From: "Marvin Häuser" <mhaeuser@posteo.de>
To: star.zeng@intel.com, jiewen.yao@intel.com,
"devel@edk2.groups.io" <devel@edk2.groups.io>
Subject: Possibly incorrect size in memory profile structure
Date: Sat, 19 Jun 2021 10:56:16 +0000 [thread overview]
Message-ID: <919c6908-40a4-7c19-c4cc-ced6d172cee4@posteo.de> (raw)
Good day,
I have a question regarding a part of the memory profiling code. Namely
this piece of code [1] introduced storing the PDB file name among the
driver information. This is implement by a string pointer in the
"MEMORY_PROFILE_DRIVER_INFO_DATA" structure (which embeds the
"MEMORY_PROFILE_DRIVER_INFO" structure [2]). The length of the embedded
"MEMORY_PROFILE_DRIVER_INFO" instance is set to the header size plus the
8B-aligned size of the PDB name [3], albeit its storage is not used for
the PDB file name, and the storage that is used instead is not aligned
by 8B [4]. Ominously, the interior structure does have a comment that
indicates it is (or was) supposed to hold the PDB file name at some
point [5].
I do not see that concept being used, and instead see the previously
described way of storage, so I believe the aligned size is a forgotten
piece from a refactoring. I imagine early on, the interior structure was
supposed to hold the PDB name, and the alignment was needed to satisfy
the following data's requirements. However, the change to the exterior
storage should make this superfluous, and the specified size seems to be
incorrect in all cases.
Can you please give this a quick look and help me determine whether this
is a bug? Thank you for your time!
Best regards,
Marvin
[1]
https://github.com/tianocore/edk2/commit/1d60fe96422206d37e1d74198bb11b2cf6195157#diff-b42ade68f10fa42dfa25570f0f9a165db4b974877c98d8845e384a40252ec220R407-R428
[2]
https://github.com/tianocore/edk2/blob/a63914d3f603580e5aeceb5edbafe56688210141/MdeModulePkg/Core/Dxe/Mem/MemoryProfileRecord.c#L25
[3]
https://github.com/tianocore/edk2/blob/a63914d3f603580e5aeceb5edbafe56688210141/MdeModulePkg/Core/Dxe/Mem/MemoryProfileRecord.c#L417
[4]
https://github.com/tianocore/edk2/blob/a63914d3f603580e5aeceb5edbafe56688210141/MdeModulePkg/Core/Dxe/Mem/MemoryProfileRecord.c#L404
[5]
https://github.com/tianocore/edk2/blob/a63914d3f603580e5aeceb5edbafe56688210141/MdeModulePkg/Include/Guid/MemoryProfile.h#L59
next reply other threads:[~2021-06-19 10:56 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-19 10:56 Marvin Häuser [this message]
2021-06-22 10:20 ` [edk2-devel] Possibly incorrect size in memory profile structure Zeng, Star
2021-06-22 11:55 ` Marvin Häuser
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