Date: Fri, 16 Nov 2018 18:49:40 -0800 From: Mark Millard <marklmi@yahoo.com> To: Jan Beich <jbeich@FreeBSD.org> Cc: ports-list freebsd <freebsd-ports@freebsd.org> Subject: Re: ports head -r487783: on armv7 x11/pixman fails to build: /usr/bin/ld: error: can't create dynamic relocation R_ARM_V4BX against local symbol in readonly segment; recompile object files with -fPIC Message-ID: <F744DFE3-DB37-4A95-8C8E-DC1A5507D402@yahoo.com> In-Reply-To: <908FD96A-9F8F-4477-8E2F-2C97D49AF35E@yahoo.com> References: <A76D7D49-E36E-4665-AA4B-D083CCF7D57B@yahoo.com> <a7m8-loy5-wny@FreeBSD.org> <03FFE5BB-777D-40D3-9AA3-C8C359BE1F2B@yahoo.com> <908FD96A-9F8F-4477-8E2F-2C97D49AF35E@yahoo.com>
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On 2018-Nov-16, at 18:15, Mark Millard <marklmi at yahoo.com> wrote:
>=20
> I finally figured out parts of the issue, I think.
> At least how the V_ARM_V4BX use is getting there
> despite lld's status for handling it . . .
>=20
> On armv7:
>=20
> # more test_bx_lr.S
> .text
> .arch armv6
> .object_arch armv4
> .arm
> .altmacro
> .p2align 2
> .func fname
> .global fname
> .hidden fname
> .type fname, %function
> fname:
> bx lr
>=20
> (I got those lines from the failing port's .S files,
> including includes. Note the .object_arch armv4 use
> and the forced armv6, not armv7.)
For reference relative to the use of .object_arch armv4 :
# grep -r object_arch =
/wrkdirs/usr/ports/x11/pixman/work/pixman-0.34.0/pixman/ | more
=
/wrkdirs/usr/ports/x11/pixman/work/pixman-0.34.0/pixman/pixman-arm-neon-as=
m.S: .object_arch armv4
=
/wrkdirs/usr/ports/x11/pixman/work/pixman-0.34.0/pixman/pixman-arm-simd-as=
m-scaled.S: .object_arch armv4
=
/wrkdirs/usr/ports/x11/pixman/work/pixman-0.34.0/pixman/pixman-arm-neon-as=
m-bilinear.S:.object_arch armv4
=
/wrkdirs/usr/ports/x11/pixman/work/pixman-0.34.0/pixman/pixman-arm-simd-as=
m.S: .object_arch armv4
Without .object_arch armv4 the assembler involved does not output
the V_ARM_V4BX *ABS* relocation records (adjusted the small example):
# objdump -x test_bx_lr.o | more
test_bx_lr.o: file format elf32-littlearm
test_bx_lr.o
architecture: arm, flags 0x00000010:
HAS_SYMS
start address 0x00000000
private flags =3D 5000000: [Version5 EABI]
Sections:
Idx Name Size VMA LMA File off Algn
0 .text 00000004 00000000 00000000 00000034 2**2
CONTENTS, ALLOC, LOAD, READONLY, CODE
1 .data 00000000 00000000 00000000 00000038 2**0
CONTENTS, ALLOC, LOAD, DATA
2 .bss 00000000 00000000 00000000 00000038 2**0
ALLOC
3 .ARM.attributes 0000001b 00000000 00000000 00000038 2**0
CONTENTS, READONLY
SYMBOL TABLE:
00000000 l d .text 00000000 .text
00000000 l d .data 00000000 .data
00000000 l d .bss 00000000 .bss
00000000 l d .ARM.attributes 00000000 .ARM.attributes
00000000 g F .text 00000000 .hidden fname
> # clang -target armv7-unknown-freebsd13.0-gnueabihf -O -pipe =
-no-integrated-as -MT test_bx_lr.lo -MD -MP -MF test_bx_lr.Tpo -c =
test_bx_lr.S -fPIC -DPIC -o test_bx_lr.o
>=20
> (The -target is not necessary. I just choose to be explicit.)
>=20
> # objdump -x test_bx_lr.o | more
>=20
> test_bx_lr.o: file format elf32-littlearm
> test_bx_lr.o
> architecture: armv4, flags 0x00000011:
> HAS_RELOC, HAS_SYMS
> start address 0x00000000
> private flags =3D 5000000: [Version5 EABI]
>=20
> Sections:
> Idx Name Size VMA LMA File off Algn
> 0 .text 00000004 00000000 00000000 00000034 2**2
> CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE
> 1 .data 00000000 00000000 00000000 00000038 2**0
> CONTENTS, ALLOC, LOAD, DATA
> 2 .bss 00000000 00000000 00000000 00000038 2**0
> ALLOC
> 3 .ARM.attributes 0000001b 00000000 00000000 00000038 2**0
> CONTENTS, READONLY
> SYMBOL TABLE:
> 00000000 l d .text 00000000 .text
> 00000000 l d .data 00000000 .data
> 00000000 l d .bss 00000000 .bss
> 00000000 l d .ARM.attributes 00000000 .ARM.attributes
> 00000000 g F .text 00000000 .hidden fname
>=20
>=20
> RELOCATION RECORDS FOR [.text]:
> OFFSET TYPE VALUE=20
> 00000000 R_ARM_V4BX *ABS*
>=20
>=20
> truss for that cc command reports looking in many
> places for as, finally finding /usr/local/bin/as :
>=20
> access("/usr/bin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) =
ERR#2 'No such file or directory'
> access("/usr/bin/as",X_OK|R_OK) ERR#2 'No such =
file or directory'
>=20
> (Note: based on WITHOUT_BINUTILS=3D for buildworld the above would =
normally
> not be found. But for WITH_BINUTILS=3D the host as would be found.)
>=20
> access("/sbin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) ERR#2 =
'No such file or directory'
> access("/bin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) ERR#2 =
'No such file or directory'
> access("/usr/sbin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) =
ERR#2 'No such file or directory'
> access("/usr/bin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) =
ERR#2 'No such file or directory'
> =
access("/usr/local/sbin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK)=
ERR#2 'No such file or directory'
> =
access("/usr/local/bin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) =
ERR#2 'No such file or directory'
> =
access("/usr/home/markmi/bin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|=
R_OK) ERR#2 'No such file or directory'
> access("/sbin/as",X_OK|R_OK) ERR#2 'No such file or =
directory'
> access("/bin/as",X_OK|R_OK) ERR#2 'No such file or =
directory'
> access("/usr/sbin/as",X_OK|R_OK) ERR#2 'No such file or =
directory'
> access("/usr/bin/as",X_OK|R_OK) ERR#2 'No such =
file or directory'
> access("/usr/local/sbin/as",X_OK|R_OK) ERR#2 'No such =
file or directory'
> access("/usr/local/bin/as",X_OK|R_OK) =3D 0 (0x0)
>=20
> (Note the /usr/home/markmi/bin/armv7-unknown-freebsd13.0-gnueabihf-as =
attempt
> before the one actually found and used. I would not have guessed the
> need to worry about such a place.)
>=20
> Then follows:
>=20
> fstatat(AT_FDCWD,"/usr/local/bin/as",{ mode=3D-r-xr-xr-x =
,inode=3D80287,size=3D21817416,blksize=3D32768 },0x0) =3D 0 (0x0)
> __sysctl(0xbfbfe020,0x2,0xbfbfe018,0xbfbfe01c,0xe,0x236c9140) =3D 0 =
(0x0)
> access("/usr/bin/clang",F_OK) =3D 0 (0x0)
> vfork() =3D 61461 =
(0xf015)
> wait4(61461,{ EXITED,val=3D0 },0x0,0x0) =3D 61461 =
(0xf015)
> access("/usr/local/bin/as",F_OK) =3D 0 (0x0)
> vfork() =3D 61462 =
(0xf016)
> wait4(61462,{ EXITED,val=3D0 },0x0,0x0) =3D 61462 =
(0xf016)
> access("/tmp/test_bx_lr-0c7bf8.s",W_OK) =3D 0 (0x0)
> fstatat(AT_FDCWD,"/tmp/test_bx_lr-0c7bf8.s",{ mode=3D-rw-r--r-- =
,inode=3D802647,size=3D210,blksize=3D32768 },0x0) =3D 0 (0x0)
> fstatat(AT_FDCWD,"/tmp/test_bx_lr-0c7bf8.s",{ mode=3D-rw-r--r-- =
,inode=3D802647,size=3D210,blksize=3D32768 },AT_SYMLINK_NOFOLLOW) =3D 0 =
(0x0)
> fstatat(AT_FDCWD,"/tmp/test_bx_lr-0c7bf8.s",{ mode=3D-rw-r--r-- =
,inode=3D802647,size=3D210,blksize=3D32768 },AT_SYMLINK_NOFOLLOW) =3D 0 =
(0x0)
> unlink("/tmp/test_bx_lr-0c7bf8.s") =3D 0 (0x0)
>=20
> llvm/clang is not providing the assembler used for -no-integrated-as .
> This would appear to imply that a system without ports or other such
> can not use -no-integrated-as with clang for buildworld buildkernel.
>=20
> In my normal armv7 command line context the above ends up using:
>=20
> # /usr/local/bin/as -v
> GNU assembler version 2.30 (armv7-portbld-freebsd13.0) using BFD =
version (GNU Binutils) 2.30
>=20
> So a GNU toolchain's as is actually in control of what goes in
> the .o file in many contexts. It is not clear that all the
> alternatives are equivalent for R_ARM_V4BX being generated
> or not.
>=20
>=20
> Simplifying the command (but still showing target):
>=20
> # clang -target armv7-unknown-freebsd13.0-gnueabihf -pipe =
-no-integrated-as -c test_bx_lr.S -o test_bx_lr.o
>=20
> # objdump -x test_bx_lr.o | more
>=20
> test_bx_lr.o: file format elf32-littlearm
> test_bx_lr.o
> architecture: armv4, flags 0x00000011:
> HAS_RELOC, HAS_SYMS
> start address 0x00000000
> private flags =3D 5000000: [Version5 EABI]
>=20
> Sections:
> Idx Name Size VMA LMA File off Algn
> 0 .text 00000004 00000000 00000000 00000034 2**2
> CONTENTS, ALLOC, LOAD, RELOC, READONLY, CODE
> 1 .data 00000000 00000000 00000000 00000038 2**0
> CONTENTS, ALLOC, LOAD, DATA
> 2 .bss 00000000 00000000 00000000 00000038 2**0
> ALLOC
> 3 .ARM.attributes 0000001b 00000000 00000000 00000038 2**0
> CONTENTS, READONLY
> SYMBOL TABLE:
> 00000000 l d .text 00000000 .text
> 00000000 l d .data 00000000 .data
> 00000000 l d .bss 00000000 .bss
> 00000000 l d .ARM.attributes 00000000 .ARM.attributes
> 00000000 g F .text 00000000 .hidden fname
>=20
>=20
> RELOCATION RECORDS FOR [.text]:
> OFFSET TYPE VALUE=20
> 00000000 R_ARM_V4BX *ABS*
>=20
>=20
> Without the -no-integrated-as the notation in the file is rejected,
> with "unknown directive" for .func .
>=20
>=20
>=20
> Using poudriere bulk with -i and installing binutils in the
> session, I see the same inside my amd64->armv7 cross build
> environment. So there still is the question of how R_ARM_V4BX
> is handled by various lld's in various contexts. (Or whatever
> linker is being used if it is not lld.)
>=20
> Back to amd64 land . . .
>=20
> Renaming the existing as files so we can see all the places
> searched before not-found is declared (on amd64 with -target
> specified):
>=20
> access("/usr/bin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) =
ERR#2 'No such file or directory'
> access("/usr/bin/as",X_OK|R_OK) ERR#2 'No such =
file or directory'
> access("/usr/bin/x86_64-unknown-freebsd13.0-as",X_OK|R_OK) ERR#2 'No =
such file or directory'
> access("/sbin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) ERR#2 =
'No such file or directory'
> access("/bin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) ERR#2 =
'No such file or directory'
> access("/usr/sbin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) =
ERR#2 'No such file or directory'
> access("/usr/bin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) =
ERR#2 'No such file or directory'
> =
access("/usr/local/sbin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK)=
ERR#2 'No such file or directory'
> =
access("/usr/local/bin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|R_OK) =
ERR#2 'No such file or directory'
> =
access("/usr/home/markmi/bin/armv7-unknown-freebsd13.0-gnueabihf-as",X_OK|=
R_OK) ERR#2 'No such file or directory'
> access("/sbin/as",X_OK|R_OK) ERR#2 'No such file or =
directory'
> access("/bin/as",X_OK|R_OK) ERR#2 'No such file or =
directory'
> access("/usr/sbin/as",X_OK|R_OK) ERR#2 'No such file or =
directory'
> access("/usr/bin/as",X_OK|R_OK) ERR#2 'No such =
file or directory'
> access("/usr/local/sbin/as",X_OK|R_OK) ERR#2 'No such =
file or directory'
> access("/usr/local/bin/as",X_OK|R_OK) ERR#2 'No such file or =
directory'
> access("/usr/home/markmi/bin/as",X_OK|R_OK) ERR#2 'No such file or =
directory'
> access("/sbin/x86_64-unknown-freebsd13.0-as",X_OK|R_OK) ERR#2 'No such =
file or directory'
> access("/bin/x86_64-unknown-freebsd13.0-as",X_OK|R_OK) ERR#2 'No such =
file or directory'
> access("/usr/sbin/x86_64-unknown-freebsd13.0-as",X_OK|R_OK) ERR#2 'No =
such file or directory'
> access("/usr/bin/x86_64-unknown-freebsd13.0-as",X_OK|R_OK) ERR#2 'No =
such file or directory'
> access("/usr/local/sbin/x86_64-unknown-freebsd13.0-as",X_OK|R_OK) =
ERR#2 'No such file or directory'
> access("/usr/local/bin/x86_64-unknown-freebsd13.0-as",X_OK|R_OK) ERR#2 =
'No such file or directory'
> access("/usr/home/markmi/bin/x86_64-unknown-freebsd13.0-as",X_OK|R_OK) =
ERR#2 'No such file or directory'
>=20
> (Note: It actually explicitly tries to use the x86_64 assembler if it
> does not find an armv7 or a generically pathed one. The generically
> pathed ones would normally also be x86_64 ones.)
>=20
>=20
> Another thing of note (using aarch64 as an example):
>=20
> /usr/local/aarch64-unknown-freebsd13.0/bin/as
>=20
> does not appear to be someplace that clang would find as
> but is a place devel/aarch64-binutils puts one.
=3D=3D=3D
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)
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