[Bug c/106745] New: segfault in bpf_core_get_sou_member_index

[Bug c/106745] New: segfault in bpf_core_get_sou_member_index

[james.hilliard1 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106745

            Bug ID: 106745
           Summary: segfault in bpf_core_get_sou_member_index
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: james.hilliard1 at gmail dot com
  Target Milestone: ---

Created attachment 53510
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53510&action=edit
bug report output

Running into this on master with the following patch(seems unrelated to the
crash):
https://patchwork.ozlabs.org/project/gcc/patch/87a681d7tf.fsf_-_@oracle.com/

[Bug target/106745] segfault in bpf_core_get_sou_member_index

[david.faust at oracle dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106745

David Faust <david.faust at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |david.faust at oracle dot com

--- Comment #1 from David Faust <david.faust at oracle dot com> ---
Thanks, I've reproduced the failure and found the issue.
The code which generates the CO-RE relocations isn't correctly handling
anonymous inner struct/union decls. So for example:
struct core_reloc_flavors___weird {
 struct {
  int b;
 };

 union {
  int a;
  int c;
 };
};

Asking to generate a CO-RE relo for access to a, b or c here will trigger the
SEGV. Working on a fix.

[Bug target/106745] segfault in bpf_core_get_sou_member_index

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106745

--- Comment #2 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by David Faust <dfaust@gcc.gnu.org>:

https://gcc.gnu.org/g:b504149d2c92ddfcfab62ea6d1ed49ae72493e38

commit r13-2255-gb504149d2c92ddfcfab62ea6d1ed49ae72493e38
Author: David Faust <david.faust@oracle.com>
Date:   Mon Aug 29 11:21:52 2022 -0700

    bpf: handle anonymous members in CO-RE reloc [PR106745]

    The old method for computing a member index for a CO-RE relocation
    relied on a name comparison, which could SEGV if the member in question
    is itself part of an anonymous inner struct or union.

    This patch changes the index computation to not rely on a name, while
    maintaining the ability to account for other sibling fields which may
    not have a representation in BTF.

    gcc/ChangeLog:

            PR target/106745
            * config/bpf/coreout.cc (bpf_core_get_sou_member_index): Fix
            computation of index for anonymous members.

    gcc/testsuite/ChangeLog:

            PR target/106745
            * gcc.target/bpf/core-pr106745.c: New test.

[Bug target/106745] segfault in bpf_core_get_sou_member_index

[jemarch at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106745

Jose E. Marchesi <jemarch at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |FIXED

--- Comment #3 from Jose E. Marchesi <jemarch at gcc dot gnu.org> ---
This is fixed.