gdb/gdb-bfd-demangled-names.patch

208 lines
7.2 KiB
Diff

Re: ASAN crash regression [Re: [PATCH 2/2] move the demangled_names_hash into the per-BFD]
https://sourceware.org/ml/gdb-patches/2014-06/msg00550.html
Jan> ./configure ... -fsanitize=address
Jan> echo 'void f(){}main(){}'|gcc -x c++ - -g;ASAN_OPTIONS=symbolize=1 ASAN_SYMBOLIZER_PATH=/usr/bin/llvm-symbolizer ./gdb -batch a.out -ex 'file a.out'
Readily seen with valgrind as well.
Here's my proposed fix.
Tom
commit 3a93a67ad0ea3495f67c9708673345b73de2d806
Author: Tom Tromey <tromey@redhat.com>
Date: Mon Jun 16 03:17:19 2014 -0600
fix memory errors with demangled name hash
This fixes a regression that Jan pointed out.
The bug is that some names were allocated by dwarf2read on the objfile
obstack, but then passed to SYMBOL_SET_NAMES with copy_name=0. This
violates the invariant that the names must have a lifetime tied to the
lifetime of the BFD.
The fix is to allocate names on the per-BFD obstack.
I looked at all callers, direct or indirect, of SYMBOL_SET_NAMES that
pass copy_name=0. Note that only the ELF and DWARF readers do this;
other symbol readers were never updated (and perhaps cannot be,
depending on the details of the formats). This is why the patch is
relatively small.
Built and regtested on x86-64 Fedora 20.
2014-06-16 Tom Tromey <tromey@redhat.com>
* dwarf2read.c (fixup_go_packaging, dwarf2_compute_name)
(dwarf2_physname, read_partial_die)
(guess_partial_die_structure_name, fixup_partial_die)
(guess_full_die_structure_name, anonymous_struct_prefix)
(dwarf2_name): Use per-BFD obstack.
### a/gdb/ChangeLog
### b/gdb/ChangeLog
## -1,5 +1,13 @@
2014-06-16 Tom Tromey <tromey@redhat.com>
+ * dwarf2read.c (fixup_go_packaging, dwarf2_compute_name)
+ (dwarf2_physname, read_partial_die)
+ (guess_partial_die_structure_name, fixup_partial_die)
+ (guess_full_die_structure_name, anonymous_struct_prefix)
+ (dwarf2_name): Use per-BFD obstack.
+
+2014-06-16 Tom Tromey <tromey@redhat.com>
+
* minsyms.h (prim_record_minimal_symbol)
(prim_record_minimal_symbol_and_info): Update comments.
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -7745,9 +7745,10 @@ fixup_go_packaging (struct dwarf2_cu *cu)
if (package_name != NULL)
{
struct objfile *objfile = cu->objfile;
- const char *saved_package_name = obstack_copy0 (&objfile->objfile_obstack,
- package_name,
- strlen (package_name));
+ const char *saved_package_name
+ = obstack_copy0 (&objfile->per_bfd->storage_obstack,
+ package_name,
+ strlen (package_name));
struct type *type = init_type (TYPE_CODE_MODULE, 0, 0,
saved_package_name, objfile);
struct symbol *sym;
@@ -8365,6 +8366,8 @@ dwarf2_compute_name (const char *name,
long length;
const char *prefix;
struct ui_file *buf;
+ char *intermediate_name;
+ const char *canonical_name = NULL;
prefix = determine_prefix (die, cu);
buf = mem_fileopen ();
@@ -8541,19 +8544,25 @@ dwarf2_compute_name (const char *name,
}
}
- name = ui_file_obsavestring (buf, &objfile->objfile_obstack,
- &length);
+ intermediate_name = ui_file_xstrdup (buf, &length);
ui_file_delete (buf);
if (cu->language == language_cplus)
- {
- const char *cname
- = dwarf2_canonicalize_name (name, cu,
- &objfile->objfile_obstack);
+ canonical_name
+ = dwarf2_canonicalize_name (intermediate_name, cu,
+ &objfile->per_bfd->storage_obstack);
+
+ /* If we only computed INTERMEDIATE_NAME, or if
+ INTERMEDIATE_NAME is already canonical, then we need to
+ copy it to the appropriate obstack. */
+ if (canonical_name == NULL || canonical_name == intermediate_name)
+ name = obstack_copy0 (&objfile->per_bfd->storage_obstack,
+ intermediate_name,
+ strlen (intermediate_name));
+ else
+ name = canonical_name;
- if (cname != NULL)
- name = cname;
- }
+ xfree (intermediate_name);
}
}
@@ -8562,7 +8571,7 @@ dwarf2_compute_name (const char *name,
/* Return the fully qualified name of DIE, based on its DW_AT_name.
If scope qualifiers are appropriate they will be added. The result
- will be allocated on the objfile_obstack, or NULL if the DIE does
+ will be allocated on the storage_obstack, or NULL if the DIE does
not have a name. NAME may either be from a previous call to
dwarf2_name or NULL.
@@ -8677,7 +8686,8 @@ dwarf2_physname (const char *name, struct die_info *die, struct dwarf2_cu *cu)
retval = canon;
if (need_copy)
- retval = obstack_copy0 (&objfile->objfile_obstack, retval, strlen (retval));
+ retval = obstack_copy0 (&objfile->per_bfd->storage_obstack,
+ retval, strlen (retval));
do_cleanups (back_to);
return retval;
@@ -15508,7 +15518,7 @@ read_partial_die (const struct die_reader_specs *reader,
default:
part_die->name
= dwarf2_canonicalize_name (DW_STRING (&attr), cu,
- &objfile->objfile_obstack);
+ &objfile->per_bfd->storage_obstack);
break;
}
break;
@@ -15793,7 +15803,7 @@ guess_partial_die_structure_name (struct partial_die_info *struct_pdi,
if (actual_class_name != NULL)
{
struct_pdi->name
- = obstack_copy0 (&cu->objfile->objfile_obstack,
+ = obstack_copy0 (&cu->objfile->per_bfd->storage_obstack,
actual_class_name,
strlen (actual_class_name));
xfree (actual_class_name);
@@ -15879,8 +15889,9 @@ fixup_partial_die (struct partial_die_info *part_die,
else
base = demangled;
- part_die->name = obstack_copy0 (&cu->objfile->objfile_obstack,
- base, strlen (base));
+ part_die->name
+ = obstack_copy0 (&cu->objfile->per_bfd->storage_obstack,
+ base, strlen (base));
xfree (demangled);
}
}
@@ -18557,7 +18568,7 @@ guess_full_die_structure_name (struct die_info *die, struct dwarf2_cu *cu)
&& actual_name[actual_name_len
- die_name_len - 1] == ':')
name =
- obstack_copy0 (&cu->objfile->objfile_obstack,
+ obstack_copy0 (&cu->objfile->per_bfd->storage_obstack,
actual_name,
actual_name_len - die_name_len - 2);
}
@@ -18603,7 +18614,7 @@ anonymous_struct_prefix (struct die_info *die, struct dwarf2_cu *cu)
if (base == NULL || base == DW_STRING (attr) || base[-1] != ':')
return "";
- return obstack_copy0 (&cu->objfile->objfile_obstack,
+ return obstack_copy0 (&cu->objfile->per_bfd->storage_obstack,
DW_STRING (attr), &base[-1] - DW_STRING (attr));
}
@@ -18943,8 +18954,9 @@ dwarf2_name (struct die_info *die, struct dwarf2_cu *cu)
char *base;
/* FIXME: we already did this for the partial symbol... */
- DW_STRING (attr) = obstack_copy0 (&cu->objfile->objfile_obstack,
- demangled, strlen (demangled));
+ DW_STRING (attr)
+ = obstack_copy0 (&cu->objfile->per_bfd->storage_obstack,
+ demangled, strlen (demangled));
DW_STRING_IS_CANONICAL (attr) = 1;
xfree (demangled);
@@ -18967,7 +18979,7 @@ dwarf2_name (struct die_info *die, struct dwarf2_cu *cu)
{
DW_STRING (attr)
= dwarf2_canonicalize_name (DW_STRING (attr), cu,
- &cu->objfile->objfile_obstack);
+ &cu->objfile->per_bfd->storage_obstack);
DW_STRING_IS_CANONICAL (attr) = 1;
}
return DW_STRING (attr);