Invalid max_timestamp produced for EventPipe block header in .NET 6 previews

[valco1994]

As far as I see, EventPipe source code was seriously refactored since .NET 5 release.

Unfortunately, this refactoring introduce the following bug. In ep-block.c there is a code updating min_timestamp and max_timestamp for EventPipe block header. This code should update min_timestamp if current event timestamp is less than min_timestamp and update max_timestamp if current timestamp is more than max_timestamp. But currently, max_timestamp is updated when current timestamp is less than it, which is impossible, because max_timestamp is initialized as INT64_MIN.

runtime/src/native/eventpipe/ep-block.c

Line 693 in 236cb21

if (event_block_base->max_timestamp > instance_timestamp)

So, currently it's

if (event_block_base->min_timestamp > instance_timestamp)
	event_block_base->min_timestamp = instance_timestamp;
if (event_block_base->max_timestamp > instance_timestamp)
	event_block_base->max_timestamp = instance_timestamp;

but should be

if (event_block_base->min_timestamp > instance_timestamp)
	event_block_base->min_timestamp = instance_timestamp;
if (event_block_base->max_timestamp < instance_timestamp)
	event_block_base->max_timestamp = instance_timestamp;

[tommcdon]

@josalem