Hello.

Does this disable ASLR completely, or `-Wl,--disable-dynamicbase` is needed as 
well? If it would just disable High-entropy VA but not ASLR, wouldn't it make 
the situation worse because there would be higher change for address space 
collision?

Radek

________________________________________
From: Cygwin-patches 
<[email protected]> on behalf of 
Jeremy Drake via Cygwin-patches <[email protected]>
Sent: Wednesday, July 9, 2025 8:47 PM
To: [email protected] <[email protected]>
Subject: [EXTERNAL] [PATCH] Cygwin: testsuite: link cygload with 
--disable-high-entropy-va
 
This is a mingw program meant to demonstrate loading the Cygwin dll in a
non-Cygwin process, but the Cygwin dll still initializes the cygheap on
load in that case.  Without --disable-high-entropy-va, Windows may
occasionally locate the PEB, TEB, and/or stacks in the address space
that Cygwin tries to reserve for the cygheap, resulting in a failure.

Fixes: 60675f1a7eb2 ("Cygwin: decouple shared mem regions from Cygwin DLL")
Signed-off-by: Jeremy Drake <[email protected]>
---
 winsup/testsuite/mingw/Makefile.am | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/winsup/testsuite/mingw/Makefile.am 
b/winsup/testsuite/mingw/Makefile.am
index 25300a15d9..775d617aef 100644
--- a/winsup/testsuite/mingw/Makefile.am
+++ b/winsup/testsuite/mingw/Makefile.am
@@ -23,7 +23,7 @@ cygrun_SOURCES = \

 cygload_SOURCES = \
         ../winsup.api/cygload.cc
-cygload_LDFLAGS=-static -Wl,-e,cygloadCRTStartup
+cygload_LDFLAGS=-static -Wl,-e,cygloadCRTStartup -Wl,--disable-high-entropy-va

 winchild_SOURCES = \
         ../winsup.api/posix_spawn/winchild.c
--
2.50.1.windows.1

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