diff options
Diffstat (limited to 'libdw/dwarf_formstring.c')
| -rw-r--r-- | libdw/dwarf_formstring.c | 131 |
1 files changed, 118 insertions, 13 deletions
diff --git a/libdw/dwarf_formstring.c b/libdw/dwarf_formstring.c index 83abd53d..c3e892a8 100644 --- a/libdw/dwarf_formstring.c +++ b/libdw/dwarf_formstring.c @@ -1,7 +1,6 @@ /* Return string associated with given attribute. - Copyright (C) 2003-2010, 2013 Red Hat, Inc. + Copyright (C) 2003-2010, 2013, 2017, 2018 Red Hat, Inc. This file is part of elfutils. - Written by Ulrich Drepper <[email protected]>, 2003. This file is free software; you can redistribute it and/or modify it under the terms of either @@ -47,8 +46,11 @@ dwarf_formstring (Dwarf_Attribute *attrp) /* A simple inlined string. */ return (const char *) attrp->valp; - Dwarf *dbg = attrp->cu->dbg; - Dwarf *dbg_ret = attrp->form == DW_FORM_GNU_strp_alt ? dbg->alt_dwarf : dbg; + Dwarf_CU *cu = attrp->cu; + Dwarf *dbg = cu->dbg; + Dwarf *dbg_ret = ((attrp->form == DW_FORM_GNU_strp_alt + || attrp->form == DW_FORM_strp_sup) + ? INTUSE(dwarf_getalt) (dbg) : dbg); if (unlikely (dbg_ret == NULL)) { @@ -56,20 +58,123 @@ dwarf_formstring (Dwarf_Attribute *attrp) return NULL; } - - if (unlikely (attrp->form != DW_FORM_strp - && attrp->form != DW_FORM_GNU_strp_alt) - || dbg_ret->sectiondata[IDX_debug_str] == NULL) + Elf_Data *data = ((attrp->form == DW_FORM_line_strp) + ? dbg_ret->sectiondata[IDX_debug_line_str] + : dbg_ret->sectiondata[IDX_debug_str]); + if (data == NULL) { - __libdw_seterrno (DWARF_E_NO_STRING); + __libdw_seterrno ((attrp->form == DW_FORM_line_strp) + ? DWARF_E_NO_DEBUG_LINE_STR + : DWARF_E_NO_DEBUG_STR); return NULL; } uint64_t off; - if (__libdw_read_offset (dbg, dbg_ret, cu_sec_idx (attrp->cu), attrp->valp, - attrp->cu->offset_size, &off, IDX_debug_str, 1)) - return NULL; + if (attrp->form == DW_FORM_strp + || attrp->form == DW_FORM_GNU_strp_alt + || attrp->form == DW_FORM_strp_sup) + { + if (__libdw_read_offset (dbg, dbg_ret, cu_sec_idx (cu), + attrp->valp, cu->offset_size, &off, + IDX_debug_str, 1)) + return NULL; + } + else if (attrp->form == DW_FORM_line_strp) + { + if (__libdw_read_offset (dbg, dbg_ret, cu_sec_idx (cu), + attrp->valp, cu->offset_size, &off, + IDX_debug_line_str, 1)) + return NULL; + } + else + { + Dwarf_Word idx; + const unsigned char *datap = attrp->valp; + const unsigned char *endp = cu->endp; + switch (attrp->form) + { + case DW_FORM_strx: + case DW_FORM_GNU_str_index: + if (datap >= endp) + { + invalid: + __libdw_seterrno (DWARF_E_INVALID_DWARF); + return NULL; + } + get_uleb128 (idx, datap, endp); + break; + + case DW_FORM_strx1: + if (datap >= endp - 1) + goto invalid; + idx = *datap; + break; + + case DW_FORM_strx2: + if (datap >= endp - 2) + goto invalid; + idx = read_2ubyte_unaligned (dbg, datap); + break; + + case DW_FORM_strx3: + if (datap >= endp - 3) + goto invalid; + idx = read_3ubyte_unaligned (dbg, datap); + break; + + case DW_FORM_strx4: + if (datap >= endp - 4) + goto invalid; + idx = read_4ubyte_unaligned (dbg, datap); + break; + + default: + __libdw_seterrno (DWARF_E_NO_STRING); + return NULL; + } + + /* So we got an index in the .debug_str_offsets. Lets see if it + is valid and we can get the actual .debug_str offset. */ + Dwarf_Off str_off = __libdw_cu_str_off_base (cu); + if (str_off == (Dwarf_Off) -1) + return NULL; + + if (dbg->sectiondata[IDX_debug_str_offsets] == NULL) + { + __libdw_seterrno (DWARF_E_NO_STR_OFFSETS); + return NULL; + } + + /* The section should at least contain room for one offset. */ + int offset_size = cu->offset_size; + if (cu->offset_size > dbg->sectiondata[IDX_debug_str_offsets]->d_size) + { + invalid_offset: + __libdw_seterrno (DWARF_E_INVALID_OFFSET); + return NULL; + } + + /* And the base offset should be at least inside the section. */ + if (str_off > (dbg->sectiondata[IDX_debug_str_offsets]->d_size + - offset_size)) + goto invalid_offset; + + size_t max_idx = (dbg->sectiondata[IDX_debug_str_offsets]->d_size + - offset_size - str_off) / offset_size; + if (idx > max_idx) + goto invalid_offset; + + datap = (dbg->sectiondata[IDX_debug_str_offsets]->d_buf + + str_off + (idx * offset_size)); + if (offset_size == 4) + off = read_4ubyte_unaligned (dbg, datap); + else + off = read_8ubyte_unaligned (dbg, datap); + + if (off > dbg->sectiondata[IDX_debug_str]->d_size) + goto invalid_offset; + } - return (const char *) dbg_ret->sectiondata[IDX_debug_str]->d_buf + off; + return (const char *) data->d_buf + off; } INTDEF(dwarf_formstring) |