[v5,3/5] libio: Remove the usage of __libc_IO_vtables

From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>

Instead of using a special ELF section along with a linker script
directive to put the IO vtables within the RELRO section, the libio
vtables are all moved to an array marked as data.relro (so linker
will place in the RELRO segment without the need of extra directives).

To avoid static linking namespace issues and including all vtable
referenced objects, all required function pointers are set to weak alias.

Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
---
 Makerules                             |  24 --
 elf/Makefile                          |  16 +-
 include/libc-symbols.h                |  18 +-
 libio/Makefile                        |   2 +
 libio/fileops.c                       |  81 +----
 libio/iofopncook.c                    |  60 +---
 libio/iopopen.c                       |  25 --
 libio/libio-macros.sym                |   7 +
 libio/libioP.h                        | 136 ++++++--
 libio/memstream.c                     |  32 +-
 libio/oldfileops.c                    |  23 --
 libio/oldiopopen.c                    |  23 --
 libio/stdio.c                         |   3 +
 libio/strfile.h                       |   2 -
 libio/strops.c                        |  24 --
 libio/tst-vtables-interposed.c        |   5 +
 libio/vtables.c                       | 478 ++++++++++++++++++++++++++
 libio/wfileops.c                      |  79 +----
 libio/wmemstream.c                    |  32 +-
 libio/wstrops.c                       |  24 --
 stdio-common/printf_buffer_as_file.c  |  28 +-
 stdio-common/wprintf_buffer_as_file.c |  28 +-
 22 files changed, 637 insertions(+), 513 deletions(-)
 create mode 100644 libio/libio-macros.sym

On 3/6/23 14:16, Adhemerval Zanella wrote:
> From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
> 
> Instead of using a special ELF section along with a linker script
> directive to put the IO vtables within the RELRO section, the libio
> vtables are all moved to an array marked as data.relro (so linker
> will place in the RELRO segment without the need of extra directives).
> 
> To avoid static linking namespace issues and including all vtable
> referenced objects, all required function pointers are set to weak alias.

As part of bug 23313 we added backwards compatibility testing for the vtables, and
as such if this test passes those backwards compat tests then we should be OK.

Given that we have coverage I'm OK with these changes. I would rather see them in
early than late in the release.

The overall design looks good to me. We stop using special sections and define the
tables as required and put it in a data.relro array using attribute_relro.

Reviewed-by: Carlos O'Donell <carlos@redhat.com>

> 
> Checked on x86_64-linux-gnu, i686-linux-gnu, and aarch64-linux-gnu.
> ---
>  Makerules                             |  24 --
>  elf/Makefile                          |  16 +-
>  include/libc-symbols.h                |  18 +-
>  libio/Makefile                        |   2 +
>  libio/fileops.c                       |  81 +----
>  libio/iofopncook.c                    |  60 +---
>  libio/iopopen.c                       |  25 --
>  libio/libio-macros.sym                |   7 +
>  libio/libioP.h                        | 136 ++++++--
>  libio/memstream.c                     |  32 +-
>  libio/oldfileops.c                    |  23 --
>  libio/oldiopopen.c                    |  23 --
>  libio/stdio.c                         |   3 +
>  libio/strfile.h                       |   2 -
>  libio/strops.c                        |  24 --
>  libio/tst-vtables-interposed.c        |   5 +
>  libio/vtables.c                       | 478 ++++++++++++++++++++++++++
>  libio/wfileops.c                      |  79 +----
>  libio/wmemstream.c                    |  32 +-
>  libio/wstrops.c                       |  24 --
>  stdio-common/printf_buffer_as_file.c  |  28 +-
>  stdio-common/wprintf_buffer_as_file.c |  28 +-
>  22 files changed, 637 insertions(+), 513 deletions(-)
>  create mode 100644 libio/libio-macros.sym
> 
> diff --git a/Makerules b/Makerules
> index 57b3f093c4..16887cb443 100644
> --- a/Makerules
> +++ b/Makerules
> @@ -544,34 +544,10 @@ $(LINK.o) -shared -static-libgcc -Wl,-O1 $(sysdep-LDFLAGS) \
>  	  -L$(subst :, -L,$(rpath-link)) -Wl,-rpath-link=$(rpath-link)
>  endef
>  
> -ifeq (yes,$(use-default-link))
>  # If the linker is good enough, we can let it use its default linker script.
>  # In the long term the custom linker script will be removed.
>  shlib-lds =
>  shlib-lds-flags =
> -else
> -# binutils only position loadable notes into the first page for binaries,
> -# not for shared objects
> -# lld --verbose does not dump a linker script.  Use -fuse-ld=bfd.
> -$(common-objpfx)shlib.lds: $(common-objpfx)config.make $(..)Makerules
> -	$(LINK.o) -shared -Wl,-O1 \
> -		  -nostdlib -nostartfiles -fuse-ld=bfd \
> -		  $(sysdep-LDFLAGS) $(rtld-LDFLAGS) $(LDFLAGS.so) \
> -		  -Wl,--verbose 2>/dev/null | \
> -	  sed > $@T \
> -	      -e '/^=========/,/^=========/!d;/^=========/d' \
> -	      -e 's@^.*\*(\.jcr).*$$@& \
> -		 PROVIDE(__start___libc_IO_vtables = .);\
> -		 __libc_IO_vtables : { *(__libc_IO_vtables) }\
> -		 PROVIDE(__stop___libc_IO_vtables = .);\
> -		 /DISCARD/ : { *(.gnu.glibc-stub.*) }@'
> -	test -s $@T
> -	mv -f $@T $@
> -common-generated += shlib.lds
> -
> -shlib-lds = $(common-objpfx)shlib.lds
> -shlib-lds-flags = -T $(shlib-lds)
> -endif

OK. Removes the custom script.

>  
>  define build-shlib
>  $(build-shlib-helper) -o $@ $(shlib-lds-flags) \
> diff --git a/elf/Makefile b/elf/Makefile
> index 0d19964d42..b7f31cdf1c 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -595,23 +595,9 @@ $(objpfx)tst-relro-ldso.out: tst-relro-symbols.py $(..)/scripts/glibcelf.py \
>  $(objpfx)tst-relro-libc.out: tst-relro-symbols.py $(..)/scripts/glibcelf.py \
>    $(common-objpfx)libc.so
>  	$(PYTHON) tst-relro-symbols.py $(common-objpfx)libc.so \
> -	    --required=_IO_cookie_jumps \
>  	    --required=_IO_file_jumps \
> -	    --required=_IO_file_jumps_maybe_mmap \
> -	    --required=_IO_file_jumps_mmap \
> -	    --required=_IO_mem_jumps \
> -	    --required=_IO_printf_buffer_as_file_jumps \
> -	    --required=_IO_proc_jumps \
> -	    --required=_IO_str_jumps \
>  	    --required=_IO_wfile_jumps \
> -	    --required=_IO_wfile_jumps_maybe_mmap \
> -	    --required=_IO_wfile_jumps_mmap \
> -	    --required=_IO_wmem_jumps \
> -	    --required=_IO_wprintf_buffer_as_file_jumps \
> -	    --required=_IO_wstr_jumps \
> -	    --optional=_IO_old_cookie_jumps \
> -	    --optional=_IO_old_file_jumps \
> -	    --optional=_IO_old_proc_jumps \
> +	    --required=__io_vtables \

OK. Adds __io_vtables. Leaves _IO_file_jumps and _IO_wfile_jumps.

>  	  > $@ 2>&1; $(evaluate-test)
>  
>  ifeq ($(run-built-tests),yes)
> diff --git a/include/libc-symbols.h b/include/libc-symbols.h
> index 155781d448..37c91bb3a4 100644
> --- a/include/libc-symbols.h
> +++ b/include/libc-symbols.h
> @@ -243,20 +243,26 @@ for linking")
>     This is only necessary when defining something in assembly, or playing
>     funny alias games where the size should be other than what the compiler
>     thinks it is.  */
> -#ifdef __ASSEMBLER__
> -# define declare_object_symbol_alias(symbol, original, size) \
> +#define declare_object_symbol_alias(symbol, original, size) \
>    declare_object_symbol_alias_1 (symbol, original, size)
> +#ifdef __ASSEMBLER__
>  # define declare_object_symbol_alias_1(symbol, original, s_size) \
>     strong_alias (original, symbol) ASM_LINE_SEP \
>     .type C_SYMBOL_NAME (symbol), %object ASM_LINE_SEP \
>     .size C_SYMBOL_NAME (symbol), s_size ASM_LINE_SEP
>  #else /* Not __ASSEMBLER__.  */
>  # ifdef HAVE_ASM_SET_DIRECTIVE
> -#  define declare_symbol_alias_1_alias(symbol, original) \
> -     ".set " __SYMBOL_PREFIX #symbol ", " __SYMBOL_PREFIX #original
> +#  define declare_object_symbol_alias_1(symbol, original, size) \
> +     asm (".global " __SYMBOL_PREFIX # symbol "\n" \
> +	  ".type " __SYMBOL_PREFIX # symbol ", %object\n" \
> +	  ".set " __SYMBOL_PREFIX #symbol ", " __SYMBOL_PREFIX original "\n" \
> +	  ".size " __SYMBOL_PREFIX #symbol ", " #size "\n");
>  # else
> -#  define declare_symbol_alias_1_alias(symbol, original) \
> -     __SYMBOL_PREFIX #symbol " = " __SYMBOL_PREFIX #original
> +#  define declare_object_symbol_alias_1(symbol, original, size) \
> +     asm (".global " __SYMBOL_PREFIX # symbol "\n" \
> +	  ".type " __SYMBOL_PREFIX # symbol ", %object\n" \
> +	  __SYMBOL_PREFIX #symbol " = " __SYMBOL_PREFIX original "\n" \
> +	  ".size " __SYMBOL_PREFIX #symbol ", " #size "\n");
>  # endif /* HAVE_ASM_SET_DIRECTIVE */
>  #endif /* __ASSEMBLER__ */
>  
> diff --git a/libio/Makefile b/libio/Makefile
> index 52892a282e..2877fec484 100644
> --- a/libio/Makefile
> +++ b/libio/Makefile
> @@ -51,6 +51,8 @@ routines	:=							      \
>  									      \
>  	libc_fatal fmemopen oldfmemopen vtables
>  
> +gen-as-const-headers += libio-macros.sym

OK. New sym list.

> +
>  tests = tst_swprintf tst_wprintf tst_swscanf tst_wscanf tst_getwc tst_putwc   \
>  	tst_wprintf2 tst-widetext test-fmemopen tst-ext tst-ext2 \
>  	tst-fgetws tst-ungetwc1 tst-ungetwc2 tst-swscanf tst-sscanf	      \
> diff --git a/libio/fileops.c b/libio/fileops.c
> index b75d748539..58c9e985e4 100644
> --- a/libio/fileops.c
> +++ b/libio/fileops.c
> @@ -815,7 +815,7 @@ _IO_new_file_sync (FILE *fp)
>  }
>  libc_hidden_ver (_IO_new_file_sync, _IO_file_sync)
>  
> -static int
> +int
>  _IO_file_sync_mmap (FILE *fp)
>  {
>    if (fp->_IO_read_ptr != fp->_IO_read_end)
> @@ -1109,7 +1109,7 @@ _IO_file_seekoff_mmap (FILE *fp, off64_t offset, int dir, int mode)
>    return offset;
>  }
>  
> -static off64_t
> +off64_t
>  _IO_file_seekoff_maybe_mmap (FILE *fp, off64_t offset, int dir,
>  			     int mode)
>  {
> @@ -1360,7 +1360,7 @@ _IO_file_xsgetn (FILE *fp, void *data, size_t n)
>  }
>  libc_hidden_def (_IO_file_xsgetn)
>  
> -static size_t
> +size_t
>  _IO_file_xsgetn_mmap (FILE *fp, void *data, size_t n)
>  {
>    size_t have;
> @@ -1405,7 +1405,7 @@ _IO_file_xsgetn_mmap (FILE *fp, void *data, size_t n)
>    return s - (char *) data;
>  }
>  
> -static size_t
> +size_t
>  _IO_file_xsgetn_maybe_mmap (FILE *fp, void *data, size_t n)
>  {
>    /* We only get here if this is the first attempt to read something.
> @@ -1428,76 +1428,3 @@ versioned_symbol (libc, _IO_new_file_seekoff, _IO_file_seekoff, GLIBC_2_1);
>  versioned_symbol (libc, _IO_new_file_underflow, _IO_file_underflow, GLIBC_2_1);
>  versioned_symbol (libc, _IO_new_file_write, _IO_file_write, GLIBC_2_1);
>  versioned_symbol (libc, _IO_new_file_xsputn, _IO_file_xsputn, GLIBC_2_1);
> -
> -const struct _IO_jump_t _IO_file_jumps libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_file_finish),
> -  JUMP_INIT(overflow, _IO_file_overflow),
> -  JUMP_INIT(underflow, _IO_file_underflow),
> -  JUMP_INIT(uflow, _IO_default_uflow),
> -  JUMP_INIT(pbackfail, _IO_default_pbackfail),
> -  JUMP_INIT(xsputn, _IO_file_xsputn),
> -  JUMP_INIT(xsgetn, _IO_file_xsgetn),
> -  JUMP_INIT(seekoff, _IO_new_file_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_new_file_setbuf),
> -  JUMP_INIT(sync, _IO_new_file_sync),
> -  JUMP_INIT(doallocate, _IO_file_doallocate),
> -  JUMP_INIT(read, _IO_file_read),
> -  JUMP_INIT(write, _IO_new_file_write),
> -  JUMP_INIT(seek, _IO_file_seek),
> -  JUMP_INIT(close, _IO_file_close),
> -  JUMP_INIT(stat, _IO_file_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> -libc_hidden_data_def (_IO_file_jumps)
> -
> -const struct _IO_jump_t _IO_file_jumps_mmap libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_file_finish),
> -  JUMP_INIT(overflow, _IO_file_overflow),
> -  JUMP_INIT(underflow, _IO_file_underflow_mmap),
> -  JUMP_INIT(uflow, _IO_default_uflow),
> -  JUMP_INIT(pbackfail, _IO_default_pbackfail),
> -  JUMP_INIT(xsputn, _IO_new_file_xsputn),
> -  JUMP_INIT(xsgetn, _IO_file_xsgetn_mmap),
> -  JUMP_INIT(seekoff, _IO_file_seekoff_mmap),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, (_IO_setbuf_t) _IO_file_setbuf_mmap),
> -  JUMP_INIT(sync, _IO_file_sync_mmap),
> -  JUMP_INIT(doallocate, _IO_file_doallocate),
> -  JUMP_INIT(read, _IO_file_read),
> -  JUMP_INIT(write, _IO_new_file_write),
> -  JUMP_INIT(seek, _IO_file_seek),
> -  JUMP_INIT(close, _IO_file_close_mmap),
> -  JUMP_INIT(stat, _IO_file_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> -
> -const struct _IO_jump_t _IO_file_jumps_maybe_mmap libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_file_finish),
> -  JUMP_INIT(overflow, _IO_file_overflow),
> -  JUMP_INIT(underflow, _IO_file_underflow_maybe_mmap),
> -  JUMP_INIT(uflow, _IO_default_uflow),
> -  JUMP_INIT(pbackfail, _IO_default_pbackfail),
> -  JUMP_INIT(xsputn, _IO_new_file_xsputn),
> -  JUMP_INIT(xsgetn, _IO_file_xsgetn_maybe_mmap),
> -  JUMP_INIT(seekoff, _IO_file_seekoff_maybe_mmap),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, (_IO_setbuf_t) _IO_file_setbuf_mmap),
> -  JUMP_INIT(sync, _IO_new_file_sync),
> -  JUMP_INIT(doallocate, _IO_file_doallocate),
> -  JUMP_INIT(read, _IO_file_read),
> -  JUMP_INIT(write, _IO_new_file_write),
> -  JUMP_INIT(seek, _IO_file_seek),
> -  JUMP_INIT(close, _IO_file_close),
> -  JUMP_INIT(stat, _IO_file_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> diff --git a/libio/iofopncook.c b/libio/iofopncook.c
> index d6a06c5acb..5511c07c18 100644
> --- a/libio/iofopncook.c
> +++ b/libio/iofopncook.c
> @@ -30,7 +30,7 @@
>  #include <shlib-compat.h>
>  #include <pointer_guard.h>
>  
> -static ssize_t
> +ssize_t
>  _IO_cookie_read (FILE *fp, void *buf, ssize_t size)
>  {
>    struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
> @@ -43,7 +43,7 @@ _IO_cookie_read (FILE *fp, void *buf, ssize_t size)
>    return read_cb (cfile->__cookie, buf, size);
>  }
>  
> -static ssize_t
> +ssize_t
>  _IO_cookie_write (FILE *fp, const void *buf, ssize_t size)
>  {
>    struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
> @@ -63,7 +63,7 @@ _IO_cookie_write (FILE *fp, const void *buf, ssize_t size)
>    return n;
>  }
>  
> -static off64_t
> +off64_t
>  _IO_cookie_seek (FILE *fp, off64_t offset, int dir)
>  {
>    struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
> @@ -77,7 +77,7 @@ _IO_cookie_seek (FILE *fp, off64_t offset, int dir)
>  	  ? _IO_pos_BAD : offset);
>  }
>  
> -static int
> +int
>  _IO_cookie_close (FILE *fp)
>  {
>    struct _IO_cookie_file *cfile = (struct _IO_cookie_file *) fp;
> @@ -91,7 +91,7 @@ _IO_cookie_close (FILE *fp)
>  }
>  
>  
> -static off64_t
> +off64_t
>  _IO_cookie_seekoff (FILE *fp, off64_t offset, int dir, int mode)
>  {
>    /* We must force the fileops code to always use seek to determine
> @@ -100,31 +100,6 @@ _IO_cookie_seekoff (FILE *fp, off64_t offset, int dir, int mode)
>    return _IO_file_seekoff (fp, offset, dir, mode);
>  }
>  
> -
> -static const struct _IO_jump_t _IO_cookie_jumps libio_vtable = {
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_file_finish),
> -  JUMP_INIT(overflow, _IO_file_overflow),
> -  JUMP_INIT(underflow, _IO_file_underflow),
> -  JUMP_INIT(uflow, _IO_default_uflow),
> -  JUMP_INIT(pbackfail, _IO_default_pbackfail),
> -  JUMP_INIT(xsputn, _IO_file_xsputn),
> -  JUMP_INIT(xsgetn, _IO_default_xsgetn),
> -  JUMP_INIT(seekoff, _IO_cookie_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_file_setbuf),
> -  JUMP_INIT(sync, _IO_file_sync),
> -  JUMP_INIT(doallocate, _IO_file_doallocate),
> -  JUMP_INIT(read, _IO_cookie_read),
> -  JUMP_INIT(write, _IO_cookie_write),
> -  JUMP_INIT(seek, _IO_cookie_seek),
> -  JUMP_INIT(close, _IO_cookie_close),
> -  JUMP_INIT(stat, _IO_default_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue),
> -};
> -
> -
>  /* Copy the callbacks from SOURCE to *TARGET, with pointer
>     mangling.  */
>  static void
> @@ -209,7 +184,7 @@ versioned_symbol (libc, _IO_fopencookie, fopencookie, GLIBC_2_2);
>  
>  #if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
>  
> -static off64_t
> +off64_t
>  attribute_compat_text_section
>  _IO_old_cookie_seek (FILE *fp, off64_t offset, int dir)
>  {
> @@ -226,29 +201,6 @@ _IO_old_cookie_seek (FILE *fp, off64_t offset, int dir)
>    return (ret == -1) ? _IO_pos_BAD : ret;
>  }
>  
> -static const struct _IO_jump_t _IO_old_cookie_jumps libio_vtable = {
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_file_finish),
> -  JUMP_INIT(overflow, _IO_file_overflow),
> -  JUMP_INIT(underflow, _IO_file_underflow),
> -  JUMP_INIT(uflow, _IO_default_uflow),
> -  JUMP_INIT(pbackfail, _IO_default_pbackfail),
> -  JUMP_INIT(xsputn, _IO_file_xsputn),
> -  JUMP_INIT(xsgetn, _IO_default_xsgetn),
> -  JUMP_INIT(seekoff, _IO_cookie_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_file_setbuf),
> -  JUMP_INIT(sync, _IO_file_sync),
> -  JUMP_INIT(doallocate, _IO_file_doallocate),
> -  JUMP_INIT(read, _IO_cookie_read),
> -  JUMP_INIT(write, _IO_cookie_write),
> -  JUMP_INIT(seek, _IO_old_cookie_seek),
> -  JUMP_INIT(close, _IO_cookie_close),
> -  JUMP_INIT(stat, _IO_default_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue),
> -};
> -
>  FILE *
>  attribute_compat_text_section
>  _IO_old_fopencookie (void *cookie, const char *mode,
> diff --git a/libio/iopopen.c b/libio/iopopen.c
> index d0545ad5ea..a64033e60f 100644
> --- a/libio/iopopen.c
> +++ b/libio/iopopen.c
> @@ -45,8 +45,6 @@ struct _IO_proc_file
>  };
>  typedef struct _IO_proc_file _IO_proc_file;
>  
> -static const struct _IO_jump_t _IO_proc_jumps;
> -
>  static struct _IO_proc_file *proc_file_chain;
>  
>  #ifdef _IO_MTSAFE_IO
> @@ -297,29 +295,6 @@ _IO_new_proc_close (FILE *fp)
>    return wstatus;
>  }
>  
> -static const struct _IO_jump_t _IO_proc_jumps libio_vtable = {
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_new_file_finish),
> -  JUMP_INIT(overflow, _IO_new_file_overflow),
> -  JUMP_INIT(underflow, _IO_new_file_underflow),
> -  JUMP_INIT(uflow, _IO_default_uflow),
> -  JUMP_INIT(pbackfail, _IO_default_pbackfail),
> -  JUMP_INIT(xsputn, _IO_new_file_xsputn),
> -  JUMP_INIT(xsgetn, _IO_default_xsgetn),
> -  JUMP_INIT(seekoff, _IO_new_file_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_new_file_setbuf),
> -  JUMP_INIT(sync, _IO_new_file_sync),
> -  JUMP_INIT(doallocate, _IO_file_doallocate),
> -  JUMP_INIT(read, _IO_file_read),
> -  JUMP_INIT(write, _IO_new_file_write),
> -  JUMP_INIT(seek, _IO_file_seek),
> -  JUMP_INIT(close, _IO_new_proc_close),
> -  JUMP_INIT(stat, _IO_file_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> -
>  strong_alias (_IO_new_popen, __new_popen)
>  versioned_symbol (libc, _IO_new_popen, _IO_popen, GLIBC_2_1);
>  versioned_symbol (libc, __new_popen, popen, GLIBC_2_1);
> diff --git a/libio/libio-macros.sym b/libio/libio-macros.sym
> new file mode 100644
> index 0000000000..cfb5cf2841
> --- /dev/null
> +++ b/libio/libio-macros.sym
> @@ -0,0 +1,7 @@
> +#include <libioP.h>
> +
> +--
> +
> +IO_JUMP_T_SIZE		sizeof (struct _IO_jump_t)
> +IO_FILE_JUMPS_OFFSET	sizeof (struct _IO_jump_t) * IO_FILE_JUMPS
> +IO_WFILE_JUMPS_OFFSET	sizeof (struct _IO_jump_t) * IO_WFILE_JUMPS
> diff --git a/libio/libioP.h b/libio/libioP.h
> index 80941b763f..d777553cb0 100644
> --- a/libio/libioP.h
> +++ b/libio/libioP.h
> @@ -469,19 +469,68 @@ extern int _IO_default_sync (FILE *) __THROW;
>  extern int _IO_default_showmanyc (FILE *) __THROW;
>  extern void _IO_default_imbue (FILE *, void *) __THROW;
>  
> -extern const struct _IO_jump_t _IO_file_jumps;
> -libc_hidden_proto (_IO_file_jumps)
> -extern const struct _IO_jump_t _IO_file_jumps_mmap attribute_hidden;
> -extern const struct _IO_jump_t _IO_file_jumps_maybe_mmap attribute_hidden;
> -extern const struct _IO_jump_t _IO_wfile_jumps;
> -libc_hidden_proto (_IO_wfile_jumps)
> -extern const struct _IO_jump_t _IO_wfile_jumps_mmap attribute_hidden;
> -extern const struct _IO_jump_t _IO_wfile_jumps_maybe_mmap attribute_hidden;
> -extern const struct _IO_jump_t _IO_old_file_jumps attribute_hidden;
> -extern const struct _IO_jump_t _IO_streambuf_jumps;
> -extern const struct _IO_jump_t _IO_old_proc_jumps attribute_hidden;
> -extern const struct _IO_jump_t _IO_str_jumps attribute_hidden;
> -extern const struct _IO_jump_t _IO_wstr_jumps attribute_hidden;
> +extern int __printf_buffer_as_file_overflow (FILE *fp, int ch);
> +extern size_t __printf_buffer_as_file_xsputn (FILE *fp, const void *buf,
> +					      size_t len);
> +extern wint_t __wprintf_buffer_as_file_overflow (FILE *fp, int ch);
> +extern size_t __wprintf_buffer_as_file_xsputn (FILE *fp, const void *buf,
> +					       size_t len);
> +
> +enum
> +{
> +  IO_STR_JUMPS                    = 0,
> +  IO_WSTR_JUMPS                   = 1,
> +  IO_FILE_JUMPS                   = 2,
> +  IO_FILE_JUMPS_MMAP              = 3,
> +  IO_FILE_JUMPS_MAYBE_MMAP        = 4,
> +  IO_WFILE_JUMPS                  = 5,
> +  IO_WFILE_JUMPS_MMAP             = 6,
> +  IO_WFILE_JUMPS_MAYBE_MMAP       = 7,
> +  IO_COOKIE_JUMPS                 = 8,
> +  IO_PROC_JUMPS                   = 9,
> +  IO_MEM_JUMPS                    = 10,
> +  IO_WMEM_JUMPS                   = 11,
> +  IO_PRINTF_BUFFER_AS_FILE_JUMPS  = 12,
> +  IO_WPRINTF_BUFFER_AS_FILE_JUMPS = 13,
> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)
> +  IO_OLD_FILE_JUMPS               = 14,
> +  IO_OLD_PROC_JUMPS               = 15,
> +  IO_OLD_COOKIED_JUMPS            = 16,
> +  IO_VTABLES_NUM		  = IO_OLD_COOKIED_JUMPS + 1,
> +#elif SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)
> +  IO_OLD_COOKIED_JUMPS            = 14,
> +  IO_VTABLES_NUM		  = IO_OLD_COOKIED_JUMPS + 1,
> +#else
> +  IO_VTABLES_NUM		  = IO_WPRINTF_BUFFER_AS_FILE_JUMPS + 1

OK. Define IO_VTABLES_NUM (needed), but varies by ABI (SHLIB_COMPAT).

> +#endif
> +};
> +#define IO_VTABLES_LEN (IO_VTABLES_NUM * sizeof (struct _IO_jump_t))

OK. Define IO_VTABLES_LEN (needed).

> +
> +extern const struct _IO_jump_t __io_vtables[] attribute_hidden;
> +#define _IO_str_jumps                    (__io_vtables[IO_STR_JUMPS])
> +#define _IO_wstr_jumps                   (__io_vtables[IO_WSTR_JUMPS])
> +#define _IO_file_jumps                   (__io_vtables[IO_FILE_JUMPS])
> +#define _IO_file_jumps_mmap              (__io_vtables[IO_FILE_JUMPS_MMAP])
> +#define _IO_file_jumps_maybe_mmap        (__io_vtables[IO_FILE_JUMPS_MAYBE_MMAP])
> +#define _IO_wfile_jumps                  (__io_vtables[IO_WFILE_JUMPS])
> +#define _IO_wfile_jumps_mmap             (__io_vtables[IO_WFILE_JUMPS_MMAP])
> +#define _IO_wfile_jumps_maybe_mmap       (__io_vtables[IO_WFILE_JUMPS_MAYBE_MMAP])
> +#define _IO_cookie_jumps                 (__io_vtables[IO_COOKIE_JUMPS])
> +#define _IO_proc_jumps                   (__io_vtables[IO_PROC_JUMPS])
> +#define _IO_mem_jumps                    (__io_vtables[IO_MEM_JUMPS])
> +#define _IO_wmem_jumps                   (__io_vtables[IO_WMEM_JUMPS])
> +#define _IO_printf_buffer_as_file_jumps  (__io_vtables[IO_PRINTF_BUFFER_AS_FILE_JUMPS])
> +#define _IO_wprintf_buffer_as_file_jumps (__io_vtables[IO_WPRINTF_BUFFER_AS_FILE_JUMPS])
> +#define _IO_old_file_jumps               (__io_vtables[IO_OLD_FILE_JUMPS])
> +#define _IO_old_proc_jumps               (__io_vtables[IO_OLD_PROC_JUMPS])
> +#define _IO_old_cookie_jumps             (__io_vtables[IO_OLD_COOKIED_JUMPS])
> +
> +#ifdef SHARED
> +# define libio_static_fn_required(name)
> +#else
> +# define libio_static_fn_required(name) __asm (".globl " #name);
> +#endif
> +
>  extern int _IO_do_write (FILE *, const char *, size_t);
>  libc_hidden_proto (_IO_do_write)
>  extern int _IO_new_do_write (FILE *, const char *, size_t);
> @@ -593,6 +642,14 @@ extern void _IO_new_file_init_internal (struct _IO_FILE_plus *)
>  extern FILE* _IO_new_file_setbuf (FILE *, char *, ssize_t);
>  extern FILE* _IO_file_setbuf_mmap (FILE *, char *, ssize_t);
>  extern int _IO_new_file_sync (FILE *);
> +extern int _IO_file_sync_mmap (FILE *) attribute_hidden;
> +extern size_t  _IO_file_xsgetn_maybe_mmap (FILE *fp, void *data, size_t n)
> +  attribute_hidden;
> +extern size_t _IO_file_xsgetn_mmap (FILE *fp, void *data, size_t n)
> +  attribute_hidden;
> +extern off64_t _IO_file_seekoff_maybe_mmap (FILE *fp, off64_t offset, int dir,
> +					    int mode)
> +     attribute_hidden;
>  extern int _IO_new_file_underflow (FILE *);
>  extern int _IO_new_file_overflow (FILE *, int);
>  extern off64_t _IO_new_file_seekoff (FILE *, off64_t, int, int);
> @@ -625,6 +682,10 @@ extern wint_t _IO_wfile_overflow (FILE *, wint_t);
>  libc_hidden_proto (_IO_wfile_overflow)
>  extern off64_t _IO_wfile_seekoff (FILE *, off64_t, int, int);
>  libc_hidden_proto (_IO_wfile_seekoff)
> +extern wint_t _IO_wfile_underflow_maybe_mmap (FILE *fp)
> +     attribute_hidden;
> +extern wint_t _IO_wfile_underflow_mmap (FILE *fp)
> +     attribute_hidden;
>  
>  /* Jumptable functions for proc_files. */
>  extern FILE* _IO_proc_open (FILE *, const char *, const char *)
> @@ -643,13 +704,41 @@ extern int _IO_str_overflow (FILE *, int) __THROW;
>  libc_hidden_proto (_IO_str_overflow)
>  extern int _IO_str_pbackfail (FILE *, int) __THROW;
>  libc_hidden_proto (_IO_str_pbackfail)
> -extern off64_t _IO_str_seekoff (FILE *, off64_t, int, int) __THROW;
> +extern off64_t _IO_str_seekoff (FILE *, off64_t, int, int) __THROW
> + ;
>  libc_hidden_proto (_IO_str_seekoff)
>  extern void _IO_str_finish (FILE *, int) __THROW;
> +extern int _IO_str_chk_overflow (FILE *fp, int c) __THROW
> +  attribute_hidden;
> +
> +/* Jumptable functions for fopencookie.  */
> +extern ssize_t _IO_cookie_read (FILE *fp, void *buf, ssize_t size)
> +  attribute_hidden;
> +extern ssize_t _IO_cookie_write (FILE *fp, const void *buf, ssize_t size)
> +  attribute_hidden;
> +extern off64_t _IO_cookie_seek (FILE *fp, off64_t offset, int dir)
> +  attribute_hidden;
> +extern int _IO_cookie_close (FILE *fp) attribute_hidden;
> +extern off64_t _IO_cookie_seekoff (FILE *fp, off64_t offset, int dir, int mode)
> +  attribute_hidden;
> +extern off64_t _IO_old_cookie_seek (FILE *fp, off64_t offset, int dir)
> +  attribute_hidden;
> +
> +/* Jumptable functions for obstack.  */
> +extern int __IO_obstack_overflow (FILE *fp, int c) attribute_hidden;
> +extern size_t __IO_obstack_xsputn (FILE *fp, const void *data, size_t n)
> +  attribute_hidden;
> +
> +/* Jumptable functions for open_{w}memstream.  */
> +extern int _IO_mem_sync (FILE* fp) __THROW attribute_hidden;
> +extern void _IO_mem_finish (FILE* fp, int) __THROW attribute_hidden;
> +extern int _IO_wmem_sync (FILE* fp) __THROW attribute_hidden;
> +extern void _IO_wmem_finish (FILE* fp, int) __THROW attribute_hidden;
>  
>  /* Other strfile functions */
>  struct _IO_strfile_;
>  extern ssize_t _IO_str_count (FILE *) __THROW;
> +extern int _IO_strn_overflow (FILE *fp, int c) __THROW attribute_hidden;
>  
>  /* And the wide character versions.  */
>  extern void _IO_wstr_init_static (FILE *, wchar_t *, size_t, wchar_t *)
> @@ -662,6 +751,10 @@ extern off64_t _IO_wstr_seekoff (FILE *, off64_t, int, int)
>  extern wint_t _IO_wstr_pbackfail (FILE *, wint_t) __THROW;
>  extern void _IO_wstr_finish (FILE *, int) __THROW;
>  
> +/* Helper functions.  */
> +int _IO_helper_overflow (FILE *s, int c);
> +int _IO_whelper_overflow (FILE *s, int c);
> +
>  /* Internal versions of v*printf that take an additional flags
>     parameter.  */
>  extern int __vfprintf_internal (FILE *fp, const char *format, va_list ap,
> @@ -895,14 +988,6 @@ _IO_acquire_lock_fct (FILE **p)
>    } while (0)
>  #endif
>  
> -/* Collect all vtables in a special section for vtable verification.
> -   These symbols cover the extent of this section.  */
> -symbol_set_declare (__libc_IO_vtables)
> -
> -/* libio vtables need to carry this attribute so that they pass
> -   validation.  */
> -#define libio_vtable __attribute__ ((section ("__libc_IO_vtables")))
> -

OK. Removed.

>  #ifdef SHARED
>  /* If equal to &_IO_vtable_check (with pointer guard protection),
>     unknown vtable pointers are valid.  This function pointer is solely
> @@ -937,12 +1022,9 @@ void _IO_vtable_check (void) attribute_hidden;
>  static inline const struct _IO_jump_t *
>  IO_validate_vtable (const struct _IO_jump_t *vtable)
>  {
> -  /* Fast path: The vtable pointer is within the __libc_IO_vtables
> -     section.  */
> -  uintptr_t section_length = __stop___libc_IO_vtables - __start___libc_IO_vtables;
>    uintptr_t ptr = (uintptr_t) vtable;
> -  uintptr_t offset = ptr - (uintptr_t) __start___libc_IO_vtables;
> -  if (__glibc_unlikely (offset >= section_length))
> +  uintptr_t offset = ptr - (uintptr_t) &__io_vtables;
> +  if (__glibc_unlikely (offset >= IO_VTABLES_LEN))

OK. Use IO_VTABLES_LEN.

>      /* The vtable pointer is not in the expected section.  Use the
>         slow path, which will terminate the process if necessary.  */
>      _IO_vtable_check ();
> diff --git a/libio/memstream.c b/libio/memstream.c
> index ad5726baf8..90b42d1e0e 100644
> --- a/libio/memstream.c
> +++ b/libio/memstream.c
> @@ -29,34 +29,6 @@ struct _IO_FILE_memstream
>  };
>  
>  
> -static int _IO_mem_sync (FILE* fp) __THROW;
> -static void _IO_mem_finish (FILE* fp, int) __THROW;
> -
> -
> -static const struct _IO_jump_t _IO_mem_jumps libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT (finish, _IO_mem_finish),
> -  JUMP_INIT (overflow, _IO_str_overflow),
> -  JUMP_INIT (underflow, _IO_str_underflow),
> -  JUMP_INIT (uflow, _IO_default_uflow),
> -  JUMP_INIT (pbackfail, _IO_str_pbackfail),
> -  JUMP_INIT (xsputn, _IO_default_xsputn),
> -  JUMP_INIT (xsgetn, _IO_default_xsgetn),
> -  JUMP_INIT (seekoff, _IO_str_seekoff),
> -  JUMP_INIT (seekpos, _IO_default_seekpos),
> -  JUMP_INIT (setbuf, _IO_default_setbuf),
> -  JUMP_INIT (sync, _IO_mem_sync),
> -  JUMP_INIT (doallocate, _IO_default_doallocate),
> -  JUMP_INIT (read, _IO_default_read),
> -  JUMP_INIT (write, _IO_default_write),
> -  JUMP_INIT (seek, _IO_default_seek),
> -  JUMP_INIT (close, _IO_default_close),
> -  JUMP_INIT (stat, _IO_default_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> -
>  /* Open a stream that writes into a malloc'd buffer that is expanded as
>     necessary.  *BUFLOC and *SIZELOC are updated with the buffer's location
>     and the number of characters written on fflush or fclose.  */
> @@ -105,7 +77,7 @@ libc_hidden_def (__open_memstream)
>  weak_alias (__open_memstream, open_memstream)
>  
>  
> -static int
> +int
>  _IO_mem_sync (FILE *fp)
>  {
>    struct _IO_FILE_memstream *mp = (struct _IO_FILE_memstream *) fp;
> @@ -123,7 +95,7 @@ _IO_mem_sync (FILE *fp)
>  }
>  
>  
> -static void
> +void
>  _IO_mem_finish (FILE *fp, int dummy)
>  {
>    struct _IO_FILE_memstream *mp = (struct _IO_FILE_memstream *) fp;
> diff --git a/libio/oldfileops.c b/libio/oldfileops.c
> index dd455a8ace..d6abbfdc3c 100644
> --- a/libio/oldfileops.c
> +++ b/libio/oldfileops.c
> @@ -716,29 +716,6 @@ _IO_old_file_xsputn (FILE *f, const void *data, size_t n)
>    return n - to_do;
>  }
>  
> -
> -const struct _IO_jump_t _IO_old_file_jumps libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_old_file_finish),
> -  JUMP_INIT(overflow, _IO_old_file_overflow),
> -  JUMP_INIT(underflow, _IO_old_file_underflow),
> -  JUMP_INIT(uflow, _IO_default_uflow),
> -  JUMP_INIT(pbackfail, _IO_default_pbackfail),
> -  JUMP_INIT(xsputn, _IO_old_file_xsputn),
> -  JUMP_INIT(xsgetn, _IO_default_xsgetn),
> -  JUMP_INIT(seekoff, _IO_old_file_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_old_file_setbuf),
> -  JUMP_INIT(sync, _IO_old_file_sync),
> -  JUMP_INIT(doallocate, _IO_file_doallocate),
> -  JUMP_INIT(read, _IO_file_read),
> -  JUMP_INIT(write, _IO_old_file_write),
> -  JUMP_INIT(seek, _IO_file_seek),
> -  JUMP_INIT(close, _IO_file_close),
> -  JUMP_INIT(stat, _IO_file_stat)
> -};
> -
>  compat_symbol (libc, _IO_old_do_write, _IO_do_write, GLIBC_2_0);
>  compat_symbol (libc, _IO_old_file_attach, _IO_file_attach, GLIBC_2_0);
>  compat_symbol (libc, _IO_old_file_close_it, _IO_file_close_it, GLIBC_2_0);
> diff --git a/libio/oldiopopen.c b/libio/oldiopopen.c
> index aa5e379c85..b3eccc1352 100644
> --- a/libio/oldiopopen.c
> +++ b/libio/oldiopopen.c
> @@ -208,29 +208,6 @@ _IO_old_proc_close (FILE *fp)
>    return wstatus;
>  }
>  
> -const struct _IO_jump_t _IO_old_proc_jumps libio_vtable = {
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_old_file_finish),
> -  JUMP_INIT(overflow, _IO_old_file_overflow),
> -  JUMP_INIT(underflow, _IO_old_file_underflow),
> -  JUMP_INIT(uflow, _IO_default_uflow),
> -  JUMP_INIT(pbackfail, _IO_default_pbackfail),
> -  JUMP_INIT(xsputn, _IO_old_file_xsputn),
> -  JUMP_INIT(xsgetn, _IO_default_xsgetn),
> -  JUMP_INIT(seekoff, _IO_old_file_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_old_file_setbuf),
> -  JUMP_INIT(sync, _IO_old_file_sync),
> -  JUMP_INIT(doallocate, _IO_file_doallocate),
> -  JUMP_INIT(read, _IO_file_read),
> -  JUMP_INIT(write, _IO_old_file_write),
> -  JUMP_INIT(seek, _IO_file_seek),
> -  JUMP_INIT(close, _IO_old_proc_close),
> -  JUMP_INIT(stat, _IO_file_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> -
>  strong_alias (_IO_old_popen, __old_popen)
>  compat_symbol (libc, _IO_old_popen, _IO_popen, GLIBC_2_0);
>  compat_symbol (libc, __old_popen, popen, GLIBC_2_0);
> diff --git a/libio/stdio.c b/libio/stdio.c
> index fd94b76b56..c7c1b85c75 100644
> --- a/libio/stdio.c
> +++ b/libio/stdio.c
> @@ -33,3 +33,6 @@
>  FILE *stdin = (FILE *) &_IO_2_1_stdin_;
>  FILE *stdout = (FILE *) &_IO_2_1_stdout_;
>  FILE *stderr = (FILE *) &_IO_2_1_stderr_;
> +
> +libio_static_fn_required (_IO_file_open);
> +libio_static_fn_required (_IO_file_doallocate);
> diff --git a/libio/strfile.h b/libio/strfile.h
> index c50b34abd1..f21100f963 100644
> --- a/libio/strfile.h
> +++ b/libio/strfile.h
> @@ -78,8 +78,6 @@ typedef struct
>    wchar_t overflow_buf[64];
>  } _IO_wstrnfile;
>  
> -extern const struct _IO_jump_t _IO_wstrn_jumps attribute_hidden;
> -
>  /* Initialize an _IO_strfile SF to read from narrow string STRING, and
>     return the corresponding FILE object.  It is not necessary to fclose
>     the FILE when it is no longer needed.  */
> diff --git a/libio/strops.c b/libio/strops.c
> index b5c850b626..6379a87319 100644
> --- a/libio/strops.c
> +++ b/libio/strops.c
> @@ -352,27 +352,3 @@ _IO_str_finish (FILE *fp, int dummy)
>  
>    _IO_default_finish (fp, 0);
>  }
> -
> -const struct _IO_jump_t _IO_str_jumps libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_str_finish),
> -  JUMP_INIT(overflow, _IO_str_overflow),
> -  JUMP_INIT(underflow, _IO_str_underflow),
> -  JUMP_INIT(uflow, _IO_default_uflow),
> -  JUMP_INIT(pbackfail, _IO_str_pbackfail),
> -  JUMP_INIT(xsputn, _IO_default_xsputn),
> -  JUMP_INIT(xsgetn, _IO_default_xsgetn),
> -  JUMP_INIT(seekoff, _IO_str_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_default_setbuf),
> -  JUMP_INIT(sync, _IO_default_sync),
> -  JUMP_INIT(doallocate, _IO_default_doallocate),
> -  JUMP_INIT(read, _IO_default_read),
> -  JUMP_INIT(write, _IO_default_write),
> -  JUMP_INIT(seek, _IO_default_seek),
> -  JUMP_INIT(close, _IO_default_close),
> -  JUMP_INIT(stat, _IO_default_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> diff --git a/libio/tst-vtables-interposed.c b/libio/tst-vtables-interposed.c
> index 9068e53b88..e656f2b203 100644
> --- a/libio/tst-vtables-interposed.c
> +++ b/libio/tst-vtables-interposed.c
> @@ -21,7 +21,12 @@
>  /* Provide an interposed definition of the standard file handles with
>     our own vtable.  stdout/stdin/stderr will not work as a result, but
>     a succesful test does not print anything, so this is fine.  */
> +#include "libioP.h"
> +#undef _IO_file_jumps
>  #define _IO_file_jumps jumps
> +#undef _IO_wfile_jumps
> +extern const struct _IO_jump_t _IO_wfile_jumps;
> +#define _IO_wfile_jumps _IO_wfile_jumps
>  #include "stdfiles.c"
>  
>  static int
> diff --git a/libio/vtables.c b/libio/vtables.c
> index 5d5906a818..3facd40a51 100644
> --- a/libio/vtables.c
> +++ b/libio/vtables.c
> @@ -21,6 +21,472 @@
>  #include <stdio.h>
>  #include <ldsodefs.h>
>  #include <pointer_guard.h>
> +#include <libio-macros.h>
> +
> +/* Both _IO_str_* and _IO_new_file functions are pulled into every link (from
> +   stdio initialization).  */

OK.

> +#ifndef SHARED
> +/* NB: the following directives do add pragma weak for _IO_default _* and
> +   _IO_wdefault_* symbols to potentially avoid link failures, since they
> +   are always used when the __io_vtables is used.  */
> +# pragma weak _IO_wstr_finish
> +# pragma weak _IO_wstr_overflow
> +# pragma weak _IO_wstr_pbackfail
> +# pragma weak _IO_wstr_seekoff
> +# pragma weak _IO_wstr_underflow
> +
> +# pragma weak _IO_file_close
> +# pragma weak _IO_file_close_mmap
> +# pragma weak _IO_file_doallocate
> +# pragma weak _IO_file_finish
> +# pragma weak _IO_file_jumps_alias
> +# pragma weak _IO_file_overflow
> +# pragma weak _IO_file_read
> +# pragma weak _IO_file_seek
> +# pragma weak _IO_file_seekoff_maybe_mmap
> +# pragma weak _IO_file_seekoff_mmap
> +# pragma weak _IO_file_setbuf
> +# pragma weak _IO_file_setbuf_mmap
> +# pragma weak _IO_file_setbuf_mmap
> +# pragma weak _IO_file_stat
> +# pragma weak _IO_file_sync
> +# pragma weak _IO_file_sync_mmap
> +# pragma weak _IO_file_underflow
> +# pragma weak _IO_file_underflow_maybe_mmap
> +# pragma weak _IO_file_underflow_mmap
> +# pragma weak _IO_file_xsgetn
> +# pragma weak _IO_file_xsgetn_maybe_mmap
> +# pragma weak _IO_file_xsgetn_mmap
> +# pragma weak _IO_file_xsputn
> +
> +# pragma weak _IO_wfile_overflow
> +# pragma weak _IO_wfile_sync
> +# pragma weak _IO_wfile_underflow
> +# pragma weak _IO_wfile_underflow_maybe_mmap
> +# pragma weak _IO_wfile_underflow_mmap
> +# pragma weak _IO_wfile_doallocate
> +# pragma weak _IO_wfile_jumps_alia
> +# pragma weak _IO_wfile_seekoff
> +# pragma weak _IO_wfile_xsputn
> +
> +# pragma weak _IO_new_proc_close
> +
> +# pragma weak _IO_cookie_close
> +# pragma weak _IO_cookie_read
> +# pragma weak _IO_cookie_seek
> +# pragma weak _IO_cookie_seekoff
> +# pragma weak _IO_cookie_write
> +
> +# pragma weak _IO_mem_finish
> +# pragma weak _IO_mem_sync
> +
> +# pragma weak _IO_wmem_finish
> +# pragma weak _IO_wmem_sync
> +
> +# pragma weak __printf_buffer_as_file_overflow
> +# pragma weak __printf_buffer_as_file_xsputn
> +
> +# pragma weak __wprintf_buffer_as_file_overflow
> +# pragma weak __wprintf_buffer_as_file_xsputn
> +#endif
> +
> +const struct _IO_jump_t __io_vtables[IO_VTABLES_LEN] attribute_relro =
> +{
> +  /* _IO_str_jumps  */
> +  [IO_STR_JUMPS] =
> +  {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_str_finish),
> +    JUMP_INIT (overflow, _IO_str_overflow),
> +    JUMP_INIT (underflow, _IO_str_underflow),
> +    JUMP_INIT (uflow, _IO_default_uflow),
> +    JUMP_INIT (pbackfail, _IO_str_pbackfail),
> +    JUMP_INIT (xsputn, _IO_default_xsputn),
> +    JUMP_INIT (xsgetn, _IO_default_xsgetn),
> +    JUMP_INIT (seekoff, _IO_str_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_default_setbuf),
> +    JUMP_INIT (sync, _IO_default_sync),
> +    JUMP_INIT (doallocate, _IO_default_doallocate),
> +    JUMP_INIT (read, _IO_default_read),
> +    JUMP_INIT (write, _IO_default_write),
> +    JUMP_INIT (seek, _IO_default_seek),
> +    JUMP_INIT (close, _IO_default_close),
> +    JUMP_INIT (stat, _IO_default_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  /* _IO_wstr_jumps  */
> +  [IO_WSTR_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_wstr_finish),
> +    JUMP_INIT (overflow, (_IO_overflow_t) _IO_wstr_overflow),
> +    JUMP_INIT (underflow, (_IO_underflow_t) _IO_wstr_underflow),
> +    JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
> +    JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
> +    JUMP_INIT (xsputn, _IO_wdefault_xsputn),
> +    JUMP_INIT (xsgetn, _IO_wdefault_xsgetn),
> +    JUMP_INIT (seekoff, _IO_wstr_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_default_setbuf),
> +    JUMP_INIT (sync, _IO_default_sync),
> +    JUMP_INIT (doallocate, _IO_wdefault_doallocate),
> +    JUMP_INIT (read, _IO_default_read),
> +    JUMP_INIT (write, _IO_default_write),
> +    JUMP_INIT (seek, _IO_default_seek),
> +    JUMP_INIT (close, _IO_default_close),
> +    JUMP_INIT (stat, _IO_default_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  /* _IO_file_jumps  */
> +  [IO_FILE_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_file_finish),
> +    JUMP_INIT (overflow, _IO_file_overflow),
> +    JUMP_INIT (underflow, _IO_file_underflow),
> +    JUMP_INIT (uflow, _IO_default_uflow),
> +    JUMP_INIT (pbackfail, _IO_default_pbackfail),
> +    JUMP_INIT (xsputn, _IO_file_xsputn),
> +    JUMP_INIT (xsgetn, _IO_file_xsgetn),
> +    JUMP_INIT (seekoff, _IO_new_file_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_new_file_setbuf),
> +    JUMP_INIT (sync, _IO_new_file_sync),
> +    JUMP_INIT (doallocate, _IO_file_doallocate),
> +    JUMP_INIT (read, _IO_file_read),
> +    JUMP_INIT (write, _IO_new_file_write),
> +    JUMP_INIT (seek, _IO_file_seek),
> +    JUMP_INIT (close, _IO_file_close),
> +    JUMP_INIT (stat, _IO_file_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  /* _IO_file_jumps_mmap  */
> +  [IO_FILE_JUMPS_MMAP] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_file_finish),
> +    JUMP_INIT (overflow, _IO_file_overflow),
> +    JUMP_INIT (underflow, _IO_file_underflow_mmap),
> +    JUMP_INIT (uflow, _IO_default_uflow),
> +    JUMP_INIT (pbackfail, _IO_default_pbackfail),
> +    JUMP_INIT (xsputn, _IO_new_file_xsputn),
> +    JUMP_INIT (xsgetn, _IO_file_xsgetn_mmap),
> +    JUMP_INIT (seekoff, _IO_file_seekoff_mmap),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, (_IO_setbuf_t) _IO_file_setbuf_mmap),
> +    JUMP_INIT (sync, _IO_file_sync_mmap),
> +    JUMP_INIT (doallocate, _IO_file_doallocate),
> +    JUMP_INIT (read, _IO_file_read),
> +    JUMP_INIT (write, _IO_new_file_write),
> +    JUMP_INIT (seek, _IO_file_seek),
> +    JUMP_INIT (close, _IO_file_close_mmap),
> +    JUMP_INIT (stat, _IO_file_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  /* _IO_file_jumps_maybe_mmap  */
> +  [IO_FILE_JUMPS_MAYBE_MMAP] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_file_finish),
> +    JUMP_INIT (overflow, _IO_file_overflow),
> +    JUMP_INIT (underflow, _IO_file_underflow_maybe_mmap),
> +    JUMP_INIT (uflow, _IO_default_uflow),
> +    JUMP_INIT (pbackfail, _IO_default_pbackfail),
> +    JUMP_INIT (xsputn, _IO_new_file_xsputn),
> +    JUMP_INIT (xsgetn, _IO_file_xsgetn_maybe_mmap),
> +    JUMP_INIT (seekoff, _IO_file_seekoff_maybe_mmap),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, (_IO_setbuf_t) _IO_file_setbuf_mmap),
> +    JUMP_INIT (sync, _IO_new_file_sync),
> +    JUMP_INIT (doallocate, _IO_file_doallocate),
> +    JUMP_INIT (read, _IO_file_read),
> +    JUMP_INIT (write, _IO_new_file_write),
> +    JUMP_INIT (seek, _IO_file_seek),
> +    JUMP_INIT (close, _IO_file_close),
> +    JUMP_INIT (stat, _IO_file_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  /* _IO_wfile_jumps  */
> +  [IO_WFILE_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_new_file_finish),
> +    JUMP_INIT (overflow, (_IO_overflow_t) _IO_wfile_overflow),
> +    JUMP_INIT (underflow, (_IO_underflow_t) _IO_wfile_underflow),
> +    JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
> +    JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wdefault_pbackfail),
> +    JUMP_INIT (xsputn, _IO_wfile_xsputn),
> +    JUMP_INIT (xsgetn, _IO_file_xsgetn),
> +    JUMP_INIT (seekoff, _IO_wfile_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_new_file_setbuf),
> +    JUMP_INIT (sync, (_IO_sync_t) _IO_wfile_sync),
> +    JUMP_INIT (doallocate, _IO_wfile_doallocate),
> +    JUMP_INIT (read, _IO_file_read),
> +    JUMP_INIT (write, _IO_new_file_write),
> +    JUMP_INIT (seek, _IO_file_seek),
> +    JUMP_INIT (close, _IO_file_close),
> +    JUMP_INIT (stat, _IO_file_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  /* _IO_wfile_jumps_mmap  */
> +  [IO_WFILE_JUMPS_MMAP] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_new_file_finish),
> +    JUMP_INIT (overflow, (_IO_overflow_t) _IO_wfile_overflow),
> +    JUMP_INIT (underflow, (_IO_underflow_t) _IO_wfile_underflow_mmap),
> +    JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
> +    JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wdefault_pbackfail),
> +    JUMP_INIT (xsputn, _IO_wfile_xsputn),
> +    JUMP_INIT (xsgetn, _IO_file_xsgetn),
> +    JUMP_INIT (seekoff, _IO_wfile_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_file_setbuf_mmap),
> +    JUMP_INIT (sync, (_IO_sync_t) _IO_wfile_sync),
> +    JUMP_INIT (doallocate, _IO_wfile_doallocate),
> +    JUMP_INIT (read, _IO_file_read),
> +    JUMP_INIT (write, _IO_new_file_write),
> +    JUMP_INIT (seek, _IO_file_seek),
> +    JUMP_INIT (close, _IO_file_close_mmap),
> +    JUMP_INIT (stat, _IO_file_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  /* _IO_wfile_jumps_maybe_mmap  */
> +  [IO_WFILE_JUMPS_MAYBE_MMAP] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_new_file_finish),
> +    JUMP_INIT (overflow, (_IO_overflow_t) _IO_wfile_overflow),
> +    JUMP_INIT (underflow, (_IO_underflow_t) _IO_wfile_underflow_maybe_mmap),
> +    JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
> +    JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wdefault_pbackfail),
> +    JUMP_INIT (xsputn, _IO_wfile_xsputn),
> +    JUMP_INIT (xsgetn, _IO_file_xsgetn),
> +    JUMP_INIT (seekoff, _IO_wfile_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_file_setbuf_mmap),
> +    JUMP_INIT (sync, (_IO_sync_t) _IO_wfile_sync),
> +    JUMP_INIT (doallocate, _IO_wfile_doallocate),
> +    JUMP_INIT (read, _IO_file_read),
> +    JUMP_INIT (write, _IO_new_file_write),
> +    JUMP_INIT (seek, _IO_file_seek),
> +    JUMP_INIT (close, _IO_file_close),
> +    JUMP_INIT (stat, _IO_file_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  /* _IO_cookie_jumps  */
> +  [IO_COOKIE_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_file_finish),
> +    JUMP_INIT (overflow, _IO_file_overflow),
> +    JUMP_INIT (underflow, _IO_file_underflow),
> +    JUMP_INIT (uflow, _IO_default_uflow),
> +    JUMP_INIT (pbackfail, _IO_default_pbackfail),
> +    JUMP_INIT (xsputn, _IO_file_xsputn),
> +    JUMP_INIT (xsgetn, _IO_default_xsgetn),
> +    JUMP_INIT (seekoff, _IO_cookie_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_file_setbuf),
> +    JUMP_INIT (sync, _IO_file_sync),
> +    JUMP_INIT (doallocate, _IO_file_doallocate),
> +    JUMP_INIT (read, _IO_cookie_read),
> +    JUMP_INIT (write, _IO_cookie_write),
> +    JUMP_INIT (seek, _IO_cookie_seek),
> +    JUMP_INIT (close, _IO_cookie_close),
> +    JUMP_INIT (stat, _IO_default_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue),
> +  },
> +  /* _IO_proc_jumps  */
> +  [IO_PROC_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_new_file_finish),
> +    JUMP_INIT (overflow, _IO_new_file_overflow),
> +    JUMP_INIT (underflow, _IO_new_file_underflow),
> +    JUMP_INIT (uflow, _IO_default_uflow),
> +    JUMP_INIT (pbackfail, _IO_default_pbackfail),
> +    JUMP_INIT (xsputn, _IO_new_file_xsputn),
> +    JUMP_INIT (xsgetn, _IO_default_xsgetn),
> +    JUMP_INIT (seekoff, _IO_new_file_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_new_file_setbuf),
> +    JUMP_INIT (sync, _IO_new_file_sync),
> +    JUMP_INIT (doallocate, _IO_file_doallocate),
> +    JUMP_INIT (read, _IO_file_read),
> +    JUMP_INIT (write, _IO_new_file_write),
> +    JUMP_INIT (seek, _IO_file_seek),
> +    JUMP_INIT (close, _IO_new_proc_close),
> +    JUMP_INIT (stat, _IO_file_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  /* _IO_mem_jumps  */
> +  [IO_MEM_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_mem_finish),
> +    JUMP_INIT (overflow, _IO_str_overflow),
> +    JUMP_INIT (underflow, _IO_str_underflow),
> +    JUMP_INIT (uflow, _IO_default_uflow),
> +    JUMP_INIT (pbackfail, _IO_str_pbackfail),
> +    JUMP_INIT (xsputn, _IO_default_xsputn),
> +    JUMP_INIT (xsgetn, _IO_default_xsgetn),
> +    JUMP_INIT (seekoff, _IO_str_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_default_setbuf),
> +    JUMP_INIT (sync, _IO_mem_sync),
> +    JUMP_INIT (doallocate, _IO_default_doallocate),
> +    JUMP_INIT (read, _IO_default_read),
> +    JUMP_INIT (write, _IO_default_write),
> +    JUMP_INIT (seek, _IO_default_seek),
> +    JUMP_INIT (close, _IO_default_close),
> +    JUMP_INIT (stat, _IO_default_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  /* _IO_wmem_jumps  */
> +  [IO_WMEM_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_wmem_finish),
> +    JUMP_INIT (overflow, (_IO_overflow_t) _IO_wstr_overflow),
> +    JUMP_INIT (underflow, (_IO_underflow_t) _IO_wstr_underflow),
> +    JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
> +    JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
> +    JUMP_INIT (xsputn, _IO_wdefault_xsputn),
> +    JUMP_INIT (xsgetn, _IO_wdefault_xsgetn),
> +    JUMP_INIT (seekoff, _IO_wstr_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_default_setbuf),
> +    JUMP_INIT (sync, _IO_wmem_sync),
> +    JUMP_INIT (doallocate, _IO_wdefault_doallocate),
> +    JUMP_INIT (read, _IO_default_read),
> +    JUMP_INIT (write, _IO_default_write),
> +    JUMP_INIT (seek, _IO_default_seek),
> +    JUMP_INIT (close, _IO_default_close),
> +    JUMP_INIT (stat, _IO_default_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +  [IO_PRINTF_BUFFER_AS_FILE_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, NULL),
> +    JUMP_INIT (overflow, __printf_buffer_as_file_overflow),
> +    JUMP_INIT (underflow, NULL),
> +    JUMP_INIT (uflow, NULL),
> +    JUMP_INIT (pbackfail, NULL),
> +    JUMP_INIT (xsputn, __printf_buffer_as_file_xsputn),
> +    JUMP_INIT (xsgetn, NULL),
> +    JUMP_INIT (seekoff, NULL),
> +    JUMP_INIT (seekpos, NULL),
> +    JUMP_INIT (setbuf, NULL),
> +    JUMP_INIT (sync, NULL),
> +    JUMP_INIT (doallocate, NULL),
> +    JUMP_INIT (read, NULL),
> +    JUMP_INIT (write, NULL),
> +    JUMP_INIT (seek, NULL),
> +    JUMP_INIT (close, NULL),
> +    JUMP_INIT (stat, NULL),
> +    JUMP_INIT (showmanyc, NULL),
> +    JUMP_INIT (imbue, NULL)
> +  },
> +  [IO_WPRINTF_BUFFER_AS_FILE_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, NULL),
> +    JUMP_INIT (overflow, (_IO_overflow_t) __wprintf_buffer_as_file_overflow),
> +    JUMP_INIT (underflow, NULL),
> +    JUMP_INIT (uflow, NULL),
> +    JUMP_INIT (pbackfail, NULL),
> +    JUMP_INIT (xsputn, __wprintf_buffer_as_file_xsputn),
> +    JUMP_INIT (xsgetn, NULL),
> +    JUMP_INIT (seekoff, NULL),
> +    JUMP_INIT (seekpos, NULL),
> +    JUMP_INIT (setbuf, NULL),
> +    JUMP_INIT (sync, NULL),
> +    JUMP_INIT (doallocate, NULL),
> +    JUMP_INIT (read, NULL),
> +    JUMP_INIT (write, NULL),
> +    JUMP_INIT (seek, NULL),
> +    JUMP_INIT (close, NULL),
> +    JUMP_INIT (stat, NULL),
> +    JUMP_INIT (showmanyc, NULL),
> +    JUMP_INIT (imbue, NULL)
> +  },
> +
> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_1)

OK.

> +  /* _IO_old_file_jumps  */
> +  [IO_OLD_FILE_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_old_file_finish),
> +    JUMP_INIT (overflow, _IO_old_file_overflow),
> +    JUMP_INIT (underflow, _IO_old_file_underflow),
> +    JUMP_INIT (uflow, _IO_default_uflow),
> +    JUMP_INIT (pbackfail, _IO_default_pbackfail),
> +    JUMP_INIT (xsputn, _IO_old_file_xsputn),
> +    JUMP_INIT (xsgetn, _IO_default_xsgetn),
> +    JUMP_INIT (seekoff, _IO_old_file_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_old_file_setbuf),
> +    JUMP_INIT (sync, _IO_old_file_sync),
> +    JUMP_INIT (doallocate, _IO_file_doallocate),
> +    JUMP_INIT (read, _IO_file_read),
> +    JUMP_INIT (write, _IO_old_file_write),
> +    JUMP_INIT (seek, _IO_file_seek),
> +    JUMP_INIT (close, _IO_file_close),
> +    JUMP_INIT (stat, _IO_file_stat)
> +  },
> +  /*  _IO_old_proc_jumps  */
> +  [IO_OLD_PROC_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_old_file_finish),
> +    JUMP_INIT (overflow, _IO_old_file_overflow),
> +    JUMP_INIT (underflow, _IO_old_file_underflow),
> +    JUMP_INIT (uflow, _IO_default_uflow),
> +    JUMP_INIT (pbackfail, _IO_default_pbackfail),
> +    JUMP_INIT (xsputn, _IO_old_file_xsputn),
> +    JUMP_INIT (xsgetn, _IO_default_xsgetn),
> +    JUMP_INIT (seekoff, _IO_old_file_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_old_file_setbuf),
> +    JUMP_INIT (sync, _IO_old_file_sync),
> +    JUMP_INIT (doallocate, _IO_file_doallocate),
> +    JUMP_INIT (read, _IO_file_read),
> +    JUMP_INIT (write, _IO_old_file_write),
> +    JUMP_INIT (seek, _IO_file_seek),
> +    JUMP_INIT (close, _IO_old_proc_close),
> +    JUMP_INIT (stat, _IO_file_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue)
> +  },
> +#endif
> +
> +#if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_2)

OK.

> +  /* _IO_old_cookie_jumps  */
> +  [IO_OLD_COOKIED_JUMPS] = {
> +    JUMP_INIT_DUMMY,
> +    JUMP_INIT (finish, _IO_file_finish),
> +    JUMP_INIT (overflow, _IO_file_overflow),
> +    JUMP_INIT (underflow, _IO_file_underflow),
> +    JUMP_INIT (uflow, _IO_default_uflow),
> +    JUMP_INIT (pbackfail, _IO_default_pbackfail),
> +    JUMP_INIT (xsputn, _IO_file_xsputn),
> +    JUMP_INIT (xsgetn, _IO_default_xsgetn),
> +    JUMP_INIT (seekoff, _IO_cookie_seekoff),
> +    JUMP_INIT (seekpos, _IO_default_seekpos),
> +    JUMP_INIT (setbuf, _IO_file_setbuf),
> +    JUMP_INIT (sync, _IO_file_sync),
> +    JUMP_INIT (doallocate, _IO_file_doallocate),
> +    JUMP_INIT (read, _IO_cookie_read),
> +    JUMP_INIT (write, _IO_cookie_write),
> +    JUMP_INIT (seek, _IO_old_cookie_seek),
> +    JUMP_INIT (close, _IO_cookie_close),
> +    JUMP_INIT (stat, _IO_default_stat),
> +    JUMP_INIT (showmanyc, _IO_default_showmanyc),
> +    JUMP_INIT (imbue, _IO_default_imbue),
> +  },
> +#endif
> +};
>  
>  #ifdef SHARED
>  
> @@ -82,3 +548,15 @@ check_stdfiles_vtables (void)
>      IO_set_accept_foreign_vtables (&_IO_vtable_check);
>  }
>  #endif
> +
> +#define STR(s)  XSTR(s)
> +#define XSTR(s) #s
> +
> +#undef _IO_file_jumps
> +#define _IO_file_jumps_alias  "__io_vtables + " STR(IO_FILE_JUMPS_OFFSET)
> +declare_object_symbol_alias (_IO_file_jumps, _IO_file_jumps_alias,
> +			     IO_JUMP_T_SIZE)
> +#undef _IO_wfile_jumps
> +#define _IO_wfile_jumps_alias  "__io_vtables + " STR(IO_WFILE_JUMPS_OFFSET)
> +declare_object_symbol_alias (_IO_wfile_jumps, _IO_wfile_jumps_alias,
> +			     IO_JUMP_T_SIZE)
> diff --git a/libio/wfileops.c b/libio/wfileops.c
> index cecea21c1c..f16f6db1c3 100644
> --- a/libio/wfileops.c
> +++ b/libio/wfileops.c
> @@ -328,7 +328,7 @@ _IO_wfile_underflow (FILE *fp)
>  libc_hidden_def (_IO_wfile_underflow)
>  
>  
> -static wint_t
> +wint_t
>  _IO_wfile_underflow_mmap (FILE *fp)
>  {
>    struct _IO_codecvt *cd;
> @@ -389,7 +389,7 @@ _IO_wfile_underflow_mmap (FILE *fp)
>    return WEOF;
>  }
>  
> -static wint_t
> +wint_t
>  _IO_wfile_underflow_maybe_mmap (FILE *fp)
>  {
>    /* This is the first read attempt.  Doing the underflow will choose mmap
> @@ -1017,78 +1017,3 @@ _IO_wfile_xsputn (FILE *f, const void *data, size_t n)
>    return n - to_do;
>  }
>  libc_hidden_def (_IO_wfile_xsputn)
> -
> -
> -const struct _IO_jump_t _IO_wfile_jumps libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_new_file_finish),
> -  JUMP_INIT(overflow, (_IO_overflow_t) _IO_wfile_overflow),
> -  JUMP_INIT(underflow, (_IO_underflow_t) _IO_wfile_underflow),
> -  JUMP_INIT(uflow, (_IO_underflow_t) _IO_wdefault_uflow),
> -  JUMP_INIT(pbackfail, (_IO_pbackfail_t) _IO_wdefault_pbackfail),
> -  JUMP_INIT(xsputn, _IO_wfile_xsputn),
> -  JUMP_INIT(xsgetn, _IO_file_xsgetn),
> -  JUMP_INIT(seekoff, _IO_wfile_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_new_file_setbuf),
> -  JUMP_INIT(sync, (_IO_sync_t) _IO_wfile_sync),
> -  JUMP_INIT(doallocate, _IO_wfile_doallocate),
> -  JUMP_INIT(read, _IO_file_read),
> -  JUMP_INIT(write, _IO_new_file_write),
> -  JUMP_INIT(seek, _IO_file_seek),
> -  JUMP_INIT(close, _IO_file_close),
> -  JUMP_INIT(stat, _IO_file_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> -libc_hidden_data_def (_IO_wfile_jumps)
> -
> -
> -const struct _IO_jump_t _IO_wfile_jumps_mmap libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_new_file_finish),
> -  JUMP_INIT(overflow, (_IO_overflow_t) _IO_wfile_overflow),
> -  JUMP_INIT(underflow, (_IO_underflow_t) _IO_wfile_underflow_mmap),
> -  JUMP_INIT(uflow, (_IO_underflow_t) _IO_wdefault_uflow),
> -  JUMP_INIT(pbackfail, (_IO_pbackfail_t) _IO_wdefault_pbackfail),
> -  JUMP_INIT(xsputn, _IO_wfile_xsputn),
> -  JUMP_INIT(xsgetn, _IO_file_xsgetn),
> -  JUMP_INIT(seekoff, _IO_wfile_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_file_setbuf_mmap),
> -  JUMP_INIT(sync, (_IO_sync_t) _IO_wfile_sync),
> -  JUMP_INIT(doallocate, _IO_wfile_doallocate),
> -  JUMP_INIT(read, _IO_file_read),
> -  JUMP_INIT(write, _IO_new_file_write),
> -  JUMP_INIT(seek, _IO_file_seek),
> -  JUMP_INIT(close, _IO_file_close_mmap),
> -  JUMP_INIT(stat, _IO_file_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> -
> -const struct _IO_jump_t _IO_wfile_jumps_maybe_mmap libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_new_file_finish),
> -  JUMP_INIT(overflow, (_IO_overflow_t) _IO_wfile_overflow),
> -  JUMP_INIT(underflow, (_IO_underflow_t) _IO_wfile_underflow_maybe_mmap),
> -  JUMP_INIT(uflow, (_IO_underflow_t) _IO_wdefault_uflow),
> -  JUMP_INIT(pbackfail, (_IO_pbackfail_t) _IO_wdefault_pbackfail),
> -  JUMP_INIT(xsputn, _IO_wfile_xsputn),
> -  JUMP_INIT(xsgetn, _IO_file_xsgetn),
> -  JUMP_INIT(seekoff, _IO_wfile_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_file_setbuf_mmap),
> -  JUMP_INIT(sync, (_IO_sync_t) _IO_wfile_sync),
> -  JUMP_INIT(doallocate, _IO_wfile_doallocate),
> -  JUMP_INIT(read, _IO_file_read),
> -  JUMP_INIT(write, _IO_new_file_write),
> -  JUMP_INIT(seek, _IO_file_seek),
> -  JUMP_INIT(close, _IO_file_close),
> -  JUMP_INIT(stat, _IO_file_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> diff --git a/libio/wmemstream.c b/libio/wmemstream.c
> index 6560d7001f..7b04b15cbc 100644
> --- a/libio/wmemstream.c
> +++ b/libio/wmemstream.c
> @@ -30,34 +30,6 @@ struct _IO_FILE_wmemstream
>  };
>  
>  
> -static int _IO_wmem_sync (FILE* fp) __THROW;
> -static void _IO_wmem_finish (FILE* fp, int) __THROW;
> -
> -
> -static const struct _IO_jump_t _IO_wmem_jumps libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT (finish, _IO_wmem_finish),
> -  JUMP_INIT (overflow, (_IO_overflow_t) _IO_wstr_overflow),
> -  JUMP_INIT (underflow, (_IO_underflow_t) _IO_wstr_underflow),
> -  JUMP_INIT (uflow, (_IO_underflow_t) _IO_wdefault_uflow),
> -  JUMP_INIT (pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
> -  JUMP_INIT (xsputn, _IO_wdefault_xsputn),
> -  JUMP_INIT (xsgetn, _IO_wdefault_xsgetn),
> -  JUMP_INIT (seekoff, _IO_wstr_seekoff),
> -  JUMP_INIT (seekpos, _IO_default_seekpos),
> -  JUMP_INIT (setbuf, _IO_default_setbuf),
> -  JUMP_INIT (sync, _IO_wmem_sync),
> -  JUMP_INIT (doallocate, _IO_wdefault_doallocate),
> -  JUMP_INIT (read, _IO_default_read),
> -  JUMP_INIT (write, _IO_default_write),
> -  JUMP_INIT (seek, _IO_default_seek),
> -  JUMP_INIT (close, _IO_default_close),
> -  JUMP_INIT (stat, _IO_default_stat),
> -  JUMP_INIT (showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT (imbue, _IO_default_imbue)
> -};
> -
>  /* Open a stream that writes into a malloc'd buffer that is expanded as
>     necessary.  *BUFLOC and *SIZELOC are updated with the buffer's location
>     and the number of characters written on fflush or fclose.  */
> @@ -105,7 +77,7 @@ open_wmemstream (wchar_t **bufloc, size_t *sizeloc)
>  }
>  
>  
> -static int
> +int
>  _IO_wmem_sync (FILE *fp)
>  {
>    struct _IO_FILE_wmemstream *mp = (struct _IO_FILE_wmemstream *) fp;
> @@ -124,7 +96,7 @@ _IO_wmem_sync (FILE *fp)
>  }
>  
>  
> -static void
> +void
>  _IO_wmem_finish (FILE *fp, int dummy)
>  {
>    struct _IO_FILE_wmemstream *mp = (struct _IO_FILE_wmemstream *) fp;
> diff --git a/libio/wstrops.c b/libio/wstrops.c
> index 9c9d303968..632fc123a2 100644
> --- a/libio/wstrops.c
> +++ b/libio/wstrops.c
> @@ -361,27 +361,3 @@ _IO_wstr_finish (FILE *fp, int dummy)
>  
>    _IO_wdefault_finish (fp, 0);
>  }
> -
> -const struct _IO_jump_t _IO_wstr_jumps libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, _IO_wstr_finish),
> -  JUMP_INIT(overflow, (_IO_overflow_t) _IO_wstr_overflow),
> -  JUMP_INIT(underflow, (_IO_underflow_t) _IO_wstr_underflow),
> -  JUMP_INIT(uflow, (_IO_underflow_t) _IO_wdefault_uflow),
> -  JUMP_INIT(pbackfail, (_IO_pbackfail_t) _IO_wstr_pbackfail),
> -  JUMP_INIT(xsputn, _IO_wdefault_xsputn),
> -  JUMP_INIT(xsgetn, _IO_wdefault_xsgetn),
> -  JUMP_INIT(seekoff, _IO_wstr_seekoff),
> -  JUMP_INIT(seekpos, _IO_default_seekpos),
> -  JUMP_INIT(setbuf, _IO_default_setbuf),
> -  JUMP_INIT(sync, _IO_default_sync),
> -  JUMP_INIT(doallocate, _IO_wdefault_doallocate),
> -  JUMP_INIT(read, _IO_default_read),
> -  JUMP_INIT(write, _IO_default_write),
> -  JUMP_INIT(seek, _IO_default_seek),
> -  JUMP_INIT(close, _IO_default_close),
> -  JUMP_INIT(stat, _IO_default_stat),
> -  JUMP_INIT(showmanyc, _IO_default_showmanyc),
> -  JUMP_INIT(imbue, _IO_default_imbue)
> -};
> diff --git a/stdio-common/printf_buffer_as_file.c b/stdio-common/printf_buffer_as_file.c
> index 12b0e13f41..fe23797da2 100644
> --- a/stdio-common/printf_buffer_as_file.c
> +++ b/stdio-common/printf_buffer_as_file.c
> @@ -48,7 +48,7 @@ __printf_buffer_as_file_switch_to_buffer (struct __printf_buffer_as_file *file)
>  /* Only a small subset of the vtable functions is implemented here,
>     following _IO_obstack_jumps.  */
>  
> -static int
> +int
>  __printf_buffer_as_file_overflow (FILE *fp, int ch)
>  {
>    struct __printf_buffer_as_file *file = (struct __printf_buffer_as_file *) fp;
> @@ -72,7 +72,7 @@ __printf_buffer_as_file_overflow (FILE *fp, int ch)
>      return EOF;
>  }
>  
> -static size_t
> +size_t
>  __printf_buffer_as_file_xsputn (FILE *fp, const void *buf, size_t len)
>  {
>    struct __printf_buffer_as_file *file = (struct __printf_buffer_as_file *) fp;
> @@ -93,30 +93,6 @@ __printf_buffer_as_file_xsputn (FILE *fp, const void *buf, size_t len)
>      return 0;
>  }
>  
> -static const struct _IO_jump_t _IO_printf_buffer_as_file_jumps libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, NULL),
> -  JUMP_INIT(overflow, __printf_buffer_as_file_overflow),
> -  JUMP_INIT(underflow, NULL),
> -  JUMP_INIT(uflow, NULL),
> -  JUMP_INIT(pbackfail, NULL),
> -  JUMP_INIT(xsputn, __printf_buffer_as_file_xsputn),
> -  JUMP_INIT(xsgetn, NULL),
> -  JUMP_INIT(seekoff, NULL),
> -  JUMP_INIT(seekpos, NULL),
> -  JUMP_INIT(setbuf, NULL),
> -  JUMP_INIT(sync, NULL),
> -  JUMP_INIT(doallocate, NULL),
> -  JUMP_INIT(read, NULL),
> -  JUMP_INIT(write, NULL),
> -  JUMP_INIT(seek, NULL),
> -  JUMP_INIT(close, NULL),
> -  JUMP_INIT(stat, NULL),
> -  JUMP_INIT(showmanyc, NULL),
> -  JUMP_INIT(imbue, NULL)
> -};
> -
>  void
>  __printf_buffer_as_file_init (struct __printf_buffer_as_file *file,
>                                struct __printf_buffer *next)
> diff --git a/stdio-common/wprintf_buffer_as_file.c b/stdio-common/wprintf_buffer_as_file.c
> index b2e5b5ada9..dbdb8cc535 100644
> --- a/stdio-common/wprintf_buffer_as_file.c
> +++ b/stdio-common/wprintf_buffer_as_file.c
> @@ -48,7 +48,7 @@ __wprintf_buffer_as_file_switch_to_buffer (struct __wprintf_buffer_as_file *file
>  /* Only a small subset of the vtable functions is implemented here,
>     following _IO_obstack_jumps.  */
>  
> -static wint_t
> +wint_t
>  __wprintf_buffer_as_file_overflow (FILE *fp, int ch)
>  {
>    struct __wprintf_buffer_as_file *file
> @@ -75,7 +75,7 @@ __wprintf_buffer_as_file_overflow (FILE *fp, int ch)
>      return WEOF;
>  }
>  
> -static size_t
> +size_t
>  __wprintf_buffer_as_file_xsputn (FILE *fp, const void *buf, size_t len)
>  {
>    struct __wprintf_buffer_as_file *file
> @@ -97,30 +97,6 @@ __wprintf_buffer_as_file_xsputn (FILE *fp, const void *buf, size_t len)
>      return 0;
>  }
>  
> -static const struct _IO_jump_t _IO_wprintf_buffer_as_file_jumps libio_vtable =
> -{
> -  JUMP_INIT_DUMMY,
> -  JUMP_INIT(finish, NULL),
> -  JUMP_INIT(overflow, (_IO_overflow_t) __wprintf_buffer_as_file_overflow),
> -  JUMP_INIT(underflow, NULL),
> -  JUMP_INIT(uflow, NULL),
> -  JUMP_INIT(pbackfail, NULL),
> -  JUMP_INIT(xsputn, __wprintf_buffer_as_file_xsputn),
> -  JUMP_INIT(xsgetn, NULL),
> -  JUMP_INIT(seekoff, NULL),
> -  JUMP_INIT(seekpos, NULL),
> -  JUMP_INIT(setbuf, NULL),
> -  JUMP_INIT(sync, NULL),
> -  JUMP_INIT(doallocate, NULL),
> -  JUMP_INIT(read, NULL),
> -  JUMP_INIT(write, NULL),
> -  JUMP_INIT(seek, NULL),
> -  JUMP_INIT(close, NULL),
> -  JUMP_INIT(stat, NULL),
> -  JUMP_INIT(showmanyc, NULL),
> -  JUMP_INIT(imbue, NULL)
> -};
> -
>  void
>  __wprintf_buffer_as_file_init (struct __wprintf_buffer_as_file *file,
>                                 struct __wprintf_buffer *next)