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5 commits

Author SHA1 Message Date
Mitch Phillips
e4adff0721 [MTE] Cleanup tagged si_addr refs to fix mappings OOB bug.
Currently, all MTE failures end up displaying 'Fault address falls at
0x<addr> after any mapped regions'. Clearly when scanning, we should use
the untagged address to figure out which ranges it's in.

I've taken the liberty of removing all si_addr parsing and moving it
into the common ProcessInfo, as well as making it really explicit
whether you want the (possibly tagged) original si_addr, or whether you
want the untagged variant (for scanning /proc/maps or whatever).

This is not particularly easily testable, as ReadCrashInfo isn't easily
injectable and `dump_all_maps` should already be passed the untagged
pointer to scan for. I've tested this locally on FVP under SYNC MTE with
a simple UaF binary and noted the problem is fixed. Given that this is
making the code more clear, I'm hoping the owners see no need for a
regression test :).

Bug: 135772972
Test: On FVP, run 'adb shell MEMTAG_OPTIONS=sync sanitizer-status' and
      check that the use-after-free test ends up with the /proc/maps
      desription in the right place.
Change-Id: I220e4200c75a72474a95a67e5bbc36173a438dd2
2021-01-21 20:49:06 -08:00
Mitch Phillips
b9c072c551 Move PC-only unwind frame generation to libunwindstack.
GWP-ASan uses frame-pointer based unwinding internally on
allocation/deallocation to collect stack traces that are used when
crashes are reported.

This should be generic, so pull it out into libunwindstack so it can be
used by MTE as well.

Bug: 152412331
Test: atest debuggerd_test
Change-Id: I27b32263aac63446f5fe398af108676b70cd3971
2020-03-26 13:39:05 -07:00
Peter Collingbourne
5ac3927878 Make GetPcAdjustment a free function.
We're now using it in contexts that don't have all of the registers available,
such as GWP-ASan and soon MTE, so it doesn't make sense to have it be a
member function of Regs.

Bug: 135772972
Change-Id: I18b104ea0adb78588d7e475d0624cefc701ba52c
2020-03-19 17:51:20 -07:00
Peter Collingbourne
843f7e645d Create a ProcessInfo structure with the process-wide information from the crasher.
We're now passing around a couple of addresses for GWP-ASan in addition
to abort_msg_address and fdsan_table_address, and I'm going to need to add
more of them for MTE. Move them into a data structure in order to simplify
various function signatures.

Bug: 135772972
Change-Id: Ie01e1bd93a9ab64f21865f56574696825a6a125f
2020-02-28 19:12:19 -08:00
Mitch Phillips
e0b4bb1b2e [GWP-ASan] Add GWP-ASan information to tombstones.
GWP-ASan can provide information about a crash that it caused. Grab the
GWP-ASan regions from the globals shared by the linker for crash-handler
purpopses, pull the information from GWP-ASan, and display it.

This adds two regions:
 1. Causality tracking by GWP-ASan. We now print a cause header about
 the crash, like `Cause: [GWP-ASan]: Use After Free on a 1-byte
 allocation at 0x7365bb3ff8`
 2. Allocation and deallocation stack traces.

Bug: 135634846
Test: atest debuggerd_test

Change-Id: Id28d5400c9a9a053fcde83a4788f971e677d4643
2020-02-18 16:49:50 -08:00