/* Find debugging and symbol information for a module in libdwfl.
- Copyright (C) 2005-2010 Red Hat, Inc.
- This file is part of Red Hat elfutils.
+ Copyright (C) 2005-2013 Red Hat, Inc.
+ This file is part of elfutils.
- Red Hat elfutils is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by the
- Free Software Foundation; version 2 of the License.
+ This file is free software; you can redistribute it and/or modify
+ it under the terms of either
- Red Hat elfutils is distributed in the hope that it will be useful, but
+ * the GNU Lesser General Public License as published by the Free
+ Software Foundation; either version 3 of the License, or (at
+ your option) any later version
+
+ or
+
+ * the GNU General Public License as published by the Free
+ Software Foundation; either version 2 of the License, or (at
+ your option) any later version
+
+ or both in parallel, as here.
+
+ elfutils is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
- You should have received a copy of the GNU General Public License along
- with Red Hat elfutils; if not, write to the Free Software Foundation,
- Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301 USA.
-
- In addition, as a special exception, Red Hat, Inc. gives You the
- additional right to link the code of Red Hat elfutils with code licensed
- under any Open Source Initiative certified open source license
- (http://www.opensource.org/licenses/index.php) which requires the
- distribution of source code with any binary distribution and to
- distribute linked combinations of the two. Non-GPL Code permitted under
- this exception must only link to the code of Red Hat elfutils through
- those well defined interfaces identified in the file named EXCEPTION
- found in the source code files (the "Approved Interfaces"). The files
- of Non-GPL Code may instantiate templates or use macros or inline
- functions from the Approved Interfaces without causing the resulting
- work to be covered by the GNU General Public License. Only Red Hat,
- Inc. may make changes or additions to the list of Approved Interfaces.
- Red Hat's grant of this exception is conditioned upon your not adding
- any new exceptions. If you wish to add a new Approved Interface or
- exception, please contact Red Hat. You must obey the GNU General Public
- License in all respects for all of the Red Hat elfutils code and other
- code used in conjunction with Red Hat elfutils except the Non-GPL Code
- covered by this exception. If you modify this file, you may extend this
- exception to your version of the file, but you are not obligated to do
- so. If you do not wish to provide this exception without modification,
- you must delete this exception statement from your version and license
- this file solely under the GPL without exception.
-
- Red Hat elfutils is an included package of the Open Invention Network.
- An included package of the Open Invention Network is a package for which
- Open Invention Network licensees cross-license their patents. No patent
- license is granted, either expressly or impliedly, by designation as an
- included package. Should you wish to participate in the Open Invention
- Network licensing program, please visit www.openinventionnetwork.com
- <http://www.openinventionnetwork.com>. */
+ You should have received copies of the GNU General Public License and
+ the GNU Lesser General Public License along with this program. If
+ not, see <http://www.gnu.org/licenses/>. */
-#include "libdwflP.h"
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
-/* Returns the name of the symbol "closest" to ADDR.
- Never returns symbols at addresses above ADDR. */
+#include "libdwflP.h"
-const char *
-dwfl_module_addrsym (Dwfl_Module *mod, GElf_Addr addr,
- GElf_Sym *closest_sym, GElf_Word *shndxp)
+struct search_state
{
- int syments = INTUSE(dwfl_module_getsymtab) (mod);
- if (syments < 0)
- return NULL;
-
- /* Return true iff we consider ADDR to lie in the same section as SYM. */
- GElf_Word addr_shndx = SHN_UNDEF;
- inline bool same_section (const GElf_Sym *sym, GElf_Word shndx)
- {
- /* For absolute symbols and the like, only match exactly. */
- if (shndx >= SHN_LORESERVE)
- return sym->st_value == addr;
-
- /* Figure out what section ADDR lies in. */
- if (addr_shndx == SHN_UNDEF)
- {
- GElf_Addr mod_addr = dwfl_deadjust_st_value (mod, addr);
- Elf_Scn *scn = NULL;
- addr_shndx = SHN_ABS;
- while ((scn = elf_nextscn (mod->symfile->elf, scn)) != NULL)
- {
- GElf_Shdr shdr_mem;
- GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
- if (likely (shdr != NULL)
- && mod_addr >= shdr->sh_addr
- && mod_addr < shdr->sh_addr + shdr->sh_size)
- {
- addr_shndx = elf_ndxscn (scn);
- break;
- }
- }
- }
+ Dwfl_Module *mod;
+ GElf_Addr addr;
- return shndx == addr_shndx;
- }
+ GElf_Sym *closest_sym;
+ bool adjust_st_value;
+ GElf_Word addr_shndx;
+ Elf *addr_symelf;
/* Keep track of the closest symbol we have seen so far.
Here we store only symbols with nonzero st_size. */
- const char *closest_name = NULL;
- GElf_Word closest_shndx = SHN_UNDEF;
+ const char *closest_name;
+ GElf_Addr closest_value;
+ GElf_Word closest_shndx;
+ Elf *closest_elf;
/* Keep track of an eligible symbol with st_size == 0 as a fallback. */
- const char *sizeless_name = NULL;
- GElf_Sym sizeless_sym = { 0, 0, 0, 0, 0, SHN_UNDEF };
- GElf_Word sizeless_shndx = SHN_UNDEF;
+ const char *sizeless_name;
+ GElf_Sym sizeless_sym;
+ GElf_Addr sizeless_value;
+ GElf_Word sizeless_shndx;
+ Elf *sizeless_elf;
/* Keep track of the lowest address a relevant sizeless symbol could have. */
- GElf_Addr min_label = 0;
+ GElf_Addr min_label;
+};
- /* Look through the symbol table for a matching symbol. */
- for (int i = 1; i < syments; ++i)
+/* Return true iff we consider ADDR to lie in the same section as SYM. */
+static inline bool
+same_section (struct search_state *state,
+ GElf_Addr value, Elf *symelf, GElf_Word shndx)
+{
+ /* For absolute symbols and the like, only match exactly. */
+ if (shndx >= SHN_LORESERVE)
+ return value == state->addr;
+
+ /* If value might not be st_value, the shndx of the symbol might
+ not match the section of the value. Explicitly look both up. */
+ if (! state->adjust_st_value)
{
- GElf_Sym sym;
- GElf_Word shndx;
- const char *name = INTUSE(dwfl_module_getsym) (mod, i, &sym, &shndx);
- if (name != NULL && name[0] != '\0'
- && sym.st_shndx != SHN_UNDEF
- && sym.st_value <= addr
- && GELF_ST_TYPE (sym.st_info) != STT_SECTION
- && GELF_ST_TYPE (sym.st_info) != STT_FILE
- && GELF_ST_TYPE (sym.st_info) != STT_TLS)
- {
- /* Even if we don't choose this symbol, its existence excludes
- any sizeless symbol (assembly label) that is below its upper
- bound. */
- if (sym.st_value + sym.st_size > min_label)
- min_label = sym.st_value + sym.st_size;
+ Dwarf_Addr v;
+ if (state->addr_shndx == SHN_UNDEF)
+ {
+ v = state->addr;
+ state->addr_shndx = __libdwfl_find_section_ndx (state->mod, &v);
+ }
+
+ v = value;
+ return state->addr_shndx == __libdwfl_find_section_ndx (state->mod, &v);
+ }
+
+ /* Figure out what section ADDR lies in. */
+ if (state->addr_shndx == SHN_UNDEF || state->addr_symelf != symelf)
+ {
+ GElf_Addr mod_addr = dwfl_deadjust_st_value (state->mod, symelf,
+ state->addr);
+ Elf_Scn *scn = NULL;
+ state->addr_shndx = SHN_ABS;
+ state->addr_symelf = symelf;
+ while ((scn = elf_nextscn (symelf, scn)) != NULL)
+ {
+ GElf_Shdr shdr_mem;
+ GElf_Shdr *shdr = gelf_getshdr (scn, &shdr_mem);
+ if (likely (shdr != NULL)
+ && mod_addr >= shdr->sh_addr
+ && mod_addr < shdr->sh_addr + shdr->sh_size)
+ {
+ state->addr_shndx = elf_ndxscn (scn);
+ break;
+ }
+ }
+ }
+
+ return shndx == state->addr_shndx && state->addr_symelf == symelf;
+}
+
+/* Return GELF_ST_BIND as higher-is-better integer. */
+static inline int
+binding_value (const GElf_Sym *symp)
+{
+ switch (GELF_ST_BIND (symp->st_info))
+ {
+ case STB_GLOBAL:
+ return 3;
+ case STB_WEAK:
+ return 2;
+ case STB_LOCAL:
+ return 1;
+ default:
+ return 0;
+ }
+}
- if (sym.st_size == 0 || addr - sym.st_value < sym.st_size)
+/* Try one symbol and associated value from the search table. */
+static inline void
+try_sym_value (struct search_state *state,
+ GElf_Addr value, GElf_Sym *sym,
+ const char *name, GElf_Word shndx,
+ Elf *elf, bool resolved)
+{
+ /* Even if we don't choose this symbol, its existence excludes
+ any sizeless symbol (assembly label) that is below its upper
+ bound. */
+ if (value + sym->st_size > state->min_label)
+ state->min_label = value + sym->st_size;
+
+ if (sym->st_size == 0 || state->addr - value < sym->st_size)
+ {
+ /* This symbol is a better candidate than the current one
+ if it's closer to ADDR or is global when it was local. */
+ if (state->closest_name == NULL
+ || state->closest_value < value
+ || binding_value (state->closest_sym) < binding_value (sym))
+ {
+ if (sym->st_size != 0)
+ {
+ *state->closest_sym = *sym;
+ state->closest_value = value;
+ state->closest_shndx = shndx;
+ state->closest_elf = elf;
+ state->closest_name = name;
+ }
+ else if (state->closest_name == NULL
+ && value >= state->min_label
+ && same_section (state, value,
+ resolved ? state->mod->main.elf : elf,
+ shndx))
+ {
+ /* Handwritten assembly symbols sometimes have no
+ st_size. If no symbol with proper size includes
+ the address, we'll use the closest one that is in
+ the same section as ADDR. */
+ state->sizeless_sym = *sym;
+ state->sizeless_value = value;
+ state->sizeless_shndx = shndx;
+ state->sizeless_elf = elf;
+ state->sizeless_name = name;
+ }
+ }
+ /* When the beginning of its range is no closer,
+ the end of its range might be. Otherwise follow
+ GELF_ST_BIND preference. If all are equal prefer
+ the first symbol found. */
+ else if (sym->st_size != 0
+ && state->closest_value == value
+ && ((state->closest_sym->st_size > sym->st_size
+ && (binding_value (state->closest_sym)
+ <= binding_value (sym)))
+ || (state->closest_sym->st_size >= sym->st_size
+ && (binding_value (state->closest_sym)
+ < binding_value (sym)))))
+ {
+ *state->closest_sym = *sym;
+ state->closest_value = value;
+ state->closest_shndx = shndx;
+ state->closest_elf = elf;
+ state->closest_name = name;
+ }
+ }
+}
+
+/* Look through the symbol table for a matching symbol. */
+static inline void
+search_table (struct search_state *state, int start, int end)
+{
+ for (int i = start; i < end; ++i)
+ {
+ GElf_Sym sym;
+ GElf_Addr value;
+ GElf_Word shndx;
+ Elf *elf;
+ bool resolved;
+ const char *name = __libdwfl_getsym (state->mod, i, &sym, &value,
+ &shndx, &elf, NULL,
+ &resolved,
+ state->adjust_st_value);
+ if (name != NULL && name[0] != '\0'
+ && sym.st_shndx != SHN_UNDEF
+ && value <= state->addr
+ && GELF_ST_TYPE (sym.st_info) != STT_SECTION
+ && GELF_ST_TYPE (sym.st_info) != STT_FILE
+ && GELF_ST_TYPE (sym.st_info) != STT_TLS)
{
- /* This symbol is a better candidate than the current one
- if it's closer to ADDR or is global when it was local. */
- if (closest_name == NULL
- || closest_sym->st_value < sym.st_value
- || (GELF_ST_BIND (closest_sym->st_info)
- < GELF_ST_BIND (sym.st_info)))
- {
- if (sym.st_size != 0)
- {
- *closest_sym = sym;
- closest_shndx = shndx;
- closest_name = name;
- }
- else if (same_section (&sym, shndx))
- {
- /* Handwritten assembly symbols sometimes have no
- st_size. If no symbol with proper size includes
- the address, we'll use the closest one that is in
- the same section as ADDR. */
- sizeless_sym = sym;
- sizeless_shndx = shndx;
- sizeless_name = name;
- }
- }
- /* When the beginning of its range is no closer,
- the end of its range might be. But do not
- replace a global symbol with a local! */
- else if (sym.st_size != 0
- && closest_sym->st_value == sym.st_value
- && closest_sym->st_size > sym.st_size
- && (GELF_ST_BIND (closest_sym->st_info)
- <= GELF_ST_BIND (sym.st_info)))
+ try_sym_value (state, value, &sym, name, shndx, elf, resolved);
+
+ /* If this is an addrinfo variant and the value could be
+ resolved then also try matching the (adjusted) st_value. */
+ if (resolved && state->mod->e_type != ET_REL)
{
- *closest_sym = sym;
- closest_shndx = shndx;
- closest_name = name;
+ GElf_Addr adjusted_st_value;
+ adjusted_st_value = dwfl_adjusted_st_value (state->mod, elf,
+ sym.st_value);
+ if (value != adjusted_st_value
+ && adjusted_st_value <= state->addr)
+ try_sym_value (state, adjusted_st_value, &sym, name, shndx,
+ elf, false);
}
}
}
- }
+}
+
+/* Returns the name of the symbol "closest" to ADDR.
+ Never returns symbols at addresses above ADDR. */
+const char *
+internal_function
+__libdwfl_addrsym (Dwfl_Module *_mod, GElf_Addr _addr, GElf_Off *off,
+ GElf_Sym *_closest_sym, GElf_Word *shndxp,
+ Elf **elfp, Dwarf_Addr *biasp, bool _adjust_st_value)
+{
+ int syments = INTUSE(dwfl_module_getsymtab) (_mod);
+ if (syments < 0)
+ return NULL;
+
+ struct search_state state =
+ {
+ .addr = _addr,
+ .mod = _mod,
+ .closest_sym = _closest_sym,
+ .adjust_st_value = _adjust_st_value,
+ .addr_shndx = SHN_UNDEF,
+ .addr_symelf = NULL,
+ .closest_name = NULL,
+ .closest_value = 0,
+ .closest_shndx = SHN_UNDEF,
+ .closest_elf = NULL,
+ .sizeless_name = NULL,
+ .sizeless_sym = { 0, 0, 0, 0, 0, SHN_UNDEF },
+ .sizeless_value = 0,
+ .sizeless_shndx = SHN_UNDEF,
+ .sizeless_elf = NULL,
+ .min_label = 0
+ };
+
+ /* First go through global symbols. mod->first_global and
+ mod->aux_first_global are setup by dwfl_module_getsymtab to the
+ index of the first global symbol in those symbol tables. Both
+ are non-zero when the table exist, except when there is only a
+ dynsym table loaded through phdrs, then first_global is zero and
+ there will be no auxiliary table. All symbols with local binding
+ come first in the symbol table, then all globals. The zeroth,
+ null entry, in the auxiliary table is skipped if there is a main
+ table. */
+ int first_global = INTUSE (dwfl_module_getsymtab_first_global) (state.mod);
+ if (first_global < 0)
+ return NULL;
+ search_table (&state, first_global == 0 ? 1 : first_global, syments);
+
+ /* If we found nothing searching the global symbols, then try the locals.
+ Unless we have a global sizeless symbol that matches exactly. */
+ if (state.closest_name == NULL && first_global > 1
+ && (state.sizeless_name == NULL || state.sizeless_value != state.addr))
+ search_table (&state, 1, first_global);
/* If we found no proper sized symbol to use, fall back to the best
candidate sizeless symbol we found, if any. */
- if (closest_name == NULL
- && sizeless_name != NULL && sizeless_sym.st_value >= min_label)
+ if (state.closest_name == NULL
+ && state.sizeless_name != NULL
+ && state.sizeless_value >= state.min_label)
{
- *closest_sym = sizeless_sym;
- closest_shndx = sizeless_shndx;
- closest_name = sizeless_name;
+ *state.closest_sym = state.sizeless_sym;
+ state.closest_value = state.sizeless_value;
+ state.closest_shndx = state.sizeless_shndx;
+ state.closest_elf = state.sizeless_elf;
+ state.closest_name = state.sizeless_name;
}
+ *off = state.addr - state.closest_value;
+
if (shndxp != NULL)
- *shndxp = closest_shndx;
- return closest_name;
+ *shndxp = state.closest_shndx;
+ if (elfp != NULL)
+ *elfp = state.closest_elf;
+ if (biasp != NULL)
+ *biasp = dwfl_adjusted_st_value (state.mod, state.closest_elf, 0);
+ return state.closest_name;
+}
+
+
+const char *
+dwfl_module_addrsym (Dwfl_Module *mod, GElf_Addr addr,
+ GElf_Sym *closest_sym, GElf_Word *shndxp)
+{
+ GElf_Off off;
+ return __libdwfl_addrsym (mod, addr, &off, closest_sym, shndxp,
+ NULL, NULL, true);
}
INTDEF (dwfl_module_addrsym)
+
+const char
+*dwfl_module_addrinfo (Dwfl_Module *mod, GElf_Addr address,
+ GElf_Off *offset, GElf_Sym *sym,
+ GElf_Word *shndxp, Elf **elfp, Dwarf_Addr *bias)
+{
+ return __libdwfl_addrsym (mod, address, offset, sym, shndxp, elfp, bias,
+ false);
+}
+INTDEF (dwfl_module_addrinfo)
projects / platform / upstream / elfutils.git / blobdiff