| 19b39f371be5250e7b9e88016be1e5e665367b3f |
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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
/system/core/include/corkscrew/backtrace.h
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| f0c5872637a63e28e3cd314cfc915c07f76df9c6 |
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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
/system/core/include/corkscrew/backtrace.h
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| 501edd29b823ce1301d2effdd3a9e4b6e2b20b76 |
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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
/system/core/include/corkscrew/backtrace.h
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