Request: Add PDB checksum (type 19) to ModuleDCStart/ModuleDCStop events

[pharring]

Nuget’s symbol server requires clients to know up-front the SHA256 hash of the PDB they’re requesting -- not just the usual PDB signature stuff (because that’s too weak, cryptographically). The SHA256 hash is included in the PE header's debug directory. If you’re working with a live process or a dump, you can read the relevant debug directory out of the loaded module's PE header. However, if you’re starting with a perf trace, you don’t have it.

The Loader's ModuleDCStart and ModuleDCStop events include the "CodeView" PDB signature and age. Could we augment that event to emit the new checksum algorithm and value -- possibly enabled via a new keyword for backwards compatibility?

[tommcdon]

@pharring I've put this issue into .net 8 however please let me know if this is something blocking you and is needed for .net 7

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Issue Details

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Nuget’s symbol server requires clients to know up-front the SHA256 hash of the PDB they’re requesting -- not just the usual PDB signature stuff (because that’s too weak, cryptographically). The SHA256 hash is included in the PE header's debug directory. If you’re working with a live process or a dump, you can read the relevant debug directory out of the loaded module's PE header. However, if you’re starting with a perf trace, you don’t have it.

The Loader's ModuleDCStart and ModuleDCStop events include the "CodeView" PDB signature and age. Could we augment that event to emit the new checksum algorithm and value -- possibly enabled via a new keyword for backwards compatibility?

Author:	pharring
Assignees:	-
Labels:	enhancement, area-Single-File, area-Tracing-coreclr
Milestone:	8.0.0

[pharring]

Sorry. Mis-keyed the tag (area-Single-File) please ignore.

[pharring]

Hey, @tommcdon is this going to happen for .NET 8?

[pharring]

Without this, we are unable to "go to source" for assemblies like Newtonsoft.json which are open-source on github.com and publish their PDBs to nuget's symbol server. You can do it if you have a memory dump (because then you have the full PE header with the SHA256 checksum), but not from a performance trace (ETL).