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bbfb54930c
Since shadow stack is only supported for x86-64, ignore --enable-cet for i386. Always setting $(enable-cet) for i386 to "no" to support ifneq ($(enable-cet),no) in x86 Makefiles. We can't use ifeq ($(enable-cet),yes) since $(enable-cet) can be "yes", "no" or "permissive". Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
64 lines
2.6 KiB
Text
64 lines
2.6 KiB
Text
GLIBC_PROVIDES dnl See aclocal.m4 in the top level source directory.
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# Local configure fragment for sysdeps/i386.
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# CET is only supported for x86-64. Set enable-cet to "no" to allow
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# "ifneq ($(enable-cet),no)" in x86 Makefiles.
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LIBC_CONFIG_VAR([enable-cet], ["no"])
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# We no longer support i386 since it lacks the atomic instructions
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# required to implement NPTL threading.
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if test "$config_machine" = i386; then
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AC_MSG_ERROR([
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*** ERROR: Support for i386 is deprecated.
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*** Please use host i786, i686, i585 or i486.
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*** For example: /src/glibc/configure --host=i686-pc-linux-gnu ..."])
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fi
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# The GNU C Library can't be built for i386. There are several reasons for
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# this restriction. The primary reason is that i386 lacks the atomic
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# operations required to support the current NPTL implementation. While it is
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# possible that such atomic operations could be emulated in the kernel to date
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# no such work has been done to enable this. Even with NPTL disabled you still
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# have no atomic.h implementation. Given the declining use of i386 we disable
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# support for building with `-march=i386' or `-mcpu=i386.' We don't explicitly
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# check for i386, instead we make sure the compiler has support for inlining
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# the builtin __sync_val_compare_and_swap. If it does then we should have no
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# problem building for i386.
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LIBC_COMPILER_BUILTIN_INLINED(
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[__sync_val_compare_and_swap],
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[int a, b, c; __sync_val_compare_and_swap (&a, b, c);],
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[-O0],
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[libc_cv_unsupported_i386=no],
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[AC_MSG_ERROR([
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*** Building with -march=i386/-mcpu=i386 is not supported.
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*** Please use host i786, i686, i586, or i486.
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*** For example: /source/glibc/configure CFLAGS='-O2 -march=i686' ...])])
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dnl Check if linker can convert "movl main@GOT(%ebx), %eax" to
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dnl "leal main@GOTOFF(%ebx), %eax" for static PIE.
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if test "$static_pie" = yes; then
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AC_CACHE_CHECK(for linker static PIE support, libc_cv_ld_static_pie, [dnl
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cat > conftest.s <<\EOF
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.text
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.global _start
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_start:
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movl _start@GOT(%ebx), %eax
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EOF
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libc_cv_pie_option="-Wl,-pie"
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libc_cv_ld_static_pie=no
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if AC_TRY_COMMAND(${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -nostartfiles -nostdlib $no_ssp $libc_cv_pie_option -o conftest conftest.s 1>&AS_MESSAGE_LOG_FD); then
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if $READELF -r conftest | grep 'There are no relocations in this file.' > /dev/null; then
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libc_cv_ld_static_pie=yes
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fi
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fi
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rm -f conftest*])
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if test "$libc_cv_ld_static_pie" != yes; then
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AC_MSG_ERROR([linker support for static PIE needed])
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fi
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fi
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dnl When multi-arch is enabled, all external functions must be called
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dnl via PIC PLT in PIE, which requires setting up EBX register.
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if test x"$multi_arch" != xno; then
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AC_DEFINE(NO_HIDDEN_EXTERN_FUNC_IN_PIE)
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fi
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