diff options
Diffstat (limited to 'libdw/dwarf_child.c')
| -rw-r--r-- | libdw/dwarf_child.c | 68 |
1 files changed, 27 insertions, 41 deletions
diff --git a/libdw/dwarf_child.c b/libdw/dwarf_child.c index 1d3a3371..58a438b5 100644 --- a/libdw/dwarf_child.c +++ b/libdw/dwarf_child.c @@ -1,5 +1,5 @@ /* Return child of current DIE. - Copyright (C) 2003-2011 Red Hat, Inc. + Copyright (C) 2003-2011, 2014 Red Hat, Inc. This file is part of elfutils. Written by Ulrich Drepper <[email protected]>, 2003. @@ -44,21 +44,11 @@ __libdw_find_attr (Dwarf_Die *die, unsigned int search_name, unsigned int *codep, unsigned int *formp) { Dwarf *dbg = die->cu->dbg; - const unsigned char *readp = (unsigned char *) die->addr; - - /* First we have to get the abbreviation code so that we can decode - the data in the DIE. */ - unsigned int abbrev_code; - get_uleb128 (abbrev_code, readp); + const unsigned char *readp; /* Find the abbreviation entry. */ - Dwarf_Abbrev *abbrevp = die->abbrev; - if (abbrevp == NULL) - { - abbrevp = __libdw_findabbrev (die->cu, abbrev_code); - die->abbrev = abbrevp ?: DWARF_END_ABBREV; - } - if (unlikely (die->abbrev == DWARF_END_ABBREV)) + Dwarf_Abbrev *abbrevp = __libdw_dieabbrev (die, &readp); + if (unlikely (abbrevp == DWARF_END_ABBREV)) { invalid_dwarf: __libdw_seterrno (DWARF_E_INVALID_DWARF); @@ -70,21 +60,19 @@ __libdw_find_attr (Dwarf_Die *die, unsigned int search_name, = ((unsigned char *) dbg->sectiondata[IDX_debug_abbrev]->d_buf + dbg->sectiondata[IDX_debug_abbrev]->d_size); - const unsigned char *attrp = die->abbrev->attrp; + const unsigned char *attrp = abbrevp->attrp; while (1) { - /* Are we still in bounds? This test needs to be refined. */ - if (unlikely (attrp + 1 >= endp)) + /* Get attribute name and form. */ + if (unlikely (attrp >= endp)) goto invalid_dwarf; - - /* Get attribute name and form. - - XXX We don't check whether this reads beyond the end of the - section. */ unsigned int attr_name; - get_uleb128 (attr_name, attrp); + get_uleb128 (attr_name, attrp, endp); + + if (unlikely (attrp >= endp)) + goto invalid_dwarf; unsigned int attr_form; - get_uleb128 (attr_form, attrp); + get_uleb128 (attr_form, attrp, endp); /* We can stop if we found the attribute with value zero. */ if (attr_name == 0 && attr_form == 0) @@ -104,15 +92,14 @@ __libdw_find_attr (Dwarf_Die *die, unsigned int search_name, /* Skip over the rest of this attribute (if there is any). */ if (attr_form != 0) { - size_t len = __libdw_form_val_len (dbg, die->cu, attr_form, readp); - + size_t len = __libdw_form_val_len (die->cu, attr_form, readp); if (unlikely (len == (size_t) -1l)) { readp = NULL; break; } - // XXX We need better boundary checks. + // __libdw_form_val_len will have done a bounds check. readp += len; } } @@ -136,33 +123,32 @@ dwarf_child (die, result) if (die == NULL) return -1; - /* Skip past the last attribute. */ - void *addr = NULL; - - /* If we already know there are no children do not search. */ - if (die->abbrev != DWARF_END_ABBREV - && (die->abbrev == NULL || die->abbrev->has_children)) - addr = __libdw_find_attr (die, INVALID, NULL, NULL); - if (unlikely (die->abbrev == (Dwarf_Abbrev *) -1l)) - return -1; + /* Find the abbreviation entry. */ + Dwarf_Abbrev *abbrevp = __libdw_dieabbrev (die, NULL); + if (unlikely (abbrevp == DWARF_END_ABBREV)) + { + __libdw_seterrno (DWARF_E_INVALID_DWARF); + return -1; + } - /* Make sure the DIE really has children. */ - if (! die->abbrev->has_children) - /* There cannot be any children. */ + /* If there are no children, do not search. */ + if (! abbrevp->has_children) return 1; + /* Skip past the last attribute. */ + void *addr = __libdw_find_attr (die, INVALID, NULL, NULL); + if (addr == NULL) return -1; /* RESULT can be the same as DIE. So preserve what we need. */ struct Dwarf_CU *cu = die->cu; - Elf_Data *cu_sec = cu_data (cu); /* It's kosher (just suboptimal) to have a null entry first thing (7.5.3). So if this starts with ULEB128 of 0 (even with silly encoding of 0), it is a kosher null entry and we do not really have any children. */ const unsigned char *code = addr; - const unsigned char *endp = (cu_sec->d_buf + cu_sec->d_size); + const unsigned char *endp = cu->endp; while (1) { if (unlikely (code >= endp)) /* Truncated section. */ |