Commit graph

6 commits

Author SHA1 Message Date
Vic Yang
80aba5494a Move DwarfCfaInfo::kTable from data.rel.ro to rodata
Pages in .data.rel.ro are always dirty.  Move whatever we can to
.rodata so that we reduce memory pressure.

The size of rodata, text, and data.rel.ro  sections of linker64 on
cuttlefish before/after this change:
  rodata: 0x170e4 -> 0x17964 (+2176 bytes)
  text: 0xec919 -> 0xec919 (no change)
  data.rel.ro: 0x9cf0 -> 0x98f0 (-1024 bytes)

Test: Boot cuttlefish
Change-Id: Ib2fd2bb0afb50208d441731d8c31bc8f287272c3
2018-12-14 06:03:09 -08:00
Christopher Ferris
4cc36d2b43 Fix handling of load bias values.
It turns out that for the dwarf information, if a FDE indicates it's pc
relative, then pc has to be incremented by the load bias. If not, then
it should not be incremented.

Previously, the code always subtracted load bias values from pcs, and assumed
that all fdes were incremented by load bias values. The new code actually
reads the fdes and adjusted the pcs in the fde and in the eh frame hdr so
that load bias values are already handled properly.

In addition, add dumping of arm exidx values in unwind_reg_info. This allowed
verifying that the debug frame in those elf files was being handled properly.

Added a new unit test that only has a debug frame that has a non-zero load
bias and has fde entries that do not have pc relative encoding.

Fix a couple of other small bugs.

Bug: 109824792

Test: All libbacktrace/libunwindstack unit tests pass.
Test: Ran ART 137-cfi test and 004-ThreadStress.
Test: Verify that displaying the fde start and end pc actually match the
Test: real data for fde that have pc relative set, and that don't.
Test: Verified that the unwind information for arm exidx matches the
Test: debug frame data.

Change-Id: I707555286b5cb05df9f25489e8c5ede753cfe0fb
2018-06-11 18:53:55 -07:00
Christopher Ferris
2fcf4cf13e Add error propagation into Unwinder/Elf objects.
The backtrace offline code uses these error codes to diagnose errors.
In addtion, I've had cases where seeing these errors would help diagnose
failures.

This also allows us to add a few features to indicate why an unwind
terminated (such as max frames exceeded).

Bug: 65682279

Test: Updated unit tests pass.
Change-Id: If82b5092698e8a194016d670efff1320f9b44d50
2018-01-24 17:50:46 -08:00
Christopher Ferris
d226a51409 Make the library usable as a library.
- Add namespace unwindstack everywhere so that it's easier for other
  code to use the library.
- Move some of the header files into include/unwindstack so that they
  can be exposed.
- Modify the headers so that only a limited number need to be exposed.
- Update the tools to use the new headers.
- Add a GetLoadBias() call on the Elf object. This prevents the need
  to get the interface object out of the Elf object.
- Move the GetRelPc() call out of the Reg class, to the Elf class. It's
  not always the case that a Reg object will be around when you want to
  get a relative pc. The tests for this moved to ElfTest.cpp.

Bug: 23762183

Test: Unit tests pass.
Change-Id: Iac609dac1dd90ed83d1a1e24ff2579c96c023bc3
2017-07-14 12:20:23 -07:00
Christopher Ferris
53a3c9b4ab Add DwarfSection classes.
Bug: 23762183

Test: Ran new unit tests.
Change-Id: Icca2a73c50d467718ba4ac41e1c8f541488620dd
2017-06-01 13:12:31 -07:00
Christopher Ferris
8642fcbad2 Add the Dwarf CFA handling.
Bug: 23762183

Test: Ran new unit tests.
Change-Id: I31abac1238cc671b78a505da655fb6298be072b4
2017-04-24 13:24:33 -07:00