On Tue, 2022-02-08 at 14:14 -0800, Andrii Nakryiko wrote:
> On Mon, Feb 7, 2022 at 9:16 PM Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
> wrote:
> >
> > These macros are useful for both libbpf and bpf progs, so put them
> > into
> > a separate header dedicated to this use case.
> >
> > Signed-off-by: Ilya Leoshkevich <iii@xxxxxxxxxxxxx>
> > ---
> > tools/lib/bpf/Makefile | 2 +-
> > tools/lib/bpf/bpf_common_helpers.h | 30
> > ++++++++++++++++++++++++++
> > tools/lib/bpf/bpf_helpers.h | 15 +------------
> > tools/testing/selftests/bpf/bpf_util.h | 10 +--------
> > 4 files changed, 33 insertions(+), 24 deletions(-)
> > create mode 100644 tools/lib/bpf/bpf_common_helpers.h
> >
> > diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
> > index b8b37fe76006..60b06c22e0a1 100644
> > --- a/tools/lib/bpf/Makefile
> > +++ b/tools/lib/bpf/Makefile
> > @@ -239,7 +239,7 @@ install_lib: all_cmd
> >
> > SRC_HDRS := bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h
> > xsk.h \
> > bpf_helpers.h bpf_tracing.h bpf_endian.h
> > bpf_core_read.h \
> > - skel_internal.h libbpf_version.h
> > + skel_internal.h libbpf_version.h bpf_common_helpers.h
>
> Wait, how did we get from fixing s390x syscall arg fetching to
> exposing a new public API header from libbpf?... I feel like I missed
> a few revisions and discussion threads.
I didn't want to add yet another copy of
offsetof/sizeof_field/offsetofend to the code. However, since we don't
need offsetofend anymore, this patch will be dropped.
>
> > GEN_HDRS := $(BPF_GENERATED)
> >
> > INSTALL_PFX := $(DESTDIR)$(prefix)/include/bpf
> > diff --git a/tools/lib/bpf/bpf_common_helpers.h
> > b/tools/lib/bpf/bpf_common_helpers.h
> > new file mode 100644
> > index 000000000000..79db303b6ae2
> > --- /dev/null
> > +++ b/tools/lib/bpf/bpf_common_helpers.h
> > @@ -0,0 +1,30 @@
> > +/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */
> > +#ifndef __BPF_COMMON_HELPERS__
> > +#define __BPF_COMMON_HELPERS__
> > +
> > +/*
> > + * Helper macros that can be used both by libbpf and bpf progs.
> > + */
> > +
> > +#ifndef offsetof
> > +#define offsetof(TYPE, MEMBER) ((unsigned long)&((TYPE *)0)-
> > >MEMBER)
> > +#endif
> > +
> > +#ifndef sizeof_field
> > +#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
> > +#endif
> > +
> > +#ifndef offsetofend
> > +#define offsetofend(TYPE, MEMBER) \
> > + (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER))
> > +#endif
> > +
> > +#ifndef container_of
> > +#define container_of(ptr, type,
> > member) \
> > + ({ \
> > + void *__mptr = (void *)(ptr); \
> > + ((type *)(__mptr - offsetof(type, member))); \
> > + })
> > +#endif
> > +
> > +#endif
> > diff --git a/tools/lib/bpf/bpf_helpers.h
> > b/tools/lib/bpf/bpf_helpers.h
> > index 44df982d2a5c..1e8b609c1000 100644
> > --- a/tools/lib/bpf/bpf_helpers.h
> > +++ b/tools/lib/bpf/bpf_helpers.h
> > @@ -2,6 +2,7 @@
> > #ifndef __BPF_HELPERS__
> > #define __BPF_HELPERS__
> >
> > +#include "bpf_common_helpers.h"
> > /*
> > * Note that bpf programs need to include either
> > * vmlinux.h (auto-generated from BTF) or linux/types.h
> > @@ -61,20 +62,6 @@
> > #define KERNEL_VERSION(a, b, c) (((a) << 16) + ((b) << 8) + ((c) >
> > 255 ? 255 : (c)))
> > #endif
> >
> > -/*
> > - * Helper macros to manipulate data structures
> > - */
> > -#ifndef offsetof
> > -#define offsetof(TYPE, MEMBER) ((unsigned long)&((TYPE *)0)-
> > >MEMBER)
> > -#endif
> > -#ifndef container_of
> > -#define container_of(ptr, type,
> > member) \
> > - ({ \
> > - void *__mptr = (void *)(ptr); \
> > - ((type *)(__mptr - offsetof(type, member))); \
> > - })
> > -#endif
> > -
> > /*
> > * Helper macro to throw a compilation error if
> > __bpf_unreachable() gets
> > * built into the resulting code. This works given BPF back end
> > does not
> > diff --git a/tools/testing/selftests/bpf/bpf_util.h
> > b/tools/testing/selftests/bpf/bpf_util.h
> > index a3352a64c067..bc0b741b1eef 100644
> > --- a/tools/testing/selftests/bpf/bpf_util.h
> > +++ b/tools/testing/selftests/bpf/bpf_util.h
> > @@ -6,6 +6,7 @@
> > #include <stdlib.h>
> > #include <string.h>
> > #include <errno.h>
> > +#include <bpf/bpf_common_helpers.h>
> > #include <bpf/libbpf.h> /* libbpf_num_possible_cpus */
> >
> > static inline unsigned int bpf_num_possible_cpus(void)
> > @@ -31,13 +32,4 @@ static inline unsigned int
> > bpf_num_possible_cpus(void)
> > # define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
> > #endif
> >
> > -#ifndef sizeof_field
> > -#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
> > -#endif
> > -
> > -#ifndef offsetofend
> > -#define offsetofend(TYPE, MEMBER) \
> > - (offsetof(TYPE, MEMBER) + sizeof_field(TYPE, MEMBER))
> > -#endif
> > -
> > #endif /* __BPF_UTIL__ */
> > --
> > 2.34.1
> >
