diff options
Diffstat (limited to 'libdw/dwarf_getlocation.c')
| -rw-r--r-- | libdw/dwarf_getlocation.c | 323 |
1 files changed, 233 insertions, 90 deletions
diff --git a/libdw/dwarf_getlocation.c b/libdw/dwarf_getlocation.c index a4a2761e..fc59a2ab 100644 --- a/libdw/dwarf_getlocation.c +++ b/libdw/dwarf_getlocation.c @@ -1,7 +1,6 @@ /* Return location expression list. - Copyright (C) 2000-2010, 2013-2015 Red Hat, Inc. + Copyright (C) 2000-2010, 2013-2015, 2017, 2018 Red Hat, Inc. This file is part of elfutils. - Written by Ulrich Drepper <drepper@redhat.com>, 2000. This file is free software; you can redistribute it and/or modify it under the terms of either @@ -45,10 +44,34 @@ attr_ok (Dwarf_Attribute *attr) if (attr == NULL) return false; - /* Must be one of the attributes listed below. */ + /* If it is an exprloc, it is obviously OK. */ + if (dwarf_whatform (attr) == DW_FORM_exprloc) + return true; + + /* Otherwise must be one of the attributes listed below. Older + DWARF versions might have encoded the exprloc as block, and we + cannot easily distinquish attributes in the loclist class because + the same forms are used for different classes. */ switch (attr->code) { case DW_AT_location: + case DW_AT_byte_size: + case DW_AT_bit_offset: + case DW_AT_bit_size: + case DW_AT_lower_bound: + case DW_AT_bit_stride: + case DW_AT_upper_bound: + case DW_AT_count: + case DW_AT_allocated: + case DW_AT_associated: + case DW_AT_data_location: + case DW_AT_byte_stride: + case DW_AT_rank: + case DW_AT_call_value: + case DW_AT_call_target: + case DW_AT_call_target_clobbered: + case DW_AT_call_data_location: + case DW_AT_call_data_value: case DW_AT_data_member_location: case DW_AT_vtable_elem_location: case DW_AT_string_length: @@ -64,7 +87,7 @@ attr_ok (Dwarf_Attribute *attr) break; default: - __libdw_seterrno (DWARF_E_NO_LOCLIST); + __libdw_seterrno (DWARF_E_NO_LOC_VALUE); return false; } @@ -97,19 +120,23 @@ loc_compare (const void *p1, const void *p2) } /* For each DW_OP_implicit_value, we store a special entry in the cache. - This points us directly to the block data for later fetching. */ -static void + This points us directly to the block data for later fetching. + Returns zero on success, -1 on bad DWARF or 1 if tsearch failed. */ +static int store_implicit_value (Dwarf *dbg, void **cache, Dwarf_Op *op) { struct loc_block_s *block = libdw_alloc (dbg, struct loc_block_s, sizeof (struct loc_block_s), 1); const unsigned char *data = (const unsigned char *) (uintptr_t) op->number2; - // Ignored, equal to op->number. And data length already checked. - (void) __libdw_get_uleb128 (&data, data + len_leb128 (Dwarf_Word)); + uint64_t len = __libdw_get_uleb128 (&data, data + len_leb128 (Dwarf_Word)); + if (unlikely (len != op->number)) + return -1; block->addr = op; block->data = (unsigned char *) data; block->length = op->number; - (void) tsearch (block, cache, loc_compare); + if (unlikely (tsearch (block, cache, loc_compare) == NULL)) + return 1; + return 0; } int @@ -147,6 +174,8 @@ check_constant_offset (Dwarf_Attribute *attr, default: return 1; + /* Note, we don't regard DW_FORM_data16 as a constant form, + even though technically it is according to the standard. */ case DW_FORM_data1: case DW_FORM_data2: case DW_FORM_data4: @@ -299,6 +328,7 @@ __libdw_intern_expression (Dwarf *dbg, bool other_byte_order, break; case DW_OP_call_ref: + case DW_OP_GNU_variable_value: /* DW_FORM_ref_addr, depends on offset size of CU. */ if (dbg == NULL || __libdw_read_offset_inc (dbg, sec_index, &data, ref_size, @@ -427,8 +457,14 @@ __libdw_intern_expression (Dwarf *dbg, bool other_byte_order, case DW_OP_plus_uconst: case DW_OP_regx: case DW_OP_piece: + case DW_OP_convert: case DW_OP_GNU_convert: + case DW_OP_reinterpret: case DW_OP_GNU_reinterpret: + case DW_OP_addrx: + case DW_OP_GNU_addr_index: + case DW_OP_constx: + case DW_OP_GNU_const_index: get_uleb128 (newloc->number, data, end_data); break; @@ -446,6 +482,7 @@ __libdw_intern_expression (Dwarf *dbg, bool other_byte_order, break; case DW_OP_bit_piece: + case DW_OP_regval_type: case DW_OP_GNU_regval_type: get_uleb128 (newloc->number, data, end_data); if (unlikely (data >= end_data)) @@ -454,6 +491,7 @@ __libdw_intern_expression (Dwarf *dbg, bool other_byte_order, break; case DW_OP_implicit_value: + case DW_OP_entry_value: case DW_OP_GNU_entry_value: /* This cannot be used in a CFI expression. */ if (unlikely (dbg == NULL)) @@ -467,6 +505,7 @@ __libdw_intern_expression (Dwarf *dbg, bool other_byte_order, data += newloc->number; /* Skip the block. */ break; + case DW_OP_implicit_pointer: case DW_OP_GNU_implicit_pointer: /* DW_FORM_ref_addr, depends on offset size of CU. */ if (dbg == NULL || __libdw_read_offset_inc (dbg, sec_index, &data, @@ -479,13 +518,16 @@ __libdw_intern_expression (Dwarf *dbg, bool other_byte_order, get_uleb128 (newloc->number2, data, end_data); /* Byte offset. */ break; + case DW_OP_deref_type: case DW_OP_GNU_deref_type: + case DW_OP_xderef_type: if (unlikely (data + 1 >= end_data)) goto invalid; newloc->number = *data++; get_uleb128 (newloc->number2, data, end_data); break; + case DW_OP_const_type: case DW_OP_GNU_const_type: { size_t size; @@ -553,7 +595,16 @@ __libdw_intern_expression (Dwarf *dbg, bool other_byte_order, result[n].offset = loclist->offset; if (result[n].atom == DW_OP_implicit_value) - store_implicit_value (dbg, cache, &result[n]); + { + int store = store_implicit_value (dbg, cache, &result[n]); + if (unlikely (store != 0)) + { + if (store < 0) + goto invalid; + else + goto nomem; + } + } struct loclist *loc = loclist; loclist = loclist->next; @@ -616,7 +667,13 @@ dwarf_getlocation (Dwarf_Attribute *attr, Dwarf_Op **llbuf, size_t *listlen) if (result != 1) return result; - /* If it has a block form, it's a single location expression. */ + /* If it has a block form, it's a single location expression. + Except for DW_FORM_data16, which is a 128bit constant. */ + if (attr->form == DW_FORM_data16) + { + __libdw_seterrno (DWARF_E_NO_BLOCK); + return -1; + } Dwarf_Block block; if (INTUSE(dwarf_formblock) (attr, &block) != 0) return -1; @@ -624,47 +681,113 @@ dwarf_getlocation (Dwarf_Attribute *attr, Dwarf_Op **llbuf, size_t *listlen) return getlocation (attr->cu, &block, llbuf, listlen, cu_sec_idx (attr->cu)); } -static int -attr_base_address (Dwarf_Attribute *attr, Dwarf_Addr *basep) +Dwarf_Addr +__libdw_cu_base_address (Dwarf_CU *cu) { - /* Fetch the CU's base address. */ - Dwarf_Die cudie = CUDIE (attr->cu); - - /* Find the base address of the compilation unit. It will - normally be specified by DW_AT_low_pc. In DWARF-3 draft 4, - the base address could be overridden by DW_AT_entry_pc. It's - been removed, but GCC emits DW_AT_entry_pc and not DW_AT_lowpc - for compilation units with discontinuous ranges. */ - Dwarf_Attribute attr_mem; - if (unlikely (INTUSE(dwarf_lowpc) (&cudie, basep) != 0) - && INTUSE(dwarf_formaddr) (INTUSE(dwarf_attr) (&cudie, - DW_AT_entry_pc, - &attr_mem), - basep) != 0) + if (cu->base_address == (Dwarf_Addr) -1) { - if (INTUSE(dwarf_errno) () != 0) - return -1; - - /* The compiler provided no base address when it should - have. Buggy GCC does this when it used absolute - addresses in the location list and no DW_AT_ranges. */ - *basep = 0; + Dwarf_Addr base; + + /* Fetch the CU's base address. */ + Dwarf_Die cudie = CUDIE (cu); + + /* Find the base address of the compilation unit. It will + normally be specified by DW_AT_low_pc. In DWARF-3 draft 4, + the base address could be overridden by DW_AT_entry_pc. It's + been removed, but GCC emits DW_AT_entry_pc and not DW_AT_lowpc + for compilation units with discontinuous ranges. */ + Dwarf_Attribute attr_mem; + if (INTUSE(dwarf_lowpc) (&cudie, &base) != 0 + && INTUSE(dwarf_formaddr) (INTUSE(dwarf_attr) (&cudie, + DW_AT_entry_pc, + &attr_mem), + &base) != 0) + { + /* The compiler provided no base address when it should + have. Buggy GCC does this when it used absolute + addresses in the location list and no DW_AT_ranges. */ + base = 0; + } + cu->base_address = base; } - return 0; + + return cu->base_address; } static int -initial_offset_base (Dwarf_Attribute *attr, ptrdiff_t *offset, - Dwarf_Addr *basep) +initial_offset (Dwarf_Attribute *attr, ptrdiff_t *offset) { - if (attr_base_address (attr, basep) != 0) - return -1; + size_t secidx = (attr->cu->version < 5 + ? IDX_debug_loc : IDX_debug_loclists); Dwarf_Word start_offset; - if (__libdw_formptr (attr, IDX_debug_loc, - DWARF_E_NO_LOCLIST, - NULL, &start_offset) == NULL) - return -1; + if (attr->form == DW_FORM_loclistx) + { + Dwarf_Word idx; + Dwarf_CU *cu = attr->cu; + const unsigned char *datap = attr->valp; + const unsigned char *endp = cu->endp; + if (datap >= endp) + { + __libdw_seterrno (DWARF_E_INVALID_DWARF); + return -1; + } + get_uleb128 (idx, datap, endp); + + Elf_Data *data = cu->dbg->sectiondata[secidx]; + if (data == NULL && cu->unit_type == DW_UT_split_compile) + { + cu = __libdw_find_split_unit (cu); + if (cu != NULL) + data = cu->dbg->sectiondata[secidx]; + } + + if (data == NULL) + { + __libdw_seterrno (secidx == IDX_debug_loc + ? DWARF_E_NO_DEBUG_LOC + : DWARF_E_NO_DEBUG_LOCLISTS); + return -1; + } + + Dwarf_Off loc_base_off = __libdw_cu_locs_base (cu); + + /* The section should at least contain room for one offset. */ + size_t sec_size = cu->dbg->sectiondata[secidx]->d_size; + size_t offset_size = cu->offset_size; + if (offset_size > sec_size) + { + invalid_offset: + __libdw_seterrno (DWARF_E_INVALID_OFFSET); + return -1; + } + + /* And the base offset should be at least inside the section. */ + if (loc_base_off > (sec_size - offset_size)) + goto invalid_offset; + + size_t max_idx = (sec_size - offset_size - loc_base_off) / offset_size; + if (idx > max_idx) + goto invalid_offset; + + datap = (cu->dbg->sectiondata[secidx]->d_buf + + loc_base_off + (idx * offset_size)); + if (offset_size == 4) + start_offset = read_4ubyte_unaligned (cu->dbg, datap); + else + start_offset = read_8ubyte_unaligned (cu->dbg, datap); + + start_offset += loc_base_off; + } + else + { + if (__libdw_formptr (attr, secidx, + (secidx == IDX_debug_loc + ? DWARF_E_NO_DEBUG_LOC + : DWARF_E_NO_DEBUG_LOCLISTS), + NULL, &start_offset) == NULL) + return -1; + } *offset = start_offset; return 0; @@ -676,22 +799,19 @@ getlocations_addr (Dwarf_Attribute *attr, ptrdiff_t offset, Dwarf_Addr address, const Elf_Data *locs, Dwarf_Op **expr, size_t *exprlen) { - unsigned char *readp = locs->d_buf + offset; - unsigned char *readendp = locs->d_buf + locs->d_size; - - next: - if (readendp - readp < attr->cu->address_size * 2) - { - invalid: - __libdw_seterrno (DWARF_E_INVALID_DWARF); - return -1; - } + Dwarf_CU *cu = attr->cu; + Dwarf *dbg = cu->dbg; + size_t secidx = cu->version < 5 ? IDX_debug_loc : IDX_debug_loclists; + const unsigned char *readp = locs->d_buf + offset; + const unsigned char *readendp = locs->d_buf + locs->d_size; Dwarf_Addr begin; Dwarf_Addr end; - switch (__libdw_read_begin_end_pair_inc (attr->cu->dbg, IDX_debug_loc, - &readp, attr->cu->address_size, + next: + switch (__libdw_read_begin_end_pair_inc (cu, secidx, + &readp, readendp, + cu->address_size, &begin, &end, basep)) { case 0: /* got location range. */ @@ -704,25 +824,38 @@ getlocations_addr (Dwarf_Attribute *attr, ptrdiff_t offset, return -1; } - if (readendp - readp < 2) - goto invalid; - /* We have a location expression. */ Dwarf_Block block; - block.length = read_2ubyte_unaligned_inc (attr->cu->dbg, readp); - block.data = readp; + if (secidx == IDX_debug_loc) + { + if (readendp - readp < 2) + { + invalid: + __libdw_seterrno (DWARF_E_INVALID_DWARF); + return -1; + } + block.length = read_2ubyte_unaligned_inc (dbg, readp); + } + else + { + if (readendp - readp < 1) + goto invalid; + get_uleb128 (block.length, readp, readendp); + } + block.data = (unsigned char *) readp; if (readendp - readp < (ptrdiff_t) block.length) goto invalid; readp += block.length; - *startp = *basep + begin; - *endp = *basep + end; + /* Note these addresses include any base (if necessary) already. */ + *startp = begin; + *endp = end; /* If address is minus one we want them all, otherwise only matching. */ if (address != (Dwarf_Word) -1 && (address < *startp || address >= *endp)) goto next; - if (getlocation (attr->cu, &block, expr, exprlen, IDX_debug_loc) != 0) + if (getlocation (cu, &block, expr, exprlen, secidx) != 0) return -1; return readp - (unsigned char *) locs->d_buf; @@ -738,9 +871,11 @@ dwarf_getlocation_addr (Dwarf_Attribute *attr, Dwarf_Addr address, if (llbufs == NULL) maxlocs = SIZE_MAX; - /* If it has a block form, it's a single location expression. */ + /* If it has a block form, it's a single location expression. + Except for DW_FORM_data16, which is a 128bit constant. */ Dwarf_Block block; - if (INTUSE(dwarf_formblock) (attr, &block) == 0) + if (attr->form != DW_FORM_data16 + && INTUSE(dwarf_formblock) (attr, &block) == 0) { if (maxlocs == 0) return 0; @@ -751,11 +886,14 @@ dwarf_getlocation_addr (Dwarf_Attribute *attr, Dwarf_Addr address, return listlens[0] == 0 ? 0 : 1; } - int error = INTUSE(dwarf_errno) (); - if (unlikely (error != DWARF_E_NO_BLOCK)) + if (attr->form != DW_FORM_data16) { - __libdw_seterrno (error); - return -1; + int error = INTUSE(dwarf_errno) (); + if (unlikely (error != DWARF_E_NO_BLOCK)) + { + __libdw_seterrno (error); + return -1; + } } int result = check_constant_offset (attr, &llbufs[0], &listlens[0]); @@ -769,19 +907,19 @@ dwarf_getlocation_addr (Dwarf_Attribute *attr, Dwarf_Addr address, size_t got = 0; /* This is a true loclistptr, fetch the initial base address and offset. */ - if (initial_offset_base (attr, &off, &base) != 0) + base = __libdw_cu_base_address (attr->cu); + if (base == (Dwarf_Addr) -1) return -1; - const Elf_Data *d = attr->cu->dbg->sectiondata[IDX_debug_loc]; - if (d == NULL) - { - __libdw_seterrno (DWARF_E_NO_LOCLIST); - return -1; - } + if (initial_offset (attr, &off) != 0) + return -1; + + size_t secidx = attr->cu->version < 5 ? IDX_debug_loc : IDX_debug_loclists; + const Elf_Data *d = attr->cu->dbg->sectiondata[secidx]; while (got < maxlocs && (off = getlocations_addr (attr, off, &base, &start, &end, - address, d, &expr, &expr_len)) > 0) + address, d, &expr, &expr_len)) > 0) { /* This one matches the address. */ if (llbufs != NULL) @@ -813,9 +951,11 @@ dwarf_getlocations (Dwarf_Attribute *attr, ptrdiff_t offset, Dwarf_Addr *basep, if (offset == 0) { - /* If it has a block form, it's a single location expression. */ + /* If it has a block form, it's a single location expression. + Except for DW_FORM_data16, which is a 128bit constant. */ Dwarf_Block block; - if (INTUSE(dwarf_formblock) (attr, &block) == 0) + if (attr->form != DW_FORM_data16 + && INTUSE(dwarf_formblock) (attr, &block) == 0) { if (getlocation (attr->cu, &block, expr, exprlen, cu_sec_idx (attr->cu)) != 0) @@ -827,11 +967,14 @@ dwarf_getlocations (Dwarf_Attribute *attr, ptrdiff_t offset, Dwarf_Addr *basep, return 1; } - int error = INTUSE(dwarf_errno) (); - if (unlikely (error != DWARF_E_NO_BLOCK)) + if (attr->form != DW_FORM_data16) { - __libdw_seterrno (error); - return -1; + int error = INTUSE(dwarf_errno) (); + if (unlikely (error != DWARF_E_NO_BLOCK)) + { + __libdw_seterrno (error); + return -1; + } } int result = check_constant_offset (attr, expr, exprlen); @@ -849,17 +992,17 @@ dwarf_getlocations (Dwarf_Attribute *attr, ptrdiff_t offset, Dwarf_Addr *basep, /* We must be looking at a true loclistptr, fetch the initial base address and offset. */ - if (initial_offset_base (attr, &offset, basep) != 0) + *basep = __libdw_cu_base_address (attr->cu); + if (*basep == (Dwarf_Addr) -1) return -1; - } - const Elf_Data *d = attr->cu->dbg->sectiondata[IDX_debug_loc]; - if (d == NULL) - { - __libdw_seterrno (DWARF_E_NO_LOCLIST); - return -1; + if (initial_offset (attr, &offset) != 0) + return -1; } + size_t secidx = attr->cu->version < 5 ? IDX_debug_loc : IDX_debug_loclists; + const Elf_Data *d = attr->cu->dbg->sectiondata[secidx]; + return getlocations_addr (attr, offset, basep, startp, endp, (Dwarf_Word) -1, d, expr, exprlen); } |