/* Read ELF (Executable and Linking Format) object files for GDB.
Copyright (C) 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
- 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
+ 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011
Free Software Foundation, Inc.
Written by Fred Fish at Cygnus Support.
#include "gdb-stabs.h"
#include "complaints.h"
#include "demangle.h"
+#include "psympriv.h"
+#include "filenames.h"
+#include "gdbtypes.h"
+#include "value.h"
+#include "infcall.h"
+#include "gdbthread.h"
+#include "regcache.h"
extern void _initialize_elfread (void);
+/* Forward declarations. */
+static const struct sym_fns elf_sym_fns_gdb_index;
+static const struct sym_fns elf_sym_fns_lazy_psyms;
+
/* The struct elfinfo is available only during ELF symbol table and
psymtab reading. It is destroyed at the completion of psymtab-reading.
It's local to elf_symfile_read. */
static void free_elfinfo (void *);
+/* Minimal symbols located at the GOT entries for .plt - that is the real
+ pointer where the given entry will jump to. It gets updated by the real
+ function address during lazy ld.so resolving in the inferior. These
+ minimal symbols are indexed for <tab>-completion. */
+
+#define SYMBOL_GOT_PLT_SUFFIX "@got.plt"
+
/* Locate the segments in ABFD. */
static struct symfile_segment_data *
for (j = 0; j < num_segments; j++)
if (segments[j]->p_memsz > 0
&& vma >= segments[j]->p_vaddr
- && vma < segments[j]->p_vaddr + segments[j]->p_memsz)
+ && (vma - segments[j]->p_vaddr) < segments[j]->p_memsz)
{
data->segment_info[i] = j + 1;
break;
}
- if (bfd_get_section_size (sect) > 0 && j == num_segments)
+ /* We should have found a segment for every non-empty section.
+ If we haven't, we will not relocate this section by any
+ offsets we apply to the segments. As an exception, do not
+ warn about SHT_NOBITS sections; in normal ELF execution
+ environments, SHT_NOBITS means zero-initialized and belongs
+ in a segment, but in no-OS environments some tools (e.g. ARM
+ RealView) use SHT_NOBITS for uninitialized data. Since it is
+ uninitialized, it doesn't need a program header. Such
+ binaries are not relocatable. */
+ if (bfd_get_section_size (sect) > 0 && j == num_segments
+ && (bfd_get_section_flags (abfd, sect) & SEC_LOAD) != 0)
warning (_("Loadable segment \"%s\" outside of ELF segments"),
bfd_section_name (abfd, sect));
}
FIXME: The section names should not be hardwired strings (what
should they be? I don't think most object file formats have enough
- section flags to specify what kind of debug section it is
+ section flags to specify what kind of debug section it is.
-kingdon). */
static void
}
static struct minimal_symbol *
-record_minimal_symbol (char *name, CORE_ADDR address,
+record_minimal_symbol (const char *name, int name_len, int copy_name,
+ CORE_ADDR address,
enum minimal_symbol_type ms_type,
asection *bfd_section, struct objfile *objfile)
{
struct gdbarch *gdbarch = get_objfile_arch (objfile);
- if (ms_type == mst_text || ms_type == mst_file_text)
+ if (ms_type == mst_text || ms_type == mst_file_text
+ || ms_type == mst_text_gnu_ifunc)
address = gdbarch_smash_text_address (gdbarch, address);
- return prim_record_minimal_symbol_and_info
- (name, address, ms_type, NULL, bfd_section->index, bfd_section, objfile);
+ return prim_record_minimal_symbol_full (name, name_len, copy_name, address,
+ ms_type, bfd_section->index,
+ bfd_section, objfile);
}
/*
static void
elf_symtab_read (struct objfile *objfile, int type,
- long number_of_symbols, asymbol **symbol_table)
+ long number_of_symbols, asymbol **symbol_table,
+ int copy_names)
{
struct gdbarch *gdbarch = get_objfile_arch (objfile);
- long storage_needed;
asymbol *sym;
long i;
CORE_ADDR symaddr;
/* If filesym is nonzero, it points to a file symbol, but we haven't
seen any section info for it yet. */
asymbol *filesym = 0;
- /* Name of filesym, as saved on the objfile_obstack. */
- char *filesymname = obsavestring ("", 0, &objfile->objfile_obstack);
+ /* Name of filesym. This is either a constant string or is saved on
+ the objfile's obstack. */
+ char *filesymname = "";
struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info;
int stripped = (bfd_get_symcount (objfile->obfd) == 0);
if (sym->name == NULL || *sym->name == '\0')
{
/* Skip names that don't exist (shouldn't happen), or names
- that are null strings (may happen). */
+ that are null strings (may happen). */
continue;
}
of the corresponding entry in the procedure linkage table,
plus the desired section offset.
If its value is zero then the dynamic linker has to resolve
- the symbol. We are unable to find any meaningful address
+ the symbol. We are unable to find any meaningful address
for this symbol in the executable file, so we skip it. */
symaddr = sym->value;
if (symaddr == 0)
symaddr += ANOFFSET (objfile->section_offsets, sect->index);
msym = record_minimal_symbol
- ((char *) sym->name, symaddr, mst_solib_trampoline, sect, objfile);
+ (sym->name, strlen (sym->name), copy_names,
+ symaddr, mst_solib_trampoline, sect, objfile);
if (msym != NULL)
msym->filename = filesymname;
continue;
/* Select global/local/weak symbols. Note that bfd puts abs
symbols in their own section, so all symbols we are
- interested in will have a section. */
- /* Bfd symbols are section relative. */
+ interested in will have a section. */
+ /* Bfd symbols are section relative. */
symaddr = sym->value + sym->section->vma;
- /* Relocate all non-absolute symbols by the section offset. */
- if (sym->section != &bfd_abs_section)
+ /* Relocate all non-absolute and non-TLS symbols by the
+ section offset. */
+ if (sym->section != &bfd_abs_section
+ && !(sym->section->flags & SEC_THREAD_LOCAL))
{
symaddr += offset;
}
/* For non-absolute symbols, use the type of the section
they are relative to, to intuit text/data. Bfd provides
- no way of figuring this out for absolute symbols. */
+ no way of figuring this out for absolute symbols. */
if (sym->section == &bfd_abs_section)
{
/* This is a hack to get the minimal symbol type
}
/* If it is an Irix dynamic symbol, skip section name
- symbols, relocate all others by section offset. */
+ symbols, relocate all others by section offset. */
if (ms_type != mst_abs)
{
if (sym->name[0] == '.')
{
if (sym->flags & (BSF_GLOBAL | BSF_WEAK))
{
- ms_type = mst_text;
+ if (sym->flags & BSF_GNU_INDIRECT_FUNCTION)
+ ms_type = mst_text_gnu_ifunc;
+ else
+ ms_type = mst_text;
}
- else if ((sym->name[0] == '.' && sym->name[1] == 'L')
+ /* The BSF_SYNTHETIC check is there to omit ppc64 function
+ descriptors mistaken for static functions starting with 'L'.
+ */
+ else if ((sym->name[0] == '.' && sym->name[1] == 'L'
+ && (sym->flags & BSF_SYNTHETIC) == 0)
|| ((sym->flags & BSF_LOCAL)
&& sym->name[0] == '$'
&& sym->name[1] == 'L'))
/* Named Local variable in a Data section.
Check its name for stabs-in-elf. */
int special_local_sect;
+
if (strcmp ("Bbss.bss", sym->name) == 0)
special_local_sect = SECT_OFF_BSS (objfile);
else if (strcmp ("Ddata.data", sym->name) == 0)
int max_index;
size_t size;
- max_index
- = max (SECT_OFF_BSS (objfile),
- max (SECT_OFF_DATA (objfile),
- SECT_OFF_RODATA (objfile)));
+ max_index = SECT_OFF_BSS (objfile);
+ if (objfile->sect_index_data > max_index)
+ max_index = objfile->sect_index_data;
+ if (objfile->sect_index_rodata > max_index)
+ max_index = objfile->sect_index_rodata;
/* max_index is the largest index we'll
use into this array, so we must
need to allocate max_index aadditional
elements. */
size = (sizeof (struct stab_section_info)
- + (sizeof (CORE_ADDR)
- * max_index));
+ + (sizeof (CORE_ADDR) * max_index));
sectinfo = (struct stab_section_info *)
xmalloc (size);
memset (sectinfo, 0, size);
if (filesym == NULL)
{
complaint (&symfile_complaints,
- _("elf/stab section information %s without a preceding file symbol"),
+ _("elf/stab section information %s "
+ "without a preceding file symbol"),
sym->name);
}
else
}
if (sectinfo->sections[special_local_sect] != 0)
complaint (&symfile_complaints,
- _("duplicated elf/stab section information for %s"),
+ _("duplicated elf/stab section "
+ "information for %s"),
sectinfo->filename);
/* BFD symbols are section relative. */
symaddr = sym->value + sym->section->vma;
hob with actions like finding what function the PC
is in. Ignore them if they aren't text, data, or bss. */
/* ms_type = mst_unknown; */
- continue; /* Skip this symbol. */
+ continue; /* Skip this symbol. */
}
msym = record_minimal_symbol
- ((char *) sym->name, symaddr,
+ (sym->name, strlen (sym->name), copy_names, symaddr,
ms_type, sym->section, objfile);
if (msym)
if (elf_sym)
MSYMBOL_SIZE(msym) = elf_sym->internal_elf_sym.st_size;
+
+ msym->filename = filesymname;
+ gdbarch_elf_make_msymbol_special (gdbarch, sym, msym);
}
- if (msym != NULL)
- msym->filename = filesymname;
- gdbarch_elf_make_msymbol_special (gdbarch, sym, msym);
/* For @plt symbols, also record a trampoline to the
destination symbol. The @plt symbol will be used in
if (len > 4 && strcmp (sym->name + len - 4, "@plt") == 0)
{
- char *base_name = alloca (len - 4 + 1);
struct minimal_symbol *mtramp;
- memcpy (base_name, sym->name, len - 4);
- base_name[len - 4] = '\0';
- mtramp = record_minimal_symbol (base_name, symaddr,
+ mtramp = record_minimal_symbol (sym->name, len - 4, 1,
+ symaddr,
mst_solib_trampoline,
sym->section, objfile);
if (mtramp)
}
}
+ for later look ups of which function to call when user requests
+ a STT_GNU_IFUNC function. As the STT_GNU_IFUNC type is found at the target
+ library defining `function' we cannot yet know while reading OBJFILE which
+ of the SYMBOL_GOT_PLT_SUFFIX entries will be needed and later
+ DYN_SYMBOL_TABLE is no longer easily available for OBJFILE. */
+
+static void
+elf_rel_plt_read (struct objfile *objfile, asymbol **dyn_symbol_table)
+{
+ bfd *obfd = objfile->obfd;
+ const struct elf_backend_data *bed = get_elf_backend_data (obfd);
+ asection *plt, *relplt, *got_plt;
+ unsigned u;
+ int plt_elf_idx;
+ bfd_size_type reloc_count, reloc;
+ char *string_buffer = NULL;
+ size_t string_buffer_size = 0;
+ struct cleanup *back_to;
+ struct gdbarch *gdbarch = objfile->gdbarch;
+ struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
+ size_t ptr_size = TYPE_LENGTH (ptr_type);
+
+ if (objfile->separate_debug_objfile_backlink)
+ return;
+
+ plt = bfd_get_section_by_name (obfd, ".plt");
+ if (plt == NULL)
+ return;
+ plt_elf_idx = elf_section_data (plt)->this_idx;
+
+ got_plt = bfd_get_section_by_name (obfd, ".got.plt");
+ if (got_plt == NULL)
+ return;
+
+ /* This search algorithm is from _bfd_elf_canonicalize_dynamic_reloc. */
+ for (relplt = obfd->sections; relplt != NULL; relplt = relplt->next)
+ if (elf_section_data (relplt)->this_hdr.sh_info == plt_elf_idx
+ && (elf_section_data (relplt)->this_hdr.sh_type == SHT_REL
+ || elf_section_data (relplt)->this_hdr.sh_type == SHT_RELA))
+ break;
+ if (relplt == NULL)
+ return;
+
+ if (! bed->s->slurp_reloc_table (obfd, relplt, dyn_symbol_table, TRUE))
+ return;
+
+ back_to = make_cleanup (free_current_contents, &string_buffer);
+
+ reloc_count = relplt->size / elf_section_data (relplt)->this_hdr.sh_entsize;
+ for (reloc = 0; reloc < reloc_count; reloc++)
+ {
+ const char *name, *name_got_plt;
+ struct minimal_symbol *msym;
+ CORE_ADDR address;
+ const size_t got_suffix_len = strlen (SYMBOL_GOT_PLT_SUFFIX);
+ size_t name_len;
+
+ name = bfd_asymbol_name (*relplt->relocation[reloc].sym_ptr_ptr);
+ name_len = strlen (name);
+ address = relplt->relocation[reloc].address;
+
+ /* Does the pointer reside in the .got.plt section? */
+ if (!(bfd_get_section_vma (obfd, got_plt) <= address
+ && address < bfd_get_section_vma (obfd, got_plt)
+ + bfd_get_section_size (got_plt)))
+ continue;
+
+ /* We cannot check if NAME is a reference to mst_text_gnu_ifunc as in
+ OBJFILE the symbol is undefined and the objfile having NAME defined
+ may not yet have been loaded. */
+
+ if (string_buffer_size < name_len + got_suffix_len)
+ {
+ string_buffer_size = 2 * (name_len + got_suffix_len);
+ string_buffer = xrealloc (string_buffer, string_buffer_size);
+ }
+ memcpy (string_buffer, name, name_len);
+ memcpy (&string_buffer[name_len], SYMBOL_GOT_PLT_SUFFIX,
+ got_suffix_len);
+
+ msym = record_minimal_symbol (string_buffer, name_len + got_suffix_len,
+ 1, address, mst_slot_got_plt, got_plt,
+ objfile);
+ if (msym)
+ MSYMBOL_SIZE (msym) = ptr_size;
+ }
+
+ do_cleanups (back_to);
+}
+
+/* The data pointer is htab_t for gnu_ifunc_record_cache_unchecked. */
+
+static const struct objfile_data *elf_objfile_gnu_ifunc_cache_data;
+
+/* Map function names to CORE_ADDR in elf_objfile_gnu_ifunc_cache_data. */
+
+struct elf_gnu_ifunc_cache
+{
+ /* This is always a function entry address, not a function descriptor. */
+ CORE_ADDR addr;
+
+ char name[1];
+};
+
+/* htab_hash for elf_objfile_gnu_ifunc_cache_data. */
+
+static hashval_t
+elf_gnu_ifunc_cache_hash (const void *a_voidp)
+{
+ const struct elf_gnu_ifunc_cache *a = a_voidp;
+
+ return htab_hash_string (a->name);
+}
+
+/* htab_eq for elf_objfile_gnu_ifunc_cache_data. */
+
+static int
+elf_gnu_ifunc_cache_eq (const void *a_voidp, const void *b_voidp)
+{
+ const struct elf_gnu_ifunc_cache *a = a_voidp;
+ const struct elf_gnu_ifunc_cache *b = b_voidp;
+
+ return strcmp (a->name, b->name) == 0;
+}
+
+/* Record the target function address of a STT_GNU_IFUNC function NAME is the
+ function entry address ADDR. Return 1 if NAME and ADDR are considered as
+ valid and therefore they were successfully recorded, return 0 otherwise.
+
+ Function does not expect a duplicate entry. Use
+ elf_gnu_ifunc_resolve_by_cache first to check if the entry for NAME already
+ exists. */
+
+static int
+elf_gnu_ifunc_record_cache (const char *name, CORE_ADDR addr)
+{
+ struct minimal_symbol *msym;
+ asection *sect;
+ struct objfile *objfile;
+ htab_t htab;
+ struct elf_gnu_ifunc_cache entry_local, *entry_p;
+ void **slot;
+
+ msym = lookup_minimal_symbol_by_pc (addr);
+ if (msym == NULL)
+ return 0;
+ if (SYMBOL_VALUE_ADDRESS (msym) != addr)
+ return 0;
+ /* minimal symbols have always SYMBOL_OBJ_SECTION non-NULL. */
+ sect = SYMBOL_OBJ_SECTION (msym)->the_bfd_section;
+ objfile = SYMBOL_OBJ_SECTION (msym)->objfile;
+
+ /* If .plt jumps back to .plt the symbol is still deferred for later
+ resolution and it has no use for GDB. Besides ".text" this symbol can
+ reside also in ".opd" for ppc64 function descriptor. */
+ if (strcmp (bfd_get_section_name (objfile->obfd, sect), ".plt") == 0)
+ return 0;
+
+ htab = objfile_data (objfile, elf_objfile_gnu_ifunc_cache_data);
+ if (htab == NULL)
+ {
+ htab = htab_create_alloc_ex (1, elf_gnu_ifunc_cache_hash,
+ elf_gnu_ifunc_cache_eq,
+ NULL, &objfile->objfile_obstack,
+ hashtab_obstack_allocate,
+ dummy_obstack_deallocate);
+ set_objfile_data (objfile, elf_objfile_gnu_ifunc_cache_data, htab);
+ }
+
+ entry_local.addr = addr;
+ obstack_grow (&objfile->objfile_obstack, &entry_local,
+ offsetof (struct elf_gnu_ifunc_cache, name));
+ obstack_grow_str0 (&objfile->objfile_obstack, name);
+ entry_p = obstack_finish (&objfile->objfile_obstack);
+
+ slot = htab_find_slot (htab, entry_p, INSERT);
+ if (*slot != NULL)
+ {
+ struct elf_gnu_ifunc_cache *entry_found_p = *slot;
+ struct gdbarch *gdbarch = objfile->gdbarch;
+
+ if (entry_found_p->addr != addr)
+ {
+ /* This case indicates buggy inferior program, the resolved address
+ should never change. */
+
+ warning (_("gnu-indirect-function \"%s\" has changed its resolved "
+ "function_address from %s to %s"),
+ name, paddress (gdbarch, entry_found_p->addr),
+ paddress (gdbarch, addr));
+ }
+
+ /* New ENTRY_P is here leaked/duplicate in the OBJFILE obstack. */
+ }
+ *slot = entry_p;
+
+ return 1;
+}
+
+/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
+ function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
+ is not NULL) and the function returns 1. It returns 0 otherwise.
+
+ Only the elf_objfile_gnu_ifunc_cache_data hash table is searched by this
+ function. */
+
+static int
+elf_gnu_ifunc_resolve_by_cache (const char *name, CORE_ADDR *addr_p)
+{
+ struct objfile *objfile;
+
+ ALL_PSPACE_OBJFILES (current_program_space, objfile)
+ {
+ htab_t htab;
+ struct elf_gnu_ifunc_cache *entry_p;
+ void **slot;
+
+ htab = objfile_data (objfile, elf_objfile_gnu_ifunc_cache_data);
+ if (htab == NULL)
+ continue;
+
+ entry_p = alloca (sizeof (*entry_p) + strlen (name));
+ strcpy (entry_p->name, name);
+
+ slot = htab_find_slot (htab, entry_p, NO_INSERT);
+ if (slot == NULL)
+ continue;
+ entry_p = *slot;
+ gdb_assert (entry_p != NULL);
+
+ if (addr_p)
+ *addr_p = entry_p->addr;
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
+ function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
+ is not NULL) and the function returns 1. It returns 0 otherwise.
+
+ Only the SYMBOL_GOT_PLT_SUFFIX locations are searched by this function.
+ elf_gnu_ifunc_resolve_by_cache must have been already called for NAME to
+ prevent cache entries duplicates. */
+
+static int
+elf_gnu_ifunc_resolve_by_got (const char *name, CORE_ADDR *addr_p)
+{
+ char *name_got_plt;
+ struct objfile *objfile;
+ const size_t got_suffix_len = strlen (SYMBOL_GOT_PLT_SUFFIX);
+
+ name_got_plt = alloca (strlen (name) + got_suffix_len + 1);
+ sprintf (name_got_plt, "%s" SYMBOL_GOT_PLT_SUFFIX, name);
+
+ ALL_PSPACE_OBJFILES (current_program_space, objfile)
+ {
+ bfd *obfd = objfile->obfd;
+ struct gdbarch *gdbarch = objfile->gdbarch;
+ struct type *ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
+ size_t ptr_size = TYPE_LENGTH (ptr_type);
+ CORE_ADDR pointer_address, addr;
+ asection *plt;
+ gdb_byte *buf = alloca (ptr_size);
+ struct minimal_symbol *msym;
+
+ msym = lookup_minimal_symbol (name_got_plt, NULL, objfile);
+ if (msym == NULL)
+ continue;
+ if (MSYMBOL_TYPE (msym) != mst_slot_got_plt)
+ continue;
+ pointer_address = SYMBOL_VALUE_ADDRESS (msym);
+
+ plt = bfd_get_section_by_name (obfd, ".plt");
+ if (plt == NULL)
+ continue;
+
+ if (MSYMBOL_SIZE (msym) != ptr_size)
+ continue;
+ if (target_read_memory (pointer_address, buf, ptr_size) != 0)
+ continue;
+ addr = extract_typed_address (buf, ptr_type);
+ addr = gdbarch_convert_from_func_ptr_addr (gdbarch, addr,
+ ¤t_target);
+
+ if (addr_p)
+ *addr_p = addr;
+ if (elf_gnu_ifunc_record_cache (name, addr))
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Try to find the target resolved function entry address of a STT_GNU_IFUNC
+ function NAME. If the address is found it is stored to *ADDR_P (if ADDR_P
+ is not NULL) and the function returns 1. It returns 0 otherwise.
+
+ Both the elf_objfile_gnu_ifunc_cache_data hash table and
+ SYMBOL_GOT_PLT_SUFFIX locations are searched by this function. */
+
+static int
+elf_gnu_ifunc_resolve_name (const char *name, CORE_ADDR *addr_p)
+{
+ if (elf_gnu_ifunc_resolve_by_cache (name, addr_p))
+ return 1;
+
+ if (elf_gnu_ifunc_resolve_by_got (name, addr_p))
+ return 1;
+
+ return 0;
+}
+
+/* Call STT_GNU_IFUNC - a function returning addresss of a real function to
+ call. PC is theSTT_GNU_IFUNC resolving function entry. The value returned
+ is the entry point of the resolved STT_GNU_IFUNC target function to call.
+ */
+
+static CORE_ADDR
+elf_gnu_ifunc_resolve_addr (struct gdbarch *gdbarch, CORE_ADDR pc)
+{
+ char *name_at_pc;
+ CORE_ADDR start_at_pc, address;
+ struct type *func_func_type = builtin_type (gdbarch)->builtin_func_func;
+ struct value *function, *address_val;
+
+ /* Try first any non-intrusive methods without an inferior call. */
+
+ if (find_pc_partial_function (pc, &name_at_pc, &start_at_pc, NULL)
+ && start_at_pc == pc)
+ {
+ if (elf_gnu_ifunc_resolve_name (name_at_pc, &address))
+ return address;
+ }
+ else
+ name_at_pc = NULL;
+
+ function = allocate_value (func_func_type);
+ set_value_address (function, pc);
+
+ /* STT_GNU_IFUNC resolver functions have no parameters. FUNCTION is the
+ function entry address. ADDRESS may be a function descriptor. */
+
+ address_val = call_function_by_hand (function, 0, NULL);
+ address = value_as_address (address_val);
+ address = gdbarch_convert_from_func_ptr_addr (gdbarch, address,
+ ¤t_target);
+
+ if (name_at_pc)
+ elf_gnu_ifunc_record_cache (name_at_pc, address);
+
+ return address;
+}
+
+/* Handle inferior hit of bp_gnu_ifunc_resolver, see its definition. */
+
+static void
+elf_gnu_ifunc_resolver_stop (struct breakpoint *b)
+{
+ struct breakpoint *b_return;
+ struct frame_info *prev_frame = get_prev_frame (get_current_frame ());
+ struct frame_id prev_frame_id = get_stack_frame_id (prev_frame);
+ CORE_ADDR prev_pc = get_frame_pc (prev_frame);
+ int thread_id = pid_to_thread_id (inferior_ptid);
+
+ gdb_assert (b->type == bp_gnu_ifunc_resolver);
+
+ for (b_return = b->related_breakpoint; b_return != b;
+ b_return = b_return->related_breakpoint)
+ {
+ gdb_assert (b_return->type == bp_gnu_ifunc_resolver_return);
+ gdb_assert (b_return->loc != NULL && b_return->loc->next == NULL);
+ gdb_assert (frame_id_p (b_return->frame_id));
+
+ if (b_return->thread == thread_id
+ && b_return->loc->requested_address == prev_pc
+ && frame_id_eq (b_return->frame_id, prev_frame_id))
+ break;
+ }
+
+ if (b_return == b)
+ {
+ struct symtab_and_line sal;
+
+ /* No need to call find_pc_line for symbols resolving as this is only
+ a helper breakpointer never shown to the user. */
+
+ init_sal (&sal);
+ sal.pspace = current_inferior ()->pspace;
+ sal.pc = prev_pc;
+ sal.section = find_pc_overlay (sal.pc);
+ sal.explicit_pc = 1;
+ b_return = set_momentary_breakpoint (get_frame_arch (prev_frame), sal,
+ prev_frame_id,
+ bp_gnu_ifunc_resolver_return);
+
+ /* Add new b_return to the ring list b->related_breakpoint. */
+ gdb_assert (b_return->related_breakpoint == b_return);
+ b_return->related_breakpoint = b->related_breakpoint;
+ b->related_breakpoint = b_return;
+ }
+}
+
+/* Handle inferior hit of bp_gnu_ifunc_resolver_return, see its definition. */
+
+static void
+elf_gnu_ifunc_resolver_return_stop (struct breakpoint *b)
+{
+ struct gdbarch *gdbarch = get_frame_arch (get_current_frame ());
+ struct type *func_func_type = builtin_type (gdbarch)->builtin_func_func;
+ struct type *value_type = TYPE_TARGET_TYPE (func_func_type);
+ struct regcache *regcache = get_thread_regcache (inferior_ptid);
+ struct value *value;
+ CORE_ADDR resolved_address, resolved_pc;
+ struct symtab_and_line sal;
+ struct symtabs_and_lines sals, sals_end;
+
+ gdb_assert (b->type == bp_gnu_ifunc_resolver_return);
+
+ value = allocate_value (value_type);
+ gdbarch_return_value (gdbarch, func_func_type, value_type, regcache,
+ value_contents_raw (value), NULL);
+ resolved_address = value_as_address (value);
+ resolved_pc = gdbarch_convert_from_func_ptr_addr (gdbarch,
+ resolved_address,
+ ¤t_target);
+
+ while (b->related_breakpoint != b)
+ {
+ struct breakpoint *b_next = b->related_breakpoint;
+
+ switch (b->type)
+ {
+ case bp_gnu_ifunc_resolver:
+ break;
+ case bp_gnu_ifunc_resolver_return:
+ delete_breakpoint (b);
+ break;
+ default:
+ internal_error (__FILE__, __LINE__,
+ _("handle_inferior_event: Invalid "
+ "gnu-indirect-function breakpoint type %d"),
+ (int) b->type);
+ }
+ b = b_next;
+ }
+ gdb_assert (b->type == bp_gnu_ifunc_resolver);
+
+ gdb_assert (current_program_space == b->pspace);
+ elf_gnu_ifunc_record_cache (b->addr_string, resolved_pc);
+
+ sal = find_pc_line (resolved_pc, 0);
+ sals.nelts = 1;
+ sals.sals = &sal;
+ sals_end.nelts = 0;
+
+ b->type = bp_breakpoint;
+ update_breakpoint_locations (b, sals, sals_end);
+}
+
+struct build_id
+ {
+ size_t size;
+ gdb_byte data[1];
+ };
+
+/* Locate NT_GNU_BUILD_ID from ABFD and return its content. */
+
+static struct build_id *
+build_id_bfd_get (bfd *abfd)
+{
+ struct build_id *retval;
+
+ if (!bfd_check_format (abfd, bfd_object)
+ || bfd_get_flavour (abfd) != bfd_target_elf_flavour
+ || elf_tdata (abfd)->build_id == NULL)
+ return NULL;
+
+ retval = xmalloc (sizeof *retval - 1 + elf_tdata (abfd)->build_id_size);
+ retval->size = elf_tdata (abfd)->build_id_size;
+ memcpy (retval->data, elf_tdata (abfd)->build_id, retval->size);
+
+ return retval;
+}
+
+/* Return if FILENAME has NT_GNU_BUILD_ID matching the CHECK value. */
+
+static int
+build_id_verify (const char *filename, struct build_id *check)
+{
+ bfd *abfd;
+ struct build_id *found = NULL;
+ int retval = 0;
+
+ /* We expect to be silent on the non-existing files. */
+ abfd = bfd_open_maybe_remote (filename);
+ if (abfd == NULL)
+ return 0;
+
+ found = build_id_bfd_get (abfd);
+
+ if (found == NULL)
+ warning (_("File \"%s\" has no build-id, file skipped"), filename);
+ else if (found->size != check->size
+ || memcmp (found->data, check->data, found->size) != 0)
+ warning (_("File \"%s\" has a different build-id, file skipped"),
+ filename);
+ else
+ retval = 1;
+
+ gdb_bfd_close_or_warn (abfd);
+
+ xfree (found);
+
+ return retval;
+}
+
+static char *
+build_id_to_debug_filename (struct build_id *build_id)
+{
+ char *link, *debugdir, *retval = NULL;
+
+ /* DEBUG_FILE_DIRECTORY/.build-id/ab/cdef */
+ link = alloca (strlen (debug_file_directory) + (sizeof "/.build-id/" - 1) + 1
+ + 2 * build_id->size + (sizeof ".debug" - 1) + 1);
+
+ /* Keep backward compatibility so that DEBUG_FILE_DIRECTORY being "" will
+ cause "/.build-id/..." lookups. */
+
+ debugdir = debug_file_directory;
+ do
+ {
+ char *s, *debugdir_end;
+ gdb_byte *data = build_id->data;
+ size_t size = build_id->size;
+
+ while (*debugdir == DIRNAME_SEPARATOR)
+ debugdir++;
+
+ debugdir_end = strchr (debugdir, DIRNAME_SEPARATOR);
+ if (debugdir_end == NULL)
+ debugdir_end = &debugdir[strlen (debugdir)];
+
+ memcpy (link, debugdir, debugdir_end - debugdir);
+ s = &link[debugdir_end - debugdir];
+ s += sprintf (s, "/.build-id/");
+ if (size > 0)
+ {
+ size--;
+ s += sprintf (s, "%02x", (unsigned) *data++);
+ }
+ if (size > 0)
+ *s++ = '/';
+ while (size-- > 0)
+ s += sprintf (s, "%02x", (unsigned) *data++);
+ strcpy (s, ".debug");
+
+ /* lrealpath() is expensive even for the usually non-existent files. */
+ if (access (link, F_OK) == 0)
+ retval = lrealpath (link);
+
+ if (retval != NULL && !build_id_verify (retval, build_id))
+ {
+ xfree (retval);
+ retval = NULL;
+ }
+
+ if (retval != NULL)
+ break;
+
+ debugdir = debugdir_end;
+ }
+ while (*debugdir != 0);
+
+ return retval;
+}
+
+static char *
+find_separate_debug_file_by_buildid (struct objfile *objfile)
+{
+ struct build_id *build_id;
+
+ build_id = build_id_bfd_get (objfile->obfd);
+ if (build_id != NULL)
+ {
+ char *build_id_name;
+
+ build_id_name = build_id_to_debug_filename (build_id);
+ xfree (build_id);
+ /* Prevent looping on a stripped .debug file. */
+ if (build_id_name != NULL
+ && filename_cmp (build_id_name, objfile->name) == 0)
+ {
+ warning (_("\"%s\": separate debug info file has no debug info"),
+ build_id_name);
+ xfree (build_id_name);
+ }
+ else if (build_id_name != NULL)
+ return build_id_name;
+ }
+ return NULL;
+}
+
/* Scan and build partial symbols for a symbol file.
We have been initialized by a call to elf_symfile_init, which
currently does nothing.
in each section. We simplify it down to a single offset for all
symbols. FIXME.
- MAINLINE is true if we are reading the main symbol
- table (as opposed to a shared lib or dynamically loaded file).
-
This function only does the minimum work necessary for letting the
user "name" things symbolically; it does not read the entire symtab.
Instead, it reads the external and static symbols and puts them in partial
capability even for files compiled without -g. */
static void
-elf_symfile_read (struct objfile *objfile, int mainline)
+elf_symfile_read (struct objfile *objfile, int symfile_flags)
{
- bfd *abfd = objfile->obfd;
+ bfd *synth_abfd, *abfd = objfile->obfd;
struct elfinfo ei;
struct cleanup *back_to;
- CORE_ADDR offset;
long symcount = 0, dynsymcount = 0, synthcount, storage_needed;
asymbol **symbol_table = NULL, **dyn_symbol_table = NULL;
asymbol *synthsyms;
memset ((char *) &ei, 0, sizeof (ei));
- /* Allocate struct to keep track of the symfile */
+ /* Allocate struct to keep track of the symfile. */
objfile->deprecated_sym_stab_info = (struct dbx_symfile_info *)
xmalloc (sizeof (struct dbx_symfile_info));
- memset ((char *) objfile->deprecated_sym_stab_info, 0, sizeof (struct dbx_symfile_info));
+ memset ((char *) objfile->deprecated_sym_stab_info,
+ 0, sizeof (struct dbx_symfile_info));
make_cleanup (free_elfinfo, (void *) objfile);
- /* Process the normal ELF symbol table first. This may write some
- chain of info into the dbx_symfile_info in objfile->deprecated_sym_stab_info,
- which can later be used by elfstab_offset_sections. */
+ /* Process the normal ELF symbol table first. This may write some
+ chain of info into the dbx_symfile_info in
+ objfile->deprecated_sym_stab_info, which can later be used by
+ elfstab_offset_sections. */
storage_needed = bfd_get_symtab_upper_bound (objfile->obfd);
if (storage_needed < 0)
- error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd),
+ error (_("Can't read symbols from %s: %s"),
+ bfd_get_filename (objfile->obfd),
bfd_errmsg (bfd_get_error ()));
if (storage_needed > 0)
symcount = bfd_canonicalize_symtab (objfile->obfd, symbol_table);
if (symcount < 0)
- error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd),
+ error (_("Can't read symbols from %s: %s"),
+ bfd_get_filename (objfile->obfd),
bfd_errmsg (bfd_get_error ()));
- elf_symtab_read (objfile, ST_REGULAR, symcount, symbol_table);
+ elf_symtab_read (objfile, ST_REGULAR, symcount, symbol_table, 0);
}
/* Add the dynamic symbols. */
if (storage_needed > 0)
{
- dyn_symbol_table = (asymbol **) xmalloc (storage_needed);
- make_cleanup (xfree, dyn_symbol_table);
+ /* Memory gets permanently referenced from ABFD after
+ bfd_get_synthetic_symtab so it must not get freed before ABFD gets.
+ It happens only in the case when elf_slurp_reloc_table sees
+ asection->relocation NULL. Determining which section is asection is
+ done by _bfd_elf_get_synthetic_symtab which is all a bfd
+ implementation detail, though. */
+
+ dyn_symbol_table = bfd_alloc (abfd, storage_needed);
dynsymcount = bfd_canonicalize_dynamic_symtab (objfile->obfd,
dyn_symbol_table);
if (dynsymcount < 0)
- error (_("Can't read symbols from %s: %s"), bfd_get_filename (objfile->obfd),
+ error (_("Can't read symbols from %s: %s"),
+ bfd_get_filename (objfile->obfd),
bfd_errmsg (bfd_get_error ()));
- elf_symtab_read (objfile, ST_DYNAMIC, dynsymcount, dyn_symbol_table);
+ elf_symtab_read (objfile, ST_DYNAMIC, dynsymcount, dyn_symbol_table, 0);
+
+ elf_rel_plt_read (objfile, dyn_symbol_table);
}
+ /* Contrary to binutils --strip-debug/--only-keep-debug the strip command from
+ elfutils (eu-strip) moves even the .symtab section into the .debug file.
+
+ bfd_get_synthetic_symtab on ppc64 for each function descriptor ELF symbol
+ 'name' creates a new BSF_SYNTHETIC ELF symbol '.name' with its code
+ address. But with eu-strip files bfd_get_synthetic_symtab would fail to
+ read the code address from .opd while it reads the .symtab section from
+ a separate debug info file as the .opd section is SHT_NOBITS there.
+
+ With SYNTH_ABFD the .opd section will be read from the original
+ backlinked binary where it is valid. */
+
+ if (objfile->separate_debug_objfile_backlink)
+ synth_abfd = objfile->separate_debug_objfile_backlink->obfd;
+ else
+ synth_abfd = abfd;
+
/* Add synthetic symbols - for instance, names for any PLT entries. */
- synthcount = bfd_get_synthetic_symtab (abfd, symcount, symbol_table,
+ synthcount = bfd_get_synthetic_symtab (synth_abfd, symcount, symbol_table,
dynsymcount, dyn_symbol_table,
&synthsyms);
if (synthcount > 0)
for (i = 0; i < synthcount; i++)
synth_symbol_table[i] = synthsyms + i;
make_cleanup (xfree, synth_symbol_table);
- elf_symtab_read (objfile, ST_SYNTHETIC, synthcount, synth_symbol_table);
+ elf_symtab_read (objfile, ST_SYNTHETIC, synthcount,
+ synth_symbol_table, 1);
}
/* Install any minimal symbols that have been collected as the current
do_cleanups (back_to);
/* Now process debugging information, which is contained in
- special ELF sections. */
+ special ELF sections. */
- /* If we are reinitializing, or if we have never loaded syms yet,
- set table to empty. MAINLINE is cleared so that *_read_psymtab
- functions do not all also re-initialize the psymbol table. */
- if (mainline)
- {
- init_psymbol_list (objfile, 0);
- mainline = 0;
- }
-
- /* We first have to find them... */
+ /* We first have to find them... */
bfd_map_over_sections (abfd, elf_locate_sections, (void *) & ei);
/* ELF debugging information is inserted into the psymtab in the
and .debug_info (DWARF2) sections then .mdebug is inserted first
(searched last) and DWARF2 is inserted last (searched first). If
we don't do this then the XCOFF info is found first - for code in
- an included file XCOFF info is useless. */
+ an included file XCOFF info is useless. */
if (ei.mdebugsect)
{
/* FIXME should probably warn about a stab section without a stabstr. */
if (str_sect)
elfstab_build_psymtabs (objfile,
- mainline,
ei.stabsect,
str_sect->filepos,
bfd_section_size (abfd, str_sect));
}
- if (dwarf2_has_info (objfile))
+
+ if (dwarf2_has_info (objfile, NULL))
{
- /* DWARF 2 sections */
- dwarf2_build_psymtabs (objfile, mainline);
+ /* elf_sym_fns_gdb_index cannot handle simultaneous non-DWARF debug
+ information present in OBJFILE. If there is such debug info present
+ never use .gdb_index. */
+
+ if (!objfile_has_partial_symbols (objfile)
+ && dwarf2_initialize_objfile (objfile))
+ objfile->sf = &elf_sym_fns_gdb_index;
+ else
+ {
+ /* It is ok to do this even if the stabs reader made some
+ partial symbols, because OBJF_PSYMTABS_READ has not been
+ set, and so our lazy reader function will still be called
+ when needed. */
+ objfile->sf = &elf_sym_fns_lazy_psyms;
+ }
+ }
+ /* If the file has its own symbol tables it has no separate debug
+ info. `.dynsym'/`.symtab' go to MSYMBOLS, `.debug_info' goes to
+ SYMTABS/PSYMTABS. `.gnu_debuglink' may no longer be present with
+ `.note.gnu.build-id'. */
+ else if (!objfile_has_partial_symbols (objfile))
+ {
+ char *debugfile;
+
+ debugfile = find_separate_debug_file_by_buildid (objfile);
+
+ if (debugfile == NULL)
+ debugfile = find_separate_debug_file_by_debuglink (objfile);
+
+ if (debugfile)
+ {
+ bfd *abfd = symfile_bfd_open (debugfile);
+
+ symbol_file_add_separate (abfd, symfile_flags, objfile);
+ xfree (debugfile);
+ }
}
+}
+
+/* Callback to lazily read psymtabs. */
- /* FIXME: kettenis/20030504: This still needs to be integrated with
- dwarf2read.c in a better way. */
- dwarf2_build_frame_info (objfile);
+static void
+read_psyms (struct objfile *objfile)
+{
+ if (dwarf2_has_info (objfile, NULL))
+ dwarf2_build_psymtabs (objfile);
}
/* This cleans up the objfile's deprecated_sym_stab_info pointer, and
file is specified (not just adding some symbols from another file, e.g. a
shared library).
- We reinitialize buildsym, since we may be reading stabs from an ELF file. */
+ We reinitialize buildsym, since we may be reading stabs from an ELF
+ file. */
static void
elf_new_init (struct objfile *ignore)
/* Perform any local cleanups required when we are done with a particular
objfile. I.E, we are in the process of discarding all symbol information
for an objfile, freeing up all memory held for it, and unlinking the
- objfile struct from the global list of known objfiles. */
+ objfile struct from the global list of known objfiles. */
static void
elf_symfile_finish (struct objfile *objfile)
a pointer to "private data" which we can fill with goodies.
For now at least, we have nothing in particular to do, so this function is
- just a stub. */
+ just a stub. */
static void
elf_symfile_init (struct objfile *objfile)
void
elfstab_offset_sections (struct objfile *objfile, struct partial_symtab *pst)
{
- char *filename = pst->filename;
+ const char *filename = pst->filename;
struct dbx_symfile_info *dbx = objfile->deprecated_sym_stab_info;
struct stab_section_info *maybe = dbx->stab_section_info;
struct stab_section_info *questionable = 0;
int i;
- char *p;
/* The ELF symbol info doesn't include path names, so strip the path
(if any) from the psymtab filename. */
- while (0 != (p = strchr (filename, '/')))
- filename = p + 1;
+ filename = lbasename (filename);
/* FIXME: This linear search could speed up significantly
if it was chained in the right order to match how we search it,
- and if we unchained when we found a match. */
+ and if we unchained when we found a match. */
for (; maybe; maybe = maybe->next)
{
if (filename[0] == maybe->filename[0]
- && strcmp (filename, maybe->filename) == 0)
+ && filename_cmp (filename, maybe->filename) == 0)
{
/* We found a match. But there might be several source files
(from different directories) with the same name. */
if (maybe == 0 && questionable != 0)
{
complaint (&symfile_complaints,
- _("elf/stab section information questionable for %s"), filename);
+ _("elf/stab section information questionable for %s"),
+ filename);
maybe = questionable;
}
\f
/* Register that we are able to handle ELF object file formats. */
-static struct sym_fns elf_sym_fns =
+static const struct sym_fns elf_sym_fns =
{
bfd_target_elf_flavour,
- elf_new_init, /* sym_new_init: init anything gbl to entire symtab */
- elf_symfile_init, /* sym_init: read initial info, setup for sym_read() */
- elf_symfile_read, /* sym_read: read a symbol file into symtab */
- elf_symfile_finish, /* sym_finish: finished with file, cleanup */
- default_symfile_offsets, /* sym_offsets: Translate ext. to int. relocation */
- elf_symfile_segments, /* sym_segments: Get segment information from
- a file. */
- NULL, /* sym_read_linetable */
- NULL /* next: pointer to next struct sym_fns */
+ elf_new_init, /* init anything gbl to entire symtab */
+ elf_symfile_init, /* read initial info, setup for sym_read() */
+ elf_symfile_read, /* read a symbol file into symtab */
+ NULL, /* sym_read_psymbols */
+ elf_symfile_finish, /* finished with file, cleanup */
+ default_symfile_offsets, /* Translate ext. to int. relocation */
+ elf_symfile_segments, /* Get segment information from a file. */
+ NULL,
+ default_symfile_relocate, /* Relocate a debug section. */
+ &psym_functions
+};
+
+/* The same as elf_sym_fns, but not registered and lazily reads
+ psymbols. */
+
+static const struct sym_fns elf_sym_fns_lazy_psyms =
+{
+ bfd_target_elf_flavour,
+ elf_new_init, /* init anything gbl to entire symtab */
+ elf_symfile_init, /* read initial info, setup for sym_read() */
+ elf_symfile_read, /* read a symbol file into symtab */
+ read_psyms, /* sym_read_psymbols */
+ elf_symfile_finish, /* finished with file, cleanup */
+ default_symfile_offsets, /* Translate ext. to int. relocation */
+ elf_symfile_segments, /* Get segment information from a file. */
+ NULL,
+ default_symfile_relocate, /* Relocate a debug section. */
+ &psym_functions
+};
+
+/* The same as elf_sym_fns, but not registered and uses the
+ DWARF-specific GNU index rather than psymtab. */
+static const struct sym_fns elf_sym_fns_gdb_index =
+{
+ bfd_target_elf_flavour,
+ elf_new_init, /* init anything gbl to entire symab */
+ elf_symfile_init, /* read initial info, setup for sym_red() */
+ elf_symfile_read, /* read a symbol file into symtab */
+ NULL, /* sym_read_psymbols */
+ elf_symfile_finish, /* finished with file, cleanup */
+ default_symfile_offsets, /* Translate ext. to int. relocatin */
+ elf_symfile_segments, /* Get segment information from a file. */
+ NULL,
+ default_symfile_relocate, /* Relocate a debug section. */
+ &dwarf2_gdb_index_functions
+};
+
+/* STT_GNU_IFUNC resolver vector to be installed to gnu_ifunc_fns_p. */
+
+static const struct gnu_ifunc_fns elf_gnu_ifunc_fns =
+{
+ elf_gnu_ifunc_resolve_addr,
+ elf_gnu_ifunc_resolve_name,
+ elf_gnu_ifunc_resolver_stop,
+ elf_gnu_ifunc_resolver_return_stop
};
void
_initialize_elfread (void)
{
add_symtab_fns (&elf_sym_fns);
+
+ elf_objfile_gnu_ifunc_cache_data = register_objfile_data ();
+ gnu_ifunc_fns_p = &elf_gnu_ifunc_fns;
}
projects / binutils.git / blobdiff