Mark Mentovai c4f6ca3c6a mac: Provide a larger thread state buffer for AVX-512 on 10.13
Crashpad doesn’t use AVX-512, but when receiving replies to exceptions
forwarded to ReportCrash, may see buffers large enough to contain
AVX-512 thread state. This can result in messages like
“UniversalExceptionRaise: (ipc/rcv) msg too large (0x10004004)”.

I386_THREAD_STATE_MAX has increased from 224 to 614 in the 10.13 SDK,
meaning that the maximum supported size for old_state and new_state in
[mach_]exception_raise_state[_identity]() has increased from 896 to
2,456 bytes. This constant defines the size of the buffer that these
MIG-generated routines will work with. By providing this definition in
compat, the buffer size is increased when building with older SDKs.

Note that on the “send” side, the size of the message given to
mach_msg() will be trimmed to include only the valid part of the state
area based on the stateCnt field, so increasing the value to 614 here
won’t result Crashpad sending messages this large. That would be a
potential interoperability concern with older OS versions.

Bug: crashpad:185, crashpad:190
Change-Id: Ia46091ae46fd6227a17f59eb4bc00914be471aa7
Reviewed-on: https://chromium-review.googlesource.com/541515
Reviewed-by: Robert Sesek <rsesek@chromium.org>
2017-06-20 14:31:38 +00:00
..