Justin Cohen 3c4e37178d ios: Fix up concurrency in DumpWithoutCrashing and exception handling.
Change signal, uncaught NSExceptions and Mach exception handlers to
prevent re-entrancy with a first-exception-wins approach to prevent
concurrent exceptions from trying to use the same cached intermediate
dump writer.  Uses compare-and-swap to either return early for reentrant
signals or to wait indefinitely for anything after the first fatal
exception.

Change the NSException handler generated from the Objective-C exception
preprocessor to not used the cached intermediate dump writer and
not use the same first-exception-wins logic. This is useful because the
Objective-C exception preprocessor is imperfect and may generate
intermediate dumps that are not followed by process termination.

Simplify DumpWithoutCrashing's ownership of its intermediate dump writer
to be thread safe.

Set a handler for SIGPIPE for applications that haven't already
ignored or set a handler for SIGPIPE.

Bug: crashpad:391
Change-Id: Ia8ae61d50be81910fa0af40325300441d9dc01b6
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/3401563
Reviewed-by: Joshua Peraza <jperaza@chromium.org>
Commit-Queue: Justin Cohen <justincohen@chromium.org>
2022-03-10 18:05:16 +00:00
..