createdump segfaults on RHEL8 arm64 with .NET 8

[tmds]

With .NET 8, createdump gives a segfault on RHEL8 arm64.

Attaching the debugger shows that DumpWriter is trying to write a 64kB block here:

runtime/src/coreclr/debug/createdump/dumpwriterelf.cpp

Line 181 in de0ab15

if (!WriteDiagInfo(size)) {

using the 16kB m_tempBuffer allocated here:

runtime/src/coreclr/debug/createdump/dumpwriterelf.h

Line 45 in de0ab15

BYTE m_tempBuffer[0x4000];

This leads to stack corruption.

arm64 on RHEL8 has an atypical page size of 64kB pages.

When I update m_tempBuffer to have a 64kB size, createdump works.

cc @mikem8361 @omajid

[ghost]

Tagging subscribers to this area: @tommcdon
See info in area-owners.md if you want to be subscribed.

Issue Details

---

With .NET 8, createdump gives a segfault on RHEL8 arm64.

Attaching the debugger shows that DumpWriter is trying to write a 64kB block here:

runtime/src/coreclr/debug/createdump/dumpwriterelf.cpp

Line 181 in de0ab15

if (!WriteDiagInfo(size)) {

using the 16kB m_tempBuffer allocated here:

runtime/src/coreclr/debug/createdump/dumpwriterelf.h

Line 45 in de0ab15

BYTE m_tempBuffer[0x4000];

This leads to stack corruption.

arm64 on RHEL8 has an atypical page size of 64kB pages.

When I update m_tempBuffer to have a 64kB size, createdump works.

cc @mikem8361 @omajid

Author:	tmds
Assignees:	-
Labels:	area-Diagnostics-coreclr
Milestone:	-

[tmds]

When I update m_tempBuffer to have a 64kB size, createdump works.

I've created a PR with this change: #91865