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On i386, when multi-arch is enabled, all external functions must be called via PIC PLT in PIE, which requires setting up EBX register, since they may be IFUNC functions. * config.h.in (NO_HIDDEN_EXTERN_FUNC_IN_PIE): New. * include/libc-symbols.h (__hidden_proto_hiddenattr): Add check for PIC and NO_HIDDEN_EXTERN_FUNC_IN_PIE. * sysdeps/i386/configure.ac (NO_HIDDEN_EXTERN_FUNC_IN_PIE): New AC_DEFINE if multi-arch is enabled. * sysdeps/i386/configure: Regenerated.
57 lines
2.2 KiB
Plaintext
57 lines
2.2 KiB
Plaintext
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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# 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 whether asm supports Intel MPX
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AC_CACHE_CHECK(for Intel MPX support, libc_cv_asm_mpx, [dnl
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cat > conftest.s <<\EOF
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bndmov %bnd0,(%esp)
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EOF
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if AC_TRY_COMMAND(${CC-cc} -c $ASFLAGS conftest.s 1>&AS_MESSAGE_LOG_FD); then
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libc_cv_asm_mpx=yes
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else
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libc_cv_asm_mpx=no
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fi
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rm -f conftest*])
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if test $libc_cv_asm_mpx = yes; then
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AC_DEFINE(HAVE_MPX_SUPPORT)
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fi
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dnl It is always possible to access static and hidden symbols in an
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dnl position independent way.
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AC_DEFINE(PI_STATIC_AND_HIDDEN)
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dnl When multi-arch is enabled, all external functions must be called
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dnl via PIC PLT in PIE, which requires setting up EBX register.
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if test x"$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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