Re: [PATCH 5.8 35/99] tools/libbpf: Avoid counting local symbols in ABI check
On Wed, Sep 30, 2020 at 12:02 AM Tony Ambardar wrote:
>
> [adding Michael Ellerman, linux-ppc maintainer]
>
> Hello Justin,
>
> On Tue, 29 Sep 2020 at 14:54, Justin Forbes wrote:
> >
> > On Tue, Sep 29, 2020 at 6:53 AM Greg Kroah-Hartman
> > wrote:
> > >
> > > From: Tony Ambardar
> > >
> > > [ Upstream commit 746f534a4809e07f427f7d13d10f3a6a9641e5c3 ]
> > >
> > > Encountered the following failure building libbpf from kernel 5.8.5
> > > sources
> > > with GCC 8.4.0 and binutils 2.34: (long paths shortened)
> > >
> > > Warning: Num of global symbols in sharedobjs/libbpf-in.o (234) does NOT
> > > match with num of versioned symbols in libbpf.so (236). Please make sure
> > > all LIBBPF_API symbols are versioned in libbpf.map.
> > > # --- libbpf_global_syms.tmp2020-09-02 07:30:58.920084380 +
> > > # +++ libbpf_versioned_syms.tmp 2020-09-02 07:30:58.924084388 +
> > > @@ -1,3 +1,5 @@
> > > +_fini
> > > +_init
> > >bpf_btf_get_fd_by_id
> > >bpf_btf_get_next_id
> > >bpf_create_map
> > > make[4]: *** [Makefile:210: check_abi] Error 1
> > >
> > > Investigation shows _fini and _init are actually local symbols counted
> > > amongst global ones:
> > >
> > > $ readelf --dyn-syms --wide libbpf.so|head -10
> > >
> > > Symbol table '.dynsym' contains 343 entries:
> > > Num:Value Size TypeBind Vis Ndx Name
> > >0: 0 NOTYPE LOCAL DEFAULT UND
> > >1: 4098 0 SECTION LOCAL DEFAULT 11
> > >2: 4098 8 FUNCLOCAL DEFAULT 11 _init@@LIBBPF_0.0.1
> > >3: 00023040 8 FUNCLOCAL DEFAULT 14 _fini@@LIBBPF_0.0.1
> > >4: 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.0.4
> > >5: 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.0.1
> > >6: ffa4 8 FUNCGLOBAL DEFAULT 12
> > > bpf_object__find_map_by_offset@@LIBBPF_0.0.1
> > >
> > > A previous commit filtered global symbols in sharedobjs/libbpf-in.o. Do
> > > the
> > > same with the libbpf.so DSO for consistent comparison.
> > >
> > > Fixes: 306b267cb3c4 ("libbpf: Verify versioned symbols")
> > > Signed-off-by: Tony Ambardar
> > > Signed-off-by: Alexei Starovoitov
> > > Acked-by: Andrii Nakryiko
> > > Link:
> > > https://lore.kernel.org/bpf/20200905214831.1565465-1-tony.ambar...@gmail.com
> > > Signed-off-by: Sasha Levin
> >
> > This seems to work everywhere else, but breaks PPC64LE.
> >
>
> I also ran into a PPC build error while working on some bpf problems,
> but it seemed
> like a pre-existing PPC issue. I did submit an upstream fix, which is
> marked for stable
> and being reviewed by Michael. See here for discussion and the patch:
> https://lkml.org/lkml/2020/9/17/668.
>
> Is that the same problem you encountered? Does that patch address your issue?
It is not, the issue I see is:
Warning: Num of global symbols in sharedobjs/libbpf-in.o (259) does
NOT match with num of versioned symbols in libbpf.so (50). Please make
sure all LIBBPF_API symbols are versioned in libbpf.map.
I only see it on ppc64le with this patch, all other arch that Fedora
builds are fine (x86_64, i686, aarch64, armv7, s390). If I revert
this patch, all builds succeed. We are using gcc 10.2.1 though.
Justin
>
> Thanks,
> Tony
>
> > Justin
> >
> > > ---
> > > tools/lib/bpf/Makefile |2 ++
> > > 1 file changed, 2 insertions(+)
> > >
> > > --- a/tools/lib/bpf/Makefile
> > > +++ b/tools/lib/bpf/Makefile
> > > @@ -152,6 +152,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --
> > >awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print
> > > $$NF}' | \
> > >sort -u | wc -l)
> > > VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide
> > > $(OUTPUT)libbpf.so | \
> > > + awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print
> > > $$NF}' | \
> > > grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 |
> > > sort -u | wc -l)
> > >
> > > CMD_TARGETS = $(LIB_TARGET) $(PC_FILE)
> > > @@ -219,6 +220,7 @@ check_abi: $(OUTPUT)libbpf.so
> > > awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \
> > > sort -u > $(OUTPUT)libbpf_global_syms.tmp; \
> > > readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \
> > > + awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \
> > > grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | \
> > > sort -u > $(OUTPUT)libbpf_versioned_syms.tmp;\
> > > diff -u $(OUTPUT)libbpf_global_syms.tmp \
> > >
> > >
Re: [PATCH 5.8 35/99] tools/libbpf: Avoid counting local symbols in ABI check
[adding Michael Ellerman, linux-ppc maintainer]
Hello Justin,
On Tue, 29 Sep 2020 at 14:54, Justin Forbes wrote:
>
> On Tue, Sep 29, 2020 at 6:53 AM Greg Kroah-Hartman
> wrote:
> >
> > From: Tony Ambardar
> >
> > [ Upstream commit 746f534a4809e07f427f7d13d10f3a6a9641e5c3 ]
> >
> > Encountered the following failure building libbpf from kernel 5.8.5 sources
> > with GCC 8.4.0 and binutils 2.34: (long paths shortened)
> >
> > Warning: Num of global symbols in sharedobjs/libbpf-in.o (234) does NOT
> > match with num of versioned symbols in libbpf.so (236). Please make sure
> > all LIBBPF_API symbols are versioned in libbpf.map.
> > # --- libbpf_global_syms.tmp2020-09-02 07:30:58.920084380 +
> > # +++ libbpf_versioned_syms.tmp 2020-09-02 07:30:58.924084388 +
> > @@ -1,3 +1,5 @@
> > +_fini
> > +_init
> >bpf_btf_get_fd_by_id
> >bpf_btf_get_next_id
> >bpf_create_map
> > make[4]: *** [Makefile:210: check_abi] Error 1
> >
> > Investigation shows _fini and _init are actually local symbols counted
> > amongst global ones:
> >
> > $ readelf --dyn-syms --wide libbpf.so|head -10
> >
> > Symbol table '.dynsym' contains 343 entries:
> > Num:Value Size TypeBind Vis Ndx Name
> >0: 0 NOTYPE LOCAL DEFAULT UND
> >1: 4098 0 SECTION LOCAL DEFAULT 11
> >2: 4098 8 FUNCLOCAL DEFAULT 11 _init@@LIBBPF_0.0.1
> >3: 00023040 8 FUNCLOCAL DEFAULT 14 _fini@@LIBBPF_0.0.1
> >4: 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.0.4
> >5: 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.0.1
> >6: ffa4 8 FUNCGLOBAL DEFAULT 12
> > bpf_object__find_map_by_offset@@LIBBPF_0.0.1
> >
> > A previous commit filtered global symbols in sharedobjs/libbpf-in.o. Do the
> > same with the libbpf.so DSO for consistent comparison.
> >
> > Fixes: 306b267cb3c4 ("libbpf: Verify versioned symbols")
> > Signed-off-by: Tony Ambardar
> > Signed-off-by: Alexei Starovoitov
> > Acked-by: Andrii Nakryiko
> > Link:
> > https://lore.kernel.org/bpf/20200905214831.1565465-1-tony.ambar...@gmail.com
> > Signed-off-by: Sasha Levin
>
> This seems to work everywhere else, but breaks PPC64LE.
>
I also ran into a PPC build error while working on some bpf problems,
but it seemed
like a pre-existing PPC issue. I did submit an upstream fix, which is
marked for stable
and being reviewed by Michael. See here for discussion and the patch:
https://lkml.org/lkml/2020/9/17/668.
Is that the same problem you encountered? Does that patch address your issue?
Thanks,
Tony
> Justin
>
> > ---
> > tools/lib/bpf/Makefile |2 ++
> > 1 file changed, 2 insertions(+)
> >
> > --- a/tools/lib/bpf/Makefile
> > +++ b/tools/lib/bpf/Makefile
> > @@ -152,6 +152,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --
> >awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print
> > $$NF}' | \
> >sort -u | wc -l)
> > VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OUTPUT)libbpf.so
> > | \
> > + awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print
> > $$NF}' | \
> > grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort
> > -u | wc -l)
> >
> > CMD_TARGETS = $(LIB_TARGET) $(PC_FILE)
> > @@ -219,6 +220,7 @@ check_abi: $(OUTPUT)libbpf.so
> > awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \
> > sort -u > $(OUTPUT)libbpf_global_syms.tmp; \
> > readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \
> > + awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \
> > grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | \
> > sort -u > $(OUTPUT)libbpf_versioned_syms.tmp;\
> > diff -u $(OUTPUT)libbpf_global_syms.tmp \
> >
> >
Re: [PATCH 5.8 35/99] tools/libbpf: Avoid counting local symbols in ABI check
On Tue, Sep 29, 2020 at 6:53 AM Greg Kroah-Hartman
wrote:
>
> From: Tony Ambardar
>
> [ Upstream commit 746f534a4809e07f427f7d13d10f3a6a9641e5c3 ]
>
> Encountered the following failure building libbpf from kernel 5.8.5 sources
> with GCC 8.4.0 and binutils 2.34: (long paths shortened)
>
> Warning: Num of global symbols in sharedobjs/libbpf-in.o (234) does NOT
> match with num of versioned symbols in libbpf.so (236). Please make sure
> all LIBBPF_API symbols are versioned in libbpf.map.
> # --- libbpf_global_syms.tmp2020-09-02 07:30:58.920084380 +
> # +++ libbpf_versioned_syms.tmp 2020-09-02 07:30:58.924084388 +
> @@ -1,3 +1,5 @@
> +_fini
> +_init
>bpf_btf_get_fd_by_id
>bpf_btf_get_next_id
>bpf_create_map
> make[4]: *** [Makefile:210: check_abi] Error 1
>
> Investigation shows _fini and _init are actually local symbols counted
> amongst global ones:
>
> $ readelf --dyn-syms --wide libbpf.so|head -10
>
> Symbol table '.dynsym' contains 343 entries:
> Num:Value Size TypeBind Vis Ndx Name
>0: 0 NOTYPE LOCAL DEFAULT UND
>1: 4098 0 SECTION LOCAL DEFAULT 11
>2: 4098 8 FUNCLOCAL DEFAULT 11 _init@@LIBBPF_0.0.1
>3: 00023040 8 FUNCLOCAL DEFAULT 14 _fini@@LIBBPF_0.0.1
>4: 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.0.4
>5: 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.0.1
>6: ffa4 8 FUNCGLOBAL DEFAULT 12
> bpf_object__find_map_by_offset@@LIBBPF_0.0.1
>
> A previous commit filtered global symbols in sharedobjs/libbpf-in.o. Do the
> same with the libbpf.so DSO for consistent comparison.
>
> Fixes: 306b267cb3c4 ("libbpf: Verify versioned symbols")
> Signed-off-by: Tony Ambardar
> Signed-off-by: Alexei Starovoitov
> Acked-by: Andrii Nakryiko
> Link:
> https://lore.kernel.org/bpf/20200905214831.1565465-1-tony.ambar...@gmail.com
> Signed-off-by: Sasha Levin
This seems to work everywhere else, but breaks PPC64LE.
Justin
> ---
> tools/lib/bpf/Makefile |2 ++
> 1 file changed, 2 insertions(+)
>
> --- a/tools/lib/bpf/Makefile
> +++ b/tools/lib/bpf/Makefile
> @@ -152,6 +152,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --
>awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'
> | \
>sort -u | wc -l)
> VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OUTPUT)libbpf.so |
> \
> + awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print
> $$NF}' | \
> grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort
> -u | wc -l)
>
> CMD_TARGETS = $(LIB_TARGET) $(PC_FILE)
> @@ -219,6 +220,7 @@ check_abi: $(OUTPUT)libbpf.so
> awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \
> sort -u > $(OUTPUT)libbpf_global_syms.tmp; \
> readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \
> + awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \
> grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | \
> sort -u > $(OUTPUT)libbpf_versioned_syms.tmp;\
> diff -u $(OUTPUT)libbpf_global_syms.tmp \
>
>
[PATCH 5.8 35/99] tools/libbpf: Avoid counting local symbols in ABI check
From: Tony Ambardar
[ Upstream commit 746f534a4809e07f427f7d13d10f3a6a9641e5c3 ]
Encountered the following failure building libbpf from kernel 5.8.5 sources
with GCC 8.4.0 and binutils 2.34: (long paths shortened)
Warning: Num of global symbols in sharedobjs/libbpf-in.o (234) does NOT
match with num of versioned symbols in libbpf.so (236). Please make sure
all LIBBPF_API symbols are versioned in libbpf.map.
# --- libbpf_global_syms.tmp2020-09-02 07:30:58.920084380 +
# +++ libbpf_versioned_syms.tmp 2020-09-02 07:30:58.924084388 +
@@ -1,3 +1,5 @@
+_fini
+_init
bpf_btf_get_fd_by_id
bpf_btf_get_next_id
bpf_create_map
make[4]: *** [Makefile:210: check_abi] Error 1
Investigation shows _fini and _init are actually local symbols counted
amongst global ones:
$ readelf --dyn-syms --wide libbpf.so|head -10
Symbol table '.dynsym' contains 343 entries:
Num:Value Size TypeBind Vis Ndx Name
0: 0 NOTYPE LOCAL DEFAULT UND
1: 4098 0 SECTION LOCAL DEFAULT 11
2: 4098 8 FUNCLOCAL DEFAULT 11 _init@@LIBBPF_0.0.1
3: 00023040 8 FUNCLOCAL DEFAULT 14 _fini@@LIBBPF_0.0.1
4: 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.0.4
5: 0 OBJECT GLOBAL DEFAULT ABS LIBBPF_0.0.1
6: ffa4 8 FUNCGLOBAL DEFAULT 12
bpf_object__find_map_by_offset@@LIBBPF_0.0.1
A previous commit filtered global symbols in sharedobjs/libbpf-in.o. Do the
same with the libbpf.so DSO for consistent comparison.
Fixes: 306b267cb3c4 ("libbpf: Verify versioned symbols")
Signed-off-by: Tony Ambardar
Signed-off-by: Alexei Starovoitov
Acked-by: Andrii Nakryiko
Link:
https://lore.kernel.org/bpf/20200905214831.1565465-1-tony.ambar...@gmail.com
Signed-off-by: Sasha Levin
---
tools/lib/bpf/Makefile |2 ++
1 file changed, 2 insertions(+)
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -152,6 +152,7 @@ GLOBAL_SYM_COUNT = $(shell readelf -s --
awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}' |
\
sort -u | wc -l)
VERSIONED_SYM_COUNT = $(shell readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \
+ awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print
$$NF}' | \
grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | sort -u
| wc -l)
CMD_TARGETS = $(LIB_TARGET) $(PC_FILE)
@@ -219,6 +220,7 @@ check_abi: $(OUTPUT)libbpf.so
awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \
sort -u > $(OUTPUT)libbpf_global_syms.tmp; \
readelf --dyn-syms --wide $(OUTPUT)libbpf.so | \
+ awk '/GLOBAL/ && /DEFAULT/ && !/UND/ {print $$NF}'| \
grep -Eo '[^ ]+@LIBBPF_' | cut -d@ -f1 | \
sort -u > $(OUTPUT)libbpf_versioned_syms.tmp;\
diff -u $(OUTPUT)libbpf_global_syms.tmp \
