwinder
to prevent possible memory races between the dumper and the dumpee.
This was highly unlikely (or even impossible due to the presence
of other barriers along the way) but the code is clearer now about
its invariants.

Fixed a bug in debuggerd where the pid was being passed to have
its stack dump taken instead of the tid, resulting in short
stacks because ptrace couldn't read the data if pid != tid.
Did a full sweep to ensure that we use pid / tid correctly everywhere.

Ported old code from debuggerd to rewind the program counter back
one instruction so that it points to the branch instruction itself
instead of the return address.

Change-Id: Icc4eb08320052975a4ae7f0f5f0ac9308a2d33d7
69f4cd7f5add7a7c7f5915e5292aab7eb2a42e9f 20-Oct-2011 Steve Block <steveblock@google.com> Rename (IF_)LOGV(_IF) to (IF_)ALOGV(_IF) DO NOT MERGE

Bug: 5449033
Change-Id: Ib453f869977a6e909095a578bbf0420851f887d2
bd57bd00b2172af9f315f2d3d62d68ca369e3666 26-Oct-2011 Jeff Brown <jeffbrown@google.com> A wee little division by 8 makes all the difference.

Change-Id: Idff879a8461e1abc97dfa624c1441c16df1c7a69
9524e4158fbb988b6a5e4f5be68ee10b7e4dd6d8 24-Oct-2011 Jeff Brown <jeffbrown@google.com> Add support for explicitly dumping native stacks.

This change modifies debuggerd so that it can be used to grab
the native stacks of a process that has hung and not just crashed.
Note that only the root user can do this (for now).

adb shell debuggerd <tid>

Then use logcat to find the tombstone file that was generated
which will have the native stacks of all threads in the
requested process. The specified thread will be shown first
and will also appear in the main log.

Also made some minor tweaks to libcorkscrew so that we
could handle statically compiled executables in the future
if we compiled the library statically.

Improved the "wait_for_user_action" function to support
volume down as an alternative for devices that do not
have home keys.

Removed a mess of gotos.

Change-Id: Ic149653986b0c2f503c7f0e8b7cb1f3be7c84d1e
501edd29b823ce1301d2effdd3a9e4b6e2b20b76 20-Oct-2011 Jeff Brown <jeffbrown@google.com> Add a new library for collecting stack traces.

Supports collecting the stack trace of the current thread,
another thread in the same process, or a thread in a
different process (using ptrace).

Change-Id: Ica2594e4436edde4ceb7bcc3d78e6c31a7902cbf