119 lines
3.7 KiB
C
119 lines
3.7 KiB
C
/* Communicate dynamic linker state to the debugger at runtime.
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Copyright (C) 1996-2022 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 <ldsodefs.h>
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/* These are the members in the public `struct link_map' type.
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Sanity check that the internal type and the public type match. */
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#define VERIFY_MEMBER(name) \
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(offsetof (struct link_map_public, name) == offsetof (struct link_map, name))
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extern const int verify_link_map_members[(VERIFY_MEMBER (l_addr)
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&& VERIFY_MEMBER (l_name)
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&& VERIFY_MEMBER (l_ld)
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&& VERIFY_MEMBER (l_next)
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&& VERIFY_MEMBER (l_prev))
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? 1 : -1];
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/* Update the `r_map' member and return the address of `struct r_debug'
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of the namespace NS. */
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struct r_debug *
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_dl_debug_update (Lmid_t ns)
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{
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struct r_debug_extended *r;
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if (ns == LM_ID_BASE)
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r = &_r_debug_extended;
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else
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r = &GL(dl_ns)[ns]._ns_debug;
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if (r->base.r_map == NULL)
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atomic_store_release (&r->base.r_map,
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(void *) GL(dl_ns)[ns]._ns_loaded);
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return &r->base;
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}
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/* Initialize _r_debug_extended for the namespace NS. LDBASE is the
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run-time load address of the dynamic linker, to be put in
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_r_debug_extended.r_ldbase. Return the address of _r_debug. */
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struct r_debug *
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_dl_debug_initialize (ElfW(Addr) ldbase, Lmid_t ns)
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{
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struct r_debug_extended *r, **pp = NULL;
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if (ns == LM_ID_BASE)
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{
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r = &_r_debug_extended;
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/* Initialize r_version to 1. */
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if (_r_debug_extended.base.r_version == 0)
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_r_debug_extended.base.r_version = 1;
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}
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else if (DL_NNS > 1)
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{
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r = &GL(dl_ns)[ns]._ns_debug;
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if (r->base.r_brk == 0)
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{
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/* Add the new namespace to the linked list. After a namespace
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is initialized, r_brk becomes non-zero. A namespace becomes
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empty (r_map == NULL) when it is unused. But it is never
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removed from the linked list. */
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struct r_debug_extended *p;
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for (pp = &_r_debug_extended.r_next;
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(p = *pp) != NULL;
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pp = &p->r_next)
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;
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r->base.r_version = 2;
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}
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}
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if (r->base.r_brk == 0)
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{
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/* Tell the debugger where to find the map of loaded objects.
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This function is called from dlopen. Initialize the namespace
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only once. */
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r->base.r_ldbase = ldbase ?: _r_debug_extended.base.r_ldbase;
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r->base.r_brk = (ElfW(Addr)) &_dl_debug_state;
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r->r_next = NULL;
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}
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if (r->base.r_map == NULL)
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atomic_store_release (&r->base.r_map,
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(void *) GL(dl_ns)[ns]._ns_loaded);
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if (pp != NULL)
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{
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atomic_store_release (pp, r);
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/* Bump r_version to 2 for the new namespace. */
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atomic_store_release (&_r_debug_extended.base.r_version, 2);
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}
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return &r->base;
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}
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/* This function exists solely to have a breakpoint set on it by the
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debugger. The debugger is supposed to find this function's address by
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examining the r_brk member of struct r_debug, but GDB 4.15 in fact looks
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for this particular symbol name in the PT_INTERP file. */
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void
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_dl_debug_state (void)
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{
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}
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rtld_hidden_def (_dl_debug_state)
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