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72 lines
2.7 KiB
C
72 lines
2.7 KiB
C
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/* ABI compatibility for 'longjmp' and 'siglongjmp' symbols in libpthread ABI.
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X86 version.
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Copyright (C) 18 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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<http://www.gnu.org/licenses/>. */
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#include <pthreadP.h>
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#include <jmp_buf-ssp.h>
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#ifdef __x86_64__
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# define SHADOW_STACK_POINTER_SIZE 8
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#else
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# define SHADOW_STACK_POINTER_SIZE 4
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#endif
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/* Assert that the priv field in struct pthread_unwind_buf has space
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to store shadow stack pointer. */
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_Static_assert ((offsetof (struct pthread_unwind_buf, priv)
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<= SHADOW_STACK_POINTER_OFFSET)
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&& ((offsetof (struct pthread_unwind_buf, priv)
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+ sizeof (((struct pthread_unwind_buf *) 0)->priv))
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>= (SHADOW_STACK_POINTER_OFFSET
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+ SHADOW_STACK_POINTER_SIZE)),
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"Shadow stack pointer is not within private storage "
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"of pthread_unwind_buf.");
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#include <shlib-compat.h>
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/* libpthread once had its own longjmp (and siglongjmp alias), though there
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was no apparent reason for it. There is no use in having a separate
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symbol in libpthread, but the historical ABI requires it. For static
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linking, there is no need to provide anything here--the libc version
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will be linked in. For shared library ABI compatibility, there must be
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longjmp and siglongjmp symbols in libpthread.so.
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With an IFUNC resolver, it would be possible to avoid the indirection,
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but the IFUNC resolver might run before the __libc_longjmp symbol has
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been relocated, in which case the IFUNC resolver would not be able to
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provide the correct address. */
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#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
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static void __attribute__ ((noreturn, used))
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longjmp_compat (jmp_buf env, int val)
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{
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/* NB: We call __libc_siglongjmp, instead of __libc_longjmp, since
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__libc_longjmp is a private interface for cancellation which
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doesn't restore shadow stack register. */
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__libc_siglongjmp (env, val);
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}
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strong_alias (longjmp_compat, longjmp_alias)
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compat_symbol (libpthread, longjmp_alias, longjmp, GLIBC_2_0);
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strong_alias (longjmp_alias, siglongjmp_alias)
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compat_symbol (libpthread, siglongjmp_alias, siglongjmp, GLIBC_2_0);
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#endif
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