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58548b9d68
In the future, this will result in a compilation failure if the macros are unexpectedly undefined (due to header inclusion ordering or header inclusion missing altogether). Assembler sources are more difficult to convert. In many cases, they are hand-optimized for the mangling and no-mangling variants, which is why they are not converted. sysdeps/s390/s390-32/__longjmp.c and sysdeps/s390/s390-64/__longjmp.c are special: These are C sources, but most of the implementation is in assembler, so the PTR_DEMANGLE macro has to be undefined in some cases, to match the assembler style. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
85 lines
2.6 KiB
C
85 lines
2.6 KiB
C
/* libio vtable validation.
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Copyright (C) 2016-2022 Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, see
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<https://www.gnu.org/licenses/>. */
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#include <dlfcn.h>
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#include <libioP.h>
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#include <stdio.h>
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#include <ldsodefs.h>
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#include <pointer_guard.h>
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#ifdef SHARED
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void (*IO_accept_foreign_vtables) (void) attribute_hidden;
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#else /* !SHARED */
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/* Used to check whether static dlopen support is needed. */
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# pragma weak __dlopen
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#endif
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void attribute_hidden
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_IO_vtable_check (void)
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{
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#ifdef SHARED
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/* Honor the compatibility flag. */
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void (*flag) (void) = atomic_load_relaxed (&IO_accept_foreign_vtables);
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PTR_DEMANGLE (flag);
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if (flag == &_IO_vtable_check)
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return;
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/* In case this libc copy is in a non-default namespace, we always
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need to accept foreign vtables because there is always a
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possibility that FILE * objects are passed across the linking
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boundary. */
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{
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Dl_info di;
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struct link_map *l;
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if (!rtld_active ()
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|| (_dl_addr (_IO_vtable_check, &di, &l, NULL) != 0
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&& l->l_ns != LM_ID_BASE))
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return;
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}
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#else /* !SHARED */
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/* We cannot perform vtable validation in the static dlopen case
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because FILE * handles might be passed back and forth across the
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boundary. Therefore, we disable checking in this case. */
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if (__dlopen != NULL)
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return;
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#endif
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__libc_fatal ("Fatal error: glibc detected an invalid stdio handle\n");
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}
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/* Some variants of libstdc++ interpose _IO_2_1_stdin_ etc. and
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install their own vtables directly, without calling _IO_init or
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other functions. Detect this by looking at the vtables values
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during startup, and disable vtable validation in this case. */
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#ifdef SHARED
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__attribute__ ((constructor))
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static void
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check_stdfiles_vtables (void)
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{
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if (_IO_2_1_stdin_.vtable != &_IO_file_jumps
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|| _IO_2_1_stdout_.vtable != &_IO_file_jumps
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|| _IO_2_1_stderr_.vtable != &_IO_file_jumps)
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IO_set_accept_foreign_vtables (&_IO_vtable_check);
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}
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#endif
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