* [PATCH v2 bpf-next] libbpf: add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecations
@ 2021-09-08 6:55 Andrii Nakryiko
2021-09-08 13:01 ` Daniel Borkmann
0 siblings, 1 reply; 3+ messages in thread
From: Andrii Nakryiko @ 2021-09-08 6:55 UTC (permalink / raw)
To: bpf, ast, daniel, quentin; +Cc: andrii, kernel-team
From: Quentin Monnet <quentin@isovalent.com>
Introduce a macro LIBBPF_DEPRECATED_SINCE(major, minor, message) to prepare
the deprecation of two API functions. This macro marks functions as deprecated
when libbpf's version reaches the values passed as an argument.
As part of this change libbpf_version.h header is added with recorded major
(LIBBPF_MAJOR_VERSION) and minor (LIBBPF_MINOR_VERSION) libbpf version macros.
They are now part of libbpf public API and can be relied upon by user code.
libbpf_version.h is installed system-wide along other libbpf public headers.
Due to this new build-time auto-generated header, in-kernel applications
relying on libbpf (resolve_btfids, bpftool, bpf_preload) are updated to
include libbpf's output directory as part of a list of include search paths.
Better fix would be to use libbpf's make_install target to install public API
headers, but that clean up is left out as a future improvement. The build
changes were tested by building kernel (with KBUILD_OUTPUT and O= specified
explicitly), bpftool, libbpf, selftests/bpf, and resolve_btfids builds. No
problems were detected.
Note that because of the constraints of the C preprocessor we have to write
a few lines of macro magic for each version used to prepare deprecation (0.6
for now).
Also, use LIBBPF_DEPRECATED_SINCE() to schedule deprecation of
btf__get_from_id() and btf__load(), which are replaced by
btf__load_from_kernel_by_id() and btf__load_into_kernel(), respectively,
starting from future libbpf v0.6. This is part of libbpf 1.0 effort ([0]).
[0] Closes: https://github.com/libbpf/libbpf/issues/278
Co-developed-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
v1->v2:
- fix bpf_preload build by adding dependency for iterators/iterators.o on
libbpf.a generation (caught by BPF CI);
kernel/bpf/preload/Makefile | 7 +++++--
tools/bpf/bpftool/Makefile | 4 ++++
tools/bpf/resolve_btfids/Makefile | 4 +++-
tools/lib/bpf/Makefile | 24 +++++++++++++++++-------
tools/lib/bpf/btf.h | 2 ++
tools/lib/bpf/libbpf_common.h | 19 +++++++++++++++++++
6 files changed, 50 insertions(+), 10 deletions(-)
diff --git a/kernel/bpf/preload/Makefile b/kernel/bpf/preload/Makefile
index 1951332dd15f..ac29d4e9a384 100644
--- a/kernel/bpf/preload/Makefile
+++ b/kernel/bpf/preload/Makefile
@@ -10,12 +10,15 @@ LIBBPF_OUT = $(abspath $(obj))
$(LIBBPF_A):
$(Q)$(MAKE) -C $(LIBBPF_SRCS) O=$(LIBBPF_OUT)/ OUTPUT=$(LIBBPF_OUT)/ $(LIBBPF_OUT)/libbpf.a
-userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi \
+userccflags += -I$(LIBBPF_OUT) -I $(srctree)/tools/include/ \
+ -I $(srctree)/tools/include/uapi \
-I $(srctree)/tools/lib/ -Wno-unused-result
userprogs := bpf_preload_umd
-clean-files := $(userprogs) bpf_helper_defs.h FEATURE-DUMP.libbpf staticobjs/ feature/
+clean-files := $(userprogs) libbpf_version.h bpf_helper_defs.h FEATURE-DUMP.libbpf staticobjs/ feature/
+
+$(obj)/iterators/iterators.o: $(LIBBPF_A)
bpf_preload_umd-objs := iterators/iterators.o
bpf_preload_umd-userldlibs := $(LIBBPF_A) -lelf -lz
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index d73232be1e99..06aa1616dabe 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -60,6 +60,7 @@ CFLAGS += -W -Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers
CFLAGS += $(filter-out -Wswitch-enum -Wnested-externs,$(EXTRA_WARNINGS))
CFLAGS += -DPACKAGE='"bpftool"' -D__EXPORTED_HEADERS__ \
-I$(if $(OUTPUT),$(OUTPUT),.) \
+ $(if $(LIBBPF_OUTPUT),-I$(LIBBPF_OUTPUT)) \
-I$(srctree)/kernel/bpf/ \
-I$(srctree)/tools/include \
-I$(srctree)/tools/include/uapi \
@@ -137,7 +138,10 @@ endif
BPFTOOL_BOOTSTRAP := $(BOOTSTRAP_OUTPUT)bpftool
BOOTSTRAP_OBJS = $(addprefix $(BOOTSTRAP_OUTPUT),main.o common.o json_writer.o gen.o btf.o xlated_dumper.o btf_dumper.o disasm.o)
+$(BOOTSTRAP_OBJS): $(LIBBPF_BOOTSTRAP)
+
OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
+$(OBJS): $(LIBBPF)
VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \
$(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \
diff --git a/tools/bpf/resolve_btfids/Makefile b/tools/bpf/resolve_btfids/Makefile
index bb9fa8de7e62..d9ef8a959ed8 100644
--- a/tools/bpf/resolve_btfids/Makefile
+++ b/tools/bpf/resolve_btfids/Makefile
@@ -26,6 +26,7 @@ LIBBPF_SRC := $(srctree)/tools/lib/bpf/
SUBCMD_SRC := $(srctree)/tools/lib/subcmd/
BPFOBJ := $(OUTPUT)/libbpf/libbpf.a
+LIBBPF_OUT := $(abspath $(dir $(BPFOBJ)))/
SUBCMDOBJ := $(OUTPUT)/libsubcmd/libsubcmd.a
BINARY := $(OUTPUT)/resolve_btfids
@@ -41,11 +42,12 @@ $(SUBCMDOBJ): fixdep FORCE | $(OUTPUT)/libsubcmd
$(Q)$(MAKE) -C $(SUBCMD_SRC) OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
$(BPFOBJ): $(wildcard $(LIBBPF_SRC)/*.[ch] $(LIBBPF_SRC)/Makefile) | $(OUTPUT)/libbpf
- $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(abspath $(dir $@))/ $(abspath $@)
+ $(Q)$(MAKE) $(submake_extras) -C $(LIBBPF_SRC) OUTPUT=$(LIBBPF_OUT) $(abspath $@)
CFLAGS := -g \
-I$(srctree)/tools/include \
-I$(srctree)/tools/include/uapi \
+ -I$(LIBBPF_OUT) \
-I$(LIBBPF_SRC) \
-I$(SUBCMD_SRC)
diff --git a/tools/lib/bpf/Makefile b/tools/lib/bpf/Makefile
index 74c3b73a5fbe..dab21e0c7cc2 100644
--- a/tools/lib/bpf/Makefile
+++ b/tools/lib/bpf/Makefile
@@ -8,7 +8,8 @@ VERSION_SCRIPT := libbpf.map
LIBBPF_VERSION := $(shell \
grep -oE '^LIBBPF_([0-9.]+)' $(VERSION_SCRIPT) | \
sort -rV | head -n1 | cut -d'_' -f2)
-LIBBPF_MAJOR_VERSION := $(firstword $(subst ., ,$(LIBBPF_VERSION)))
+LIBBPF_MAJOR_VERSION := $(word 1,$(subst ., ,$(LIBBPF_VERSION)))
+LIBBPF_MINOR_VERSION := $(word 2,$(subst ., ,$(LIBBPF_VERSION)))
MAKEFLAGS += --no-print-directory
@@ -59,7 +60,8 @@ ifndef VERBOSE
VERBOSE = 0
endif
-INCLUDES = -I. -I$(srctree)/tools/include -I$(srctree)/tools/include/uapi
+INCLUDES = -I$(if $(OUTPUT),$(OUTPUT),.) \
+ -I$(srctree)/tools/include -I$(srctree)/tools/include/uapi
export prefix libdir src obj
@@ -111,7 +113,9 @@ SHARED_OBJDIR := $(OUTPUT)sharedobjs/
STATIC_OBJDIR := $(OUTPUT)staticobjs/
BPF_IN_SHARED := $(SHARED_OBJDIR)libbpf-in.o
BPF_IN_STATIC := $(STATIC_OBJDIR)libbpf-in.o
+VERSION_HDR := $(OUTPUT)libbpf_version.h
BPF_HELPER_DEFS := $(OUTPUT)bpf_helper_defs.h
+BPF_GENERATED := $(BPF_HELPER_DEFS) $(VERSION_HDR)
LIB_TARGET := $(addprefix $(OUTPUT),$(LIB_TARGET))
LIB_FILE := $(addprefix $(OUTPUT),$(LIB_FILE))
@@ -136,7 +140,7 @@ all: fixdep
all_cmd: $(CMD_TARGETS) check
-$(BPF_IN_SHARED): force $(BPF_HELPER_DEFS)
+$(BPF_IN_SHARED): force $(BPF_GENERATED)
@(test -f ../../include/uapi/linux/bpf.h -a -f ../../../include/uapi/linux/bpf.h && ( \
(diff -B ../../include/uapi/linux/bpf.h ../../../include/uapi/linux/bpf.h >/dev/null) || \
echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf.h' differs from latest version at 'include/uapi/linux/bpf.h'" >&2 )) || true
@@ -154,13 +158,19 @@ $(BPF_IN_SHARED): force $(BPF_HELPER_DEFS)
echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true
$(Q)$(MAKE) $(build)=libbpf OUTPUT=$(SHARED_OBJDIR) CFLAGS="$(CFLAGS) $(SHLIB_FLAGS)"
-$(BPF_IN_STATIC): force $(BPF_HELPER_DEFS)
+$(BPF_IN_STATIC): force $(BPF_GENERATED)
$(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR)
$(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h
$(QUIET_GEN)$(srctree)/scripts/bpf_doc.py --header \
--file $(srctree)/tools/include/uapi/linux/bpf.h > $(BPF_HELPER_DEFS)
+$(VERSION_HDR): force
+ $(QUIET_GEN)echo "/* This file was auto-generated. */" > $@
+ @echo "" >> $@
+ @echo "#define LIBBPF_MAJOR_VERSION $(LIBBPF_MAJOR_VERSION)" >> $@
+ @echo "#define LIBBPF_MINOR_VERSION $(LIBBPF_MINOR_VERSION)" >> $@
+
$(OUTPUT)libbpf.so: $(OUTPUT)libbpf.so.$(LIBBPF_VERSION)
$(OUTPUT)libbpf.so.$(LIBBPF_VERSION): $(BPF_IN_SHARED) $(VERSION_SCRIPT)
@@ -224,10 +234,10 @@ install_lib: all_cmd
cp -fpR $(LIB_FILE) $(DESTDIR)$(libdir_SQ)
INSTALL_HEADERS = bpf.h libbpf.h btf.h libbpf_common.h libbpf_legacy.h xsk.h \
- bpf_helpers.h $(BPF_HELPER_DEFS) bpf_tracing.h \
+ bpf_helpers.h $(BPF_GENERATED) bpf_tracing.h \
bpf_endian.h bpf_core_read.h skel_internal.h
-install_headers: $(BPF_HELPER_DEFS)
+install_headers: $(BPF_GENERATED)
$(call QUIET_INSTALL, headers) \
$(foreach hdr,$(INSTALL_HEADERS), \
$(call do_install,$(hdr),$(prefix)/include/bpf,644);)
@@ -240,7 +250,7 @@ install: install_lib install_pkgconfig install_headers
clean:
$(call QUIET_CLEAN, libbpf) $(RM) -rf $(CMD_TARGETS) \
- *~ .*.d .*.cmd LIBBPF-CFLAGS $(BPF_HELPER_DEFS) \
+ *~ .*.d .*.cmd LIBBPF-CFLAGS $(BPF_GENERATED) \
$(SHARED_OBJDIR) $(STATIC_OBJDIR) \
$(addprefix $(OUTPUT), \
*.o *.a *.so *.so.$(LIBBPF_MAJOR_VERSION) *.pc)
diff --git a/tools/lib/bpf/btf.h b/tools/lib/bpf/btf.h
index 4a711f990904..f2e2fab950b7 100644
--- a/tools/lib/bpf/btf.h
+++ b/tools/lib/bpf/btf.h
@@ -50,9 +50,11 @@ LIBBPF_API struct btf *libbpf_find_kernel_btf(void);
LIBBPF_API struct btf *btf__load_from_kernel_by_id(__u32 id);
LIBBPF_API struct btf *btf__load_from_kernel_by_id_split(__u32 id, struct btf *base_btf);
+LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_from_kernel_by_id instead")
LIBBPF_API int btf__get_from_id(__u32 id, struct btf **btf);
LIBBPF_API int btf__finalize_data(struct bpf_object *obj, struct btf *btf);
+LIBBPF_DEPRECATED_SINCE(0, 6, "use btf__load_into_kernel instead")
LIBBPF_API int btf__load(struct btf *btf);
LIBBPF_API int btf__load_into_kernel(struct btf *btf);
LIBBPF_API __s32 btf__find_by_name(const struct btf *btf,
diff --git a/tools/lib/bpf/libbpf_common.h b/tools/lib/bpf/libbpf_common.h
index 947d8bd8a7bb..36ac77f2bea2 100644
--- a/tools/lib/bpf/libbpf_common.h
+++ b/tools/lib/bpf/libbpf_common.h
@@ -10,6 +10,7 @@
#define __LIBBPF_LIBBPF_COMMON_H
#include <string.h>
+#include "libbpf_version.h"
#ifndef LIBBPF_API
#define LIBBPF_API __attribute__((visibility("default")))
@@ -17,6 +18,24 @@
#define LIBBPF_DEPRECATED(msg) __attribute__((deprecated(msg)))
+/* Mark a symbol as deprecated when libbpf version is >= {major}.{minor} */
+#define LIBBPF_DEPRECATED_SINCE(major, minor, msg) \
+ __LIBBPF_MARK_DEPRECATED_ ## major ## _ ## minor \
+ (LIBBPF_DEPRECATED("libbpf v" # major "." # minor "+: " msg))
+
+#define __LIBBPF_CURRENT_VERSION_GEQ(major, minor) \
+ (LIBBPF_MAJOR_VERSION > (major) || \
+ (LIBBPF_MAJOR_VERSION == (major) && LIBBPF_MINOR_VERSION >= (minor)))
+
+/* Add checks for other versions below when planning deprecation of API symbols
+ * with the LIBBPF_DEPRECATED_SINCE macro.
+ */
+#if __LIBBPF_CURRENT_VERSION_GEQ(0, 6)
+#define __LIBBPF_MARK_DEPRECATED_0_6(X) X
+#else
+#define __LIBBPF_MARK_DEPRECATED_0_6(X)
+#endif
+
/* Helper macro to declare and initialize libbpf options struct
*
* This dance with uninitialized declaration, followed by memset to zero,
--
2.30.2
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2 bpf-next] libbpf: add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecations
2021-09-08 6:55 [PATCH v2 bpf-next] libbpf: add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecations Andrii Nakryiko
@ 2021-09-08 13:01 ` Daniel Borkmann
2021-09-08 15:01 ` Andrii Nakryiko
0 siblings, 1 reply; 3+ messages in thread
From: Daniel Borkmann @ 2021-09-08 13:01 UTC (permalink / raw)
To: Andrii Nakryiko, bpf, ast, quentin; +Cc: kernel-team
On 9/8/21 8:55 AM, Andrii Nakryiko wrote:
> From: Quentin Monnet <quentin@isovalent.com>
>
> Introduce a macro LIBBPF_DEPRECATED_SINCE(major, minor, message) to prepare
> the deprecation of two API functions. This macro marks functions as deprecated
> when libbpf's version reaches the values passed as an argument.
>
> As part of this change libbpf_version.h header is added with recorded major
> (LIBBPF_MAJOR_VERSION) and minor (LIBBPF_MINOR_VERSION) libbpf version macros.
> They are now part of libbpf public API and can be relied upon by user code.
> libbpf_version.h is installed system-wide along other libbpf public headers.
>
> Due to this new build-time auto-generated header, in-kernel applications
> relying on libbpf (resolve_btfids, bpftool, bpf_preload) are updated to
> include libbpf's output directory as part of a list of include search paths.
> Better fix would be to use libbpf's make_install target to install public API
> headers, but that clean up is left out as a future improvement. The build
> changes were tested by building kernel (with KBUILD_OUTPUT and O= specified
> explicitly), bpftool, libbpf, selftests/bpf, and resolve_btfids builds. No
> problems were detected.
>
> Note that because of the constraints of the C preprocessor we have to write
> a few lines of macro magic for each version used to prepare deprecation (0.6
> for now).
>
> Also, use LIBBPF_DEPRECATED_SINCE() to schedule deprecation of
> btf__get_from_id() and btf__load(), which are replaced by
> btf__load_from_kernel_by_id() and btf__load_into_kernel(), respectively,
> starting from future libbpf v0.6. This is part of libbpf 1.0 effort ([0]).
>
> [0] Closes: https://github.com/libbpf/libbpf/issues/278
>
> Co-developed-by: Quentin Monnet <quentin@isovalent.com>
> Signed-off-by: Quentin Monnet <quentin@isovalent.com>
> Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
> ---
>
> v1->v2:
> - fix bpf_preload build by adding dependency for iterators/iterators.o on
> libbpf.a generation (caught by BPF CI);
[...]
> @@ -136,7 +140,7 @@ all: fixdep
>
> all_cmd: $(CMD_TARGETS) check
>
> -$(BPF_IN_SHARED): force $(BPF_HELPER_DEFS)
> +$(BPF_IN_SHARED): force $(BPF_GENERATED)
> @(test -f ../../include/uapi/linux/bpf.h -a -f ../../../include/uapi/linux/bpf.h && ( \
> (diff -B ../../include/uapi/linux/bpf.h ../../../include/uapi/linux/bpf.h >/dev/null) || \
> echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf.h' differs from latest version at 'include/uapi/linux/bpf.h'" >&2 )) || true
> @@ -154,13 +158,19 @@ $(BPF_IN_SHARED): force $(BPF_HELPER_DEFS)
> echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true
> $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(SHARED_OBJDIR) CFLAGS="$(CFLAGS) $(SHLIB_FLAGS)"
>
> -$(BPF_IN_STATIC): force $(BPF_HELPER_DEFS)
> +$(BPF_IN_STATIC): force $(BPF_GENERATED)
> $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR)
>
> $(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h
> $(QUIET_GEN)$(srctree)/scripts/bpf_doc.py --header \
> --file $(srctree)/tools/include/uapi/linux/bpf.h > $(BPF_HELPER_DEFS)
>
> +$(VERSION_HDR): force
> + $(QUIET_GEN)echo "/* This file was auto-generated. */" > $@
> + @echo "" >> $@
> + @echo "#define LIBBPF_MAJOR_VERSION $(LIBBPF_MAJOR_VERSION)" >> $@
> + @echo "#define LIBBPF_MINOR_VERSION $(LIBBPF_MINOR_VERSION)" >> $@
> +
Looks like CI caught a different issue this time with v2 where it cannot find libbpf_version.h:
[...]
CC bench_count.o
GEN /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bpf-helpers.rst
In file included from /home/runner/work/bpf/bpf/tools/lib/bpf/bpf.h:31,
from /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bench.h:8,
from benchs/bench_count.c:3:
/home/runner/work/bpf/bpf/tools/lib/bpf/libbpf_common.h:13:10: fatal error: libbpf_version.h: No such file or directory
13 | #include "libbpf_version.h"
| ^~~~~~~~~~~~~~~~~~
compilation terminated.
make: *** [Makefile:517: /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bench_count.o] Error 1
make: *** Waiting for unfinished jobs....
GEN /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bpf-syscall.rst
In file included from /home/runner/work/bpf/bpf/tools/lib/bpf/bpf.h:31,
from bench.h:8,
from bench.c:13:
/home/runner/work/bpf/bpf/tools/lib/bpf/libbpf_common.h:13:10: fatal error: libbpf_version.h: No such file or directory
13 | #include "libbpf_version.h"
| ^~~~~~~~~~~~~~~~~~
compilation terminated.
make: *** [Makefile:162: /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bench.o] Error 1
Thanks,
Daniel
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2 bpf-next] libbpf: add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecations
2021-09-08 13:01 ` Daniel Borkmann
@ 2021-09-08 15:01 ` Andrii Nakryiko
0 siblings, 0 replies; 3+ messages in thread
From: Andrii Nakryiko @ 2021-09-08 15:01 UTC (permalink / raw)
To: Daniel Borkmann
Cc: Andrii Nakryiko, bpf, Alexei Starovoitov, Quentin Monnet, Kernel Team
On Wed, Sep 8, 2021 at 6:01 AM Daniel Borkmann <daniel@iogearbox.net> wrote:
>
> On 9/8/21 8:55 AM, Andrii Nakryiko wrote:
> > From: Quentin Monnet <quentin@isovalent.com>
> >
> > Introduce a macro LIBBPF_DEPRECATED_SINCE(major, minor, message) to prepare
> > the deprecation of two API functions. This macro marks functions as deprecated
> > when libbpf's version reaches the values passed as an argument.
> >
> > As part of this change libbpf_version.h header is added with recorded major
> > (LIBBPF_MAJOR_VERSION) and minor (LIBBPF_MINOR_VERSION) libbpf version macros.
> > They are now part of libbpf public API and can be relied upon by user code.
> > libbpf_version.h is installed system-wide along other libbpf public headers.
> >
> > Due to this new build-time auto-generated header, in-kernel applications
> > relying on libbpf (resolve_btfids, bpftool, bpf_preload) are updated to
> > include libbpf's output directory as part of a list of include search paths.
> > Better fix would be to use libbpf's make_install target to install public API
> > headers, but that clean up is left out as a future improvement. The build
> > changes were tested by building kernel (with KBUILD_OUTPUT and O= specified
> > explicitly), bpftool, libbpf, selftests/bpf, and resolve_btfids builds. No
> > problems were detected.
> >
> > Note that because of the constraints of the C preprocessor we have to write
> > a few lines of macro magic for each version used to prepare deprecation (0.6
> > for now).
> >
> > Also, use LIBBPF_DEPRECATED_SINCE() to schedule deprecation of
> > btf__get_from_id() and btf__load(), which are replaced by
> > btf__load_from_kernel_by_id() and btf__load_into_kernel(), respectively,
> > starting from future libbpf v0.6. This is part of libbpf 1.0 effort ([0]).
> >
> > [0] Closes: https://github.com/libbpf/libbpf/issues/278
> >
> > Co-developed-by: Quentin Monnet <quentin@isovalent.com>
> > Signed-off-by: Quentin Monnet <quentin@isovalent.com>
> > Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
> > ---
> >
> > v1->v2:
> > - fix bpf_preload build by adding dependency for iterators/iterators.o on
> > libbpf.a generation (caught by BPF CI);
> [...]
> > @@ -136,7 +140,7 @@ all: fixdep
> >
> > all_cmd: $(CMD_TARGETS) check
> >
> > -$(BPF_IN_SHARED): force $(BPF_HELPER_DEFS)
> > +$(BPF_IN_SHARED): force $(BPF_GENERATED)
> > @(test -f ../../include/uapi/linux/bpf.h -a -f ../../../include/uapi/linux/bpf.h && ( \
> > (diff -B ../../include/uapi/linux/bpf.h ../../../include/uapi/linux/bpf.h >/dev/null) || \
> > echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/bpf.h' differs from latest version at 'include/uapi/linux/bpf.h'" >&2 )) || true
> > @@ -154,13 +158,19 @@ $(BPF_IN_SHARED): force $(BPF_HELPER_DEFS)
> > echo "Warning: Kernel ABI header at 'tools/include/uapi/linux/if_xdp.h' differs from latest version at 'include/uapi/linux/if_xdp.h'" >&2 )) || true
> > $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(SHARED_OBJDIR) CFLAGS="$(CFLAGS) $(SHLIB_FLAGS)"
> >
> > -$(BPF_IN_STATIC): force $(BPF_HELPER_DEFS)
> > +$(BPF_IN_STATIC): force $(BPF_GENERATED)
> > $(Q)$(MAKE) $(build)=libbpf OUTPUT=$(STATIC_OBJDIR)
> >
> > $(BPF_HELPER_DEFS): $(srctree)/tools/include/uapi/linux/bpf.h
> > $(QUIET_GEN)$(srctree)/scripts/bpf_doc.py --header \
> > --file $(srctree)/tools/include/uapi/linux/bpf.h > $(BPF_HELPER_DEFS)
> >
> > +$(VERSION_HDR): force
> > + $(QUIET_GEN)echo "/* This file was auto-generated. */" > $@
> > + @echo "" >> $@
> > + @echo "#define LIBBPF_MAJOR_VERSION $(LIBBPF_MAJOR_VERSION)" >> $@
> > + @echo "#define LIBBPF_MINOR_VERSION $(LIBBPF_MINOR_VERSION)" >> $@
> > +
>
> Looks like CI caught a different issue this time with v2 where it cannot find libbpf_version.h:
Yep, I'll keep fixing this. Couldn't repro this locally. But I'm also
going to add a long sleep in libbpf_version.h generation to force this
kind of issue more easily. Sorry for the noise.
>
> [...]
> CC bench_count.o
> GEN /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bpf-helpers.rst
> In file included from /home/runner/work/bpf/bpf/tools/lib/bpf/bpf.h:31,
> from /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bench.h:8,
> from benchs/bench_count.c:3:
> /home/runner/work/bpf/bpf/tools/lib/bpf/libbpf_common.h:13:10: fatal error: libbpf_version.h: No such file or directory
> 13 | #include "libbpf_version.h"
> | ^~~~~~~~~~~~~~~~~~
> compilation terminated.
> make: *** [Makefile:517: /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bench_count.o] Error 1
> make: *** Waiting for unfinished jobs....
> GEN /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bpf-syscall.rst
> In file included from /home/runner/work/bpf/bpf/tools/lib/bpf/bpf.h:31,
> from bench.h:8,
> from bench.c:13:
> /home/runner/work/bpf/bpf/tools/lib/bpf/libbpf_common.h:13:10: fatal error: libbpf_version.h: No such file or directory
> 13 | #include "libbpf_version.h"
> | ^~~~~~~~~~~~~~~~~~
> compilation terminated.
> make: *** [Makefile:162: /home/runner/work/bpf/bpf/tools/testing/selftests/bpf/bench.o] Error 1
>
> Thanks,
> Daniel
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2021-09-08 15:01 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2021-09-08 6:55 [PATCH v2 bpf-next] libbpf: add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecations Andrii Nakryiko
2021-09-08 13:01 ` Daniel Borkmann
2021-09-08 15:01 ` Andrii Nakryiko
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