* [PATCH] ia64: fix dl-sysdep miscompilation on gcc-10
@ 2020-05-16 13:53 slyich--- via Libc-alpha
2020-05-20 19:45 ` Adhemerval Zanella via Libc-alpha
0 siblings, 1 reply; 6+ messages in thread
From: slyich--- via Libc-alpha @ 2020-05-16 13:53 UTC (permalink / raw)
To: libc-alpha; +Cc: Sergei Trofimovich
From: Sergei Trofimovich <slyfox@gentoo.org>
gcc-10 enabled -fno-common by default. This caused glibc link failure:
```
$ ia64-unknown-linux-gnu-gcc -pipe -O2 -nostdlib -nostartfiles \
-static -o .../elf/sln ...
libc.a(dl-support.o): in function `setup_vdso':
glibc-2.31/elf/setup-vdso.h:116:(.text+0x1322):
relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
```
The difference between gcc-9 and gcc-10 is the way relocation is
generated for ia64-specific symbol '_dl_sysinfo_break', defined as:
```c
32 #ifndef __ASSEMBLER__
33 /* Don't declare this as a function---we want it's entry-point, not
34 it's function descriptor... */
35 extern int _dl_sysinfo_break attribute_hidden;
36 # define DL_SYSINFO_DEFAULT ((uintptr_t) &_dl_sysinfo_break)
37 # define DL_SYSINFO_IMPLEMENTATION \
38 asm (".text\n\t" \
39 ".hidden _dl_sysinfo_break\n\t" \
40 ".proc _dl_sysinfo_break\n\t" \
```
Note: it's declared as ".sdata" (defined nearby GOT) but assumed
to be defined in ".text" as it's really a direct function address.
As a result generated relocation changed from:
from `GPREL64I`:
```
1390: 05 00 84 1e 98 11 [MLX] st8 [r15]=r33
1391: GPREL64I .text
1396: 00 00 00 00 00 e0 movl r15=0x0;;
139c: 01 00 00 60
13a0: 0b 78 04 1e 00 20 [MMI] add r15=r1,r15;;
```
to `GPREL22`:
```
if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
1320: 0b 80 00 1c 18 10 [MMI] ld8 r16=[r14];;
1322: GPREL22 .text
1326: 00 08 3d 30 23 e0 st8 [r15]=r33
132c: 01 08 00 90 addl r15=0,r1;;
```
This change explicitly declares symbol to be in ".text" section.
That allows gcc to generate far relocations.
Regression tested on glibc-master and gcc-10.1.0 on rx3600.
Bug: https://bugs.gentoo.org/723268
Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
---
sysdeps/unix/sysv/linux/ia64/dl-sysdep.h | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h b/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h
index 78fa6dd2c9..e526e02ff4 100644
--- a/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h
+++ b/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h
@@ -32,7 +32,9 @@
#ifndef __ASSEMBLER__
/* Don't declare this as a function---we want it's entry-point, not
it's function descriptor... */
-extern int _dl_sysinfo_break attribute_hidden;
+/* Use section ".text" to force far GPREL64 relocation instead of
+ GPREL22 . */
+extern int _dl_sysinfo_break attribute_hidden __attribute__((section(".text")));
# define DL_SYSINFO_DEFAULT ((uintptr_t) &_dl_sysinfo_break)
# define DL_SYSINFO_IMPLEMENTATION \
asm (".text\n\t" \
--
2.26.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH] ia64: fix dl-sysdep miscompilation on gcc-10
2020-05-16 13:53 [PATCH] ia64: fix dl-sysdep miscompilation on gcc-10 slyich--- via Libc-alpha
@ 2020-05-20 19:45 ` Adhemerval Zanella via Libc-alpha
2020-05-31 19:34 ` Sergei Trofimovich via Libc-alpha
0 siblings, 1 reply; 6+ messages in thread
From: Adhemerval Zanella via Libc-alpha @ 2020-05-20 19:45 UTC (permalink / raw)
To: libc-alpha
On 16/05/2020 10:53, slyich--- via Libc-alpha wrote:
> From: Sergei Trofimovich <slyfox@gentoo.org>
>
> gcc-10 enabled -fno-common by default. This caused glibc link failure:
>
> ```
> $ ia64-unknown-linux-gnu-gcc -pipe -O2 -nostdlib -nostartfiles \
> -static -o .../elf/sln ...
> libc.a(dl-support.o): in function `setup_vdso':
> glibc-2.31/elf/setup-vdso.h:116:(.text+0x1322):
> relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
> ```
I can't reproduce it with master (b6ad64b907ab00) with GCC 10.1.1 20200520.
(built using build-many-glibcs.py). I tried to explicit use -fno-common on
CFLAGS. Are you sing a non default compiler option?
>
> The difference between gcc-9 and gcc-10 is the way relocation is
> generated for ia64-specific symbol '_dl_sysinfo_break', defined as:
>
> ```c
> 32 #ifndef __ASSEMBLER__
> 33 /* Don't declare this as a function---we want it's entry-point, not
> 34 it's function descriptor... */
> 35 extern int _dl_sysinfo_break attribute_hidden;
> 36 # define DL_SYSINFO_DEFAULT ((uintptr_t) &_dl_sysinfo_break)
> 37 # define DL_SYSINFO_IMPLEMENTATION \
> 38 asm (".text\n\t" \
> 39 ".hidden _dl_sysinfo_break\n\t" \
> 40 ".proc _dl_sysinfo_break\n\t" \
> ```
>
> Note: it's declared as ".sdata" (defined nearby GOT) but assumed
> to be defined in ".text" as it's really a direct function address.
>
> As a result generated relocation changed from:
>
> from `GPREL64I`:
>
> ```
> 1390: 05 00 84 1e 98 11 [MLX] st8 [r15]=r33
> 1391: GPREL64I .text
> 1396: 00 00 00 00 00 e0 movl r15=0x0;;
> 139c: 01 00 00 60
> 13a0: 0b 78 04 1e 00 20 [MMI] add r15=r1,r15;;
> ```
>
> to `GPREL22`:
>
> ```
> if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
>
> 1320: 0b 80 00 1c 18 10 [MMI] ld8 r16=[r14];;
> 1322: GPREL22 .text
> 1326: 00 08 3d 30 23 e0 st8 [r15]=r33
> 132c: 01 08 00 90 addl r15=0,r1;;
> ```
>
> This change explicitly declares symbol to be in ".text" section.
> That allows gcc to generate far relocations.
>
> Regression tested on glibc-master and gcc-10.1.0 on rx3600.
The rationale is sound, but the trick to define a function pointer a
data variable on text sections seems hacky and fragile. I still think
it could be a fix, but I think we should refactor and simplify
the over-enginnering of NEED_DL_SYSINFO/USE_DL_SYSINFO.
>
> Bug: https://bugs.gentoo.org/723268
> Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
> ---
> sysdeps/unix/sysv/linux/ia64/dl-sysdep.h | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h b/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h
> index 78fa6dd2c9..e526e02ff4 100644
> --- a/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h
> +++ b/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h
> @@ -32,7 +32,9 @@
> #ifndef __ASSEMBLER__
> /* Don't declare this as a function---we want it's entry-point, not
> it's function descriptor... */
> -extern int _dl_sysinfo_break attribute_hidden;
> +/* Use section ".text" to force far GPREL64 relocation instead of
> + GPREL22 . */
> +extern int _dl_sysinfo_break attribute_hidden __attribute__((section(".text")));
> # define DL_SYSINFO_DEFAULT ((uintptr_t) &_dl_sysinfo_break)
> # define DL_SYSINFO_IMPLEMENTATION \
> asm (".text\n\t" \
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ia64: fix dl-sysdep miscompilation on gcc-10
2020-05-20 19:45 ` Adhemerval Zanella via Libc-alpha
@ 2020-05-31 19:34 ` Sergei Trofimovich via Libc-alpha
2020-05-31 21:40 ` Sergei Trofimovich via Libc-alpha
0 siblings, 1 reply; 6+ messages in thread
From: Sergei Trofimovich via Libc-alpha @ 2020-05-31 19:34 UTC (permalink / raw)
To: Adhemerval Zanella via Libc-alpha
[-- Attachment #1: Type: text/plain, Size: 8226 bytes --]
On Wed, 20 May 2020 16:45:03 -0300
Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org> wrote:
> On 16/05/2020 10:53, slyich--- via Libc-alpha wrote:
> > From: Sergei Trofimovich <slyfox@gentoo.org>
> >
> > gcc-10 enabled -fno-common by default. This caused glibc link failure:
> >
> > ```
> > $ ia64-unknown-linux-gnu-gcc -pipe -O2 -nostdlib -nostartfiles \
> > -static -o .../elf/sln ...
> > libc.a(dl-support.o): in function `setup_vdso':
> > glibc-2.31/elf/setup-vdso.h:116:(.text+0x1322):
> > relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> > ```
>
> I can't reproduce it with master (b6ad64b907ab00) with GCC 10.1.1 20200520.
> (built using build-many-glibcs.py). I tried to explicit use -fno-common on
> CFLAGS. Are you sing a non default compiler option?
My apologies. Missed your email.
The CFLAGS options should be default. Full command is:
"""
ia64-unknown-linux-gnu-gcc -pipe -fdiagnostics-show-option -Wall -Wextra -Wstack-protector -O2 -Wl,-O1 -Wl,--as-needed -Wl,--hash-style=gnu dl-support.c -c -std=gnu11 -fgnu89-inline -pipe -fdiagnostics-show-option -Wall -Wextra -Wstack-protector -O2 -Wall -Wwrite-strings -Wundef -fmerge-all-constants -frounding-math -fno-stack-protector -Wstrict-prototypes -Wold-style-definition -fmath-errno -fpie -ftls-model=initial-exec -U_FORTIFY_SOURCE -I../include -I/tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf -I/tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl -I../sysdeps/unix/sysv/linux/ia64 -I../sysdeps/ia64/nptl -I../sysdeps/unix/sysv/linux/wordsize-64 -I../sysdeps/unix/sysv/linux/include -I../sysdeps/unix/sysv/linux -I../sysdeps/nptl -I../sysdeps/pthread -I../sysdeps/gnu -I../sysdeps/unix/inet -I../sysdeps/unix/sysv -I../sysdeps/unix -I../sysdeps/posix -I../sysdeps/ia64/fpu -I../sysdeps/ia64 -I../sysdeps/wordsize-64 -I../sysdeps/ieee754/float128 -I../sysdeps/ieee754/ldbl-96/include -I../sysdeps/ieee754/ldbl-96 -I../sysdeps/ieee754/dbl-64 -I../sysdeps/ieee754/flt-32 -I../sysdeps/ieee754 -I../sysdeps/generic -I.. -I../libio -I. -nostdinc -isystem /usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include -isystem /usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include-fixed -isystem /usr/ia64-unknown-linux-gnu/usr/include -D_LIBC_REENTRANT -include /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/libc-modules.h -DMODULE_NAME=libc -include ../include/libc-symbols.h -DPIC -DTOP_NAMESPACE=glibc -o /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o -MD -MP -MF /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o.dt -MT /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o
"""
Might be an effect of default --enable-default-pie --enable-default-ssp.
Or an effect of applied GCC patch: https://gcc.gnu.org/PR84553
I can try to extract smaller .c example that generates unlinkable
GPREL22 against cross-section symbols if it's useful.
$ LANG=C ia64-unknown-linux-gnu-gcc -v
# Using built-in specs.
COLLECT_GCC=/usr/bin/ia64-unknown-linux-gnu-gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/ia64-unknown-linux-gnu/10.1.0/lto-wrapper
Target: ia64-unknown-linux-gnu
Configured with: /tmp/portage-tmpdir/portage/cross-ia64-unknown-linux-gnu/gcc-10.1.0/work/gcc-10.1.0/configure --host=x86_64-pc-linux-gnu --target=ia64-unknown-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/ia64-unknown-linux-gnu/gcc-bin/10.1.0 --includedir=/usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include --datadir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0 --mandir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/man --infodir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/info --with-gxx-include-dir=/usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include/g++-v10 --with-python-dir=/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/python --enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 10.1.0 p1' --disable-esp --enable-libstdcxx-time --enable-poison-system-directories --with-sysroot=/usr/ia64-unknown-linux-gnu --disable-bootstrap --enable-__cxa_atexit --enable-clocale=gnu --disable-multilib --disable-altivec --disable-fixed-point --enable-libgomp --disable-libmudflap --disable-libssp --disable-libada --disable-systemtap --disable-vtable-verify --disable-libvtv --without-zstd --enable-lto --without-isl --disable-libsanitizer --enable-default-pie --enable-default-ssp
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 10.1.0 (Gentoo 10.1.0 p1)
> >
> > The difference between gcc-9 and gcc-10 is the way relocation is
> > generated for ia64-specific symbol '_dl_sysinfo_break', defined as:
> >
> > ```c
> > 32 #ifndef __ASSEMBLER__
> > 33 /* Don't declare this as a function---we want it's entry-point, not
> > 34 it's function descriptor... */
> > 35 extern int _dl_sysinfo_break attribute_hidden;
> > 36 # define DL_SYSINFO_DEFAULT ((uintptr_t) &_dl_sysinfo_break)
> > 37 # define DL_SYSINFO_IMPLEMENTATION \
> > 38 asm (".text\n\t" \
> > 39 ".hidden _dl_sysinfo_break\n\t" \
> > 40 ".proc _dl_sysinfo_break\n\t" \
> > ```
> >
> > Note: it's declared as ".sdata" (defined nearby GOT) but assumed
> > to be defined in ".text" as it's really a direct function address.
> >
> > As a result generated relocation changed from:
> >
> > from `GPREL64I`:
> >
> > ```
> > 1390: 05 00 84 1e 98 11 [MLX] st8 [r15]=r33
> > 1391: GPREL64I .text
> > 1396: 00 00 00 00 00 e0 movl r15=0x0;;
> > 139c: 01 00 00 60
> > 13a0: 0b 78 04 1e 00 20 [MMI] add r15=r1,r15;;
> > ```
> >
> > to `GPREL22`:
> >
> > ```
> > if (GLRO(dl_sysinfo) == DL_SYSINFO_DEFAULT)
> >
> > 1320: 0b 80 00 1c 18 10 [MMI] ld8 r16=[r14];;
> > 1322: GPREL22 .text
> > 1326: 00 08 3d 30 23 e0 st8 [r15]=r33
> > 132c: 01 08 00 90 addl r15=0,r1;;
> > ```
> >
> > This change explicitly declares symbol to be in ".text" section.
> > That allows gcc to generate far relocations.
> >
> > Regression tested on glibc-master and gcc-10.1.0 on rx3600.
>
> The rationale is sound, but the trick to define a function pointer a
> data variable on text sections seems hacky and fragile. I still think
> it could be a fix, but I think we should refactor and simplify
> the over-enginnering of NEED_DL_SYSINFO/USE_DL_SYSINFO.
>
> >
> > Bug: https://bugs.gentoo.org/723268
> > Signed-off-by: Sergei Trofimovich <slyfox@gentoo.org>
> > ---
> > sysdeps/unix/sysv/linux/ia64/dl-sysdep.h | 4 +++-
> > 1 file changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h b/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h
> > index 78fa6dd2c9..e526e02ff4 100644
> > --- a/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h
> > +++ b/sysdeps/unix/sysv/linux/ia64/dl-sysdep.h
> > @@ -32,7 +32,9 @@
> > #ifndef __ASSEMBLER__
> > /* Don't declare this as a function---we want it's entry-point, not
> > it's function descriptor... */
> > -extern int _dl_sysinfo_break attribute_hidden;
> > +/* Use section ".text" to force far GPREL64 relocation instead of
> > + GPREL22 . */
> > +extern int _dl_sysinfo_break attribute_hidden __attribute__((section(".text")));
> > # define DL_SYSINFO_DEFAULT ((uintptr_t) &_dl_sysinfo_break)
> > # define DL_SYSINFO_IMPLEMENTATION \
> > asm (".text\n\t" \
> >
--
Sergei
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ia64: fix dl-sysdep miscompilation on gcc-10
2020-05-31 19:34 ` Sergei Trofimovich via Libc-alpha
@ 2020-05-31 21:40 ` Sergei Trofimovich via Libc-alpha
2020-06-05 18:44 ` Adhemerval Zanella via Libc-alpha
0 siblings, 1 reply; 6+ messages in thread
From: Sergei Trofimovich via Libc-alpha @ 2020-05-31 21:40 UTC (permalink / raw)
To: Adhemerval Zanella via Libc-alpha
[-- Attachment #1: Type: text/plain, Size: 12326 bytes --]
On Sun, 31 May 2020 20:34:43 +0100
Sergei Trofimovich <slyich@gmail.com> wrote:
> On Wed, 20 May 2020 16:45:03 -0300
> Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org> wrote:
>
> > On 16/05/2020 10:53, slyich--- via Libc-alpha wrote:
> > > From: Sergei Trofimovich <slyfox@gentoo.org>
> > >
> > > gcc-10 enabled -fno-common by default. This caused glibc link failure:
> > >
> > > ```
> > > $ ia64-unknown-linux-gnu-gcc -pipe -O2 -nostdlib -nostartfiles \
> > > -static -o .../elf/sln ...
> > > libc.a(dl-support.o): in function `setup_vdso':
> > > glibc-2.31/elf/setup-vdso.h:116:(.text+0x1322):
> > > relocation truncated to fit: GPREL22 against `.text'
> > > collect2: error: ld returned 1 exit status
> > > ```
> >
> > I can't reproduce it with master (b6ad64b907ab00) with GCC 10.1.1 20200520.
> > (built using build-many-glibcs.py). I tried to explicit use -fno-common on
> > CFLAGS. Are you sing a non default compiler option?
>
> My apologies. Missed your email.
>
> The CFLAGS options should be default. Full command is:
>
> """
> ia64-unknown-linux-gnu-gcc -pipe -fdiagnostics-show-option -Wall -Wextra -Wstack-protector -O2 -Wl,-O1 -Wl,--as-needed -Wl,--hash-style=gnu dl-support.c -c -std=gnu11 -fgnu89-inline -pipe -fdiagnostics-show-option -Wall -Wextra -Wstack-protector -O2 -Wall -Wwrite-strings -Wundef -fmerge-all-constants -frounding-math -fno-stack-protector -Wstrict-prototypes -Wold-style-definition -fmath-errno -fpie -ftls-model=initial-exec -U_FORTIFY_SOURCE -I../include -I/tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf -I/tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl -I../sysdeps/unix/sysv/linux/ia64 -I../sysdeps/ia64/nptl -I../sysdeps/unix/sysv/linux/wordsize-64 -I../sysdeps/unix/sysv/linux/include -I../sysdeps/unix/sysv/linux -I../sysdeps/nptl -I../sysdeps/pthread -I../sysdeps/gnu -I../sysdeps/unix/inet -I../sysdeps/unix/sysv -I../sysdeps/unix -I../sysdeps/posix -I../sysdeps/ia64/fpu -I../sysdeps/ia64 -I../sysdeps/wordsize-64 -I../sysdeps/ieee754/float128 -I../sysdeps/ieee754/ldbl-96/include -I../sysdeps/ieee754/ldbl-96 -I../sysdeps/ieee754/dbl-64 -I../sysdeps/ieee754/flt-32 -I../sysdeps/ieee754 -I../sysdeps/generic -I.. -I../libio -I. -nostdinc -isystem /usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include -isystem /usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include-fixed -isystem /usr/ia64-unknown-linux-gnu/usr/include -D_LIBC_REENTRANT -include /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/libc-modules.h -DMODULE_NAME=libc -include ../include/libc-symbols.h -DPIC -DTOP_NAMESPACE=glibc -o /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o -MD -MP -MF /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o.dt -MT /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o
> """
>
> Might be an effect of default --enable-default-pie --enable-default-ssp.
> Or an effect of applied GCC patch: https://gcc.gnu.org/PR84553
>
> I can try to extract smaller .c example that generates unlinkable
> GPREL22 against cross-section symbols if it's useful.
>
> $ LANG=C ia64-unknown-linux-gnu-gcc -v
> # Using built-in specs.
> COLLECT_GCC=/usr/bin/ia64-unknown-linux-gnu-gcc
> COLLECT_LTO_WRAPPER=/usr/libexec/gcc/ia64-unknown-linux-gnu/10.1.0/lto-wrapper
> Target: ia64-unknown-linux-gnu
> Configured with: /tmp/portage-tmpdir/portage/cross-ia64-unknown-linux-gnu/gcc-10.1.0/work/gcc-10.1.0/configure --host=x86_64-pc-linux-gnu --target=ia64-unknown-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/ia64-unknown-linux-gnu/gcc-bin/10.1.0 --includedir=/usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include --datadir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0 --mandir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/man --infodir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/info --with-gxx-include-dir=/usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include/g++-v10 --with-python-dir=/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/python --enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 10.1.0 p1' --disable-esp --enable-libstdcxx-time --enable-poison-system-directories --with-sysroot=/usr/ia64-unknown-linux-gnu --disable-bootstrap --enable-__cxa_atexit --enable-clocale=gnu --disable-multilib --disable-altivec --disable-fixed-point --enable-libgomp --disable-libmudflap --disable-libssp --disable-libada --disable-systemtap --disable-vtable-verify --disable-libvtv --without-zstd --enable-lto --without-isl --disable-libsanitizer --enable-default-pie --enable-default-ssp
> Thread model: posix
> Supported LTO compression algorithms: zlib
> gcc version 10.1.0 (Gentoo 10.1.0 p1)
Tl;DR:
I think I managed to write small reproducer, and I think it illustrates
that my fix is not effective and still breaks in some setups :(
I hope that helps.
Detailed example:
$ cat a.c
// code reference, avoids function descriptor
#ifdef USE_TEXT
extern int asm_f __attribute__((visibility("hidden"))) __attribute__((section(".text")));
#else
extern int asm_f __attribute__((visibility("hidden")));
#endif
long asm_f_ref;
asm (
".text\n\t" \
".hidden asm_f\n\t"
".proc asm_f\n\t"
"asm_f:\n\t"
".prologue\n\t"
".body\n\t"
"br.ret.sptk.many b0;\n\t"
".endp asm_f\n\t"
".previous"
);
void _start() {
asm_f_ref = (unsigned long)&asm_f;
}
$ cat mk.bash
#!/bin/bash
local_cc_root=/home/slyfox/dev/git/gcc-ia64/gcc
for define in "" "-DUSE_TEST"; do
for static in "" "-static"; do
for fpie in "" "-fPIE"; do
for common in "-fcommon" "-fno-common"; do
echo ""
for cc in "ia64-unknown-linux-gnu-gcc" "${local_cc_root}/xgcc -B${local_cc_root}"; do
echo "define=${define} static=${static} common=${common} fpie=${fpie} cc=${cc}"
LANG=C $cc a.c -o a -O2 -nostdlib -nostartfiles ${static} ${define} ${fpie} ${common}
done
done
done
done
done
Running:
$ LANG=C ./mk.bash
define= static= common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
define= static= common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
define= static= common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
define= static= common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
/tmp/ccBYnt9X.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define= static= common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
define= static= common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
define= static= common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
define= static= common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
/tmp/ccH3sdkO.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define= static=-static common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
define= static=-static common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
define= static=-static common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
/tmp/ccUvQ1vf.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define= static=-static common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
/tmp/cc9epOsD.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define= static=-static common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
define= static=-static common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
define= static=-static common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
/tmp/ccPXdLl4.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define= static=-static common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
/tmp/cca5Gl7p.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define=-DUSE_TEST static= common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
define=-DUSE_TEST static= common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
define=-DUSE_TEST static= common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
define=-DUSE_TEST static= common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
/tmp/ccodz56d.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define=-DUSE_TEST static= common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
define=-DUSE_TEST static= common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
define=-DUSE_TEST static= common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
define=-DUSE_TEST static= common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
/tmp/cc7dWmZ3.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define=-DUSE_TEST static=-static common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
define=-DUSE_TEST static=-static common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
define=-DUSE_TEST static=-static common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
/tmp/ccJ2hnsw.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define=-DUSE_TEST static=-static common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
/tmp/ccko7sNT.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define=-DUSE_TEST static=-static common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
define=-DUSE_TEST static=-static common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
define=-DUSE_TEST static=-static common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
/tmp/cchRq1Nl.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define=-DUSE_TEST static=-static common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
/tmp/ccgQ5Y6G.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
Local compiler was build from today's gcc-master as:
#!/bin/bash
../gcc/configure \
\
--build=x86_64-pc-linux-gnu \
--host=x86_64-pc-linux-gnu \
--target=ia64-unknown-linux-gnu \
\
--with-sysroot=/usr/ia64-unknown-linux-gnu \
--enable-languages=c \
--disable-bootstrap \
--prefix="$(pwd)/../gcc-ia64-installed" \
\
--enable-languages=c \
--disable-nls \
\
CFLAGS="-O1" CXXFLAGS="-O1" LDFLAGS="-O1" \
"$@"
--
Sergei
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ia64: fix dl-sysdep miscompilation on gcc-10
2020-05-31 21:40 ` Sergei Trofimovich via Libc-alpha
@ 2020-06-05 18:44 ` Adhemerval Zanella via Libc-alpha
2020-06-05 21:31 ` Sergei Trofimovich via Libc-alpha
0 siblings, 1 reply; 6+ messages in thread
From: Adhemerval Zanella via Libc-alpha @ 2020-06-05 18:44 UTC (permalink / raw)
To: Sergei Trofimovich, Adhemerval Zanella via Libc-alpha
[-- Attachment #1.1: Type: text/plain, Size: 15728 bytes --]
On 31/05/2020 18:40, Sergei Trofimovich wrote:
> On Sun, 31 May 2020 20:34:43 +0100
> Sergei Trofimovich <slyich@gmail.com> wrote:
>
>> On Wed, 20 May 2020 16:45:03 -0300
>> Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org> wrote:
>>
>>> On 16/05/2020 10:53, slyich--- via Libc-alpha wrote:
>>>> From: Sergei Trofimovich <slyfox@gentoo.org>
>>>>
>>>> gcc-10 enabled -fno-common by default. This caused glibc link failure:
>>>>
>>>> ```
>>>> $ ia64-unknown-linux-gnu-gcc -pipe -O2 -nostdlib -nostartfiles \
>>>> -static -o .../elf/sln ...
>>>> libc.a(dl-support.o): in function `setup_vdso':
>>>> glibc-2.31/elf/setup-vdso.h:116:(.text+0x1322):
>>>> relocation truncated to fit: GPREL22 against `.text'
>>>> collect2: error: ld returned 1 exit status
>>>> ```
>>>
>>> I can't reproduce it with master (b6ad64b907ab00) with GCC 10.1.1 20200520.
>>> (built using build-many-glibcs.py). I tried to explicit use -fno-common on
>>> CFLAGS. Are you sing a non default compiler option?
>>
>> My apologies. Missed your email.
>>
>> The CFLAGS options should be default. Full command is:
>>
>> """
>> ia64-unknown-linux-gnu-gcc -pipe -fdiagnostics-show-option -Wall -Wextra -Wstack-protector -O2 -Wl,-O1 -Wl,--as-needed -Wl,--hash-style=gnu dl-support.c -c -std=gnu11 -fgnu89-inline -pipe -fdiagnostics-show-option -Wall -Wextra -Wstack-protector -O2 -Wall -Wwrite-strings -Wundef -fmerge-all-constants -frounding-math -fno-stack-protector -Wstrict-prototypes -Wold-style-definition -fmath-errno -fpie -ftls-model=initial-exec -U_FORTIFY_SOURCE -I../include -I/tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf -I/tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl -I../sysdeps/unix/sysv/linux/ia64 -I../sysdeps/ia64/nptl -I../sysdeps/unix/sysv/linux/wordsize-64 -I../sysdeps/unix/sysv/linux/include -I../sysdeps/unix/sysv/linux -I../sysdeps/nptl -I../sysdeps/pthread -I../sysdeps/gnu -I../sysdeps/unix/inet -I../sysdeps/unix/sysv -I../sysdeps/unix -I../sysdeps/posix -I../sysdeps/ia64/fpu -I../sysdeps/ia64 -I../sysdeps/wordsize-64 -I../sysdeps/ieee754/float128 -I../sysdeps/ieee754/ldbl-96/include -I../sysdeps/ieee754/ldbl-96 -I../sysdeps/ieee754/dbl-64 -I../sysdeps/ieee754/flt-32 -I../sysdeps/ieee754 -I../sysdeps/generic -I.. -I../libio -I. -nostdinc -isystem /usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include -isystem /usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include-fixed -isystem /usr/ia64-unknown-linux-gnu/usr/include -D_LIBC_REENTRANT -include /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/libc-modules.h -DMODULE_NAME=libc -include ../include/libc-symbols.h -DPIC -DTOP_NAMESPACE=glibc -o /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o -MD -MP -MF /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o.dt -MT /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o
>> """
>>
>> Might be an effect of default --enable-default-pie --enable-default-ssp.
>> Or an effect of applied GCC patch: https://gcc.gnu.org/PR84553
>>
>> I can try to extract smaller .c example that generates unlinkable
>> GPREL22 against cross-section symbols if it's useful.
>>
>> $ LANG=C ia64-unknown-linux-gnu-gcc -v
>> # Using built-in specs.
>> COLLECT_GCC=/usr/bin/ia64-unknown-linux-gnu-gcc
>> COLLECT_LTO_WRAPPER=/usr/libexec/gcc/ia64-unknown-linux-gnu/10.1.0/lto-wrapper
>> Target: ia64-unknown-linux-gnu
>> Configured with: /tmp/portage-tmpdir/portage/cross-ia64-unknown-linux-gnu/gcc-10.1.0/work/gcc-10.1.0/configure --host=x86_64-pc-linux-gnu --target=ia64-unknown-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/ia64-unknown-linux-gnu/gcc-bin/10.1.0 --includedir=/usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include --datadir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0 --mandir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/man --infodir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/info --with-gxx-include-dir=/usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include/g++-v10 --with-python-dir=/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/python --enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 10.1.0 p1' --disable-esp --enable-libstdcxx-time --enable-poison-system-directories --with-sysroot=/usr/ia64-unknown-linux-gnu --disable-bootstrap --enable-__cxa_atexit --enable-clocale=gnu --disable-multilib --disable-altivec --disable-fixed-point --enable-libgomp --disable-libmudflap --disable-libssp --disable-libada --disable-systemtap --disable-vtable-verify --disable-libvtv --without-zstd --enable-lto --without-isl --disable-libsanitizer --enable-default-pie --enable-default-ssp
>> Thread model: posix
>> Supported LTO compression algorithms: zlib
>> gcc version 10.1.0 (Gentoo 10.1.0 p1)
>
> Tl;DR:
>
> I think I managed to write small reproducer, and I think it illustrates
> that my fix is not effective and still breaks in some setups :(
In fact I think your testcase has a small typo below ;)
>
> I hope that helps.
>
> Detailed example:
>
> $ cat a.c
> // code reference, avoids function descriptor
> #ifdef USE_TEXT
> extern int asm_f __attribute__((visibility("hidden"))) __attribute__((section(".text")));
> #else
> extern int asm_f __attribute__((visibility("hidden")));
> #endif
>
> long asm_f_ref;
>
> asm (
> ".text\n\t" \
> ".hidden asm_f\n\t"
> ".proc asm_f\n\t"
> "asm_f:\n\t"
> ".prologue\n\t"
> ".body\n\t"
> "br.ret.sptk.many b0;\n\t"
> ".endp asm_f\n\t"
> ".previous"
> );
>
> void _start() {
> asm_f_ref = (unsigned long)&asm_f;
> }
>
> $ cat mk.bash
> #!/bin/bash
>
> local_cc_root=/home/slyfox/dev/git/gcc-ia64/gcc
>
> for define in "" "-DUSE_TEST"; do
I think it should be USE_TEXT instead.
> for static in "" "-static"; do
> for fpie in "" "-fPIE"; do
> for common in "-fcommon" "-fno-common"; do
> echo ""
> for cc in "ia64-unknown-linux-gnu-gcc" "${local_cc_root}/xgcc -B${local_cc_root}"; do
> echo "define=${define} static=${static} common=${common} fpie=${fpie} cc=${cc}"
> LANG=C $cc a.c -o a -O2 -nostdlib -nostartfiles ${static} ${define} ${fpie} ${common}
> done
> done
> done
> done
> done
>
> Running:
>
> $ LANG=C ./mk.bash
>
> define= static= common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
> define= static= common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
>
> define= static= common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
> define= static= common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> /tmp/ccBYnt9X.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define= static= common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> define= static= common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
>
> define= static= common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> define= static= common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> /tmp/ccH3sdkO.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define= static=-static common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
> define= static=-static common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
>
> define= static=-static common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
> /tmp/ccUvQ1vf.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
> define= static=-static common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> /tmp/cc9epOsD.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define= static=-static common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> define= static=-static common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
>
> define= static=-static common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> /tmp/ccPXdLl4.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
> define= static=-static common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> /tmp/cca5Gl7p.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define=-DUSE_TEST static= common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
> define=-DUSE_TEST static= common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
>
> define=-DUSE_TEST static= common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
> define=-DUSE_TEST static= common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> /tmp/ccodz56d.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define=-DUSE_TEST static= common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> define=-DUSE_TEST static= common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
>
> define=-DUSE_TEST static= common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> define=-DUSE_TEST static= common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> /tmp/cc7dWmZ3.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define=-DUSE_TEST static=-static common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
> define=-DUSE_TEST static=-static common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
>
> define=-DUSE_TEST static=-static common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
> /tmp/ccJ2hnsw.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
> define=-DUSE_TEST static=-static common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> /tmp/ccko7sNT.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define=-DUSE_TEST static=-static common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> define=-DUSE_TEST static=-static common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
>
> define=-DUSE_TEST static=-static common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> /tmp/cchRq1Nl.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
> define=-DUSE_TEST static=-static common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> /tmp/ccgQ5Y6G.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
With the above fix I am seeing:
---
define= static= common=-fcommon fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define= static= common=-fno-common fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
/tmp/ccwUMGjK.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define= static= common=-fcommon fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define= static= common=-fno-common fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
/tmp/cc9nPVOO.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define= static=-static common=-fcommon fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define= static=-static common=-fno-common fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
/tmp/ccV4QyrT.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define= static=-static common=-fcommon fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define= static=-static common=-fno-common fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
/tmp/ccSgHDDW.o: in function `_start':
a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
collect2: error: ld returned 1 exit status
define=-DUSE_TEXT static= common=-fcommon fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define=-DUSE_TEXT static= common=-fno-common fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define=-DUSE_TEXT static= common=-fcommon fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define=-DUSE_TEXT static= common=-fno-common fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define=-DUSE_TEXT static=-static common=-fcommon fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define=-DUSE_TEXT static=-static common=-fno-common fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define=-DUSE_TEXT static=-static common=-fcommon fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
define=-DUSE_TEXT static=-static common=-fno-common fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
---
So it does seem that using the __attribute__((section(".text"))) does help ia64
in this case. Due the current status I think it should be a better and
simpler fix.
The alternative would be remove the _dl_sysinfo_break and rewrite the syscall
mechanism (in both ASM pre-processor and INTERNAL_SYSCALL macros) to check
if the _dl_sysinfo is set (meaning a vDSO is present) and issuing the syscall
with brk if not. It will most likely increase the code size and add some
latency.
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] ia64: fix dl-sysdep miscompilation on gcc-10
2020-06-05 18:44 ` Adhemerval Zanella via Libc-alpha
@ 2020-06-05 21:31 ` Sergei Trofimovich via Libc-alpha
0 siblings, 0 replies; 6+ messages in thread
From: Sergei Trofimovich via Libc-alpha @ 2020-06-05 21:31 UTC (permalink / raw)
To: Adhemerval Zanella; +Cc: Adhemerval Zanella via Libc-alpha
[-- Attachment #1: Type: text/plain, Size: 16467 bytes --]
On Fri, 5 Jun 2020 15:44:24 -0300
Adhemerval Zanella <adhemerval.zanella@linaro.org> wrote:
> On 31/05/2020 18:40, Sergei Trofimovich wrote:
> > On Sun, 31 May 2020 20:34:43 +0100
> > Sergei Trofimovich <slyich@gmail.com> wrote:
> >
> >> On Wed, 20 May 2020 16:45:03 -0300
> >> Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org> wrote:
> >>
> >>> On 16/05/2020 10:53, slyich--- via Libc-alpha wrote:
> >>>> From: Sergei Trofimovich <slyfox@gentoo.org>
> >>>>
> >>>> gcc-10 enabled -fno-common by default. This caused glibc link failure:
> >>>>
> >>>> ```
> >>>> $ ia64-unknown-linux-gnu-gcc -pipe -O2 -nostdlib -nostartfiles \
> >>>> -static -o .../elf/sln ...
> >>>> libc.a(dl-support.o): in function `setup_vdso':
> >>>> glibc-2.31/elf/setup-vdso.h:116:(.text+0x1322):
> >>>> relocation truncated to fit: GPREL22 against `.text'
> >>>> collect2: error: ld returned 1 exit status
> >>>> ```
> >>>
> >>> I can't reproduce it with master (b6ad64b907ab00) with GCC 10.1.1 20200520.
> >>> (built using build-many-glibcs.py). I tried to explicit use -fno-common on
> >>> CFLAGS. Are you sing a non default compiler option?
> >>
> >> My apologies. Missed your email.
> >>
> >> The CFLAGS options should be default. Full command is:
> >>
> >> """
> >> ia64-unknown-linux-gnu-gcc -pipe -fdiagnostics-show-option -Wall -Wextra -Wstack-protector -O2 -Wl,-O1 -Wl,--as-needed -Wl,--hash-style=gnu dl-support.c -c -std=gnu11 -fgnu89-inline -pipe -fdiagnostics-show-option -Wall -Wextra -Wstack-protector -O2 -Wall -Wwrite-strings -Wundef -fmerge-all-constants -frounding-math -fno-stack-protector -Wstrict-prototypes -Wold-style-definition -fmath-errno -fpie -ftls-model=initial-exec -U_FORTIFY_SOURCE -I../include -I/tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf -I/tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl -I../sysdeps/unix/sysv/linux/ia64 -I../sysdeps/ia64/nptl -I../sysdeps/unix/sysv/linux/wordsize-64 -I../sysdeps/unix/sysv/linux/include -I../sysdeps/unix/sysv/linux -I../sysdeps/nptl -I../sysdeps/pthread -I../sysdeps/gnu -I../sysdeps/unix/inet -I../sysdeps/unix/sysv -I../sysdeps/unix -I../sysdeps/posix -I../sysdeps/ia64/fpu -I../sysdeps/ia64 -I../sysdeps/wordsize-64 -I../sysdeps/ieee754/float128 -I../sysdeps/ieee754/ldbl-96/include -I../sysdeps/ieee754/ldbl-96 -I../sysdeps/ieee754/dbl-64 -I../sysdeps/ieee754/flt-32 -I../sysdeps/ieee754 -I../sysdeps/generic -I.. -I../libio -I. -nostdinc -isystem /usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include -isystem /usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include-fixed -isystem /usr/ia64-unknown-linux-gnu/usr/include -D_LIBC_REENTRANT -include /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/libc-modules.h -DMODULE_NAME=libc -include ../include/libc-symbols.h -DPIC -DTOP_NAMESPACE=glibc -o /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o -MD -MP -MF /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o.dt -MT /tmp/portage/cross-ia64-unknown-linux-gnu/glibc-2.31-r3/work/build-default-ia64-unknown-linux-gnu-nptl/elf/dl-support.o
> >> """
> >>
> >> Might be an effect of default --enable-default-pie --enable-default-ssp.
> >> Or an effect of applied GCC patch: https://gcc.gnu.org/PR84553
> >>
> >> I can try to extract smaller .c example that generates unlinkable
> >> GPREL22 against cross-section symbols if it's useful.
> >>
> >> $ LANG=C ia64-unknown-linux-gnu-gcc -v
> >> # Using built-in specs.
> >> COLLECT_GCC=/usr/bin/ia64-unknown-linux-gnu-gcc
> >> COLLECT_LTO_WRAPPER=/usr/libexec/gcc/ia64-unknown-linux-gnu/10.1.0/lto-wrapper
> >> Target: ia64-unknown-linux-gnu
> >> Configured with: /tmp/portage-tmpdir/portage/cross-ia64-unknown-linux-gnu/gcc-10.1.0/work/gcc-10.1.0/configure --host=x86_64-pc-linux-gnu --target=ia64-unknown-linux-gnu --build=x86_64-pc-linux-gnu --prefix=/usr --bindir=/usr/x86_64-pc-linux-gnu/ia64-unknown-linux-gnu/gcc-bin/10.1.0 --includedir=/usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include --datadir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0 --mandir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/man --infodir=/usr/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/info --with-gxx-include-dir=/usr/lib/gcc/ia64-unknown-linux-gnu/10.1.0/include/g++-v10 --with-python-dir=/share/gcc-data/ia64-unknown-linux-gnu/10.1.0/python --enable-languages=c,c++,fortran --enable-obsolete --enable-secureplt --disable-werror --with-system-zlib --enable-nls --without-included-gettext --enable-checking=release --with-bugurl=https://bugs.gentoo.org/ --with-pkgversion='Gentoo 10.1.0 p1' --disable-esp --enable-libstdcxx-time --enable-poison-system-directories --with-sysroot=/usr/ia64-unknown-linux-gnu --disable-bootstrap --enable-__cxa_atexit --enable-clocale=gnu --disable-multilib --disable-altivec --disable-fixed-point --enable-libgomp --disable-libmudflap --disable-libssp --disable-libada --disable-systemtap --disable-vtable-verify --disable-libvtv --without-zstd --enable-lto --without-isl --disable-libsanitizer --enable-default-pie --enable-default-ssp
> >> Thread model: posix
> >> Supported LTO compression algorithms: zlib
> >> gcc version 10.1.0 (Gentoo 10.1.0 p1)
> >
> > Tl;DR:
> >
> > I think I managed to write small reproducer, and I think it illustrates
> > that my fix is not effective and still breaks in some setups :(
>
> In fact I think your testcase has a small typo below ;)
Gah, so simple! Thank you!
> >
> > I hope that helps.
> >
> > Detailed example:
> >
> > $ cat a.c
> > // code reference, avoids function descriptor
> > #ifdef USE_TEXT
> > extern int asm_f __attribute__((visibility("hidden"))) __attribute__((section(".text")));
> > #else
> > extern int asm_f __attribute__((visibility("hidden")));
> > #endif
> >
> > long asm_f_ref;
> >
> > asm (
> > ".text\n\t" \
> > ".hidden asm_f\n\t"
> > ".proc asm_f\n\t"
> > "asm_f:\n\t"
> > ".prologue\n\t"
> > ".body\n\t"
> > "br.ret.sptk.many b0;\n\t"
> > ".endp asm_f\n\t"
> > ".previous"
> > );
> >
> > void _start() {
> > asm_f_ref = (unsigned long)&asm_f;
> > }
> >
> > $ cat mk.bash
> > #!/bin/bash
> >
> > local_cc_root=/home/slyfox/dev/git/gcc-ia64/gcc
> >
> > for define in "" "-DUSE_TEST"; do
>
> I think it should be USE_TEXT instead.
>
> > for static in "" "-static"; do
> > for fpie in "" "-fPIE"; do
> > for common in "-fcommon" "-fno-common"; do
> > echo ""
> > for cc in "ia64-unknown-linux-gnu-gcc" "${local_cc_root}/xgcc -B${local_cc_root}"; do
> > echo "define=${define} static=${static} common=${common} fpie=${fpie} cc=${cc}"
> > LANG=C $cc a.c -o a -O2 -nostdlib -nostartfiles ${static} ${define} ${fpie} ${common}
> > done
> > done
> > done
> > done
> > done
> >
> > Running:
> >
> > $ LANG=C ./mk.bash
> >
> > define= static= common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
> > define= static= common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> >
> > define= static= common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
> > define= static= common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> > /tmp/ccBYnt9X.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> >
> > define= static= common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> > define= static= common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> >
> > define= static= common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> > define= static= common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> > /tmp/ccH3sdkO.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> >
> > define= static=-static common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
> > define= static=-static common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> >
> > define= static=-static common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
> > /tmp/ccUvQ1vf.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> > define= static=-static common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> > /tmp/cc9epOsD.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> >
> > define= static=-static common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> > define= static=-static common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> >
> > define= static=-static common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> > /tmp/ccPXdLl4.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> > define= static=-static common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> > /tmp/cca5Gl7p.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> >
> > define=-DUSE_TEST static= common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
> > define=-DUSE_TEST static= common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> >
> > define=-DUSE_TEST static= common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
> > define=-DUSE_TEST static= common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> > /tmp/ccodz56d.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> >
> > define=-DUSE_TEST static= common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> > define=-DUSE_TEST static= common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> >
> > define=-DUSE_TEST static= common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> > define=-DUSE_TEST static= common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> > /tmp/cc7dWmZ3.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> >
> > define=-DUSE_TEST static=-static common=-fcommon fpie= cc=ia64-unknown-linux-gnu-gcc
> > define=-DUSE_TEST static=-static common=-fcommon fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> >
> > define=-DUSE_TEST static=-static common=-fno-common fpie= cc=ia64-unknown-linux-gnu-gcc
> > /tmp/ccJ2hnsw.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> > define=-DUSE_TEST static=-static common=-fno-common fpie= cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> > /tmp/ccko7sNT.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> >
> > define=-DUSE_TEST static=-static common=-fcommon fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> > define=-DUSE_TEST static=-static common=-fcommon fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> >
> > define=-DUSE_TEST static=-static common=-fno-common fpie=-fPIE cc=ia64-unknown-linux-gnu-gcc
> > /tmp/cchRq1Nl.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
> > define=-DUSE_TEST static=-static common=-fno-common fpie=-fPIE cc=/home/slyfox/dev/git/gcc-ia64/gcc/xgcc -B/home/slyfox/dev/git/gcc-ia64/gcc
> > /tmp/ccgQ5Y6G.o: in function `_start':
> > a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> > collect2: error: ld returned 1 exit status
>
> With the above fix I am seeing:
>
> ---
> define= static= common=-fcommon fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define= static= common=-fno-common fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
> /tmp/ccwUMGjK.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define= static= common=-fcommon fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define= static= common=-fno-common fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
> /tmp/cc9nPVOO.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define= static=-static common=-fcommon fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define= static=-static common=-fno-common fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
> /tmp/ccV4QyrT.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define= static=-static common=-fcommon fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define= static=-static common=-fno-common fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
> /tmp/ccSgHDDW.o: in function `_start':
> a.c:(.text+0x42): relocation truncated to fit: GPREL22 against `.text'
> collect2: error: ld returned 1 exit status
>
> define=-DUSE_TEXT static= common=-fcommon fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define=-DUSE_TEXT static= common=-fno-common fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define=-DUSE_TEXT static= common=-fcommon fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define=-DUSE_TEXT static= common=-fno-common fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define=-DUSE_TEXT static=-static common=-fcommon fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define=-DUSE_TEXT static=-static common=-fno-common fpie= cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define=-DUSE_TEXT static=-static common=-fcommon fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
>
> define=-DUSE_TEXT static=-static common=-fno-common fpie=-fPIE cc=/home/azanella/toolchain/install/compilers/ia64-linux-gnu/bin/ia64-glibc-linux-gnu-gcc
> ---
>
> So it does seem that using the __attribute__((section(".text"))) does help ia64
> in this case. Due the current status I think it should be a better and
> simpler fix.
I agree.
> The alternative would be remove the _dl_sysinfo_break and rewrite the syscall
> mechanism (in both ASM pre-processor and INTERNAL_SYSCALL macros) to check
> if the _dl_sysinfo is set (meaning a vDSO is present) and issuing the syscall
> with brk if not. It will most likely increase the code size and add some
> latency.
I volunteer to convert to asm call when it breaks next time :)
--
Sergei
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^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-06-05 21:31 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-05-16 13:53 [PATCH] ia64: fix dl-sysdep miscompilation on gcc-10 slyich--- via Libc-alpha
2020-05-20 19:45 ` Adhemerval Zanella via Libc-alpha
2020-05-31 19:34 ` Sergei Trofimovich via Libc-alpha
2020-05-31 21:40 ` Sergei Trofimovich via Libc-alpha
2020-06-05 18:44 ` Adhemerval Zanella via Libc-alpha
2020-06-05 21:31 ` Sergei Trofimovich via Libc-alpha
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