This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH] libio: Remove codecvt vtable [BZ #24588]
- From: Adhemerval Zanella <adhemerval dot zanella at linaro dot org>
- To: libc-alpha at sourceware dot org
- Date: Mon, 20 May 2019 16:46:40 -0300
- Subject: Re: [PATCH] libio: Remove codecvt vtable [BZ #24588]
- References: <87d0kdjliz.fsf@oldenburg2.str.redhat.com>
On 20/05/2019 10:36, Florian Weimer wrote:
> The codecvt vtable is not a real vtable because it also contains the
> conversion state data. Furthermore, wide stream support was added to
> GCC 3.0, after a C++ ABI bump, so there is no compatibility requirement
> with libstdc++.
>
> This change removes several unmangled function pointers which could
> be used with a corrupted FILE object to redirect execution. (libio
> vtable verification did not cover the codecvt vtable.)
>
> 2019-05-20 Florian Weimer <fweimer@redhat.com>
>
> [BZ #24588]
> libio: Remove codecvt vtable.
> * libio/fileops.c ( _IO_new_file_fopen): Do not copy
> __libio_codecvt.
> * libio/iofgetpos.c (_IO_new_fgetpos): Call
> __libio_codecvt_encoding.
> * libio/iofgetpos64.c (_IO_new_fgetpos): Likewise.
> * libio/iofsetpos.c (_IO_new_fsetpos): Likewise.
> * libio/iofsetpos64.c (_IO_new_fsetpos): Likewise.
> * libio/iofwide.c (__libio_codecvt): Remove variable.
> (_IO_fwide): Do not copy __libio_codecvt.
> (__libio_codecvt_out): Rename from do_out and export.
> (do_unshift): Remove function.
> (__libio_codecvt_in): Rename from do_in and export.
> (__libio_codecvt_encoding): Rename from do_encoding and export.
> (do_always_noconv): Remove function.
> (__libio_codecvt_length): Rename from do_length and export.
> (do_max_length): Remove function.
> * libio/libio.h (enum __codecvt_result): Remove definition; moved
> to libioP.h.
> (struct _IO_codecvt): Remove fields __codecvt_destr,
> __codecvt_do_out, __codecvt_do_unshift, __codecvt_do_in,
> __codecvt_do_encoding, __codecvt_do_always_noconv,
> __codecvt_do_length, __codecvt_do_max_length.
> * libio/libioP.h (enum __codecvt_result): Define; moved from
> libio.h.
> (__libio_codecvt_out, __libio_codecvt_in)
> (__libio_codecvt_encoding, __libio_codecvt_length): Declare
> functions.
> * libio/wfileops.c (_IO_wdo_write): Call __libio_codecvt_out.
> (_IO_wfile_underflow): Call __libio_codecvt_in.
> (_IO_wfile_underflow): Likewise.
> (_IO_wfile_underflow_mmap): Likewise.
> (_IO_wfile_sync): Call __libio_codecvt_encoding,
> __libio_codecvt_length.
> (adjust_wide_data): Call __libio_codecvt_encoding,
> __libio_codecvt_in.
> (do_ftell_wide): Call __libio_codecvt_length, __libio_codecvt_out.
> (_IO_wfile_seekoff): Call __libio_codecvt_encoding,
> __libio_codecvt_length.
LGTM as well.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
>
> diff --git a/libio/fileops.c b/libio/fileops.c
> index d2070a856e..daa5a05877 100644
> --- a/libio/fileops.c
> +++ b/libio/fileops.c
> @@ -331,9 +331,6 @@ _IO_new_file_fopen (FILE *fp, const char *filename, const char *mode,
>
> cc = fp->_codecvt = &fp->_wide_data->_codecvt;
>
> - /* The functions are always the same. */
> - *cc = __libio_codecvt;
> -
> cc->__cd_in.__cd.__nsteps = fcts.towc_nsteps;
> cc->__cd_in.__cd.__steps = fcts.towc;
>
> diff --git a/libio/iofgetpos.c b/libio/iofgetpos.c
> index 8032192440..388c4a0708 100644
> --- a/libio/iofgetpos.c
> +++ b/libio/iofgetpos.c
> @@ -70,8 +70,7 @@ _IO_new_fgetpos (FILE *fp, __fpos_t *posp)
> else
> {
> posp->__pos = pos;
> - if (fp->_mode > 0
> - && (*fp->_codecvt->__codecvt_do_encoding) (fp->_codecvt) < 0)
> + if (fp->_mode > 0 && __libio_codecvt_encoding (fp->_codecvt) < 0)
> /* This is a stateful encoding, safe the state. */
> posp->__state = fp->_wide_data->_IO_state;
> }
> diff --git a/libio/iofgetpos64.c b/libio/iofgetpos64.c
> index 54de6a8205..6a0ba50d29 100644
> --- a/libio/iofgetpos64.c
> +++ b/libio/iofgetpos64.c
> @@ -54,8 +54,7 @@ _IO_new_fgetpos64 (FILE *fp, __fpos64_t *posp)
> else
> {
> posp->__pos = pos;
> - if (fp->_mode > 0
> - && (*fp->_codecvt->__codecvt_do_encoding) (fp->_codecvt) < 0)
> + if (fp->_mode > 0 && __libio_codecvt_encoding (fp->_codecvt) < 0)
> /* This is a stateful encoding, safe the state. */
> posp->__state = fp->_wide_data->_IO_state;
> }
> diff --git a/libio/iofsetpos.c b/libio/iofsetpos.c
> index d7b1abbc61..4df1aae082 100644
> --- a/libio/iofsetpos.c
> +++ b/libio/iofsetpos.c
> @@ -58,8 +58,7 @@ _IO_new_fsetpos (FILE *fp, const __fpos_t *posp)
> else
> {
> result = 0;
> - if (fp->_mode > 0
> - && (*fp->_codecvt->__codecvt_do_encoding) (fp->_codecvt) < 0)
> + if (fp->_mode > 0 && __libio_codecvt_encoding (fp->_codecvt) < 0)
> /* This is a stateful encoding, restore the state. */
> fp->_wide_data->_IO_state = posp->__state;
> }
> diff --git a/libio/iofsetpos64.c b/libio/iofsetpos64.c
> index d1865b728e..f382ba0dc1 100644
> --- a/libio/iofsetpos64.c
> +++ b/libio/iofsetpos64.c
> @@ -48,8 +48,7 @@ _IO_new_fsetpos64 (FILE *fp, const fpos64_t *posp)
> else
> {
> result = 0;
> - if (fp->_mode > 0
> - && (*fp->_codecvt->__codecvt_do_encoding) (fp->_codecvt) < 0)
> + if (fp->_mode > 0 && __libio_codecvt_encoding (fp->_codecvt) < 0)
> /* This is a stateful encoding, safe the state. */
> fp->_wide_data->_IO_state = posp->__state;
> }
> diff --git a/libio/iofwide.c b/libio/iofwide.c
> index 247cfde3d0..80cb2d5074 100644
> --- a/libio/iofwide.c
> +++ b/libio/iofwide.c
> @@ -39,44 +39,6 @@
> #include <sysdep.h>
>
>
> -/* Prototypes of libio's codecvt functions. */
> -static enum __codecvt_result do_out (struct _IO_codecvt *codecvt,
> - __mbstate_t *statep,
> - const wchar_t *from_start,
> - const wchar_t *from_end,
> - const wchar_t **from_stop, char *to_start,
> - char *to_end, char **to_stop);
> -static enum __codecvt_result do_unshift (struct _IO_codecvt *codecvt,
> - __mbstate_t *statep, char *to_start,
> - char *to_end, char **to_stop);
> -static enum __codecvt_result do_in (struct _IO_codecvt *codecvt,
> - __mbstate_t *statep,
> - const char *from_start,
> - const char *from_end,
> - const char **from_stop, wchar_t *to_start,
> - wchar_t *to_end, wchar_t **to_stop);
> -static int do_encoding (struct _IO_codecvt *codecvt);
> -static int do_length (struct _IO_codecvt *codecvt, __mbstate_t *statep,
> - const char *from_start,
> - const char *from_end, size_t max);
> -static int do_max_length (struct _IO_codecvt *codecvt);
> -static int do_always_noconv (struct _IO_codecvt *codecvt);
> -
> -
> -/* The functions used in `codecvt' for libio are always the same. */
> -const struct _IO_codecvt __libio_codecvt =
> -{
> - .__codecvt_destr = NULL, /* Destructor, never used. */
> - .__codecvt_do_out = do_out,
> - .__codecvt_do_unshift = do_unshift,
> - .__codecvt_do_in = do_in,
> - .__codecvt_do_encoding = do_encoding,
> - .__codecvt_do_always_noconv = do_always_noconv,
> - .__codecvt_do_length = do_length,
> - .__codecvt_do_max_length = do_max_length
> -};
> -
> -
> /* Return orientation of stream. If mode is nonzero try to change
> the orientation first. */
> #undef _IO_fwide
> @@ -118,9 +80,6 @@ _IO_fwide (FILE *fp, int mode)
> assert (fcts.towc_nsteps == 1);
> assert (fcts.tomb_nsteps == 1);
>
> - /* The functions are always the same. */
> - *cc = __libio_codecvt;
> -
> cc->__cd_in.__cd.__nsteps = fcts.towc_nsteps;
> cc->__cd_in.__cd.__steps = fcts.towc;
>
> @@ -150,11 +109,11 @@ _IO_fwide (FILE *fp, int mode)
> }
>
>
> -static enum __codecvt_result
> -do_out (struct _IO_codecvt *codecvt, __mbstate_t *statep,
> - const wchar_t *from_start, const wchar_t *from_end,
> - const wchar_t **from_stop, char *to_start, char *to_end,
> - char **to_stop)
> +enum __codecvt_result
> +__libio_codecvt_out (struct _IO_codecvt *codecvt, __mbstate_t *statep,
> + const wchar_t *from_start, const wchar_t *from_end,
> + const wchar_t **from_stop, char *to_start, char *to_end,
> + char **to_stop)
> {
> enum __codecvt_result result;
>
> @@ -202,57 +161,11 @@ do_out (struct _IO_codecvt *codecvt, __mbstate_t *statep,
> }
>
>
> -static enum __codecvt_result
> -do_unshift (struct _IO_codecvt *codecvt, __mbstate_t *statep,
> - char *to_start, char *to_end, char **to_stop)
> -{
> - enum __codecvt_result result;
> -
> - struct __gconv_step *gs = codecvt->__cd_out.__cd.__steps;
> - int status;
> - size_t dummy;
> -
> - codecvt->__cd_out.__cd.__data[0].__outbuf = (unsigned char *) to_start;
> - codecvt->__cd_out.__cd.__data[0].__outbufend = (unsigned char *) to_end;
> - codecvt->__cd_out.__cd.__data[0].__statep = statep;
> -
> - __gconv_fct fct = gs->__fct;
> -#ifdef PTR_DEMANGLE
> - if (gs->__shlib_handle != NULL)
> - PTR_DEMANGLE (fct);
> -#endif
> -
> - status = DL_CALL_FCT (fct,
> - (gs, codecvt->__cd_out.__cd.__data, NULL, NULL,
> - NULL, &dummy, 1, 0));
> -
> - *to_stop = (char *) codecvt->__cd_out.__cd.__data[0].__outbuf;
> -
> - switch (status)
> - {
> - case __GCONV_OK:
> - case __GCONV_EMPTY_INPUT:
> - result = __codecvt_ok;
> - break;
> -
> - case __GCONV_FULL_OUTPUT:
> - case __GCONV_INCOMPLETE_INPUT:
> - result = __codecvt_partial;
> - break;
> -
> - default:
> - result = __codecvt_error;
> - break;
> - }
> -
> - return result;
> -}
> -
> -
> -static enum __codecvt_result
> -do_in (struct _IO_codecvt *codecvt, __mbstate_t *statep,
> - const char *from_start, const char *from_end, const char **from_stop,
> - wchar_t *to_start, wchar_t *to_end, wchar_t **to_stop)
> +enum __codecvt_result
> +__libio_codecvt_in (struct _IO_codecvt *codecvt, __mbstate_t *statep,
> + const char *from_start, const char *from_end,
> + const char **from_stop,
> + wchar_t *to_start, wchar_t *to_end, wchar_t **to_stop)
> {
> enum __codecvt_result result;
>
> @@ -300,8 +213,8 @@ do_in (struct _IO_codecvt *codecvt, __mbstate_t *statep,
> }
>
>
> -static int
> -do_encoding (struct _IO_codecvt *codecvt)
> +int
> +__libio_codecvt_encoding (struct _IO_codecvt *codecvt)
> {
> /* See whether the encoding is stateful. */
> if (codecvt->__cd_in.__cd.__steps[0].__stateful)
> @@ -317,16 +230,10 @@ do_encoding (struct _IO_codecvt *codecvt)
> }
>
>
> -static int
> -do_always_noconv (struct _IO_codecvt *codecvt)
> -{
> - return 0;
> -}
> -
> -
> -static int
> -do_length (struct _IO_codecvt *codecvt, __mbstate_t *statep,
> - const char *from_start, const char *from_end, size_t max)
> +int
> +__libio_codecvt_length (struct _IO_codecvt *codecvt, __mbstate_t *statep,
> + const char *from_start, const char *from_end,
> + size_t max)
> {
> int result;
> const unsigned char *cp = (const unsigned char *) from_start;
> @@ -353,10 +260,3 @@ do_length (struct _IO_codecvt *codecvt, __mbstate_t *statep,
>
> return result;
> }
> -
> -
> -static int
> -do_max_length (struct _IO_codecvt *codecvt)
> -{
> - return codecvt->__cd_in.__cd.__steps[0].__max_needed_from;
> -}
> diff --git a/libio/libio.h b/libio/libio.h
> index c38095ff77..b985c386a2 100644
> --- a/libio/libio.h
> +++ b/libio/libio.h
> @@ -116,40 +116,8 @@ struct _IO_marker {
> int _pos;
> };
>
> -/* This is the structure from the libstdc++ codecvt class. */
> -enum __codecvt_result
> -{
> - __codecvt_ok,
> - __codecvt_partial,
> - __codecvt_error,
> - __codecvt_noconv
> -};
> -
> -/* The order of the elements in the following struct must match the order
> - of the virtual functions in the libstdc++ codecvt class. */
> struct _IO_codecvt
> {
> - void (*__codecvt_destr) (struct _IO_codecvt *);
> - enum __codecvt_result (*__codecvt_do_out) (struct _IO_codecvt *,
> - __mbstate_t *,
> - const wchar_t *,
> - const wchar_t *,
> - const wchar_t **, char *,
> - char *, char **);
> - enum __codecvt_result (*__codecvt_do_unshift) (struct _IO_codecvt *,
> - __mbstate_t *, char *,
> - char *, char **);
> - enum __codecvt_result (*__codecvt_do_in) (struct _IO_codecvt *,
> - __mbstate_t *,
> - const char *, const char *,
> - const char **, wchar_t *,
> - wchar_t *, wchar_t **);
> - int (*__codecvt_do_encoding) (struct _IO_codecvt *);
> - int (*__codecvt_do_always_noconv) (struct _IO_codecvt *);
> - int (*__codecvt_do_length) (struct _IO_codecvt *, __mbstate_t *,
> - const char *, const char *, size_t);
> - int (*__codecvt_do_max_length) (struct _IO_codecvt *);
> -
> _IO_iconv_t __cd_in;
> _IO_iconv_t __cd_out;
> };
> diff --git a/libio/libioP.h b/libio/libioP.h
> index 7bdec86a62..66afaa8968 100644
> --- a/libio/libioP.h
> +++ b/libio/libioP.h
> @@ -476,7 +476,6 @@ 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 const struct _IO_codecvt __libio_codecvt attribute_hidden;
> 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);
> @@ -932,4 +931,32 @@ IO_validate_vtable (const struct _IO_jump_t *vtable)
> return vtable;
> }
>
> +/* Character set conversion. */
> +
> +enum __codecvt_result
> +{
> + __codecvt_ok,
> + __codecvt_partial,
> + __codecvt_error,
> + __codecvt_noconv
> +};
> +
> +enum __codecvt_result __libio_codecvt_out (struct _IO_codecvt *,
> + __mbstate_t *,
> + const wchar_t *,
> + const wchar_t *,
> + const wchar_t **, char *,
> + char *, char **)
> + attribute_hidden;
> +enum __codecvt_result __libio_codecvt_in (struct _IO_codecvt *,
> + __mbstate_t *,
> + const char *, const char *,
> + const char **, wchar_t *,
> + wchar_t *, wchar_t **)
> + attribute_hidden;
> +int __libio_codecvt_encoding (struct _IO_codecvt *) attribute_hidden;
> +int __libio_codecvt_length (struct _IO_codecvt *, __mbstate_t *,
> + const char *, const char *, size_t)
> + attribute_hidden;
> +
> #endif /* libioP.h. */
> diff --git a/libio/wfileops.c b/libio/wfileops.c
> index 69fbb62a02..f1863db638 100644
> --- a/libio/wfileops.c
> +++ b/libio/wfileops.c
> @@ -72,11 +72,11 @@ _IO_wdo_write (FILE *fp, const wchar_t *data, size_t to_do)
> }
>
> /* Now convert from the internal format into the external buffer. */
> - result = (*cc->__codecvt_do_out) (cc, &fp->_wide_data->_IO_state,
> - data, data + to_do, &new_data,
> - write_ptr,
> - buf_end,
> - &write_ptr);
> + result = __libio_codecvt_out (cc, &fp->_wide_data->_IO_state,
> + data, data + to_do, &new_data,
> + write_ptr,
> + buf_end,
> + &write_ptr);
>
> /* Write out what we produced so far. */
> if (_IO_new_do_write (fp, write_base, write_ptr - write_base) == EOF)
> @@ -140,12 +140,12 @@ _IO_wfile_underflow (FILE *fp)
> fp->_wide_data->_IO_last_state = fp->_wide_data->_IO_state;
> fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_read_ptr =
> fp->_wide_data->_IO_buf_base;
> - status = (*cd->__codecvt_do_in) (cd, &fp->_wide_data->_IO_state,
> - fp->_IO_read_ptr, fp->_IO_read_end,
> - &read_stop,
> - fp->_wide_data->_IO_read_ptr,
> - fp->_wide_data->_IO_buf_end,
> - &fp->_wide_data->_IO_read_end);
> + status = __libio_codecvt_in (cd, &fp->_wide_data->_IO_state,
> + fp->_IO_read_ptr, fp->_IO_read_end,
> + &read_stop,
> + fp->_wide_data->_IO_read_ptr,
> + fp->_wide_data->_IO_buf_end,
> + &fp->_wide_data->_IO_read_end);
>
> fp->_IO_read_base = fp->_IO_read_ptr;
> fp->_IO_read_ptr = (char *) read_stop;
> @@ -266,11 +266,11 @@ _IO_wfile_underflow (FILE *fp)
> naccbuf += to_copy;
> from = accbuf;
> }
> - status = (*cd->__codecvt_do_in) (cd, &fp->_wide_data->_IO_state,
> - from, to, &read_ptr_copy,
> - fp->_wide_data->_IO_read_end,
> - fp->_wide_data->_IO_buf_end,
> - &fp->_wide_data->_IO_read_end);
> + status = __libio_codecvt_in (cd, &fp->_wide_data->_IO_state,
> + from, to, &read_ptr_copy,
> + fp->_wide_data->_IO_read_end,
> + fp->_wide_data->_IO_buf_end,
> + &fp->_wide_data->_IO_read_end);
>
> if (__glibc_unlikely (naccbuf != 0))
> fp->_IO_read_ptr += MAX (0, read_ptr_copy - &accbuf[naccbuf - to_copy]);
> @@ -372,12 +372,12 @@ _IO_wfile_underflow_mmap (FILE *fp)
> fp->_wide_data->_IO_last_state = fp->_wide_data->_IO_state;
> fp->_wide_data->_IO_read_base = fp->_wide_data->_IO_read_ptr =
> fp->_wide_data->_IO_buf_base;
> - (*cd->__codecvt_do_in) (cd, &fp->_wide_data->_IO_state,
> - fp->_IO_read_ptr, fp->_IO_read_end,
> - &read_stop,
> - fp->_wide_data->_IO_read_ptr,
> - fp->_wide_data->_IO_buf_end,
> - &fp->_wide_data->_IO_read_end);
> + __libio_codecvt_in (cd, &fp->_wide_data->_IO_state,
> + fp->_IO_read_ptr, fp->_IO_read_end,
> + &read_stop,
> + fp->_wide_data->_IO_read_ptr,
> + fp->_wide_data->_IO_buf_end,
> + &fp->_wide_data->_IO_read_end);
>
> fp->_IO_read_ptr = (char *) read_stop;
>
> @@ -495,7 +495,7 @@ _IO_wfile_sync (FILE *fp)
> struct _IO_codecvt *cv = fp->_codecvt;
> off64_t new_pos;
>
> - int clen = (*cv->__codecvt_do_encoding) (cv);
> + int clen = __libio_codecvt_encoding (cv);
>
> if (clen > 0)
> /* It is easy, a fixed number of input bytes are used for each
> @@ -511,9 +511,9 @@ _IO_wfile_sync (FILE *fp)
> size_t wnread = (fp->_wide_data->_IO_read_ptr
> - fp->_wide_data->_IO_read_base);
> fp->_wide_data->_IO_state = fp->_wide_data->_IO_last_state;
> - nread = (*cv->__codecvt_do_length) (cv, &fp->_wide_data->_IO_state,
> - fp->_IO_read_base,
> - fp->_IO_read_end, wnread);
> + nread = __libio_codecvt_length (cv, &fp->_wide_data->_IO_state,
> + fp->_IO_read_base,
> + fp->_IO_read_end, wnread);
> fp->_IO_read_ptr = fp->_IO_read_base + nread;
> delta = -(fp->_IO_read_end - fp->_IO_read_base - nread);
> }
> @@ -548,7 +548,7 @@ adjust_wide_data (FILE *fp, bool do_convert)
> {
> struct _IO_codecvt *cv = fp->_codecvt;
>
> - int clen = (*cv->__codecvt_do_encoding) (cv);
> + int clen = __libio_codecvt_encoding (cv);
>
> /* Take the easy way out for constant length encodings if we don't need to
> convert. */
> @@ -565,12 +565,12 @@ adjust_wide_data (FILE *fp, bool do_convert)
> {
>
> fp->_wide_data->_IO_last_state = fp->_wide_data->_IO_state;
> - status = (*cv->__codecvt_do_in) (cv, &fp->_wide_data->_IO_state,
> - fp->_IO_read_base, fp->_IO_read_ptr,
> - &read_stop,
> - fp->_wide_data->_IO_read_base,
> - fp->_wide_data->_IO_buf_end,
> - &fp->_wide_data->_IO_read_end);
> + status = __libio_codecvt_in (cv, &fp->_wide_data->_IO_state,
> + fp->_IO_read_base, fp->_IO_read_ptr,
> + &read_stop,
> + fp->_wide_data->_IO_read_base,
> + fp->_wide_data->_IO_buf_end,
> + &fp->_wide_data->_IO_read_end);
>
> /* Should we return EILSEQ? */
> if (__glibc_unlikely (status == __codecvt_error))
> @@ -648,7 +648,7 @@ do_ftell_wide (FILE *fp)
> }
>
> struct _IO_codecvt *cv = fp->_codecvt;
> - int clen = (*cv->__codecvt_do_encoding) (cv);
> + int clen = __libio_codecvt_encoding (cv);
>
> if (!unflushed_writes)
> {
> @@ -663,9 +663,9 @@ do_ftell_wide (FILE *fp)
>
> size_t delta = wide_read_ptr - wide_read_base;
> __mbstate_t state = fp->_wide_data->_IO_last_state;
> - nread = (*cv->__codecvt_do_length) (cv, &state,
> - fp->_IO_read_base,
> - fp->_IO_read_end, delta);
> + nread = __libio_codecvt_length (cv, &state,
> + fp->_IO_read_base,
> + fp->_IO_read_end, delta);
> offset -= fp->_IO_read_end - fp->_IO_read_base - nread;
> }
> }
> @@ -688,9 +688,8 @@ do_ftell_wide (FILE *fp)
> enum __codecvt_result status;
>
> __mbstate_t state = fp->_wide_data->_IO_last_state;
> - status = (*cv->__codecvt_do_out) (cv, &state,
> - in, in + delta, &in,
> - out, out + outsize, &outstop);
> + status = __libio_codecvt_out (cv, &state, in, in + delta, &in,
> + out, out + outsize, &outstop);
>
> /* We don't check for __codecvt_partial because it can be
> returned on one of two conditions: either the output
> @@ -801,7 +800,7 @@ _IO_wfile_seekoff (FILE *fp, off64_t offset, int dir, int mode)
> find out which position in the external buffer corresponds to
> the current position in the internal buffer. */
> cv = fp->_codecvt;
> - clen = (*cv->__codecvt_do_encoding) (cv);
> + clen = __libio_codecvt_encoding (cv);
>
> if (mode != 0 || !was_writing)
> {
> @@ -819,10 +818,10 @@ _IO_wfile_seekoff (FILE *fp, off64_t offset, int dir, int mode)
> delta = (fp->_wide_data->_IO_read_ptr
> - fp->_wide_data->_IO_read_base);
> fp->_wide_data->_IO_state = fp->_wide_data->_IO_last_state;
> - nread = (*cv->__codecvt_do_length) (cv,
> - &fp->_wide_data->_IO_state,
> - fp->_IO_read_base,
> - fp->_IO_read_end, delta);
> + nread = __libio_codecvt_length (cv,
> + &fp->_wide_data->_IO_state,
> + fp->_IO_read_base,
> + fp->_IO_read_end, delta);
> fp->_IO_read_ptr = fp->_IO_read_base + nread;
> fp->_wide_data->_IO_read_end = fp->_wide_data->_IO_read_ptr;
> offset -= fp->_IO_read_end - fp->_IO_read_base - nread;
>