[Bug gdb/30705] New: [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[Bug gdb/30705] New: [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[vries at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

            Bug ID: 30705
           Summary: [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp:
                    tests: osabi=AIX: arch=bpf: endian=auto: disassemble
                    0x100,+4 (segfault)
           Product: gdb
           Version: HEAD
            Status: NEW
          Severity: normal
          Priority: P2
         Component: gdb
          Assignee: unassigned at sourceware dot org
          Reporter: vries at gcc dot gnu.org
  Target Milestone: ---

I'm running into:
...
ERROR: GDB process no longer exists
FAIL: gdb.base/all-architectures-2.exp: all passed
ERROR: GDB process no longer exists
FAIL: gdb.base/all-architectures-7.exp: all passed
...

In more detail:
...
(gdb) IPASS: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf:
endian=auto: print, float
disassemble 0x100,+4
Dump of assembler code from 0x100 to 0x104:

Fatal signal: Segmentation fault
----- Backtrace -----
0x59ef98 gdb_internal_backtrace_1
        /data/vries/gdb/src/gdb/bt-utils.c:122
0x59f03b _Z22gdb_internal_backtracev
        /data/vries/gdb/src/gdb/bt-utils.c:168
0x79029e handle_fatal_signal
        /data/vries/gdb/src/gdb/event-top.c:889
0x79040a handle_sigsegv
        /data/vries/gdb/src/gdb/event-top.c:962
0x7f9076c3f90f ???
       
/usr/src/debug/glibc-2.31-150300.52.2.x86_64/nptl/../sysdeps/unix/sysv/linux/x86_64/sigaction.c:0
0xefcdc4 print_insn_bpf
        /data/vries/gdb/src/opcodes/bpf-dis.c:152
0x4d0725 _Z18default_print_insnmP16disassemble_info
        /data/vries/gdb/src/gdb/arch-utils.c:1041
0x54f544 bpf_gdb_print_insn
        /data/vries/gdb/src/gdb/bpf-tdep.c:128
0x4d9af9 _Z18gdbarch_print_insnP7gdbarchmP16disassemble_info
        /data/vries/gdb/src/gdb/gdbarch.c:3329
0x69ed16 gdb_print_insn_1
        /data/vries/gdb/src/gdb/disasm.c:1099
0x69edde _ZN16gdb_disassembler10print_insnEmPi
        /data/vries/gdb/src/gdb/disasm.c:1116
0x69cd98
_ZN29gdb_pretty_print_disassembler17pretty_print_insnEPK11disasm_insn10enum_flagsI20gdb_disassembly_flagE
        /data/vries/gdb/src/gdb/disasm.c:446
0x69d26c dump_insns
        /data/vries/gdb/src/gdb/disasm.c:543
0x69e784 do_assembly_only
        /data/vries/gdb/src/gdb/disasm.c:957
0x69f1fc
_Z15gdb_disassemblyP7gdbarchP6ui_out10enum_flagsI20gdb_disassembly_flagEimm
        /data/vries/gdb/src/gdb/disasm.c:1199
0x5f0e77 print_disassembly
        /data/vries/gdb/src/gdb/cli/cli-cmds.c:1518
0x5f16ba disassemble_command
        /data/vries/gdb/src/gdb/cli/cli-cmds.c:1694
0x5f7b4e do_simple_func
        /data/vries/gdb/src/gdb/cli/cli-decode.c:95
0x5fcb62 _Z8cmd_funcP16cmd_list_elementPKci
        /data/vries/gdb/src/gdb/cli/cli-decode.c:2735
0xc5ee29 _Z15execute_commandPKci
        /data/vries/gdb/src/gdb/top.c:575
0x78fa57 _Z15command_handlerPKc
        /data/vries/gdb/src/gdb/event-top.c:552
0x78ff5f _Z20command_line_handlerOSt10unique_ptrIcN3gdb13xfree_deleterIcEEE
        /data/vries/gdb/src/gdb/event-top.c:788
0xc8b209 tui_command_line_handler
        /data/vries/gdb/src/gdb/tui/tui-interp.c:104
0x78f3ad gdb_rl_callback_handler
        /data/vries/gdb/src/gdb/event-top.c:259
0xd98279 rl_callback_read_char
        /data/vries/gdb/src/readline/readline/callback.c:290
0x78f215 gdb_rl_callback_read_char_wrapper_noexcept
        /data/vries/gdb/src/gdb/event-top.c:195
0x78f2b1 gdb_rl_callback_read_char_wrapper
        /data/vries/gdb/src/gdb/event-top.c:234
0xcb4743 stdin_event_handler
        /data/vries/gdb/src/gdb/ui.c:155
0x14a62ab handle_file_event
        /data/vries/gdb/src/gdbsupport/event-loop.cc:573
0x14a6841 gdb_wait_for_event
        /data/vries/gdb/src/gdbsupport/event-loop.cc:694
0x14a5707 _Z16gdb_do_one_eventi
        /data/vries/gdb/src/gdbsupport/event-loop.cc:264
0x919c46 start_event_loop
        /data/vries/gdb/src/gdb/main.c:412
0x919da0 captured_command_loop
        /data/vries/gdb/src/gdb/main.c:476
0x91b58c captured_main
        /data/vries/gdb/src/gdb/main.c:1320
0x91b626 _Z8gdb_mainP18captured_main_args
        /data/vries/gdb/src/gdb/main.c:1339
0x4195cd main
        /data/vries/gdb/src/gdb/gdb.c:32
---------------------
A fatal error internal to GDB has been detected, further
debugging is not possible.  GDB will now terminate.

This is a bug, please report it.  For instructions, see:
<https://www.gnu.org/software/gdb/bugs/>.

ERROR: GDB process no longer exists
GDB process exited with wait status 25141 exp9 0 0 CHILDKILLED SIGSEGV
{segmentation violation}
UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf:
endian=auto: disassemble 0x100,+4
...

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[Bug gdb/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[vries at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

--- Comment #1 from Tom de Vries <vries at gcc dot gnu.org> ---
(In reply to Tom de Vries from comment #0)
> UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf:
> endian=auto: disassemble 0x100,+4

The other one is the same, for arch=xbfp:
...
UNRESOLVED: gdb.base/all-architectures-7.exp: tests: osabi=AIX: arch=xbpf:
endian=auto: disassemble 0x100,+4
...

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[Bug gdb/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[vries at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

--- Comment #2 from Tom de Vries <vries at gcc dot gnu.org> ---
Reproducer:
...
$ cat gdb.in
set osabi AIX
set endian little
set architecture bpf
disassemble 0x100,+4
$ gdb -q -batch -x gdb.in
...

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[Bug gdb/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[vries at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

--- Comment #3 from Tom de Vries <vries at gcc dot gnu.org> ---
It's because we dereference info->section, which is a nullptr:
...
#0  0x0000000000efcdc4 in print_insn_bpf (pc=256, info=0x7fffffffcb28) at
/data/vries/gdb/src/opcodes/bpf-dis.c:152
152           struct bfd *abfd = info->section->owner;
(gdb) p info->section
$3 = (asection *) 0x0
...

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[Bug tdep/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[vries at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

Tom de Vries <vries at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|gdb                         |tdep
                 CC|                            |jose.marchesi at oracle dot com

--- Comment #4 from Tom de Vries <vries at gcc dot gnu.org> ---
Regression since commit 1e18ffc9915 ("bpf: include, bfd, opcodes: add
EF_BPF_CPUVER ELF header flags").

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[Bug tdep/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[jose.marchesi at oracle dot com]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

Jose E. Marchesi <jose.marchesi at oracle dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Assignee|unassigned at sourceware dot org   |jose.marchesi at oracle dot com

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[Bug tdep/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[vries at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

--- Comment #5 from Tom de Vries <vries at gcc dot gnu.org> ---
Also, I'm seeming in gdb.gdb/unittest.exp:
...
Running selftest buffered_insn_length::bpf.^M
^M
^M
Fatal signal: Segmentation fault^M
...

Reproducer:
...
$ gdb -q -batch -ex "maint selftest buffered_insn_length::bpf"
...

In this case, we're segfaulting here because abfd is nullptr:
...
Thread 1 "gdb" received signal SIGSEGV, Segmentation fault.
print_insn_bpf (pc=0, info=0x7fffffffd398) at
/data/vries/gdb/src/opcodes/bpf-dis.c:153
153           Elf_Internal_Ehdr *header = elf_elfheader (abfd);
...
which gets it's value in the same line as mentioned in comment 3:
...
152           struct bfd *abfd = info->section->owner;
...

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[Bug tdep/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[vries at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

--- Comment #6 from Tom de Vries <vries at gcc dot gnu.org> ---
(In reply to Tom de Vries from comment #5)
> $ gdb -q -batch -ex "maint selftest buffered_insn_length::bpf"

FTR, likewise for "maint selftest buffered_insn_length::bpf::xbfp".

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[Bug tdep/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[mark at klomp dot org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

Mark Wielaard <mark at klomp dot org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mark at klomp dot org

--- Comment #7 from Mark Wielaard <mark at klomp dot org> ---
(In reply to Tom de Vries from comment #4)
> Regression since commit 1e18ffc9915 ("bpf: include, bfd, opcodes: add
> EF_BPF_CPUVER ELF header flags").

That is https://builder.sourceware.org/buildbot/#/changes/29867 which indeed
sees a lot of RED for the gdb check results.

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[Bug tdep/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[cvs-commit at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

--- Comment #8 from cvs-commit at gcc dot gnu.org <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jose E. Marchesi
<jemarch@sourceware.org>:

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=5b512234c874d5f82734dc6115765bc691c2c982

commit 5b512234c874d5f82734dc6115765bc691c2c982
Author: Jose E. Marchesi <jose.marchesi@oracle.com>
Date:   Mon Jul 31 15:44:36 2023 +0200

    bpf: opcodes: fix regression in BPF disassembler

    This patch fixes a regression recently introduced in the BPF
    disassembler, that was assuming an abfd was always available in
    info->section->owner.  Apparently this is not so in GDB, and therefore
    https://sourceware.org/bugzilla/show_bug.cgi?id=30705.

    Tested in bpf-unkonwn-none.

    opcodes/ChangeLog:

    2023-07-31  Jose E. Marchesi  <jose.marchesi@oracle.com>

            PR 30705
            * bpf-dis.c (print_insn_bpf): Check that info->section->owner is
            actually available before using it.

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[Bug tdep/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[vries at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

--- Comment #9 from Tom de Vries <vries at gcc dot gnu.org> ---
The commit fixes the regressions for me, thanks.

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[Bug tdep/30705] [gdb] UNRESOLVED: gdb.base/all-architectures-2.exp: tests: osabi=AIX: arch=bpf: endian=auto: disassemble 0x100,+4 (segfault)

[vries at gcc dot gnu.org]

https://sourceware.org/bugzilla/show_bug.cgi?id=30705

Tom de Vries <vries at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|NEW                         |RESOLVED
   Target Milestone|---                         |14.1

--- Comment #10 from Tom de Vries <vries at gcc dot gnu.org> ---
Fixed by commit.  Also buildbot seems happy again.

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