diff options
| author | Florian Weimer <fweimer@redhat.com> | 2022-12-19 18:56:54 +0100 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2022-12-19 18:56:54 +0100 |
| commit | 659fe9fdd14b0772f4e9722b751b9b010665e053 (patch) | |
| tree | 3098a69345fbd3474154bbba45e8f21de449f266 /elf | |
| parent | ffde06c915d10c0717a0980508ccb28506c6ec63 (diff) | |
| download | glibc-659fe9fdd14b0772f4e9722b751b9b010665e053.zip glibc-659fe9fdd14b0772f4e9722b751b9b010665e053.tar.gz glibc-659fe9fdd14b0772f4e9722b751b9b010665e053.tar.bz2 | |
stdio-common: Introduce buffers for implementing printf
These buffers will eventually be used instead of FILE * objects
to implement printf functions. The multibyte buffer is struct
__printf_buffer, the wide buffer is struct __wprintf_buffer.
To enable writing type-generic code, the header files
printf_buffer-char.h and printf_buffer-wchar_t.h define the
Xprintf macro differently, enabling Xprintf (buffer) to stand
for __printf_buffer and __wprintf_buffer as appropriate. For
common cases, macros like Xprintf_buffer are provided as a more
syntactically convenient shortcut.
Buffer-specific flush callbacks are implemented with a switch
statement instead of a function pointer, to avoid hardening issues
similar to those of libio vtables. struct __printf_buffer_as_file
is needed to support custom printf specifiers because the public
interface for that requires passing a FILE *, which is why there
is a trapdoor back from these buffers to FILE * streams.
Since the immediate user of these interfaces knows when processing
has finished, there is no flush callback for the end of processing,
only a flush callback for the intermediate buffer flush.
Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Diffstat (limited to 'elf')
| -rw-r--r-- | elf/Makefile | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/elf/Makefile b/elf/Makefile index eca7b28..0bfaffb 100644 --- a/elf/Makefile +++ b/elf/Makefile @@ -602,6 +602,7 @@ $(objpfx)tst-relro-libc.out: tst-relro-symbols.py $(..)/scripts/glibcelf.py \ --required=_IO_helper_jumps \ --required=_IO_mem_jumps \ --required=_IO_obstack_jumps \ + --required=_IO_printf_buffer_as_file_jumps \ --required=_IO_proc_jumps \ --required=_IO_str_chk_jumps \ --required=_IO_str_jumps \ @@ -610,6 +611,7 @@ $(objpfx)tst-relro-libc.out: tst-relro-symbols.py $(..)/scripts/glibcelf.py \ --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 \ --required=_IO_wstrn_jumps \ --optional=_IO_old_cookie_jumps \ |