Date: Tue, 22 Jan 2019 19:19:51 -0800 From: Mark Millard <marklmi@yahoo.com> To: John Baldwin <jhb@freebsd.org> Cc: "freebsd-ppc@freebsd.org" <freebsd-ppc@FreeBSD.org> Subject: Re: GDB TLS testing [actually running some tests finally but these tests fail] Message-ID: <493AC0BE-3EC6-42B7-B027-FFB6454761B5@yahoo.com> In-Reply-To: <2AAC9738-73BD-475A-888A-252EE853A5C6@yahoo.com> References: <b0f5b62f-54fb-309f-a578-7b4d9e340a55@FreeBSD.org> <19343397-859C-4629-A4A5-B0DCDE25957B@yahoo.com> <AB56B3D1-1762-4115-B7B4-91D4B997F1C4@yahoo.com> <eff896f3-e385-9a12-5132-3884e69689ca@FreeBSD.org> <D0B83B01-5428-42F0-B785-221826AF7EC4@yahoo.com> <a1da2471-535d-1497-ddf3-93aa0d29df59@FreeBSD.org> <5AA68ED2-2615-438B-A6AE-406CBD8E49F7@yahoo.com> <20027C29-0093-4001-A135-23783F8B87F3@yahoo.com> <4048D2A4-7E14-481C-9B5D-00567BCF4463@yahoo.com> <2AAC9738-73BD-475A-888A-252EE853A5C6@yahoo.com>
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On 2019-Jan-22, at 18:32, Mark Millard <marklm at yahoo.com> wrote:
> On 2019-Jan-22, at 17:06, Mark Millard <marklmi at yahoo.com> wrote:
>=20
>=20
>=20
> . . .
> So I'm trying:
>=20
> # git clean -f
> # rm */config.cache */*/config.cache
> # env CPATH=3D/usr/local/include ./configure
> . . .
> # env CPATH=3D/usr/local/include gmake
> . . .
>=20
> in order to try to add paths after the command line -I paths.
>=20
> . . . This looks like it built. I've not used the build yet.
>=20
Looking at a *.core did not go well for my context:
# cc -g -O2 tls_gdb_test.c=20
tls_gdb_test.c:16:2: warning: indirection of non-volatile null pointer =
will be deleted, not trap [-Wnull-dereference]
*(char *)NULL =3D 1;
^~~~~~~~~~~~~
tls_gdb_test.c:16:2: note: consider using __builtin_trap() or qualifying =
pointer with 'volatile'
1 warning generated.
FBSDG5L# ./a.out
main: PID 70304
id =3D 70304 (0x810054020)
Trace/BPT trap (core dumped)
# ppc64_tls_git/gdb/gdb a.out a.out.70304.core=20
GNU gdb (GDB) 8.2.50.20190115-git
Copyright (C) 2019 Free Software Foundation, Inc.
. . .
Reading symbols from a.out...
[New LWP 100166]
Core was generated by `./a.out'.
Program terminated with signal SIGTRAP, Trace/breakpoint trap.
#0 main (ac=3D<optimized out>, av=3D<optimized out>) at =
tls_gdb_test.c:16
16 *(char *)NULL =3D 1;
(gdb) bt
#0 main (ac=3D<optimized out>, av=3D<optimized out>) at =
tls_gdb_test.c:16
(gdb) p id
Cannot find thread-local storage for LWP 100166, executable file =
/root/c_tests/a.out:
Cannot fetch runtime linker structure offsets
(gdb) p &id
Cannot find thread-local storage for LWP 100166, executable file =
/root/c_tests/a.out:
Cannot fetch runtime linker structure offsets
(gdb)=20
Trying running under the gdb variant got stuck with gdb looping =
indefinately:
70322 root 1 103 0 30M 20M 0 CPU2 2 3:12 =
101.06% ppc64_tls_git/gdb/gdb a.out
That was for:
# ppc64_tls_git/gdb/gdb a.out
GNU gdb (GDB) 8.2.50.20190115-git
Copyright (C) 2019 Free Software Foundation, Inc.
. . .
But I was able to ^C to get back to a (gdb) prompt and:
(gdb) p id
Cannot find thread-local storage for LWP 100111 of process 70323, =
executable file /root/c_tests/a.out:
Cannot fetch runtime linker structure offsets
(gdb) p &id
Cannot find thread-local storage for LWP 100111 of process 70323, =
executable file /root/c_tests/a.out:
Cannot fetch runtime linker structure offsets
(gdb) info threads
Id Target Id Frame=20
* 1 LWP 100111 of process 70323 main (ac=3D<optimized out>, =
av=3D<optimized out>) at tls_gdb_test.c:16
So it looks to me to not be working with system-clang based compiles of =
the example
test from the original E-mail.
But, looking around and using stepi ( with display/i $pc ) the code is =
trying a trap instruction
over and over:
(gdb) disass
Dump of assembler code for function main:
0x0000000010000adc <+0>: mflr r0
0x0000000010000ae0 <+4>: std r31,-8(r1)
0x0000000010000ae4 <+8>: std r0,16(r1)
0x0000000010000ae8 <+12>: stdu r1,-128(r1)
0x0000000010000aec <+16>: mr r31,r1
0x0000000010000af0 <+20>: std r30,112(r31)
0x0000000010000af4 <+24>: bl 0x10000600 =
<00000017.plt_call.getpid@@FBSD_1.0>
0x0000000010000af8 <+28>: ld r2,40(r1)
0x0000000010000afc <+32>: mr r4,r3
0x0000000010000b00 <+36>: addis r3,r2,-2
0x0000000010000b04 <+40>: addi r3,r3,31952
0x0000000010000b08 <+44>: bl 0x100005e0 =
<00000017.plt_call.printf@@FBSD_1.0>
0x0000000010000b0c <+48>: ld r2,40(r1)
0x0000000010000b10 <+52>: bl 0x10000600 =
<00000017.plt_call.getpid@@FBSD_1.0>
0x0000000010000b14 <+56>: ld r2,40(r1)
0x0000000010000b18 <+60>: mr r30,r3
0x0000000010000b1c <+64>: nop
0x0000000010000b20 <+68>: nop
0x0000000010000b24 <+72>: addi r3,r13,4096
0x0000000010000b28 <+76>: nop
0x0000000010000b2c <+80>: addis r3,r3,0
0x0000000010000b30 <+84>: mr r4,r30
0x0000000010000b34 <+88>: stw r30,-32768(r3)
0x0000000010000b38 <+92>: addi r5,r3,-32768
0x0000000010000b3c <+96>: addis r3,r2,-2
0x0000000010000b40 <+100>: addi r3,r3,31966
0x0000000010000b44 <+104>: bl 0x100005e0 =
<00000017.plt_call.printf@@FBSD_1.0>
0x0000000010000b48 <+108>: ld r2,40(r1)
0x0000000010000b4c <+112>: nop
0x0000000010000b50 <+116>: nop
0x0000000010000b54 <+120>: ld r3,-32728(r2)
0x0000000010000b58 <+124>: ld r4,-32720(r2)
0x0000000010000b5c <+128>: lwz r3,0(r3)
0x0000000010000b60 <+132>: cmplwi r3,0
0x0000000010000b64 <+136>: ld r3,0(r4)
0x0000000010000b68 <+140>: bne 0x10000b8c <main+176>
0x0000000010000b6c <+144>: lwz r4,8(r3)
0x0000000010000b70 <+148>: addi r5,r4,-1
0x0000000010000b74 <+152>: cmpwi r4,0
0x0000000010000b78 <+156>: stw r5,8(r3)
0x0000000010000b7c <+160>: bgt 0x10000b98 <main+188>
0x0000000010000b80 <+164>: bl 0x10000620 =
<00000017.plt_call.__srget@@FBSD_1.0>
0x0000000010000b84 <+168>: ld r2,40(r1)
=3D> 0x0000000010000b88 <+172>: trap
0x0000000010000b8c <+176>: bl 0x10000640 =
<00000017.plt_call.getc@@FBSD_1.0>
0x0000000010000b90 <+180>: ld r2,40(r1)
0x0000000010000b94 <+184>: trap
0x0000000010000b98 <+188>: ld r4,0(r3)
0x0000000010000b9c <+192>: addi r4,r4,1
0x0000000010000ba0 <+196>: std r4,0(r3)
0x0000000010000ba4 <+200>: trap
0x0000000010000ba8 <+204>: .long 0x0
0x0000000010000bac <+208>: .long 0x0
0x0000000010000bb0 <+212>: .long 0x0
End of assembler dump.
I do not know if my context being a head -r341836 variant might =
contribute
(too old?).
I may try some fairly modern gcc* variant(s) instead to see if that =
makes a difference.
For reference: the compile of the test was based on using -g -O2 .
=3D=3D=3D
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)
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