PR24623, DWARF errors
Alan Modra
amodra@gmail.com
Wed Aug 14 04:16:00 GMT 2019
PR 24623
* dwarf2.c (stash_comp_unit): New function, extracted from..
(_bfd_dwarf2_find_nearest_line): ..here.
(find_abstract_instance): Parse comp units and decode line info
as needed.
diff --git a/bfd/dwarf2.c b/bfd/dwarf2.c
index 65bb1e4e32..057fd91317 100644
--- a/bfd/dwarf2.c
+++ b/bfd/dwarf2.c
@@ -2804,6 +2804,7 @@ lookup_symbol_in_variable_table (struct comp_unit *unit,
return FALSE;
}
+static struct comp_unit *stash_comp_unit (struct dwarf2_debug *);
static bfd_boolean comp_unit_maybe_decode_line_info (struct comp_unit *,
struct dwarf2_debug *);
@@ -2877,12 +2878,26 @@ find_abstract_instance (struct comp_unit * unit,
if (info_ptr >= u->info_ptr_unit && info_ptr < u->end_ptr)
break;
- if (u)
+ while (u == NULL)
{
- unit = u;
- info_ptr_end = unit->end_ptr;
+ u = stash_comp_unit (unit->stash);
+ if (u == NULL)
+ break;
+ if (info_ptr >= u->info_ptr_unit && info_ptr < u->end_ptr)
+ break;
+ u = NULL;
}
- /* else FIXME: What do we do now ? */
+
+ if (u == NULL)
+ {
+ _bfd_error_handler
+ (_("DWARF error: unable to locate abstract instance DIE ref %"
+ PRIu64), (uint64_t) die_ref);
+ bfd_set_error (bfd_error_bad_value);
+ return FALSE;
+ }
+ unit = u;
+ info_ptr_end = unit->end_ptr;
}
}
else if (attr_ptr->form == DW_FORM_GNU_ref_alt)
@@ -2982,6 +2997,8 @@ find_abstract_instance (struct comp_unit * unit,
}
break;
case DW_AT_decl_file:
+ if (!comp_unit_maybe_decode_line_info (unit, unit->stash))
+ return FALSE;
*filename_ptr = concat_filename (unit->line_table,
attr.u.val);
break;
@@ -3334,7 +3351,7 @@ scan_unit_for_symbols (struct comp_unit *unit)
return FALSE;
}
-/* Parse a DWARF2 compilation unit starting at INFO_PTR. This
+/* Parse a DWARF2 compilation unit starting at INFO_PTR. UNIT_LENGTH
includes the compilation unit header that proceeds the DIE's, but
does not include the length field that precedes each compilation
unit header. END_PTR points one past the end of this comp unit.
@@ -4451,6 +4468,90 @@ _bfd_dwarf2_slurp_debug_info (bfd *abfd, bfd *debug_bfd,
return TRUE;
}
+/* Parse the next DWARF2 compilation unit at STASH->INFO_PTR. */
+
+static struct comp_unit *
+stash_comp_unit (struct dwarf2_debug *stash)
+{
+ bfd_size_type length;
+ unsigned int offset_size;
+ bfd_byte *info_ptr_unit = stash->info_ptr;
+
+ if (stash->info_ptr >= stash->info_ptr_end)
+ return NULL;
+
+ length = read_4_bytes (stash->bfd_ptr, stash->info_ptr,
+ stash->info_ptr_end);
+ /* A 0xffffff length is the DWARF3 way of indicating
+ we use 64-bit offsets, instead of 32-bit offsets. */
+ if (length == 0xffffffff)
+ {
+ offset_size = 8;
+ length = read_8_bytes (stash->bfd_ptr, stash->info_ptr + 4,
+ stash->info_ptr_end);
+ stash->info_ptr += 12;
+ }
+ /* A zero length is the IRIX way of indicating 64-bit offsets,
+ mostly because the 64-bit length will generally fit in 32
+ bits, and the endianness helps. */
+ else if (length == 0)
+ {
+ offset_size = 8;
+ length = read_4_bytes (stash->bfd_ptr, stash->info_ptr + 4,
+ stash->info_ptr_end);
+ stash->info_ptr += 8;
+ }
+ /* In the absence of the hints above, we assume 32-bit DWARF2
+ offsets even for targets with 64-bit addresses, because:
+ a) most of the time these targets will not have generated
+ more than 2Gb of debug info and so will not need 64-bit
+ offsets,
+ and
+ b) if they do use 64-bit offsets but they are not using
+ the size hints that are tested for above then they are
+ not conforming to the DWARF3 standard anyway. */
+ else
+ {
+ offset_size = 4;
+ stash->info_ptr += 4;
+ }
+
+ if (length != 0
+ && stash->info_ptr + length <= stash->info_ptr_end
+ && stash->info_ptr + length > stash->info_ptr)
+ {
+ struct comp_unit *each = parse_comp_unit (stash, length, info_ptr_unit,
+ offset_size);
+ if (each)
+ {
+ if (stash->all_comp_units)
+ stash->all_comp_units->prev_unit = each;
+ else
+ stash->last_comp_unit = each;
+
+ each->next_unit = stash->all_comp_units;
+ stash->all_comp_units = each;
+
+ stash->info_ptr += length;
+
+ if ((bfd_size_type) (stash->info_ptr - stash->sec_info_ptr)
+ == stash->sec->size)
+ {
+ stash->sec = find_debug_info (stash->bfd_ptr,
+ stash->debug_sections,
+ stash->sec);
+ stash->sec_info_ptr = stash->info_ptr;
+ }
+ return each;
+ }
+ }
+
+ /* Don't trust any of the DWARF info after a corrupted length or
+ parse error. */
+ stash->info_ptr = stash->info_ptr_end;
+ return NULL;
+}
+
/* Scan the debug information in PINFO looking for a DW_TAG_subprogram
abbrev with a DW_AT_low_pc attached to it. Then lookup that same
symbol in SYMBOLS and return the difference between the low_pc and
@@ -4699,113 +4800,33 @@ _bfd_dwarf2_find_nearest_line (bfd *abfd,
}
/* Read each remaining comp. units checking each as they are read. */
- while (stash->info_ptr < stash->info_ptr_end)
+ while ((each = stash_comp_unit (stash)) != NULL)
{
- bfd_vma length;
- unsigned int offset_size;
- bfd_byte *info_ptr_unit = stash->info_ptr;
-
- length = read_4_bytes (stash->bfd_ptr, stash->info_ptr, stash->info_ptr_end);
- /* A 0xffffff length is the DWARF3 way of indicating
- we use 64-bit offsets, instead of 32-bit offsets. */
- if (length == 0xffffffff)
- {
- offset_size = 8;
- length = read_8_bytes (stash->bfd_ptr, stash->info_ptr + 4, stash->info_ptr_end);
- stash->info_ptr += 12;
- }
- /* A zero length is the IRIX way of indicating 64-bit offsets,
- mostly because the 64-bit length will generally fit in 32
- bits, and the endianness helps. */
- else if (length == 0)
- {
- offset_size = 8;
- length = read_4_bytes (stash->bfd_ptr, stash->info_ptr + 4, stash->info_ptr_end);
- stash->info_ptr += 8;
- }
- /* In the absence of the hints above, we assume 32-bit DWARF2
- offsets even for targets with 64-bit addresses, because:
- a) most of the time these targets will not have generated
- more than 2Gb of debug info and so will not need 64-bit
- offsets,
- and
- b) if they do use 64-bit offsets but they are not using
- the size hints that are tested for above then they are
- not conforming to the DWARF3 standard anyway. */
+ /* DW_AT_low_pc and DW_AT_high_pc are optional for
+ compilation units. If we don't have them (i.e.,
+ unit->high == 0), we need to consult the line info table
+ to see if a compilation unit contains the given
+ address. */
+ if (do_line)
+ found = (((symbol->flags & BSF_FUNCTION) == 0
+ || each->arange.high == 0
+ || comp_unit_contains_address (each, addr))
+ && comp_unit_find_line (each, symbol, addr,
+ filename_ptr,
+ linenumber_ptr,
+ stash));
else
- {
- offset_size = 4;
- stash->info_ptr += 4;
- }
-
- if (length > 0)
- {
- bfd_byte * new_ptr;
-
- /* PR 21151 */
- if (stash->info_ptr + length > stash->info_ptr_end)
- return FALSE;
-
- each = parse_comp_unit (stash, length, info_ptr_unit,
- offset_size);
- if (!each)
- /* The dwarf information is damaged, don't trust it any
- more. */
- break;
-
- new_ptr = stash->info_ptr + length;
- /* PR 17512: file: 1500698c. */
- if (new_ptr < stash->info_ptr)
- {
- /* A corrupt length value - do not trust the info any more. */
- found = FALSE;
- break;
- }
- else
- stash->info_ptr = new_ptr;
-
- if (stash->all_comp_units)
- stash->all_comp_units->prev_unit = each;
- else
- stash->last_comp_unit = each;
-
- each->next_unit = stash->all_comp_units;
- stash->all_comp_units = each;
-
- /* DW_AT_low_pc and DW_AT_high_pc are optional for
- compilation units. If we don't have them (i.e.,
- unit->high == 0), we need to consult the line info table
- to see if a compilation unit contains the given
- address. */
- if (do_line)
- found = (((symbol->flags & BSF_FUNCTION) == 0
- || each->arange.high == 0
- || comp_unit_contains_address (each, addr))
- && comp_unit_find_line (each, symbol, addr,
- filename_ptr,
- linenumber_ptr,
- stash));
- else
- found = ((each->arange.high == 0
- || comp_unit_contains_address (each, addr))
- && comp_unit_find_nearest_line (each, addr,
- filename_ptr,
- &function,
- linenumber_ptr,
- discriminator_ptr,
- stash) != 0);
-
- if ((bfd_vma) (stash->info_ptr - stash->sec_info_ptr)
- == stash->sec->size)
- {
- stash->sec = find_debug_info (stash->bfd_ptr, debug_sections,
- stash->sec);
- stash->sec_info_ptr = stash->info_ptr;
- }
-
- if (found)
- goto done;
- }
+ found = ((each->arange.high == 0
+ || comp_unit_contains_address (each, addr))
+ && comp_unit_find_nearest_line (each, addr,
+ filename_ptr,
+ &function,
+ linenumber_ptr,
+ discriminator_ptr,
+ stash) != 0);
+
+ if (found)
+ break;
}
done:
--
Alan Modra
Australia Development Lab, IBM
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