Don't crash is dwarf_decode_macro_bytes's 'body' is NULL, even when '!is_define'
Commit Message
Ref.: https://bugzilla.redhat.com/show_bug.cgi?id=1715008
On commit 7bede82892a06e6c26989803e70f53697392dcf9 ("Don't crash if
dwarf_decode_macro_bytes's 'body' is NULL"), I was too strict when
checking if 'body' is NULL: the check only comprised the case when
'is_define' is true. However, the corruption of .debug_macro by
rpmbuild's "debugedit" also affects the case when 'is_define' is
false, i.e., when the macro is being undefined.
This commit improves the check and covers both cases now. This has
been tested on Fedora 30 with a problematic debuginfo, and I don't see
a segfault anymore.
OK to push?
gdb/ChangeLog:
2019-05-29 Sergio Durigan Junior <sergiodj@redhat.com>
Ref.: https://bugzilla.redhat.com/show_bug.cgi?id=1708192
Ref.: https://bugzilla.redhat.com/show_bug.cgi?id=1715008
* dwarf2read.c (dwarf_decode_macro_bytes): Move check to see if
'body' is NULL to the outter 'if', protecting the '!is_define'
situation as well.
---
gdb/ChangeLog | 8 ++++++++
gdb/dwarf2read.c | 31 ++++++++++++++-----------------
2 files changed, 22 insertions(+), 17 deletions(-)
Comments
>>>>> "Sergio" == Sergio Durigan Junior <sergiodj@redhat.com> writes:
Sergio> Ref.: https://bugzilla.redhat.com/show_bug.cgi?id=1715008
Sergio> On commit 7bede82892a06e6c26989803e70f53697392dcf9 ("Don't crash if
Sergio> dwarf_decode_macro_bytes's 'body' is NULL"), I was too strict when
Sergio> checking if 'body' is NULL: the check only comprised the case when
Sergio> 'is_define' is true. However, the corruption of .debug_macro by
Sergio> rpmbuild's "debugedit" also affects the case when 'is_define' is
Sergio> false, i.e., when the macro is being undefined.
Sergio> This commit improves the check and covers both cases now. This has
Sergio> been tested on Fedora 30 with a problematic debuginfo, and I don't see
Sergio> a segfault anymore.
Sergio> OK to push?
Thanks for doing this. This is ok.
Tom
On Wednesday, May 29 2019, Tom Tromey wrote:
>>>>>> "Sergio" == Sergio Durigan Junior <sergiodj@redhat.com> writes:
>
> Sergio> Ref.: https://bugzilla.redhat.com/show_bug.cgi?id=1715008
> Sergio> On commit 7bede82892a06e6c26989803e70f53697392dcf9 ("Don't crash if
> Sergio> dwarf_decode_macro_bytes's 'body' is NULL"), I was too strict when
> Sergio> checking if 'body' is NULL: the check only comprised the case when
> Sergio> 'is_define' is true. However, the corruption of .debug_macro by
> Sergio> rpmbuild's "debugedit" also affects the case when 'is_define' is
> Sergio> false, i.e., when the macro is being undefined.
>
> Sergio> This commit improves the check and covers both cases now. This has
> Sergio> been tested on Fedora 30 with a problematic debuginfo, and I don't see
> Sergio> a segfault anymore.
>
> Sergio> OK to push?
>
> Thanks for doing this. This is ok.
Thanks for the review, Tom.
Pushed: 955b06fa576df1a6954263043ea3f3a5b9ad5940
@@ -1,3 +1,11 @@
+2019-05-29 Sergio Durigan Junior <sergiodj@redhat.com>
+
+ Ref.: https://bugzilla.redhat.com/show_bug.cgi?id=1708192
+ Ref.: https://bugzilla.redhat.com/show_bug.cgi?id=1715008
+ * dwarf2read.c (dwarf_decode_macro_bytes): Move check to see if
+ 'body' is NULL to the outter 'if', protecting the '!is_define'
+ situation as well.
+
2019-05-28 Tom Tromey <tromey@adacore.com>
* ada-lang.c (ada_remove_Xbn_suffix)
@@ -24635,25 +24635,22 @@ dwarf_decode_macro_bytes (struct dwarf2_cu *cu,
is_define ? _("definition") : _("undefinition"),
line == 0 ? _("zero") : _("non-zero"), line, body);
- if (is_define)
+ if (body == NULL)
{
- if (body != NULL)
- parse_macro_definition (current_file, line, body);
- else
- {
- /* Fedora's rpm-build's "debugedit" binary
- corrupted .debug_macro sections.
-
- For more info, see
- https://bugzilla.redhat.com/show_bug.cgi?id=1708786 */
- complaint (_("debug info gives %s invalid macro definition "
- "without body (corrupted?) at line %d"
- "on file %s"),
- at_commandline ? _("command-line")
- : _("in-file"),
- line, current_file->filename);
- }
+ /* Fedora's rpm-build's "debugedit" binary
+ corrupted .debug_macro sections.
+
+ For more info, see
+ https://bugzilla.redhat.com/show_bug.cgi?id=1708786 */
+ complaint (_("debug info gives %s invalid macro %s "
+ "without body (corrupted?) at line %d "
+ "on file %s"),
+ at_commandline ? _("command-line") : _("in-file"),
+ is_define ? _("definition") : _("undefinition"),
+ line, current_file->filename);
}
+ else if (is_define)
+ parse_macro_definition (current_file, line, body);
else
{
gdb_assert (macinfo_type == DW_MACRO_undef