https://sourceware.org/git/gitweb.cgi?p=newlib-cygwin.git;h=c5a3641ba9173144ed40b85bea83c66bd649ee18
commit c5a3641ba9173144ed40b85bea83c66bd649ee18 Author: Igor Podgainoi <[email protected]> AuthorDate: Thu Feb 12 16:26:43 2026 +0000 Commit: Corinna Vinschen <[email protected]> CommitDate: Thu Feb 12 21:11:10 2026 +0100 Cygwin: configure: disable High Entropy VA (64-bit ASLR) on AArch64 Currently Cygwin does not support the High Entropy Virtual Addressing feature, also known as IMAGE_DLL_CHARACTERISTICS_HIGH_ENTROPY_VA and 64-bit Address Space Layout Randomization in Windows. Whereas on systems running on the x86_64 architecture this feature is already disabled by default in the toolchain during the build process, the AArch64 version of the toolchain leaves it enabled, even though it is not mandatory to use it on Windows on Arm. Only the normal ASLR flag IMAGE_DLLCHARACTERISTICS_DYNAMIC_BASE is mandatory, which this patch does not address. Therefore, this patch manually introduces the addition of High Entropy VA disabling flags into several places in various Makefile.am files. This should prevent memory overlap bugs on AArch64. Tests fixed on AArch64: winsup.api/ltp/fork06.exe winsup.api/ltp/fork07.exe winsup.api/ltp/fork11.exe Signed-off-by: Igor Podgainoi <[email protected]> Diff: --- winsup/cygserver/Makefile.am | 2 +- winsup/cygwin/Makefile.am | 2 +- winsup/testsuite/Makefile.am | 2 +- winsup/utils/Makefile.am | 4 ++-- 4 files changed, 5 insertions(+), 5 deletions(-) diff --git a/winsup/cygserver/Makefile.am b/winsup/cygserver/Makefile.am index efb578e53ece..9954ebe5daf0 100644 --- a/winsup/cygserver/Makefile.am +++ b/winsup/cygserver/Makefile.am @@ -38,7 +38,7 @@ cygserver_SOURCES = \ cygserver_CXXFLAGS = $(cygserver_flags) -D__OUTSIDE_CYGWIN__ cygserver_LDADD = -lntdll -cygserver_LDFLAGS = -static -static-libgcc +cygserver_LDFLAGS = -static -static-libgcc -Wl,--disable-high-entropy-va # Note: the objects in libcygserver are built without -D__OUTSIDE_CYGWIN__, # unlike cygserver.exe diff --git a/winsup/cygwin/Makefile.am b/winsup/cygwin/Makefile.am index 90a7332a8fbf..5f5fdc5ab0e2 100644 --- a/winsup/cygwin/Makefile.am +++ b/winsup/cygwin/Makefile.am @@ -620,7 +620,7 @@ $(NEW_DLL_NAME): $(LDSCRIPT) libdll.a $(VERSION_OFILES) $(LIBSERVER)\ $(AM_V_CXXLD)$(CXX) $(CXXFLAGS) \ -mno-use-libstdc-wrappers \ -Wl,--gc-sections -nostdlib -Wl,-T$(LDSCRIPT) \ - -Wl,--dynamicbase -static \ + -Wl,--dynamicbase -Wl,--disable-high-entropy-va -static \ $${SOURCE_DATE_EPOCH:+-Wl,--no-insert-timestamp} \ -Wl,--heap=0 -Wl,--out-implib,cygdll.a -shared -o $@ \ -e @DLL_ENTRY@ $(DEF_FILE) \ diff --git a/winsup/testsuite/Makefile.am b/winsup/testsuite/Makefile.am index 0ff23d041897..529853849e2e 100644 --- a/winsup/testsuite/Makefile.am +++ b/winsup/testsuite/Makefile.am @@ -328,7 +328,7 @@ LDADD_FOR_TESTDLL = $(builddir)/../cygwin/libcygwin.a -lgcc -lkernel32 -luser32 # flags for test executables AM_CPPFLAGS = -I$(srcdir)/libltp/include -AM_LDFLAGS = $(LDFLAGS_FOR_TESTDLL) +AM_LDFLAGS = $(LDFLAGS_FOR_TESTDLL) -Wl,--disable-high-entropy-va LDADD = $(builddir)/libltp.a $(builddir)/../cygwin/binmode.o $(LDADD_FOR_TESTDLL) # additional flags for specific test executables diff --git a/winsup/utils/Makefile.am b/winsup/utils/Makefile.am index 4a7936a6efdc..e44079a41d7f 100644 --- a/winsup/utils/Makefile.am +++ b/winsup/utils/Makefile.am @@ -73,14 +73,14 @@ tzmap.h: BUILT_SOURCES = tzmap.h -AM_LDFLAGS = -static -Wl,--enable-auto-import +AM_LDFLAGS = -static -Wl,--enable-auto-import -Wl,--disable-high-entropy-va LDADD = -lnetapi32 cygpath_CXXFLAGS = -fno-threadsafe-statics $(AM_CXXFLAGS) cygpath_LDADD = $(LDADD) -luserenv -lntdll dumper_CXXFLAGS = -I$(top_srcdir)/../include $(AM_CXXFLAGS) dumper_LDADD = $(LDADD) -lpsapi -lntdll -lbfd @BFD_LIBS@ -dumper_LDFLAGS = +dumper_LDFLAGS = -Wl,--disable-high-entropy-va ldd_LDADD = $(LDADD) -lpsapi -lntdll mount_CXXFLAGS = -DFSTAB_ONLY $(AM_CXXFLAGS) minidumper_LDADD = $(LDADD) -ldbghelp
