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9e0051aba6
Adds new structures and offsets for minidump extended contexts. This
information will be captured from threads in a later CL so this CL
does not yet write different dumps, except in testing.
Minidump format for extended compacted contexts has been determined by
experiment. Offsets for where to write various parts of the context
are hardcoded to 0x550 as this matches values seen in Windows. Offsets
for misc_info_5 match those seen in working minidumps that can be opened
in windbg. Our hope is that while these could change in future, CPU
and OS vendors are unlikely to change them.
See doc[0] for a discussion of these fields and offsets in the minidump.
See "MANAGING STATE USING THE XSAVE FEATURE SET" Chapter 13 in the
Intel SDM[1]. Many of the offsets and sizes of the extended features
are provided by cpu specific values. We can access these in Windows
using the SDK, and transfer these to the saved extended context
which in turn is understandable by windbg.
Further information is available from AMD Ch. 18 "Shadow Stacks"[2].
[0] https://docs.google.com/document/d/1Dn8n97r5B7kxYouvujNnPIYd_7QeVHpahSRmB92Qn6g/edit#heading=h.hivqj2jg39y
[1] https://software.intel.com/content/www/us/en/develop/download/intel-64-and-ia-32-architectures-sdm-combined-volumes-1-2a-2b-2c-2d-3a-3b-3c-3d-and-4.html.
[2] https://www.amd.com/system/files/TechDocs/24593.pdf
Bug: 1250098
Change-Id: Ia9041acc379c6d38329ee99737a2a0a77f7a1ee0
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3536964
Reviewed-by: Joshua Peraza <jperaza@chromium.org>
Commit-Queue: Alex Gough <ajgo@chromium.org>