Re: [Bug hurd/24110] SS_DISABLE never set in stack_t value returned by sigaltstack

[Svante Signell]

On Mon, 2019-01-28 at 22:43 +0100, Samuel Thibault wrote:
> Svante Signell, le lun. 28 janv. 2019 21:50:50 +0100, a ecrit:
> > Thread 4 hit Breakpoint 2, __GI___sigaltstack (argss=0x3005c84, oss=0x0) at
> > ../sysdeps/mach/hurd/sigaltstack.c:55
> > 55      in ../sysdeps/mach/hurd/sigaltstack.c
> > (gdb) p *argss
> > $9 = {ss_sp = 0x9501c, ss_size = 45028, ss_flags = 0}
> 
> Uh, so that is really so? Maybe check a backtrace here, to see where
> these odd values come from.

(gdb) run
The program being debugged has been started already.
Start it from the beginning? (y or n) y
Starting program: /part1/DEBs/gcc-9/gcc-9-9-20190120-1.1/build/i686-
gnu/libgo/gotest3957/test/a.out 

Thread 4 hit Hardware watchpoint 3: * (void **) 0x25139ac

Old value = <unreadable>
New value = (void *) 0x0
0x022a03a1 in __GI__hurd_thread_sigstate (thread=<optimized out>) at
hurdsig.c:96
96      hurdsig.c: No such file or directory.
(gdb) c
Continuing.
[New Thread 4569.24]

Thread 4 hit Breakpoint 2, __GI___sigaltstack (argss=0x0, oss=0x3005cb4) at
../sysdeps/mach/hurd/sigaltstack.c:55
55      ../sysdeps/mach/hurd/sigaltstack.c: No such file or directory.
(gdb) c
Continuing.

Thread 4 hit Hardware watchpoint 3: * (void **) 0x25139ac

Old value = (void *) 0x0
New value = (void *) 0x9501c
0x022d18b8 in __GI___sigaltstack (argss=0x3005c84, oss=0x0) at
../sysdeps/mach/hurd/sigaltstack.c:51
51      in ../sysdeps/mach/hurd/sigaltstack.c
(gdb) p *argss
$11 = {ss_sp = 0x9501c, ss_size = 45028, ss_flags = 0}

(gdb) thread apply all bt full

Thread 5 (Thread 4569.24):
#0  0x022842ac in mach_msg_trap ()
    at /part2/DEBs/glibc.test/glibc-2.28/build-tree/hurd-i386-
libc/mach/mach_msg_trap.S:2
No locals.
#1  0x02284a56 in __GI___mach_msg (msg=0x3804f00, option=3, send_size=32,
rcv_size=4096, rcv_name=137, timeout=0, 
    notify=0) at msg.c:111
        ret = <optimized out>
#2  0x02285058 in __mach_msg_server_timeout (demux=0x22999f0 <msgport_server>,
max_size=4096, rcv_name=137, option=0, 
    timeout=0) at msgserver.c:150
        request = 0x3804f00
        reply = 0x3805f10
        mr = 0
        __PRETTY_FUNCTION__ = "__mach_msg_server_timeout"
        tmp = <optimized out>
#3  0x02285144 in __mach_msg_server (demux=0x22999f0 <msgport_server>,
max_size=4096, rcv_name=137) at msgserver.c:195
No locals.
#4  0x02299ade in _hurd_msgport_receive () at msgportdemux.c:67
No locals.
#5  0x024b094f in entry_point (self=<optimized out>, start_routine=<optimized
out>, arg=<optimized out>)
    at pt-create.c:62
No locals.
#6  0x00000000 in ?? ()
No symbol table info available.

Thread 4 (Thread 4569.23):
#0  0x022d18b8 in __GI___sigaltstack (argss=0x3005c84, oss=0x0) at
../sysdeps/mach/hurd/sigaltstack.c:51
        s = 0x2513808
        ss = {ss_sp = 0x9501c, ss_size = 45028, ss_flags = 0}
        old = {ss_sp = 0x0, ss_size = 0, ss_flags = <optimized out>}
#1  0x01520893 in runtime.signalstack (p=0x9501c "", n=45028) at
../../../src/libgo/runtime/runtime_c.c:118
        st = {ss_sp = 0x9501c, ss_size = 45028, ss_flags = 0}
#2  0x01995fad in runtime.minitSignalStack () at
../../../src/libgo/go/runtime/signal_unix.go:693
        _g_ = 0x2124040 <runtime.g0>
        st = {ss_sp = 0x0, ss_size = 0, ss_flags = 4}
        _g_ = <optimized out>
        st = <optimized out>
#3  runtime.minitSignals () at ../../../src/libgo/go/runtime/signal_unix.go:676
No locals.
#4  runtime.minit () at ../../../src/libgo/go/runtime/os_gccgo.go:28
No locals.
#5  0x0152016e in runtime_mstart (arg=0x2124540 <runtime.m0>) at
../../../src/libgo/runtime/proc.c:556
        mp = 0x2124540 <runtime.m0>
        gp = 0x2124040 <runtime.g0>
#6  0x0803b57d in main (argc=<optimized out>, argv=<optimized out>) at
../../../src/libgo/runtime/go-main.c:59
No locals.
#7  0x022ba39d in __libc_start_main (main=0x803b4a0 <main>, argc=1,
argv=0x3005da4, init=0x804a8d0 <__libc_csu_init>, 
    fini=0x804a930 <__libc_csu_fini>, rtld_fini=0x10920 <_dl_fini>,
stack_end=0x3005d9c) at ../csu/libc-start.c:339
        result = <optimized out>
#8  0x0803b5b1 in _start ()
No symbol table info available.