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	When CET is enabled, it is an error to dlopen a non CET enabled shared library in CET enabled application. It may be desirable to make CET permissive, that is disable CET when dlopening a non CET enabled shared library. With the new --enable-cet=permissive configure option, CET is disabled when dlopening a non CET enabled shared library. Add DEFAULT_DL_X86_CET_CONTROL to config.h.in: /* The default value of x86 CET control. */ #define DEFAULT_DL_X86_CET_CONTROL cet_elf_property which enables CET features based on ELF property note. --enable-cet=permissive it to /* The default value of x86 CET control. */ #define DEFAULT_DL_X86_CET_CONTROL cet_permissive which enables CET features permissively. Update tst-cet-legacy-5a, tst-cet-legacy-5b, tst-cet-legacy-6a and tst-cet-legacy-6b to check --enable-cet and --enable-cet=permissive.
		
			
				
	
	
		
			46 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
			
		
		
	
	
			46 lines
		
	
	
		
			1.3 KiB
		
	
	
	
		
			Plaintext
		
	
	
	
	
	
GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
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# Local configure fragment for sysdeps/x86.
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if test $enable_cet != no; then
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  # Check if CET can be enabled.
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  AC_CACHE_CHECK(whether CET can be enabled,
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		 libc_cv_x86_cet_available, [dnl
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cat > conftest.c <<EOF
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#if !defined __CET__ || __CET__ != 3
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# error CET isn't available.
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#endif
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EOF
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		 if AC_TRY_COMMAND(${CC-cc} -c $CFLAGS -fcf-protection -include cet.h conftest.c 1>&AS_MESSAGE_LOG_FD); then
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		   libc_cv_x86_cet_available=yes
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		 else
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		   libc_cv_x86_cet_available=no
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		 fi
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		 rm -rf conftest*])
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  if test $libc_cv_x86_cet_available != yes; then
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    AC_MSG_ERROR([$CC doesn't support CET])
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  fi
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fi
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if test $enable_cet != no; then
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  # Check if assembler supports CET.
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  AC_CACHE_CHECK(whether $AS supports CET,
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		 libc_cv_x86_cet_as, [dnl
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cat > conftest.s <<EOF
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	incsspd %ecx
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EOF
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		 if AC_TRY_COMMAND(${CC-cc} -c $CFLAGS conftest.s -o conftest.o 1>&AS_MESSAGE_LOG_FD); then
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		   libc_cv_x86_cet_as=yes
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		 else
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		   libc_cv_x86_cet_as=no
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		 fi
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		 rm -rf conftest*])
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  if test $libc_cv_x86_cet_as = no; then
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    AC_MSG_ERROR([$AS doesn't support CET])
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  fi
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fi
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if test $enable_cet = yes; then
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  AC_DEFINE(DEFAULT_DL_X86_CET_CONTROL, cet_elf_property)
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elif test $enable_cet = permissive; then
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  AC_DEFINE(DEFAULT_DL_X86_CET_CONTROL, cet_permissive)
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fi
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LIBC_CONFIG_VAR([enable-cet], [$enable_cet])
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