GNU Hurd/ open issues/ binutils-gdb

Welcome to... ... the GNU Hurd!

Here's what's to be done for maintaining GNU Binutils and GDB.

  1. General Information
    1. Binutils
    2. GDB
  2. Configuration
  3. Build
    1. Analysis
  4. Install
    1. Analysis
  5. Testsuite
    1. Analysis
  6. Open Issues
    1. open issue binutils
    2. open issue gdb
    3. GDB info files SIGSEGV
    4. GDB Watchpoints

General Information

Binutils

As these tools primarily deal with low-level parts of the target architecture and the object file format (ELF ABI), which are essentially (at least meant to be) the same, there shouldn't be many differences comparing the binutils between the GNU/Hurd and GNU/Linux ports, for example. There are a few, though, as explained below.

GDB

GDB needs an processor architecture as well as operating system port.

Configuration

Last reviewed up to Git commit c2853f3d99797a321c37948297441ca6021f719a (2014-02-14).

  • Globally

    • a.out (such as ld/emulparams/i386linux.sh, ld/emultempl/linux.em, etc.), COFF, PE image support and 64-bit support are not interesting.

    • In the testsuites, .exp and .d files very likely should not only care for *-*-linux*, but also *-*-gnu*. (If they need to be conditionalized like this at all.)

  • bfd/

    • config.bfd

      • i[3-7]86-*-gnu*

        Comparing to i[3-7]86-*-linux-*:

        • i386linux_vec -- a.out.

        • i386pei_vec -- PE.

        • 64 bit.

    • configure.host

      Souldn't need anything. x86 Linux neither.

    • configure.in

      Linux:

      • COREFILE=trad-core.lo with TRAD_HEADER='"hosts/i386linux.h"'

        We don't have any such core file support configured. TODO: should we? Where is this core file reading exactly used? GDB?

      • i386linux_vec -- a.out.

      • i386pei_vec -- PE.

  • binutils/

    • configure.tgt

  • gas/

    • config/te-gnu.h

      C.f. te-linux.h; search tree for TE_LINUX vs. TE_GNU usage.

      • tc-i386.h

        Sole TE_LINUX usage is for a.out.

    • configure.tgt

  • gdb/

    • Have a look at config/i386/i386gnu.mh.

    • configure.tgt

      • glibc-tdep et al. also for GNU/Hurd?

    • gdbserver

    • In gdb/gnu-nat.c:gnu_wait, we don't implement gdb/target/wait.h:TARGET_WNOHANG. What is this needed for?

  • libdecnumber/

    Should/can probably align to GNU/Linux.

  • ld/

    • configure.host

      • *-*-gnu*

        TODO: resolve crt0.o vs. crt1.o issue. Testsuite failures.

        • configure.tgt

        • i[3-7]86-*-gnu*

        Compare to i[3-7]86-*-linux-*, but don't need a.out (i386linux) and 64 bit support.

  • __ehdr_start symbol, c84ed8d89d0b8bf5a2968d465f77ac24bcfc40c2 -- can this be helpful in the exec server, glibc, or elsewhere? Used in GDB (BFD) commit bdbd9758806ed855af89244870fdc52cf3ff09bc. Used in glibc commit 288f7d79fe2dcc8e62c539f57b25d7662a2cd5ff Use __ehdr_start, if available, as fallback for AT_PHDR..

  • Add HOSTING_SCRT0 for PIE test, 49cc20aa5c416ea4307931cccf6353247368187d -- is for GNU/Linux only; but also seems unused.

  • 82763a3d329b0d342d0273941b1521be9ef0c604 »MODIFIED is unknown, pass it as true.«

  • Configure so that Debian system's /usr/lib/debug/[...] will be loaded automatically.

  • [low] c26e9cbb0ce70e8fca32a40c434a0837bf46750a, gdb/gnu-nat.c:set_exceptions_cmd, Make this take effect immediately in a running process.

  • [low] b27caf75c311991772b316fe7c0eecfd5788eeaf, ld, Add HOSTING_SLIBS and use it for -pie. For us, too?

Build

Here's a log of a binutils-gdb build run; this is from Git commit c2853f3d99797a321c37948297441ca6021f719a (2014-02-14) plus id:"87vbxxhww4.fsf@kepler.schwinge.homeip.net", id:"8738kyi30l.fsf@kepler.schwinge.homeip.net", id:"8761ofv62k.fsf@kepler.schwinge.homeip.net", id:"1391759958-972-2-git-send-email-yao@codesourcery.com", id:"1391759958-972-3-git-send-email-yao@codesourcery.com", run on kepler.SCHWINGE and coulomb.SCHWINGE.

$ export LC_ALL=C
$ ../W._C._Handy/configure --prefix="$PWD".install --enable-gold --with-sysroot=/ SHELL=/bin/dash CC=gcc-4.8 CXX=g++-4.8 --disable-werror 2>&1 | tee log_build
[...]
$ make 2>&1 | tee log_build_
[...]

Different hosts may default to different shells and compiler versions; thus harmonized. Debian GCC (which is used in binutils' testsuite) likes to pass --sysroot=/ to ld, so we need to configure binutils with support for sysroots. In the GDB build, there are several occurences of error: dereferencing type-punned pointer will break strict-aliasing rules in the MIG-generated stub files; thus no -Werror until that is resolved (strict aliasing).

This takes up around 1.3 GiB, and needs roughly 17 min on kepler.SCHWINGE and 79 min on coulomb.SCHWINGE.

Analysis

x86 GNU/Linux' and GNU/Hurd's configurations are slightly different, thus mask out most of the differences that are due to GNU/Linux supporting more core file formats, and more emulation vectors.

$ toolchain/logs/process binutils-gdb build

  • For GDB, why do we specify -D_GNU_SOURCE, and GNU/Linux doesn't?

  • GNU/Linux: gdb/symfile-mem.c for vDSO.

  • GNU/Linux: gdb/i386-nat.c for hardware breakpoints, etc. -- we should probably use that, too. Related to Samuel's Hurd GDB patch?

  • gdb/gnu-nat.c

    gnu-nat.c: In function 'proc_set_exception_port':
gnu-nat.c:409:3: warning: format '%d' expects argument of type 'int', but argument 8 has type 'mach_port_t' [-Wformat]
gnu-nat.c: In function 'proc_steal_exc_port':
gnu-nat.c:449:7: warning: format '%d' expects argument of type 'int', but argument 8 has type 'mach_port_t' [-Wformat]
gnu-nat.c:470:7: warning: format '%d' expects argument of type 'int', but argument 8 has type 'mach_port_t' [-Wformat]
gnu-nat.c: In function 'make_proc':
gnu-nat.c:583:7: warning: format '%d' expects argument of type 'int', but argument 2 has type 'mach_port_t' [-Wformat]
gnu-nat.c:586:7: warning: format '%d' expects argument of type 'int', but argument 8 has type 'mach_port_t' [-Wformat]
gnu-nat.c: In function 'inf_set_pid':
gnu-nat.c:761:3: warning: format '%d' expects argument of type 'int', but argument 7 has type 'task_t' [-Wformat]
gnu-nat.c: In function 'inf_validate_procs':
gnu-nat.c:1085:6: warning: format '%d' expects argument of type 'int', but argument 8 has type 'thread_t' [-Wformat]
gnu-nat.c: In function 'inf_signal':
gnu-nat.c:1349:4: warning: format '%d' expects argument of type 'int', but argument 7 has type 'thread_t' [-Wformat]
gnu-nat.c:1349:4: warning: format '%d' expects argument of type 'int', but argument 8 has type 'thread_t' [-Wformat]
gnu-nat.c: In function 'S_exception_raise_request':
gnu-nat.c:1668:3: warning: format '%d' expects argument of type 'int', but argument 7 has type 'thread_t' [-Wformat]
gnu-nat.c:1668:3: warning: format '%d' expects argument of type 'int', but argument 8 has type 'task_t' [-Wformat]
gnu-nat.c:1705:8: warning: format '%d' expects argument of type 'int', but argument 7 has type 'mach_port_t' [-Wformat]
gnu-nat.c:1711:8: warning: format '%d' expects argument of type 'int', but argument 7 has type 'mach_port_t' [-Wformat]
gnu-nat.c: In function 'do_mach_notify_dead_name':
gnu-nat.c:1762:3: warning: format '%d' expects argument of type 'int', but argument 7 has type 'mach_port_t' [-Wformat]
gnu-nat.c: In function 'gnu_write_inferior':
gnu-nat.c:2383:8: warning: format '%x' expects argument of type 'unsigned int', but argument 2 has type 'vm_address_t' [-Wformat]
gnu-nat.c:2393:8: warning: format '%x' expects argument of type 'unsigned int', but argument 2 has type 'vm_address_t' [-Wformat]
gnu-nat.c: In function 'steal_exc_port':
gnu-nat.c:2864:5: warning: format '%d' expects argument of type 'int', but argument 2 has type 'mach_port_t' [-Wformat]

  • fe19822761b4635f392875a186e48af446b40f41..7a63e9515491f21eaf07301df87d389def20e317:

    -Wmissing-prototypes

    notify_S.c:305:24: warning: no previous prototype for 'notify_server' []
notify_S.c:341:28: warning: no previous prototype for 'notify_server_routine' []
process_reply_S.c:343:24: warning: no previous prototype for 'process_reply_server' []
process_reply_S.c:379:28: warning: no previous prototype for 'process_reply_server_routine' []
msg_reply_S.c:165:24: warning: no previous prototype for 'msg_reply_server' []
msg_reply_S.c:201:28: warning: no previous prototype for 'msg_reply_server_routine' []
exc_request_S.c:157:24: warning: no previous prototype for 'exc_server' []
exc_request_S.c:193:28: warning: no previous prototype for 'exc_server_routine' []

  • O_NOFOLLOW

    First seen in 20f498edfd7e57d3297febcf9c7c7d667cc74239..69a5e2b022c7d15ec4c7c49e6f53a8d924d3b72b:

    -checking for working fcntl.h... yes
+checking for working fcntl.h... no (bad O_NOFOLLOW)

    open issue glibc?

Install

$ make install 2>&1 | tee log_install
[...]

This takes up around 200 MiB, and needs roughly 2 min on kepler.SCHWINGE and 6 min on coulomb.SCHWINGE.

Analysis

$ toolchain/logs/process binutils-gdb install
  • libtool: finish: ldconfig is not run for the Hurd.

Testsuite

$ make -k check 2>&1 | tee log_test
[...]

This needs roughly 20 min on kepler.SCHWINGE and 140 min on coulomb.SCHWINGE.

When running make -k check 2>&1 | tee log_test, at the end of the testsuite the tee process does not terminate if there are still stray leftover processes that have their stdout/stderr open. killing these (SIGKILL may be needed), makes the tee process terminate, too. On GNU/Hurd, these generally are gdb.multi/watchpoint-multi, and an unknown (?) GDB one ("57 PIDs before" expect [...] gdb.cp).

Analysis

GDB's testsuite uses the system's default gcc (and similar) compilers, not those specified on the configure line (open issue gdb?), see find_gcc (and similar) usage in the testsuite and DejaGnu. Maybe something like gdb/testsuite/boards/cc-with-tweaks.exp would help, or setting CC_FOR_TARGET (and similar) per gdb/testsuite/lib/future.exp?

$ toolchain/logs/process binutils-gdb test

  • FAIL: static [...]

    The testsuite isn't prepared for using crt0.o instead of crt1.o depending on whether a static or dynamic executable is created. Documented in ld/configure.host. Perhaps we should finally rewrite this messy code in glibc? Or, something similar to commit 49cc20aa5c416ea4307931cccf6353247368187d Add HOSTING_SCRT0 for PIE test or commit b27caf75c311991772b316fe7c0eecfd5788eeaf Add HOSTING_SLIBS and use it for -pie can be used.

    Same issue for FAIL: Common symbol override ifunc * ones?

  • FAIL: ld-elf/64ksec

    On the idle grubber, this one takes a few minutes wall time to complete successfully (I/O system weakness), so assuming some system load variation, the testsuite's timeout may trigger.

  • FAIL: gas/i386/rept (intermittently)

    Added in commit 06f1247c54126b9f1e6acb8ff8c7be35aec6f44c (2012-06-07) as part of the fix for sourceware [BZ #14201], renamed in commit d654e24bbc2f601df4dc43b26049b0339528b93a (2012-06-07):

    WARNING: program timed out.
FAIL: gas/i386/rept

  • ld IFUNC execution tests

    Missing IFUNC support on GNU/Hurd.

    Added in commit 82c5587db078581cfe94a4385ed99de1d1fa6657 (2012-09-19):

    FAIL: Common symbol override ifunc test 1a
FAIL: Common symbol override ifunc test 1b

  • gold GNU/Linux vs. GNU/Hurd

    -FAIL: relro_test.sh
+PASS: relro_test.sh


-PASS: ver_matching_test.sh
+FAIL: ver_matching_test.sh


-PASS: script_test_3
+FAIL: script_test_3


-PASS: tls_phdrs_script_test
+FAIL: tls_phdrs_script_test

  • gdb.base/attach-pie-misread.exp

    Is only run for GNU/Linux; needs prelink.

  • Disabled

    • gdb.base/interrupt.exp

       PASS: gdb.base/interrupt.exp: child process is alive
 a
 a
 PASS: gdb.base/interrupt.exp: child process ate our char
 ^C
 Program received signal SIGINT, Interrupt.
-0x010bf5a2 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
+0x010bdb09 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
 (gdb) PASS: gdb.base/interrupt.exp: send_gdb control C
 p func1 ()


 Program received signal SIGTRAP, Trace/breakpoint trap.
-0x010bf5a2 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
+0x010bdb09 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
 The program being debugged was signaled while in a function called from GDB.
 GDB remains in the frame where the signal was received.
 To change this behavior use "set unwindonsignal on".
 Evaluation of the expression containing the function
 (func1) will be abandoned.
 When the function is done executing, GDB will silently stop.
 (gdb) FAIL: gdb.base/interrupt.exp: call function when asleep (wrong output)
 p func1 ()


 Program received signal SIGTRAP, Trace/breakpoint trap.
-0x010bf5a2 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
+0x010bdb09 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
 The program being debugged was signaled while in a function called from GDB.
 GDB remains in the frame where the signal was received.
 To change this behavior use "set unwindonsignal on".
 Evaluation of the expression containing the function
 (func1) will be abandoned.
 When the function is done executing, GDB will silently stop.
 (gdb) FAIL: gdb.base/interrupt.exp: call function a second time
 continue
 Continuing.
-PASS: gdb.base/interrupt.exp: continue
+
+Program received signal SIGSEGV, Segmentation fault.
+0x010bdb09 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
+(gdb) FAIL: gdb.base/interrupt.exp: continue
 data
 PASS: gdb.base/interrupt.exp: echo data
 ^C(gdb) Quit
 (gdb) FAIL: gdb.base/interrupt.exp: Send Control-C, second time
 signal SIGINT
 Continuing with signal SIGINT.
 PASS: gdb.base/interrupt.exp: signal SIGINT
 more data
 PASS: gdb.base/interrupt.exp: echo more data


 Program received signal SIGSEGV, Segmentation fault.
-0x010bf6c8 in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
+0x010bdc9d in _hurd_intr_rpc_mach_msg () from /lib/i386-gnu/libc.so.0.3
 (gdb) more data
 Undefined command: "more".  Try "help".
 (gdb) FAIL: gdb.base/interrupt.exp: send end of file
-testcase ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/interrupt.exp completed in 6 seconds
+[hangs]


 7939 1000  6817  7939  7939  2  144M 8.92M 93.8  5:29.23    10hrs /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/testsuite/../../gdb/gdb -nw -nx -data-directory /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/testsuite/../data-directory
 7944 1000  7939  7944  7939  2  146M  744K  0.0  0:00.00  0:00.01 /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/testsuite/gdb.base/interrupt


$ gdb -q tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/gdb 7961
Reading symbols from /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/gdb...done.
Attaching to program `/media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/gdb', pid 7961
[New Thread 7961.1]
[New Thread 7961.2]


warning: Can't modify tracing state for pid 7961: (ipc/rcv) timed out
Reading symbols [...]
(gdb) thread apply all bt full


Thread 2 (Thread 7961.2):
#0  0x014949cc in swtch_pri () at /build/eglibc-wYOBb2/eglibc-2.17/build-tree/hurd-i386-libc/mach/swtch_pri.S:2
No locals.
#1  0x01496354 in __spin_lock_solid (lock=0x168100c) at spin-solid.c:26
No locals.
#2  0x014aa677 in __spin_lock (__lock=<optimized out>) at ../mach/lock-intern.h:54
No locals.
#3  _hurd_sigstate_lock (ss=0x1681808) at hurdsig.c:175
No locals.
#4  0x014acbfb in post_signal (untraced=untraced@entry=0) at hurdsig.c:680
        err = <optimized out>
        handler = <optimized out>
        blocked = <optimized out>
        __PRETTY_FUNCTION__ = "post_signal"
        signo = 11
        act = 23593696
        ss = 0x1681808
        thread_state = {set = 0, basic = {gs = 1, fs = 17840912, es = 23594144, ds = 17840912, edi = 23290621, esi = 21506724, ebp = 23281960, esp = 1, ebx = 3, edx = 27255556, ecx = 23599112, eax = 163840, eip = 23273912, 
            cs = 29351492, efl = 29351424, uesp = 0, ss = 29351336}, fpu = {fpkind = 17840912, initialized = 29351344, 
            hw_state = "\364\213\002\000\000\000\000\000\000\000\000\000cfH\001\000\000\000\000\377\377\377\377\000 c\001T\244G\001\020;\020\001\b\030h\001\000\260g\001\370ݿ\001\060\357\277\001p\000\000\000\233\322e\001\220ݿ\001\216\246J\001\000\300b\001\260\341J\001\b\030h\001\000\000\000\000\000\000\000\000\000 c\001\022\000\000\000\000\200\002\000\020;\020\001\030\306b\001", exc_status = 359}}
        ss_suspended = 0
        reply = 0x1bfddf4
        detail = 0x1bfde4c
#5  0x014ae29e in _hurd_internal_post_signal (ss=ss@entry=0x1681808, signo=11, detail=detail@entry=0x1bfde4c, reply_port=reply_port@entry=0, reply_port_type=reply_port_type@entry=17, untraced=untraced@entry=0) at hurdsig.c:1221
        reply_rpc = 0x165d200 <__msg_sig_post_reply>
#6  0x014af98f in _S_catch_exception_raise (port=142, thread=112, task=1, exception=1, code=2, subcode=19137735) at catch-exc.c:88
        ss = 0x1681808
        signo = 11
        d = {exc = 1, exc_code = 2, exc_subcode = 19137735, code = 2, error = EKERN_PROTECTION_FAILURE}
#7  0x016442c2 in _Xexception_raise (OutHeadP=0x1bfdf20, InHeadP=0x1bfef30) at /build/eglibc-wYOBb2/eglibc-2.17/build-tree/hurd-i386-libc/mach/mach/exc_server.c:150
No locals.
#8  _Xexception_raise (InHeadP=0x1bfef30, OutHeadP=0x1bfdf20) at /build/eglibc-wYOBb2/eglibc-2.17/build-tree/hurd-i386-libc/mach/mach/exc_server.c:41
        In0P = 0x1bfef30
        OutP = 0x1bfdf20
#9  0x01644344 in _S_exc_server (InHeadP=InHeadP@entry=0x1bfef30, OutHeadP=OutHeadP@entry=0x1bfdf20) at /build/eglibc-wYOBb2/eglibc-2.17/build-tree/hurd-i386-libc/mach/mach/exc_server.c:189
        InP = 0x1bfef30
        OutP = 0x1bfdf20
        routine = 0x1644220 <_Xexception_raise>
#10 0x014a58ec in msgport_server (outp=0x1bfdf20, inp=0x1bfef30) at msgportdemux.c:49
No locals.
#11 msgport_server (inp=inp@entry=0x1bfef30, outp=outp@entry=0x1bfdf20) at msgportdemux.c:36
        d = 0x0
#12 0x01495898 in __mach_msg_server_timeout (demux=demux@entry=0x14a5890 <msgport_server>, max_size=max_size@entry=4096, rcv_name=rcv_name@entry=142, option=option@entry=0, timeout=timeout@entry=0) at msgserver.c:108
        request = 0x1bfef30
        reply = 0x1bfdf20
        mr = <optimized out>
        __PRETTY_FUNCTION__ = "__mach_msg_server_timeout"
#13 0x014959cb in __mach_msg_server (demux=demux@entry=0x14a5890 <msgport_server>, max_size=4096, rcv_name=142) at msgserver.c:195
No locals.
#14 0x014a597d in _hurd_msgport_receive () at msgportdemux.c:67
No locals.
#15 0x010f7956 in entry_point (self=0x8520788, start_routine=0x14a5920 <_hurd_msgport_receive>, arg=0x0) at ./pthread/pt-create.c:61
No locals.
#16 0x00000000 in ?? ()
No symbol table info available.


Thread 1 (Thread 7961.1):
#0  _hurd_userlink_unlink (link=0x81c2a20 <command_handler+48>) at ../hurd/hurd/userlink.h:123
No locals.
#1  __sigreturn (scp=0x81c2950 <handle_sigint>) at ../sysdeps/mach/hurd/i386/sigreturn.c:47
        link = 0x81c2a20 <command_handler+48>
        reply_port = <optimized out>
#2  0x014aef46 in trampoline () from /lib/i386-gnu/libc.so.0.3
No locals.
#3  0x081c2950 in ?? () at ../../Ferry_Tagscherer/gdb/event-top.c:869
        sigtstp_token = 0x860a7c0
        sighup_token = 0x86089e0
        more_to_come = 0
        sigfpe_token = 0x860a7a8
        sigquit_token = 0x86089c8
        sigint_token = 0x860a3b0
        call_readline = 0x81c2ab0 <rl_callback_read_char_wrapper>
        exec_done_display_p = 0
        input_handler = 0x81c2c50 <command_line_handler>
        async_command_editing_p = 1
        after_char_processing_hook = 0x0
        async_annotation_suffix = 0x83d8648 "prompt"
        input_fd = 0
        readline_input_state = {linebuffer = 0x0, linebuffer_ptr = 0x0}
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb) kill
Kill the program being debugged? (y or n) y

    • gdb.base/readline.exp

      term blocking issue.

    • gdb.base/sigall.exp

      From send signal TSTP on, all FAIL running into timeouts.

    • gdb.python/py-inferior.exp (mostly disabled)

      Running ../../../Ferry_Tagscherer/gdb/testsuite/gdb.python/py-inferior.exp ...
[...]
python print 'result =', i0.was_attached
result = False
(gdb) PASS: gdb.python/py-inferior.exp: test Inferior.was_attached
python print i0.threads ()
(<gdb.InferiorThread object at 0x61170>, <gdb.InferiorThread object at 0x61160>)
(gdb) FAIL: gdb.python/py-inferior.exp: test Inferior.threads
break check_threads
Breakpoint 2 at 0x8048869: file ../../../Ferry_Tagscherer/gdb/testsuite/gdb.python/py-inferior.c, line 61.
(gdb) continue
Continuing.
[New Thread 25670.6]
[New Thread 25670.7]
[New Thread 25670.8]
[New Thread 25670.9]
[New Thread 25670.10]
[New Thread 25670.11]
[New Thread 25670.12]
[New Thread 25670.13]


Breakpoint 2, check_threads (barrier=0x15ff144) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.python/py-inferior.c:61
61        pthread_barrier_wait (barrier);
(gdb) PASS: gdb.python/py-inferior.exp: continue to breakpoint: cont to check_threads
python print len (i0.threads ())
10
(gdb) FAIL: gdb.python/py-inferior.exp: test Inferior.threads 2
break 28
Breakpoint 3 at 0x80487c2: file ../../../Ferry_Tagscherer/gdb/testsuite/gdb.python/py-inferior.c, line 28.
(gdb) continue
Continuing.
FAIL: gdb.python/py-inferior.exp: continue to breakpoint: cont to Break here. (timeout)
python addr = gdb.selected_frame ().read_var ('str')
FAIL: gdb.python/py-inferior.exp: read str address (timeout)
[All following tests FAIL with timeout.]
FAIL: gdb.python/py-inferior.exp: Switch to first inferior (timeout)
remove-inferiors 3
FAIL: gdb.python/py-inferior.exp: Remove second inferior (timeout)

      At this point, the system hangs; no new processes can be spawned, so perhaps an issue with the exec server.

    • gdb.threads/manythreads.exp

      open issue libpthread. Perhaps fails due to pthread attributes usage? Doesn't execute properly:

      $ gdb/testsuite/gdb.threads/manythreads
manythreads: ../libpthread/sysdeps/mach/pt-thread-halt.c:51: __pthread_thread_halt: Unexpected error: (ipc/rcv) invalid name.
Killed

  • Linux syscall usage, <asm/unistd.h>

    • UNSUPPORTED: gdb.threads/ia64-sigill.exp: Couldn't compile ../../../master/gdb/testsuite/gdb.threads/ia64-sigill.c: unrecognized error

    • UNSUPPORTED: gdb.threads/siginfo-threads.exp: Couldn't compile ../../../Ferry_Tagscherer/gdb/testsuite/gdb.threads/siginfo-threads.c: unrecognized error

    • gdb.threads/sigstep-threads.c

      Also uses tgkill.

    • UNSUPPORTED: gdb.threads/watchpoint-fork.exp: parent: multithreaded: Couldn't compile ../../../Ferry_Tagscherer/gdb/testsuite/gdb.threads/watchpoint-fork-mt.c ../../../Ferry_Tagscherer/gdb/testsuite/gdb.threads/watchpoint-fork-parent.c: unrecognized error

  • UNSUPPORTED: gdb.threads/multi-create.exp: Couldn't compile ../../../master/gdb/testsuite/gdb.threads/multi-create.c: unrecognized error ../../../master/gdb/testsuite/gdb.threads/multi-create.c: In function 'create_function': ../../../master/gdb/testsuite/gdb.threads/multi-create.c:46:39: error: 'PTHREAD_STACK_MIN' undeclared (first use in this function) ../../../master/gdb/testsuite/gdb.threads/multi-create.c:46:39: note: each undeclared identifier is reported only once for each function it appears in ../../../master/gdb/testsuite/gdb.threads/multi-create.c: In function 'main': ../../../master/gdb/testsuite/gdb.threads/multi-create.c:73:39: error: 'PTHREAD_STACK_MIN' undeclared (first use in this function)

  • UNSUPPORTED: gdb.threads/staticthreads.exp: Couldn't compile ../../../master/gdb/testsuite/gdb.threads/staticthreads.c: unrecognized error

    ../../../master/gdb/testsuite/gdb.threads/staticthreads.c: In function 'main':
../../../master/gdb/testsuite/gdb.threads/staticthreads.c:52:37: error: 'PTHREAD_STACK_MIN' undeclared (first use in this function)
../../../master/gdb/testsuite/gdb.threads/staticthreads.c:52:37: note: each undeclared identifier is reported only once for each function it appears in

  • UNSUPPORTED: gdb.threads/create-fail.exp: Couldn't compile ../../../Ferry_Tagscherer/gdb/testsuite/gdb.threads/create-fail.c: unrecognized error

    [...]/gdb.threads/create-fail.c:77: undefined reference to `pthread_attr_setaffinity_np'
[...]/gdb.threads/create-fail.c:83: undefined reference to `pthread_create'

  • UNTESTED: gdb.base/longest-types.exp: longest-types.exp

    ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/longest-types.c:20:8: error: size of array 'buf' is too large

    Also on GNU/Linux.

  • FAIL: gdb.base/jit.exp: PIE: one_jit_test-1: Can't run to main

    (gdb) break main
Breakpoint 1 at 0xb84: file ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/jit-main.c, line 128.
(gdb) run 
Starting program: /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/testsuite/gdb.base/jit-main 
Cannot access memory at address 0x393
Cannot access memory at address 0x38f
(gdb) FAIL: gdb.base/jit.exp: PIE: one_jit_test-1: Can't run to main

    PIE.

    Is the following supposed to terminate in this way?

    (gdb) break main
Breakpoint 1 at 0x675: file ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/attach-pie-noexec.c, line 23.
(gdb) run 
Starting program: /media/erich/home/thomas/tmp/gdb/tschwinge/Ferry_Tagscherer.build/gdb/testsuite/gdb.base/attach-pie-noexec 
Cannot access memory at address 0x6c626172
Cannot access memory at address 0x6c62616e
(gdb) testcase ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/attach-pie-noexec.exp completed in 3 seconds

    IRC, freenode, #hurd, 2013-09-06:

    <gnu_srs1> How to debug a program that works in the shell but Cannot
  access memory at address ... in gdb?
<tschwinge> Build it without -pie -- but that is just a guess of what
  might be going on.
* tschwinge clearly has spent enough time with obscure things to be
    able to make such guesses.
<gnu_srs1> tschwinge: looks like -fPIE is used.
<gnu_srs1> verified: some (all?) executables compiled with -fPIE, -fpie
  and linked with -pie cannot be debugged in gdb :(

  • solib-event stop

    Running ../../../Ferry_Tagscherer/gdb/testsuite/gdb.mi/mi-catch-load.exp ...
PASS: gdb.mi/mi-catch-load.exp: breakpoint at main
PASS: gdb.mi/mi-catch-load.exp: mi runto main
PASS: gdb.mi/mi-catch-load.exp: catch-load: auto-solib-add on
PASS: gdb.mi/mi-catch-load.exp: catch-load: catch load
FAIL: gdb.mi/mi-catch-load.exp: catch-load: solib-event stop
PASS: gdb.mi/mi-catch-load.exp: breakpoint at main
PASS: gdb.mi/mi-catch-load.exp: mi runto main
PASS: gdb.mi/mi-catch-load.exp: catch-unload: auto-solib-add on
PASS: gdb.mi/mi-catch-load.exp: catch-unload: catch unload
FAIL: gdb.mi/mi-catch-load.exp: catch-unload: solib-event stop


*stopped,reason="signal-received",signal-name="SIGSEGV",signal-meaning="Segmentation fault",frame={addr="0x00014add",func="??",args=[],from="/lib/ld.so"},thread-id="4",stopped-threads="all"

  • gdb.base/call-signal-resume.exp

    $ gdb -q gdb/testsuite/gdb.base/call-signals
(gdb) break stop_one
(gdb) r
(gdb) call gen_signal()
(gdb) bt
(gdb) frame [<function called from gdb>]
(gdb) return
(gdb) break handle_signal
(gdb) c
(gdb) c

    kepler.SCHWINGE:

    Breakpoint 2, handle_signal (sig=6) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:28
28      }
(gdb) bt
#0  handle_signal (sig=6) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:28
#1  <signal handler called>
#2  0xb7fde416 in __kernel_vsyscall ()
#3  0xb7dffd96 in kill () at ../sysdeps/unix/syscall-template.S:81
#4  0x0804859c in gen_signal () at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:35
#5  0x08048610 in main () at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:81

    coulomb.SCHWINGE:

    Breakpoint 2, handle_signal (sig=6) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:28
28      }
(gdb) bt
#0  handle_signal (sig=6) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:28
#1  0x010baac2 in trampoline () from /lib/i386-gnu/libc.so.0.3
#2  0x00000006 in ?? ()
#3  0x00000000 in ?? ()

    kepler.SCHWINGE:

    (gdb) c
Continuing.
no signal
[Inferior 1 (process 10401) exited normally]

    coulomb.SCHWINGE:

    (gdb) c
Continuing.
no signal


Program received signal SIGSEGV, Segmentation fault.
0x00000000 in ?? ()
(gdb) bt
#0  0x00000000 in ?? ()
#1  0x01116c28 in _IO_acquire_lock_fct (p=<synthetic pointer>) at libioP.h:905
#2  _IO_puts (str=0x80487e0 "no signal") at ioputs.c:45
#3  0x080486d8 in gen_signal () at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:38
#4  0x0804873d in main () at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/call-signals.c:81

    This is apparently new with the glibc 2.17 upgrade. If not doing the manual gen_signal call, it works fine. TODO.

  • gdb.base/relativedebug.exp

    (gdb) PASS: gdb.base/relativedebug.exp: continue
bt
#0  0x010a1afc in ?? () from /lib/i386-gnu/libc.so.0.3
#1  0x010a23be in mach_msg () from /lib/i386-gnu/libc.so.0.3
#2  0x0126cd98 in msg_sig_post () from /lib/i386-gnu/libhurduser.so.0.3
#3  0x010e2141 in ?? () from /lib/i386-gnu/libc.so.0.3
#4  0x010e23ed in kill () from /lib/i386-gnu/libc.so.0.3
#5  0x010e17f4 in raise () from /lib/i386-gnu/libc.so.0.3
#6  0x010e5b7c in abort () from /lib/i386-gnu/libc.so.0.3
#7  0x08048607 in handler (signo=14) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/relativedebug.c:25
#8  0x010bdac2 in ?? () from /lib/i386-gnu/libc.so.0.3
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb) FAIL: gdb.base/relativedebug.exp: pause found in backtrace

    This is apparently new with the glibc 2.17 upgrade. Previously it said:

    (gdb) PASS: gdb.base/relativedebug.exp: continue
bt
#0  0x0107c85c in ?? () from /lib/i386-gnu/libc.so.0.3
#1  0x0107d069 in mach_msg () from /lib/i386-gnu/libc.so.0.3
#2  0x01220d4f in msg_sig_post () from /lib/i386-gnu/libhurduser.so.0.3
#3  0x010bb683 in ?? () from /lib/i386-gnu/libc.so.0.3
#4  0x010bb8f6 in kill () from /lib/i386-gnu/libc.so.0.3
#5  0x010bad76 in raise () from /lib/i386-gnu/libc.so.0.3
#6  0x010bf029 in abort () from /lib/i386-gnu/libc.so.0.3
#7  0x08048597 in handler (signo=14) at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/relativedebug.c:25
#8  0x01098282 in ?? () from /lib/i386-gnu/libc.so.0.3
#9  0x010bbe5a in sigsuspend () from /lib/i386-gnu/libc.so.0.3
#10 0x0112fee1 in pause () from /lib/i386-gnu/libc.so.0.3
#11 0x080485c5 in main () at ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/relativedebug.c:32
(gdb) PASS: gdb.base/relativedebug.exp: pause found in backtrace

    TODO.

  • gdb.gdb/selftest.exp

    (gdb) PASS: gdb.gdb/selftest.exp: send SIGINT signal to child process
backtrace
#0  0x0146fafc in ?? () from /lib/i386-gnu/libc.so.0.3
#1  0x014703be in mach_msg () from /lib/i386-gnu/libc.so.0.3
#2  0x0163bd98 in msg_sig_post () from /lib/i386-gnu/libhurduser.so.0.3
#3  0x014b0141 in ?? () from /lib/i386-gnu/libc.so.0.3
#4  0x014b03ed in kill () from /lib/i386-gnu/libc.so.0.3
#5  0x082cf471 in _rl_handle_signal (sig=2) at ../../Ferry_Tagscherer/readline/signals.c:221
#6  0x0148bac2 in ?? () from /lib/i386-gnu/libc.so.0.3
Backtrace stopped: previous frame inner to this frame (corrupt stack?)
(gdb) FAIL: gdb.gdb/selftest.exp: backtrace through signal handler

    This is apparently new with the glibc 2.17 upgrade. Previously it said:

    (gdb) PASS: gdb.gdb/selftest.exp: send SIGINT signal to child process
backtrace
#0  0x0144885c in ?? () from /lib/i386-gnu/libc.so.0.3
#1  0x01449069 in mach_msg () from /lib/i386-gnu/libc.so.0.3
#2  0x015ecd4f in msg_sig_post () from /lib/i386-gnu/libhurduser.so.0.3
#3  0x01487683 in ?? () from /lib/i386-gnu/libc.so.0.3
#4  0x014878f6 in kill () from /lib/i386-gnu/libc.so.0.3
#5  0x082cf401 in _rl_handle_signal (sig=2) at ../../Ferry_Tagscherer/readline/signals.c:221
#6  0x01464282 in ?? () from /lib/i386-gnu/libc.so.0.3
#7  0x0144fce3 in ?? () from /lib/i386-gnu/libc.so.0.3
#8  0x0153975b in poll () from /lib/i386-gnu/libc.so.0.3
#9  0x081c91c2 in gdb_wait_for_event (block=1) at ../../Ferry_Tagscherer/gdb/event-loop.c:804
#10 0x081c998f in gdb_do_one_event () at ../../Ferry_Tagscherer/gdb/event-loop.c:402
#11 0x081c9b07 in start_event_loop () at ../../Ferry_Tagscherer/gdb/event-loop.c:431
#12 0x081c2f42 in captured_command_loop (data=data@entry=0x0) at ../../Ferry_Tagscherer/gdb/main.c:260
#13 0x081c0e57 in catch_errors (func=func@entry=0x81c2f30 <captured_command_loop>, func_args=func_args@entry=0x0, errstring=errstring@entry=0x83
5b81b "", mask=mask@entry=6) at ../../Ferry_Tagscherer/gdb/exceptions.c:546
#14 0x081c388c in captured_main (data=data@entry=0x19ff150) at ../../Ferry_Tagscherer/gdb/main.c:1055
#15 0x081c0e57 in catch_errors (func=func@entry=0x81c3130 <captured_main>, func_args=func_args@entry=0x19ff150, errstring=errstring@entry=0x835b
81b "", mask=mask@entry=6) at ../../Ferry_Tagscherer/gdb/exceptions.c:546
#16 0x081c43c0 in gdb_main (args=0x19ff150) at ../../Ferry_Tagscherer/gdb/main.c:1064
#17 0x08099533 in main (argc=5, argv=0x19ff1e8) at ../../Ferry_Tagscherer/gdb/gdb.c:34
(gdb) PASS: gdb.gdb/selftest.exp: backtrace through signal handler

    TODO.

  • gdb.base/restore.exp, gdb.base/store.exp

    Several FAILs, starting with GCC 4.8 usage:

    (gdb) PASS: gdb.base/restore.exp: caller3 calls callee1; return callee now
print l1
$16 = <optimized out>
(gdb) FAIL: gdb.base/restore.exp: caller3 calls callee1; return restored l1 to 32492

    GCC [BZ #55056], id:"20130126202645.GA4888@host2.jankratochvil.net", and maybe id:"CAO2gOZXvCLdaKE2=ZKpjGVGq8A0wQ94-AUo7eKvvWHWncrU yg@mail.gmail.com" look related.

  • gdb.base/default.exp

    shell echo Hi dad!
bash: relocation error: /lib/i386-gnu/libdl.so.2: symbol __libc_lock_self, version GLIBC_PRIVATE not defined in file libc.so.0.3 with link time reference
(gdb) FAIL: gdb.base/default.exp: shell echo Hi dad!

    TODO.

  • gdb.base/exitsignal.exp

    Running ../../../Ferry_Tagscherer/gdb/testsuite/gdb.base/exitsignal.exp ...
PASS: gdb.base/exitsignal.exp: $_exitsignal is void before running
PASS: gdb.base/exitsignal.exp: $_exitcode is void before running
PASS: gdb.base/exitsignal.exp: trigger SIGSEGV
PASS: gdb.base/exitsignal.exp: program terminated with SIGSEGV
FAIL: gdb.base/exitsignal.exp: $_exitsignal is 11 (SIGSEGV) after SIGSEGV.
PASS: gdb.base/exitsignal.exp: $_exitcode is still void after SIGSEGV
PASS: gdb.base/exitsignal.exp: rerun to main
FAIL: gdb.base/exitsignal.exp: $_exitsignal is 11 (SIGSEGV) after restarting the inferior
PASS: gdb.base/exitsignal.exp: $_exitcode is still void after restarting the inferior
PASS: gdb.base/exitsignal.exp: $_exitsignal is void before normal inferior is executed
PASS: gdb.base/exitsignal.exp: $_exitcode is void before normal inferior is executed
PASS: gdb.base/exitsignal.exp: continue until exit
PASS: gdb.base/exitsignal.exp: $_exitcode is zero after normal inferior is executed
PASS: gdb.base/exitsignal.exp: $_exitsignal is still void after normal inferior is executed

    TODO.

  • gdb.arch/i386-prologue.exp

    There are several FAILs, where there are unexpected frames showing up in backtraces, for example. Earlier on, these just FAILed on coulomb.SCHWINGE; since 9939e1314f970c6ba568956148a518ac710a280a..c2853f3d99797a321c37948297441ca6021f719a on kepler.SCHWINGE, too. TODO.

  • libgc GC_find_limit_with_bound SIGSEGVs

    On coulomb.SCHWINGE, in 9939e1314f970c6ba568956148a518ac710a280a..c2853f3d99797a321c37948297441ca6021f719a several PASSes regressed to FAILs:

    Starting program: [...]/gdb/testsuite/gdb.gdb/xgdb -nw -nx -data-directory [...]/gdb/testsuite/../data-directory
[New Thread 13417.5]


Program received signal SIGSEGV, Segmentation fault.
0x0126b961 in GC_find_limit_with_bound () from /usr/lib/i386-gnu/libgc.so.1
(gdb) FAIL: gdb.gdb/complaints.exp: run until breakpoint at captured_command_loop
WARNING: Couldn't test self


Starting program: [...]/gdb/testsuite/gdb.gdb/xgdb -nw -nx -data-directory [...]/gdb/testsuite/../data-directory
[New Thread 13448.5]


Program received signal SIGSEGV, Segmentation fault.
0x0126b961 in GC_find_limit_with_bound () from /usr/lib/i386-gnu/libgc.so.1
(gdb) FAIL: gdb.gdb/python-interrupts.exp: run until breakpoint at captured_command_loop
WARNING: Couldn't test self


Starting program: [...]/gdb/testsuite/gdb.gdb/xgdb -nw -nx -data-directory [...]/gdb/testsuite/../data-directory
[New Thread 13464.3]


Program received signal SIGSEGV, Segmentation fault.
0x0126b961 in GC_find_limit_with_bound () from /usr/lib/i386-gnu/libgc.so.1
(gdb) FAIL: gdb.gdb/python-selftest.exp: run until breakpoint at captured_command_loop
WARNING: Couldn't test self


(gdb) PASS: gdb.gdb/selftest.exp: step into xmalloc call
continue
Continuing.


Program received signal SIGSEGV, Segmentation fault.
0x0126b961 in GC_find_limit_with_bound () from /usr/lib/i386-gnu/libgc.so.1
(gdb) FAIL: gdb.gdb/selftest.exp: xgdb is at prompt

    These are all tests where GDB examines itself; being linked against libgc (new dependency due to new Guile scripting support; all Guile scripting tests PASS). So, probably some bad interaction between GDB and a debuggee that is using libgc; maybe libgc is using SIGSEGV for internal signalling purposes; see the HEURISTIC2 discussion on boehm gc.

    #0  0x0126b961 in GC_find_limit_with_bound () from /usr/lib/i386-gnu/libgc.so.1
#1  0x0126ba2e in GC_find_limit () from /usr/lib/i386-gnu/libgc.so.1
#2  0x0126bb15 in GC_get_stack_base () from /usr/lib/i386-gnu/libgc.so.1
#3  0x011be0ec in scm_init_guile () from /usr/lib/libguile-2.0.so.22
#4  0x081203ba in _initialize_guile () at ../../W._C._Handy/gdb/guile/guile.c:704
#5  0x082dc94d in initialize_all_files () at init.c:291
#6  0x082a3c7f in gdb_init (argv0=0x8563e90 "[...]/gdb/testsuite/gdb.gdb/xgdb") at ../../W._C._Handy/gdb/top.c:1822
#7  0x081da3b8 in captured_main (data=0x1bff164) at ../../W._C._Handy/gdb/main.c:747
#8  0x081d70e9 in catch_errors (func=func@entry=0x81da110 <captured_main>, func_args=func_args@entry=0x1bff164, errstring=errstring@entry=0x837a0e5 "", mask=mask@entry=RETURN_MASK_ALL) at ../../W._C._Handy/gdb/exceptions.c:524
#9  0x081db277 in gdb_main (args=0x1bff164) at ../../W._C._Handy/gdb/main.c:1062
#10 0x0809714b in main (argc=5, argv=0x1bff1f4) at ../../W._C._Handy/gdb/gdb.c:33

    TODO.

TODO.

Open Issues

open issue binutils

open issue gdb

GDB info files SIGSEGV

IRC, freenode, #hurd, 2013-09-07

<rekado> I'm trying to debug pfinet, but I'm not very familiar with gdb.
  Tried to attach to the running pfinet process (built with debug symbols),
  set a breakpoint and ... when I ran "info files" the process segfaulted.
<teythoon> which process segfaults, pfinet or gdb?
<rekado> gdb segfaults.

GDB Watchpoints

IRC, freenode, #hurd, 2013-09-16

<gnu_srs> tschwinge: Is gdb watch known to fail on hurd? It hangs for me
  when logged in via ssh.
<tschwinge> gnu_srs: Don't know about GDB's watch command.  Are you sure it
  is hanging?