* [PATCH bpf] samples: bpf: Fix vmlinux.h generation for XDP samples
@ 2021-09-28 4:13 Kumar Kartikeya Dwivedi
2021-09-28 4:36 ` Andrii Nakryiko
0 siblings, 1 reply; 5+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-09-28 4:13 UTC (permalink / raw)
To: bpf; +Cc: Kumar Kartikeya Dwivedi, Toke Høiland-Jørgensen
Generate vmlinux.h only from the in-tree vmlinux, and remove enum
declarations that would cause a build failure in case of version
mismatches.
There are now two options when building the samples:
1. Compile the kernel to use in-tree vmlinux for vmlinux.h
2. Override VMLINUX_BTF for samples using something like this:
make VMLINUX_BTF=/sys/kernel/btf/vmlinux -C samples/bpf
This change was tested with relative builds, e.g. cases like:
* make O=build -C samples/bpf
* make KBUILD_OUTPUT=build -C samples/bpf
* make -C samples/bpf
* cd samples/bpf && make
When a suitable VMLINUX_BTF is not found, the following message is
printed:
/home/kkd/src/linux/samples/bpf/Makefile:333: *** Cannot find a vmlinux
for VMLINUX_BTF at any of " ./vmlinux", build the kernel or set
VMLINUX_BTF variable. Stop.
Cc: Toke Høiland-Jørgensen <toke@redhat.com>
Fixes: 384b6b3bbf0d (samples: bpf: Add vmlinux.h generation support)
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
samples/bpf/Makefile | 13 ++++++-------
samples/bpf/xdp_redirect_map_multi.bpf.c | 5 -----
2 files changed, 6 insertions(+), 12 deletions(-)
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
index 4dc20be5fb96..a05130e91403 100644
--- a/samples/bpf/Makefile
+++ b/samples/bpf/Makefile
@@ -324,15 +324,9 @@ $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
$(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
- ../../../../vmlinux \
- /sys/kernel/btf/vmlinux \
- /boot/vmlinux-$(shell uname -r)
+ ./vmlinux
VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
-ifeq ($(VMLINUX_BTF),)
-$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)")
-endif
-
$(obj)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL)
ifeq ($(VMLINUX_H),)
$(Q)$(BPFTOOL) btf dump file $(VMLINUX_BTF) format c > $@
@@ -340,6 +334,11 @@ else
$(Q)cp "$(VMLINUX_H)" $@
endif
+ifeq ($(VMLINUX_BTF),)
+ $(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)",\
+ build the kernel or set VMLINUX_BTF variable)
+endif
+
clean-files += vmlinux.h
# Get Clang's default includes on this system, as opposed to those seen by
diff --git a/samples/bpf/xdp_redirect_map_multi.bpf.c b/samples/bpf/xdp_redirect_map_multi.bpf.c
index 8f59d430cb64..bb0a5a3bfcf0 100644
--- a/samples/bpf/xdp_redirect_map_multi.bpf.c
+++ b/samples/bpf/xdp_redirect_map_multi.bpf.c
@@ -5,11 +5,6 @@
#include "xdp_sample.bpf.h"
#include "xdp_sample_shared.h"
-enum {
- BPF_F_BROADCAST = (1ULL << 3),
- BPF_F_EXCLUDE_INGRESS = (1ULL << 4),
-};
-
struct {
__uint(type, BPF_MAP_TYPE_DEVMAP_HASH);
__uint(key_size, sizeof(int));
--
2.33.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH bpf] samples: bpf: Fix vmlinux.h generation for XDP samples
2021-09-28 4:13 [PATCH bpf] samples: bpf: Fix vmlinux.h generation for XDP samples Kumar Kartikeya Dwivedi
@ 2021-09-28 4:36 ` Andrii Nakryiko
2021-09-28 4:51 ` Kumar Kartikeya Dwivedi
0 siblings, 1 reply; 5+ messages in thread
From: Andrii Nakryiko @ 2021-09-28 4:36 UTC (permalink / raw)
To: Kumar Kartikeya Dwivedi; +Cc: bpf, Toke Høiland-Jørgensen
On Mon, Sep 27, 2021 at 9:16 PM Kumar Kartikeya Dwivedi
<memxor@gmail.com> wrote:
>
> Generate vmlinux.h only from the in-tree vmlinux, and remove enum
> declarations that would cause a build failure in case of version
> mismatches.
>
> There are now two options when building the samples:
> 1. Compile the kernel to use in-tree vmlinux for vmlinux.h
> 2. Override VMLINUX_BTF for samples using something like this:
> make VMLINUX_BTF=/sys/kernel/btf/vmlinux -C samples/bpf
>
> This change was tested with relative builds, e.g. cases like:
> * make O=build -C samples/bpf
> * make KBUILD_OUTPUT=build -C samples/bpf
> * make -C samples/bpf
> * cd samples/bpf && make
>
> When a suitable VMLINUX_BTF is not found, the following message is
> printed:
> /home/kkd/src/linux/samples/bpf/Makefile:333: *** Cannot find a vmlinux
> for VMLINUX_BTF at any of " ./vmlinux", build the kernel or set
> VMLINUX_BTF variable. Stop.
>
> Cc: Toke Høiland-Jørgensen <toke@redhat.com>
> Fixes: 384b6b3bbf0d (samples: bpf: Add vmlinux.h generation support)
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> ---
> samples/bpf/Makefile | 13 ++++++-------
> samples/bpf/xdp_redirect_map_multi.bpf.c | 5 -----
> 2 files changed, 6 insertions(+), 12 deletions(-)
>
> diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> index 4dc20be5fb96..a05130e91403 100644
> --- a/samples/bpf/Makefile
> +++ b/samples/bpf/Makefile
> @@ -324,15 +324,9 @@ $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
>
> VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
> $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
> - ../../../../vmlinux \
> - /sys/kernel/btf/vmlinux \
> - /boot/vmlinux-$(shell uname -r)
> + ./vmlinux
isn't this relative to samples/bpf subdirectory, so shouldn't it be
../../vmlinux?
> VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
>
> -ifeq ($(VMLINUX_BTF),)
> -$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)")
> -endif
> -
[...]
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH bpf] samples: bpf: Fix vmlinux.h generation for XDP samples
2021-09-28 4:36 ` Andrii Nakryiko
@ 2021-09-28 4:51 ` Kumar Kartikeya Dwivedi
2021-09-28 5:28 ` Andrii Nakryiko
0 siblings, 1 reply; 5+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-09-28 4:51 UTC (permalink / raw)
To: Andrii Nakryiko; +Cc: bpf, Toke Høiland-Jørgensen
On Tue, Sep 28, 2021 at 10:06:09AM IST, Andrii Nakryiko wrote:
> On Mon, Sep 27, 2021 at 9:16 PM Kumar Kartikeya Dwivedi
> <memxor@gmail.com> wrote:
> >
> > Generate vmlinux.h only from the in-tree vmlinux, and remove enum
> > declarations that would cause a build failure in case of version
> > mismatches.
> >
> > There are now two options when building the samples:
> > 1. Compile the kernel to use in-tree vmlinux for vmlinux.h
> > 2. Override VMLINUX_BTF for samples using something like this:
> > make VMLINUX_BTF=/sys/kernel/btf/vmlinux -C samples/bpf
> >
> > This change was tested with relative builds, e.g. cases like:
> > * make O=build -C samples/bpf
> > * make KBUILD_OUTPUT=build -C samples/bpf
> > * make -C samples/bpf
> > * cd samples/bpf && make
> >
> > When a suitable VMLINUX_BTF is not found, the following message is
> > printed:
> > /home/kkd/src/linux/samples/bpf/Makefile:333: *** Cannot find a vmlinux
> > for VMLINUX_BTF at any of " ./vmlinux", build the kernel or set
> > VMLINUX_BTF variable. Stop.
> >
> > Cc: Toke Høiland-Jørgensen <toke@redhat.com>
> > Fixes: 384b6b3bbf0d (samples: bpf: Add vmlinux.h generation support)
> > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> > ---
> > samples/bpf/Makefile | 13 ++++++-------
> > samples/bpf/xdp_redirect_map_multi.bpf.c | 5 -----
> > 2 files changed, 6 insertions(+), 12 deletions(-)
> >
> > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> > index 4dc20be5fb96..a05130e91403 100644
> > --- a/samples/bpf/Makefile
> > +++ b/samples/bpf/Makefile
> > @@ -324,15 +324,9 @@ $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
> >
> > VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
> > $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
> > - ../../../../vmlinux \
> > - /sys/kernel/btf/vmlinux \
> > - /boot/vmlinux-$(shell uname -r)
> > + ./vmlinux
>
> isn't this relative to samples/bpf subdirectory, so shouldn't it be
> ../../vmlinux?
>
I was confused about this too; but it executes this when you call make:
# Trick to allow make to be run from this directory
all:
$(MAKE) -C ../../ M=$(CURDIR) BPF_SAMPLES_PATH=$(CURDIR)
so it fails if the path isn't relative to kernel source root.
> > VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
> >
> > -ifeq ($(VMLINUX_BTF),)
> > -$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)")
> > -endif
> > -
>
> [...]
--
Kartikeya
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH bpf] samples: bpf: Fix vmlinux.h generation for XDP samples
2021-09-28 4:51 ` Kumar Kartikeya Dwivedi
@ 2021-09-28 5:28 ` Andrii Nakryiko
2021-09-28 5:44 ` Kumar Kartikeya Dwivedi
0 siblings, 1 reply; 5+ messages in thread
From: Andrii Nakryiko @ 2021-09-28 5:28 UTC (permalink / raw)
To: Kumar Kartikeya Dwivedi; +Cc: bpf, Toke Høiland-Jørgensen
On Mon, Sep 27, 2021 at 9:51 PM Kumar Kartikeya Dwivedi
<memxor@gmail.com> wrote:
>
> On Tue, Sep 28, 2021 at 10:06:09AM IST, Andrii Nakryiko wrote:
> > On Mon, Sep 27, 2021 at 9:16 PM Kumar Kartikeya Dwivedi
> > <memxor@gmail.com> wrote:
> > >
> > > Generate vmlinux.h only from the in-tree vmlinux, and remove enum
> > > declarations that would cause a build failure in case of version
> > > mismatches.
> > >
> > > There are now two options when building the samples:
> > > 1. Compile the kernel to use in-tree vmlinux for vmlinux.h
> > > 2. Override VMLINUX_BTF for samples using something like this:
> > > make VMLINUX_BTF=/sys/kernel/btf/vmlinux -C samples/bpf
> > >
> > > This change was tested with relative builds, e.g. cases like:
> > > * make O=build -C samples/bpf
> > > * make KBUILD_OUTPUT=build -C samples/bpf
> > > * make -C samples/bpf
> > > * cd samples/bpf && make
> > >
> > > When a suitable VMLINUX_BTF is not found, the following message is
> > > printed:
> > > /home/kkd/src/linux/samples/bpf/Makefile:333: *** Cannot find a vmlinux
> > > for VMLINUX_BTF at any of " ./vmlinux", build the kernel or set
> > > VMLINUX_BTF variable. Stop.
> > >
> > > Cc: Toke Høiland-Jørgensen <toke@redhat.com>
> > > Fixes: 384b6b3bbf0d (samples: bpf: Add vmlinux.h generation support)
> > > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> > > ---
> > > samples/bpf/Makefile | 13 ++++++-------
> > > samples/bpf/xdp_redirect_map_multi.bpf.c | 5 -----
> > > 2 files changed, 6 insertions(+), 12 deletions(-)
> > >
> > > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> > > index 4dc20be5fb96..a05130e91403 100644
> > > --- a/samples/bpf/Makefile
> > > +++ b/samples/bpf/Makefile
> > > @@ -324,15 +324,9 @@ $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
> > >
> > > VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
> > > $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
> > > - ../../../../vmlinux \
> > > - /sys/kernel/btf/vmlinux \
> > > - /boot/vmlinux-$(shell uname -r)
> > > + ./vmlinux
> >
> > isn't this relative to samples/bpf subdirectory, so shouldn't it be
> > ../../vmlinux?
> >
>
> I was confused about this too; but it executes this when you call make:
>
> # Trick to allow make to be run from this directory
> all:
> $(MAKE) -C ../../ M=$(CURDIR) BPF_SAMPLES_PATH=$(CURDIR)
>
> so it fails if the path isn't relative to kernel source root.
Hm... what if we do $(abspath ./vmlinux) here (and probably same for
$(O) and $(KBUILD_OUTPUT) just in case those are relative as well,
would that do the right thing here? The way it is right now it's
extremely confusing (and obviously ../../../../vmlinux never worked
and we never knew that).
>
> > > VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
> > >
> > > -ifeq ($(VMLINUX_BTF),)
> > > -$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)")
> > > -endif
> > > -
> >
> > [...]
>
> --
> Kartikeya
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH bpf] samples: bpf: Fix vmlinux.h generation for XDP samples
2021-09-28 5:28 ` Andrii Nakryiko
@ 2021-09-28 5:44 ` Kumar Kartikeya Dwivedi
0 siblings, 0 replies; 5+ messages in thread
From: Kumar Kartikeya Dwivedi @ 2021-09-28 5:44 UTC (permalink / raw)
To: Andrii Nakryiko; +Cc: bpf, Toke Høiland-Jørgensen
On Tue, Sep 28, 2021 at 10:58:01AM IST, Andrii Nakryiko wrote:
> On Mon, Sep 27, 2021 at 9:51 PM Kumar Kartikeya Dwivedi
> <memxor@gmail.com> wrote:
> >
> > On Tue, Sep 28, 2021 at 10:06:09AM IST, Andrii Nakryiko wrote:
> > > On Mon, Sep 27, 2021 at 9:16 PM Kumar Kartikeya Dwivedi
> > > <memxor@gmail.com> wrote:
> > > >
> > > > Generate vmlinux.h only from the in-tree vmlinux, and remove enum
> > > > declarations that would cause a build failure in case of version
> > > > mismatches.
> > > >
> > > > There are now two options when building the samples:
> > > > 1. Compile the kernel to use in-tree vmlinux for vmlinux.h
> > > > 2. Override VMLINUX_BTF for samples using something like this:
> > > > make VMLINUX_BTF=/sys/kernel/btf/vmlinux -C samples/bpf
> > > >
> > > > This change was tested with relative builds, e.g. cases like:
> > > > * make O=build -C samples/bpf
> > > > * make KBUILD_OUTPUT=build -C samples/bpf
> > > > * make -C samples/bpf
> > > > * cd samples/bpf && make
> > > >
> > > > When a suitable VMLINUX_BTF is not found, the following message is
> > > > printed:
> > > > /home/kkd/src/linux/samples/bpf/Makefile:333: *** Cannot find a vmlinux
> > > > for VMLINUX_BTF at any of " ./vmlinux", build the kernel or set
> > > > VMLINUX_BTF variable. Stop.
> > > >
> > > > Cc: Toke Høiland-Jørgensen <toke@redhat.com>
> > > > Fixes: 384b6b3bbf0d (samples: bpf: Add vmlinux.h generation support)
> > > > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> > > > ---
> > > > samples/bpf/Makefile | 13 ++++++-------
> > > > samples/bpf/xdp_redirect_map_multi.bpf.c | 5 -----
> > > > 2 files changed, 6 insertions(+), 12 deletions(-)
> > > >
> > > > diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile
> > > > index 4dc20be5fb96..a05130e91403 100644
> > > > --- a/samples/bpf/Makefile
> > > > +++ b/samples/bpf/Makefile
> > > > @@ -324,15 +324,9 @@ $(obj)/hbm_edt_kern.o: $(src)/hbm.h $(src)/hbm_kern.h
> > > >
> > > > VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
> > > > $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
> > > > - ../../../../vmlinux \
> > > > - /sys/kernel/btf/vmlinux \
> > > > - /boot/vmlinux-$(shell uname -r)
> > > > + ./vmlinux
> > >
> > > isn't this relative to samples/bpf subdirectory, so shouldn't it be
> > > ../../vmlinux?
> > >
> >
> > I was confused about this too; but it executes this when you call make:
> >
> > # Trick to allow make to be run from this directory
> > all:
> > $(MAKE) -C ../../ M=$(CURDIR) BPF_SAMPLES_PATH=$(CURDIR)
> >
> > so it fails if the path isn't relative to kernel source root.
>
> Hm... what if we do $(abspath ./vmlinux) here (and probably same for
> $(O) and $(KBUILD_OUTPUT) just in case those are relative as well,
> would that do the right thing here? The way it is right now it's
Yeah, that works. I'll send a v2.
> extremely confusing (and obviously ../../../../vmlinux never worked
> and we never knew that).
>
Indeed.
> >
> > > > VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS))))
> > > >
> > > > -ifeq ($(VMLINUX_BTF),)
> > > > -$(error Cannot find a vmlinux for VMLINUX_BTF at any of "$(VMLINUX_BTF_PATHS)")
> > > > -endif
> > > > -
> > >
> > > [...]
> >
> > --
> > Kartikeya
--
Kartikeya
^ permalink raw reply [flat|nested] 5+ messages in thread
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2021-09-28 4:13 [PATCH bpf] samples: bpf: Fix vmlinux.h generation for XDP samples Kumar Kartikeya Dwivedi
2021-09-28 4:36 ` Andrii Nakryiko
2021-09-28 4:51 ` Kumar Kartikeya Dwivedi
2021-09-28 5:28 ` Andrii Nakryiko
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