* resolve_btfids breaks kernel cross-compilation
@ 2020-09-16 19:47 Seth Forshee
2020-09-17 8:04 ` Jiri Olsa
0 siblings, 1 reply; 8+ messages in thread
From: Seth Forshee @ 2020-09-16 19:47 UTC (permalink / raw)
To: Jiri Olsa; +Cc: Alexei Starovoitov, Daniel Borkmann, netdev, bpf, linux-kernel
The requirement to build resolve_btfids whenever CONFIG_DEBUG_INFO_BTF
is enabled breaks some cross builds. For example, when building a 64-bit
powerpc kernel on amd64 I get:
Auto-detecting system features:
... libelf: [ [32mon[m ]
... zlib: [ [32mon[m ]
... bpf: [ [31mOFF[m ]
BPF API too old
make[6]: *** [Makefile:295: bpfdep] Error 1
The contents of tools/bpf/resolve_btfids/feature/test-bpf.make.output:
In file included from /home/sforshee/src/u-k/unstable/tools/arch/powerpc/include/uapi/asm/bitsperlong.h:11,
from /usr/include/asm-generic/int-ll64.h:12,
from /usr/include/asm-generic/types.h:7,
from /usr/include/x86_64-linux-gnu/asm/types.h:1,
from /home/sforshee/src/u-k/unstable/tools/include/linux/types.h:10,
from /home/sforshee/src/u-k/unstable/tools/include/uapi/linux/bpf.h:11,
from test-bpf.c:3:
/home/sforshee/src/u-k/unstable/tools/include/asm-generic/bitsperlong.h:14:2: error: #error Inconsistent word size. Check asm/bitsperlong.h
14 | #error Inconsistent word size. Check asm/bitsperlong.h
| ^~~~~
This is because tools/arch/powerpc/include/uapi/asm/bitsperlong.h sets
__BITS_PER_LONG based on the predefinied compiler macro __powerpc64__,
which is not defined by the host compiler. What can we do to get cross
builds working again?
Thanks,
Seth
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: resolve_btfids breaks kernel cross-compilation
2020-09-16 19:47 resolve_btfids breaks kernel cross-compilation Seth Forshee
@ 2020-09-17 8:04 ` Jiri Olsa
2020-09-17 8:38 ` Jiri Olsa
0 siblings, 1 reply; 8+ messages in thread
From: Jiri Olsa @ 2020-09-17 8:04 UTC (permalink / raw)
To: Seth Forshee
Cc: Jiri Olsa, Alexei Starovoitov, Daniel Borkmann, netdev, bpf,
linux-kernel
On Wed, Sep 16, 2020 at 02:47:33PM -0500, Seth Forshee wrote:
> The requirement to build resolve_btfids whenever CONFIG_DEBUG_INFO_BTF
> is enabled breaks some cross builds. For example, when building a 64-bit
> powerpc kernel on amd64 I get:
>
> Auto-detecting system features:
> ... libelf: [ [32mon[m ]
> ... zlib: [ [32mon[m ]
> ... bpf: [ [31mOFF[m ]
>
> BPF API too old
> make[6]: *** [Makefile:295: bpfdep] Error 1
>
> The contents of tools/bpf/resolve_btfids/feature/test-bpf.make.output:
>
> In file included from /home/sforshee/src/u-k/unstable/tools/arch/powerpc/include/uapi/asm/bitsperlong.h:11,
> from /usr/include/asm-generic/int-ll64.h:12,
> from /usr/include/asm-generic/types.h:7,
> from /usr/include/x86_64-linux-gnu/asm/types.h:1,
> from /home/sforshee/src/u-k/unstable/tools/include/linux/types.h:10,
> from /home/sforshee/src/u-k/unstable/tools/include/uapi/linux/bpf.h:11,
> from test-bpf.c:3:
> /home/sforshee/src/u-k/unstable/tools/include/asm-generic/bitsperlong.h:14:2: error: #error Inconsistent word size. Check asm/bitsperlong.h
> 14 | #error Inconsistent word size. Check asm/bitsperlong.h
> | ^~~~~
>
> This is because tools/arch/powerpc/include/uapi/asm/bitsperlong.h sets
> __BITS_PER_LONG based on the predefinied compiler macro __powerpc64__,
> which is not defined by the host compiler. What can we do to get cross
> builds working again?
could you please share the command line and setup?
thanks,
jirka
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: resolve_btfids breaks kernel cross-compilation
2020-09-17 8:04 ` Jiri Olsa
@ 2020-09-17 8:38 ` Jiri Olsa
2020-09-17 9:14 ` Jiri Olsa
0 siblings, 1 reply; 8+ messages in thread
From: Jiri Olsa @ 2020-09-17 8:38 UTC (permalink / raw)
To: Seth Forshee
Cc: Jiri Olsa, Alexei Starovoitov, Daniel Borkmann, netdev, bpf,
linux-kernel
On Thu, Sep 17, 2020 at 10:04:55AM +0200, Jiri Olsa wrote:
> On Wed, Sep 16, 2020 at 02:47:33PM -0500, Seth Forshee wrote:
> > The requirement to build resolve_btfids whenever CONFIG_DEBUG_INFO_BTF
> > is enabled breaks some cross builds. For example, when building a 64-bit
> > powerpc kernel on amd64 I get:
> >
> > Auto-detecting system features:
> > ... libelf: [ [32mon[m ]
> > ... zlib: [ [32mon[m ]
> > ... bpf: [ [31mOFF[m ]
> >
> > BPF API too old
> > make[6]: *** [Makefile:295: bpfdep] Error 1
> >
> > The contents of tools/bpf/resolve_btfids/feature/test-bpf.make.output:
> >
> > In file included from /home/sforshee/src/u-k/unstable/tools/arch/powerpc/include/uapi/asm/bitsperlong.h:11,
> > from /usr/include/asm-generic/int-ll64.h:12,
> > from /usr/include/asm-generic/types.h:7,
> > from /usr/include/x86_64-linux-gnu/asm/types.h:1,
> > from /home/sforshee/src/u-k/unstable/tools/include/linux/types.h:10,
> > from /home/sforshee/src/u-k/unstable/tools/include/uapi/linux/bpf.h:11,
> > from test-bpf.c:3:
> > /home/sforshee/src/u-k/unstable/tools/include/asm-generic/bitsperlong.h:14:2: error: #error Inconsistent word size. Check asm/bitsperlong.h
> > 14 | #error Inconsistent word size. Check asm/bitsperlong.h
> > | ^~~~~
> >
> > This is because tools/arch/powerpc/include/uapi/asm/bitsperlong.h sets
> > __BITS_PER_LONG based on the predefinied compiler macro __powerpc64__,
> > which is not defined by the host compiler. What can we do to get cross
> > builds working again?
>
> could you please share the command line and setup?
I just reproduced.. checking on fix
jirka
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: resolve_btfids breaks kernel cross-compilation
2020-09-17 8:38 ` Jiri Olsa
@ 2020-09-17 9:14 ` Jiri Olsa
2020-09-17 9:54 ` Jiri Olsa
2020-09-17 12:54 ` Seth Forshee
0 siblings, 2 replies; 8+ messages in thread
From: Jiri Olsa @ 2020-09-17 9:14 UTC (permalink / raw)
To: Seth Forshee
Cc: Jiri Olsa, Alexei Starovoitov, Daniel Borkmann, netdev, bpf,
linux-kernel
On Thu, Sep 17, 2020 at 10:38:12AM +0200, Jiri Olsa wrote:
> On Thu, Sep 17, 2020 at 10:04:55AM +0200, Jiri Olsa wrote:
> > On Wed, Sep 16, 2020 at 02:47:33PM -0500, Seth Forshee wrote:
> > > The requirement to build resolve_btfids whenever CONFIG_DEBUG_INFO_BTF
> > > is enabled breaks some cross builds. For example, when building a 64-bit
> > > powerpc kernel on amd64 I get:
> > >
> > > Auto-detecting system features:
> > > ... libelf: [ [32mon[m ]
> > > ... zlib: [ [32mon[m ]
> > > ... bpf: [ [31mOFF[m ]
> > >
> > > BPF API too old
> > > make[6]: *** [Makefile:295: bpfdep] Error 1
> > >
> > > The contents of tools/bpf/resolve_btfids/feature/test-bpf.make.output:
> > >
> > > In file included from /home/sforshee/src/u-k/unstable/tools/arch/powerpc/include/uapi/asm/bitsperlong.h:11,
> > > from /usr/include/asm-generic/int-ll64.h:12,
> > > from /usr/include/asm-generic/types.h:7,
> > > from /usr/include/x86_64-linux-gnu/asm/types.h:1,
> > > from /home/sforshee/src/u-k/unstable/tools/include/linux/types.h:10,
> > > from /home/sforshee/src/u-k/unstable/tools/include/uapi/linux/bpf.h:11,
> > > from test-bpf.c:3:
> > > /home/sforshee/src/u-k/unstable/tools/include/asm-generic/bitsperlong.h:14:2: error: #error Inconsistent word size. Check asm/bitsperlong.h
> > > 14 | #error Inconsistent word size. Check asm/bitsperlong.h
> > > | ^~~~~
> > >
> > > This is because tools/arch/powerpc/include/uapi/asm/bitsperlong.h sets
> > > __BITS_PER_LONG based on the predefinied compiler macro __powerpc64__,
> > > which is not defined by the host compiler. What can we do to get cross
> > > builds working again?
> >
> > could you please share the command line and setup?
>
> I just reproduced.. checking on fix
I still need to check on few things, but patch below should help
we might have a problem for cross builds with different endianity
than the host because libbpf does not support reading BTF data
with different endianity, and we get:
BTFIDS vmlinux
libbpf: non-native ELF endianness is not supported
jirka
---
diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
index a88cd4426398..d3c818b8d8d3 100644
--- a/tools/bpf/resolve_btfids/Makefile
+++ b/tools/bpf/resolve_btfids/Makefile
@@ -1,5 +1,6 @@
# SPDX-License-Identifier: GPL-2.0-only
include ../../scripts/Makefile.include
+include ../../scripts/Makefile.arch
ifeq ($(srctree),)
srctree := $(patsubst %/,%,$(dir $(CURDIR)))
@@ -29,6 +30,7 @@ endif
AR = $(HOSTAR)
CC = $(HOSTCC)
LD = $(HOSTLD)
+ARCH = $(HOSTARCH)
OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: resolve_btfids breaks kernel cross-compilation
2020-09-17 9:14 ` Jiri Olsa
@ 2020-09-17 9:54 ` Jiri Olsa
2020-09-17 12:54 ` Seth Forshee
1 sibling, 0 replies; 8+ messages in thread
From: Jiri Olsa @ 2020-09-17 9:54 UTC (permalink / raw)
To: Seth Forshee
Cc: Jiri Olsa, Alexei Starovoitov, Daniel Borkmann, netdev, bpf,
linux-kernel
On Thu, Sep 17, 2020 at 11:14:08AM +0200, Jiri Olsa wrote:
> On Thu, Sep 17, 2020 at 10:38:12AM +0200, Jiri Olsa wrote:
> > On Thu, Sep 17, 2020 at 10:04:55AM +0200, Jiri Olsa wrote:
> > > On Wed, Sep 16, 2020 at 02:47:33PM -0500, Seth Forshee wrote:
> > > > The requirement to build resolve_btfids whenever CONFIG_DEBUG_INFO_BTF
> > > > is enabled breaks some cross builds. For example, when building a 64-bit
> > > > powerpc kernel on amd64 I get:
> > > >
> > > > Auto-detecting system features:
> > > > ... libelf: [ [32mon[m ]
> > > > ... zlib: [ [32mon[m ]
> > > > ... bpf: [ [31mOFF[m ]
> > > >
> > > > BPF API too old
> > > > make[6]: *** [Makefile:295: bpfdep] Error 1
> > > >
> > > > The contents of tools/bpf/resolve_btfids/feature/test-bpf.make.output:
> > > >
> > > > In file included from /home/sforshee/src/u-k/unstable/tools/arch/powerpc/include/uapi/asm/bitsperlong.h:11,
> > > > from /usr/include/asm-generic/int-ll64.h:12,
> > > > from /usr/include/asm-generic/types.h:7,
> > > > from /usr/include/x86_64-linux-gnu/asm/types.h:1,
> > > > from /home/sforshee/src/u-k/unstable/tools/include/linux/types.h:10,
> > > > from /home/sforshee/src/u-k/unstable/tools/include/uapi/linux/bpf.h:11,
> > > > from test-bpf.c:3:
> > > > /home/sforshee/src/u-k/unstable/tools/include/asm-generic/bitsperlong.h:14:2: error: #error Inconsistent word size. Check asm/bitsperlong.h
> > > > 14 | #error Inconsistent word size. Check asm/bitsperlong.h
> > > > | ^~~~~
> > > >
> > > > This is because tools/arch/powerpc/include/uapi/asm/bitsperlong.h sets
> > > > __BITS_PER_LONG based on the predefinied compiler macro __powerpc64__,
> > > > which is not defined by the host compiler. What can we do to get cross
> > > > builds working again?
> > >
> > > could you please share the command line and setup?
> >
> > I just reproduced.. checking on fix
>
> I still need to check on few things, but patch below should help
>
> we might have a problem for cross builds with different endianity
> than the host because libbpf does not support reading BTF data
> with different endianity, and we get:
>
> BTFIDS vmlinux
> libbpf: non-native ELF endianness is not supported
>
> jirka
>
>
> ---
> diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
> index a88cd4426398..d3c818b8d8d3 100644
> --- a/tools/bpf/resolve_btfids/Makefile
> +++ b/tools/bpf/resolve_btfids/Makefile
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0-only
> include ../../scripts/Makefile.include
> +include ../../scripts/Makefile.arch
>
> ifeq ($(srctree),)
> srctree := $(patsubst %/,%,$(dir $(CURDIR)))
> @@ -29,6 +30,7 @@ endif
> AR = $(HOSTAR)
> CC = $(HOSTCC)
> LD = $(HOSTLD)
> +ARCH = $(HOSTARCH)
>
> OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
>
and I realized we can have CONFIG_DEBUG_INFO_BTF without
CONFIG_BPF, so we need also fix below for such cases
jirka
---
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index e6e2d9e5ff48..8a990933a690 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -343,7 +343,10 @@ vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o}
# fill in BTF IDs
if [ -n "${CONFIG_DEBUG_INFO_BTF}" ]; then
info BTFIDS vmlinux
-${RESOLVE_BTFIDS} vmlinux
+if [ -z "${CONFIG_BPF}" ]; then
+ no_fail=--no-fail
+fi
+${RESOLVE_BTFIDS} $no_fail vmlinux
fi
if [ -n "${CONFIG_BUILDTIME_TABLE_SORT}" ]; then
^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: resolve_btfids breaks kernel cross-compilation
2020-09-17 9:14 ` Jiri Olsa
2020-09-17 9:54 ` Jiri Olsa
@ 2020-09-17 12:54 ` Seth Forshee
2020-09-18 10:05 ` Jiri Olsa
1 sibling, 1 reply; 8+ messages in thread
From: Seth Forshee @ 2020-09-17 12:54 UTC (permalink / raw)
To: Jiri Olsa
Cc: Jiri Olsa, Alexei Starovoitov, Daniel Borkmann, netdev, bpf,
linux-kernel
On Thu, Sep 17, 2020 at 11:14:06AM +0200, Jiri Olsa wrote:
> On Thu, Sep 17, 2020 at 10:38:12AM +0200, Jiri Olsa wrote:
> > On Thu, Sep 17, 2020 at 10:04:55AM +0200, Jiri Olsa wrote:
> > > On Wed, Sep 16, 2020 at 02:47:33PM -0500, Seth Forshee wrote:
> > > > The requirement to build resolve_btfids whenever CONFIG_DEBUG_INFO_BTF
> > > > is enabled breaks some cross builds. For example, when building a 64-bit
> > > > powerpc kernel on amd64 I get:
> > > >
> > > > Auto-detecting system features:
> > > > ... libelf: [ [32mon[m ]
> > > > ... zlib: [ [32mon[m ]
> > > > ... bpf: [ [31mOFF[m ]
> > > >
> > > > BPF API too old
> > > > make[6]: *** [Makefile:295: bpfdep] Error 1
> > > >
> > > > The contents of tools/bpf/resolve_btfids/feature/test-bpf.make.output:
> > > >
> > > > In file included from /home/sforshee/src/u-k/unstable/tools/arch/powerpc/include/uapi/asm/bitsperlong.h:11,
> > > > from /usr/include/asm-generic/int-ll64.h:12,
> > > > from /usr/include/asm-generic/types.h:7,
> > > > from /usr/include/x86_64-linux-gnu/asm/types.h:1,
> > > > from /home/sforshee/src/u-k/unstable/tools/include/linux/types.h:10,
> > > > from /home/sforshee/src/u-k/unstable/tools/include/uapi/linux/bpf.h:11,
> > > > from test-bpf.c:3:
> > > > /home/sforshee/src/u-k/unstable/tools/include/asm-generic/bitsperlong.h:14:2: error: #error Inconsistent word size. Check asm/bitsperlong.h
> > > > 14 | #error Inconsistent word size. Check asm/bitsperlong.h
> > > > | ^~~~~
> > > >
> > > > This is because tools/arch/powerpc/include/uapi/asm/bitsperlong.h sets
> > > > __BITS_PER_LONG based on the predefinied compiler macro __powerpc64__,
> > > > which is not defined by the host compiler. What can we do to get cross
> > > > builds working again?
> > >
> > > could you please share the command line and setup?
> >
> > I just reproduced.. checking on fix
>
> I still need to check on few things, but patch below should help
It does help with the word size problem, thanks.
> we might have a problem for cross builds with different endianity
> than the host because libbpf does not support reading BTF data
> with different endianity, and we get:
>
> BTFIDS vmlinux
> libbpf: non-native ELF endianness is not supported
Yes, I see this now when cross building for s390.
Thanks,
Seth
>
> jirka
>
>
> ---
> diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
> index a88cd4426398..d3c818b8d8d3 100644
> --- a/tools/bpf/resolve_btfids/Makefile
> +++ b/tools/bpf/resolve_btfids/Makefile
> @@ -1,5 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0-only
> include ../../scripts/Makefile.include
> +include ../../scripts/Makefile.arch
>
> ifeq ($(srctree),)
> srctree := $(patsubst %/,%,$(dir $(CURDIR)))
> @@ -29,6 +30,7 @@ endif
> AR = $(HOSTAR)
> CC = $(HOSTCC)
> LD = $(HOSTLD)
> +ARCH = $(HOSTARCH)
>
> OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
>
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: resolve_btfids breaks kernel cross-compilation
2020-09-17 12:54 ` Seth Forshee
@ 2020-09-18 10:05 ` Jiri Olsa
2020-09-18 18:50 ` Andrii Nakryiko
0 siblings, 1 reply; 8+ messages in thread
From: Jiri Olsa @ 2020-09-18 10:05 UTC (permalink / raw)
To: Seth Forshee, Andrii Nakryiko
Cc: Jiri Olsa, Alexei Starovoitov, Daniel Borkmann, netdev, bpf,
linux-kernel
On Thu, Sep 17, 2020 at 07:54:50AM -0500, Seth Forshee wrote:
> On Thu, Sep 17, 2020 at 11:14:06AM +0200, Jiri Olsa wrote:
> > On Thu, Sep 17, 2020 at 10:38:12AM +0200, Jiri Olsa wrote:
> > > On Thu, Sep 17, 2020 at 10:04:55AM +0200, Jiri Olsa wrote:
> > > > On Wed, Sep 16, 2020 at 02:47:33PM -0500, Seth Forshee wrote:
> > > > > The requirement to build resolve_btfids whenever CONFIG_DEBUG_INFO_BTF
> > > > > is enabled breaks some cross builds. For example, when building a 64-bit
> > > > > powerpc kernel on amd64 I get:
> > > > >
> > > > > Auto-detecting system features:
> > > > > ... libelf: [ [32mon[m ]
> > > > > ... zlib: [ [32mon[m ]
> > > > > ... bpf: [ [31mOFF[m ]
> > > > >
> > > > > BPF API too old
> > > > > make[6]: *** [Makefile:295: bpfdep] Error 1
> > > > >
> > > > > The contents of tools/bpf/resolve_btfids/feature/test-bpf.make.output:
> > > > >
> > > > > In file included from /home/sforshee/src/u-k/unstable/tools/arch/powerpc/include/uapi/asm/bitsperlong.h:11,
> > > > > from /usr/include/asm-generic/int-ll64.h:12,
> > > > > from /usr/include/asm-generic/types.h:7,
> > > > > from /usr/include/x86_64-linux-gnu/asm/types.h:1,
> > > > > from /home/sforshee/src/u-k/unstable/tools/include/linux/types.h:10,
> > > > > from /home/sforshee/src/u-k/unstable/tools/include/uapi/linux/bpf.h:11,
> > > > > from test-bpf.c:3:
> > > > > /home/sforshee/src/u-k/unstable/tools/include/asm-generic/bitsperlong.h:14:2: error: #error Inconsistent word size. Check asm/bitsperlong.h
> > > > > 14 | #error Inconsistent word size. Check asm/bitsperlong.h
> > > > > | ^~~~~
> > > > >
> > > > > This is because tools/arch/powerpc/include/uapi/asm/bitsperlong.h sets
> > > > > __BITS_PER_LONG based on the predefinied compiler macro __powerpc64__,
> > > > > which is not defined by the host compiler. What can we do to get cross
> > > > > builds working again?
> > > >
> > > > could you please share the command line and setup?
> > >
> > > I just reproduced.. checking on fix
> >
> > I still need to check on few things, but patch below should help
>
> It does help with the word size problem, thanks.
>
> > we might have a problem for cross builds with different endianity
> > than the host because libbpf does not support reading BTF data
> > with different endianity, and we get:
> >
> > BTFIDS vmlinux
> > libbpf: non-native ELF endianness is not supported
>
> Yes, I see this now when cross building for s390.
Andrii,
I read you might be already working on this?
https://lore.kernel.org/bpf/CAEf4Bza9tZ-Jj0dj9Ne0fmxa95t=9XxxJR+Ce=6hDmw_d8uVFA@mail.gmail.com/
thanks,
jirka
>
> Thanks,
> Seth
>
> >
> > jirka
> >
> >
> > ---
> > diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
> > index a88cd4426398..d3c818b8d8d3 100644
> > --- a/tools/bpf/resolve_btfids/Makefile
> > +++ b/tools/bpf/resolve_btfids/Makefile
> > @@ -1,5 +1,6 @@
> > # SPDX-License-Identifier: GPL-2.0-only
> > include ../../scripts/Makefile.include
> > +include ../../scripts/Makefile.arch
> >
> > ifeq ($(srctree),)
> > srctree := $(patsubst %/,%,$(dir $(CURDIR)))
> > @@ -29,6 +30,7 @@ endif
> > AR = $(HOSTAR)
> > CC = $(HOSTCC)
> > LD = $(HOSTLD)
> > +ARCH = $(HOSTARCH)
> >
> > OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
> >
> >
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: resolve_btfids breaks kernel cross-compilation
2020-09-18 10:05 ` Jiri Olsa
@ 2020-09-18 18:50 ` Andrii Nakryiko
0 siblings, 0 replies; 8+ messages in thread
From: Andrii Nakryiko @ 2020-09-18 18:50 UTC (permalink / raw)
To: Jiri Olsa
Cc: Seth Forshee, Andrii Nakryiko, Jiri Olsa, Alexei Starovoitov,
Daniel Borkmann, Networking, bpf, open list
On Fri, Sep 18, 2020 at 3:07 AM Jiri Olsa <jolsa@redhat.com> wrote:
>
> On Thu, Sep 17, 2020 at 07:54:50AM -0500, Seth Forshee wrote:
> > On Thu, Sep 17, 2020 at 11:14:06AM +0200, Jiri Olsa wrote:
> > > On Thu, Sep 17, 2020 at 10:38:12AM +0200, Jiri Olsa wrote:
> > > > On Thu, Sep 17, 2020 at 10:04:55AM +0200, Jiri Olsa wrote:
> > > > > On Wed, Sep 16, 2020 at 02:47:33PM -0500, Seth Forshee wrote:
> > > > > > The requirement to build resolve_btfids whenever CONFIG_DEBUG_INFO_BTF
> > > > > > is enabled breaks some cross builds. For example, when building a 64-bit
> > > > > > powerpc kernel on amd64 I get:
> > > > > >
> > > > > > Auto-detecting system features:
> > > > > > ... libelf: [ [32mon[m ]
> > > > > > ... zlib: [ [32mon[m ]
> > > > > > ... bpf: [ [31mOFF[m ]
> > > > > >
> > > > > > BPF API too old
> > > > > > make[6]: *** [Makefile:295: bpfdep] Error 1
> > > > > >
> > > > > > The contents of tools/bpf/resolve_btfids/feature/test-bpf.make.output:
> > > > > >
> > > > > > In file included from /home/sforshee/src/u-k/unstable/tools/arch/powerpc/include/uapi/asm/bitsperlong.h:11,
> > > > > > from /usr/include/asm-generic/int-ll64.h:12,
> > > > > > from /usr/include/asm-generic/types.h:7,
> > > > > > from /usr/include/x86_64-linux-gnu/asm/types.h:1,
> > > > > > from /home/sforshee/src/u-k/unstable/tools/include/linux/types.h:10,
> > > > > > from /home/sforshee/src/u-k/unstable/tools/include/uapi/linux/bpf.h:11,
> > > > > > from test-bpf.c:3:
> > > > > > /home/sforshee/src/u-k/unstable/tools/include/asm-generic/bitsperlong.h:14:2: error: #error Inconsistent word size. Check asm/bitsperlong.h
> > > > > > 14 | #error Inconsistent word size. Check asm/bitsperlong.h
> > > > > > | ^~~~~
> > > > > >
> > > > > > This is because tools/arch/powerpc/include/uapi/asm/bitsperlong.h sets
> > > > > > __BITS_PER_LONG based on the predefinied compiler macro __powerpc64__,
> > > > > > which is not defined by the host compiler. What can we do to get cross
> > > > > > builds working again?
> > > > >
> > > > > could you please share the command line and setup?
> > > >
> > > > I just reproduced.. checking on fix
> > >
> > > I still need to check on few things, but patch below should help
> >
> > It does help with the word size problem, thanks.
> >
> > > we might have a problem for cross builds with different endianity
> > > than the host because libbpf does not support reading BTF data
> > > with different endianity, and we get:
> > >
> > > BTFIDS vmlinux
> > > libbpf: non-native ELF endianness is not supported
> >
> > Yes, I see this now when cross building for s390.
>
> Andrii,
> I read you might be already working on this?
> https://lore.kernel.org/bpf/CAEf4Bza9tZ-Jj0dj9Ne0fmxa95t=9XxxJR+Ce=6hDmw_d8uVFA@mail.gmail.com/
>
Yes, it's one of the limitations I'm solving, stay tuned.
> thanks,
> jirka
>
> >
> > Thanks,
> > Seth
> >
> > >
> > > jirka
> > >
> > >
> > > ---
> > > diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
> > > index a88cd4426398..d3c818b8d8d3 100644
> > > --- a/tools/bpf/resolve_btfids/Makefile
> > > +++ b/tools/bpf/resolve_btfids/Makefile
> > > @@ -1,5 +1,6 @@
> > > # SPDX-License-Identifier: GPL-2.0-only
> > > include ../../scripts/Makefile.include
> > > +include ../../scripts/Makefile.arch
> > >
> > > ifeq ($(srctree),)
> > > srctree := $(patsubst %/,%,$(dir $(CURDIR)))
> > > @@ -29,6 +30,7 @@ endif
> > > AR = $(HOSTAR)
> > > CC = $(HOSTCC)
> > > LD = $(HOSTLD)
> > > +ARCH = $(HOSTARCH)
> > >
> > > OUTPUT ?= $(srctree)/tools/bpf/resolve_btfids/
> > >
> > >
> >
>
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2020-09-18 18:50 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-16 19:47 resolve_btfids breaks kernel cross-compilation Seth Forshee
2020-09-17 8:04 ` Jiri Olsa
2020-09-17 8:38 ` Jiri Olsa
2020-09-17 9:14 ` Jiri Olsa
2020-09-17 9:54 ` Jiri Olsa
2020-09-17 12:54 ` Seth Forshee
2020-09-18 10:05 ` Jiri Olsa
2020-09-18 18:50 ` Andrii Nakryiko
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