superpmi: `Method X is of low integrity` errors

[BruceForstall]

I noticed the Linux-arm64 PMI coreclr_tests collection has 8 cases of:

ERROR: Method 301 is of low integrity.

during the mcs -merge step. These should never occur: they indicate file corruption.

At the end, I see terminate called after throwing an instance of 'PAL_SEHException' which I believe comes from mcs, meaning we're probably not getting the full set of collected MCs into the base.mch file.

I didn't check to see if other collections or platforms have similar errors.

category:eng-sys
theme:super-pmi
skill-level:intermediate
cost:medium
impact:medium

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Issue Details

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I noticed the Linux-arm64 PMI coreclr_tests collection has 8 cases of:

ERROR: Method 301 is of low integrity.

during the mcs -merge step. These should never occur: they indicate file corruption.

At the end, I see terminate called after throwing an instance of 'PAL_SEHException' which I believe comes from mcs, meaning we're probably not getting the full set of collected MCs into the base.mch file.

I didn't check to see if other collections or platforms have similar errors.

Author:	BruceForstall
Assignees:	-
Labels:	arch-arm64, os-linux, area-CodeGen-coreclr
Milestone:	8.0.0

[BruceForstall]

I see this error in the SuperPMI collect libraries_tests pmi Linux x64 checked job as well (just one, no "terminate" error).

[jakobbotsch]

One thing I have noticed long ago is that we call WriteFile without any synchronization from superpmi-shim-collector. We also assume that WriteFile also writes the entire buffer, even though it can potentially only write parts of it. I'll try to investigate and find the culprit.