[patch] Fix BZ#16374 -- don't use mmap for FILE buffers

[Paul Pluzhnikov <ppluzhnikov at gmail dot com>]

Greetings,

I believe we've reached a consensus in
https://sourceware.org/ml/libc-alpha/2015-02/msg00010.html -- using
mmap to allocate FILE buffers is really not a good idea.

Attached patch replaces mmap()s with calloc()s. Doing this revealed a
few cleanup bugs: wide stream and input-only buffers were not cleaned
up under some conditions.

Tested on Linux/x86_64 with no new failures.


2015-02-16  Paul Pluzhnikov  <ppluzhnikov@google.com>

        [BZ #16374]
        * NEWS: mention 16374
        * libio/filedoalloc.c (_IO_file_doallocate,
_IO_default_doallocate): Use calloc instead of ALLOC_BUF
        (_IO_setb, _IO_default_finish): Use free instead of FREE_BUF
        (_IO_default_finish): Likewise. Fix cleanup bugs.
        (libc_freeres_fn): Clean up wide stream buffers.
        * libio/libio.h (struct _IO_FILE_complete): Delete
_freeres_size, add _freeres_wbuf
        * libio/libioP.h (ROUND_TO_PAGE, FREE_BUF, ALLOC_BUF,
ALLOC_WBUF): Delete
        * libio/wfiledoalloc.c (_IO_wfile_doallocate): Use calloc
instead of ALLOC_WBUF
        * libio/wgenops.c (_IO_wdefault_doallocate): Likewise
        (_IO_wsetb, _IO_wdefault_finish): Use free instead of FREE_BUF


--
Paul Pluzhnikov

Attachment: bz16734.patch5.txt
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