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* [PATCH v2 bpf-next 0/3] Fixes for bpftool-prog-profile
@ 2020-03-11 22:18 Song Liu
  2020-03-11 22:18 ` [PATCH v2 bpf-next 1/3] bpftool: only build bpftool-prog-profile if supported by clang Song Liu
                   ` (2 more replies)
  0 siblings, 3 replies; 8+ messages in thread
From: Song Liu @ 2020-03-11 22:18 UTC (permalink / raw)
  To: netdev, bpf
  Cc: john.fastabend, quentin, kernel-team, ast, daniel, arnaldo.melo,
	jolsa, Song Liu

1. Fix build for older clang;
2. Fix skeleton's dependency on libbpf;
3. Add files to .gitignore.

Changes v1 => v2:
1. Rewrite patch 1 with real feature detection (Quentin, Alexei).
2. Add files to .gitignore (Andrii).

Song Liu (3):
  bpftool: only build bpftool-prog-profile if supported by clang
  bpftool: skeleton should depend on libbpf
  bpftool: add _bpftool and profiler.skel.h to .gitignore

 tools/bpf/bpftool/.gitignore                    |  2 ++
 tools/bpf/bpftool/Makefile                      | 17 ++++++++++++-----
 tools/bpf/bpftool/prog.c                        |  2 ++
 tools/build/feature/Makefile                    |  9 ++++++++-
 tools/build/feature/test-clang-bpf-global-var.c |  4 ++++
 5 files changed, 28 insertions(+), 6 deletions(-)
 create mode 100644 tools/build/feature/test-clang-bpf-global-var.c

--
2.17.1

^ permalink raw reply	[flat|nested] 8+ messages in thread

* [PATCH v2 bpf-next 1/3] bpftool: only build bpftool-prog-profile if supported by clang
  2020-03-11 22:18 [PATCH v2 bpf-next 0/3] Fixes for bpftool-prog-profile Song Liu
@ 2020-03-11 22:18 ` Song Liu
  2020-03-12 11:46   ` Quentin Monnet
  2020-03-11 22:18 ` [PATCH v2 bpf-next 2/3] bpftool: skeleton should depend on libbpf Song Liu
  2020-03-11 22:18 ` [PATCH v2 bpf-next 3/3] bpftool: add _bpftool and profiler.skel.h to .gitignore Song Liu
  2 siblings, 1 reply; 8+ messages in thread
From: Song Liu @ 2020-03-11 22:18 UTC (permalink / raw)
  To: netdev, bpf
  Cc: john.fastabend, quentin, kernel-team, ast, daniel, arnaldo.melo,
	jolsa, Song Liu

bpftoo-prog-profile requires clang to generate BTF for global variables.
When compared with older clang, skip this command. This is achieved by
adding a new feature, clang-bpf-global-var, to tools/build/feature.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/bpf/bpftool/Makefile                      | 15 +++++++++++----
 tools/bpf/bpftool/prog.c                        |  2 ++
 tools/build/feature/Makefile                    |  9 ++++++++-
 tools/build/feature/test-clang-bpf-global-var.c |  4 ++++
 4 files changed, 25 insertions(+), 5 deletions(-)
 create mode 100644 tools/build/feature/test-clang-bpf-global-var.c

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 20a90d8450f8..0d9ede8e7340 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -62,8 +62,9 @@ RM ?= rm -f
 CLANG ?= clang
 
 FEATURE_USER = .bpftool
-FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib
-FEATURE_DISPLAY = libbfd disassembler-four-args zlib
+FEATURE_TESTS = libbfd disassembler-four-args reallocarray zlib \
+	clang-bpf-global-var
+FEATURE_DISPLAY = libbfd disassembler-four-args zlib clang-bpf-global-var
 
 check_feat := 1
 NON_CHECK_FEAT_TARGETS := clean uninstall doc doc-clean doc-install doc-uninstall
@@ -113,6 +114,12 @@ endif
 OBJS = $(patsubst %.c,$(OUTPUT)%.o,$(SRCS)) $(OUTPUT)disasm.o
 _OBJS = $(filter-out $(OUTPUT)prog.o,$(OBJS)) $(OUTPUT)_prog.o
 
+ifeq ($(feature-clang-bpf-global-var),1)
+	__OBJS = $(OBJS)
+else
+	__OBJS = $(_OBJS)
+endif
+
 $(OUTPUT)_prog.o: prog.c
 	$(QUIET_CC)$(COMPILE.c) -MMD -DBPFTOOL_WITHOUT_SKELETONS -o $@ $<
 
@@ -133,8 +140,8 @@ $(OUTPUT)disasm.o: $(srctree)/kernel/bpf/disasm.c
 
 $(OUTPUT)feature.o: | zdep
 
-$(OUTPUT)bpftool: $(OBJS) $(LIBBPF)
-	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(OBJS) $(LIBS)
+$(OUTPUT)bpftool: $(__OBJS) $(LIBBPF)
+	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(__OBJS) $(LIBS)
 
 $(OUTPUT)%.o: %.c
 	$(QUIET_CC)$(COMPILE.c) -MMD -o $@ $<
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index 576ddd82bc96..03b1979dfad8 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -1545,6 +1545,8 @@ static int do_loadall(int argc, char **argv)
 
 static int do_profile(int argc, char **argv)
 {
+	fprintf(stdout, "bpftool prog profile command is not supported.\n"
+		"Please build bpftool with clang >= 10.0.0\n");
 	return 0;
 }
 
diff --git a/tools/build/feature/Makefile b/tools/build/feature/Makefile
index 7ac0d8088565..ab8e89a7009c 100644
--- a/tools/build/feature/Makefile
+++ b/tools/build/feature/Makefile
@@ -67,7 +67,8 @@ FILES=                                          \
          test-llvm.bin				\
          test-llvm-version.bin			\
          test-libaio.bin			\
-         test-libzstd.bin
+         test-libzstd.bin			\
+         test-clang-bpf-global-var.bin
 
 FILES := $(addprefix $(OUTPUT),$(FILES))
 
@@ -75,6 +76,7 @@ CC ?= $(CROSS_COMPILE)gcc
 CXX ?= $(CROSS_COMPILE)g++
 PKG_CONFIG ?= $(CROSS_COMPILE)pkg-config
 LLVM_CONFIG ?= llvm-config
+CLANG ?= clang
 
 all: $(FILES)
 
@@ -321,6 +323,11 @@ $(OUTPUT)test-libaio.bin:
 $(OUTPUT)test-libzstd.bin:
 	$(BUILD) -lzstd
 
+$(OUTPUT)test-clang-bpf-global-var.bin:
+	$(CLANG) -S -g -target bpf -o - $(patsubst %.bin,%.c,$(@F)) |	\
+		grep BTF_KIND_VAR
+
+
 ###############################
 
 clean:
diff --git a/tools/build/feature/test-clang-bpf-global-var.c b/tools/build/feature/test-clang-bpf-global-var.c
new file mode 100644
index 000000000000..221f1481d52e
--- /dev/null
+++ b/tools/build/feature/test-clang-bpf-global-var.c
@@ -0,0 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2020 Facebook
+
+volatile int global_value_for_test = 1;
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH v2 bpf-next 2/3] bpftool: skeleton should depend on libbpf
  2020-03-11 22:18 [PATCH v2 bpf-next 0/3] Fixes for bpftool-prog-profile Song Liu
  2020-03-11 22:18 ` [PATCH v2 bpf-next 1/3] bpftool: only build bpftool-prog-profile if supported by clang Song Liu
@ 2020-03-11 22:18 ` Song Liu
  2020-03-12 11:46   ` Quentin Monnet
  2020-03-11 22:18 ` [PATCH v2 bpf-next 3/3] bpftool: add _bpftool and profiler.skel.h to .gitignore Song Liu
  2 siblings, 1 reply; 8+ messages in thread
From: Song Liu @ 2020-03-11 22:18 UTC (permalink / raw)
  To: netdev, bpf
  Cc: john.fastabend, quentin, kernel-team, ast, daniel, arnaldo.melo,
	jolsa, Song Liu

Add the dependency to libbpf, to fix build errors like:

  In file included from skeleton/profiler.bpf.c:5:
  .../bpf_helpers.h:5:10: fatal error: 'bpf_helper_defs.h' file not found
  #include "bpf_helper_defs.h"
           ^~~~~~~~~~~~~~~~~~~
  1 error generated.
  make: *** [skeleton/profiler.bpf.o] Error 1
  make: *** Waiting for unfinished jobs....

Fixes: 47c09d6a9f67 ("bpftool: Introduce "prog profile" command")
Acked-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/bpf/bpftool/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 0d9ede8e7340..45a37e2fb6e6 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -126,7 +126,7 @@ $(OUTPUT)_prog.o: prog.c
 $(OUTPUT)_bpftool: $(_OBJS) $(LIBBPF)
 	$(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(_OBJS) $(LIBS)
 
-skeleton/profiler.bpf.o: skeleton/profiler.bpf.c
+skeleton/profiler.bpf.o: skeleton/profiler.bpf.c $(LIBBPF)
 	$(QUIET_CLANG)$(CLANG) -I$(srctree)/tools/lib -g -O2 -target bpf -c $< -o $@
 
 profiler.skel.h: $(OUTPUT)_bpftool skeleton/profiler.bpf.o
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* [PATCH v2 bpf-next 3/3] bpftool: add _bpftool and profiler.skel.h to .gitignore
  2020-03-11 22:18 [PATCH v2 bpf-next 0/3] Fixes for bpftool-prog-profile Song Liu
  2020-03-11 22:18 ` [PATCH v2 bpf-next 1/3] bpftool: only build bpftool-prog-profile if supported by clang Song Liu
  2020-03-11 22:18 ` [PATCH v2 bpf-next 2/3] bpftool: skeleton should depend on libbpf Song Liu
@ 2020-03-11 22:18 ` Song Liu
  2020-03-12 11:47   ` Quentin Monnet
  2 siblings, 1 reply; 8+ messages in thread
From: Song Liu @ 2020-03-11 22:18 UTC (permalink / raw)
  To: netdev, bpf
  Cc: john.fastabend, quentin, kernel-team, ast, daniel, arnaldo.melo,
	jolsa, Song Liu

These files are generated, so ignore them.

Signed-off-by: Song Liu <songliubraving@fb.com>
---
 tools/bpf/bpftool/.gitignore | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/bpf/bpftool/.gitignore b/tools/bpf/bpftool/.gitignore
index b13926432b84..8d6e8901ed2b 100644
--- a/tools/bpf/bpftool/.gitignore
+++ b/tools/bpf/bpftool/.gitignore
@@ -1,7 +1,9 @@
 *.d
+/_bpftool
 /bpftool
 bpftool*.8
 bpf-helpers.*
 FEATURE-DUMP.bpftool
 feature
 libbpf
+profiler.skel.h
-- 
2.17.1


^ permalink raw reply related	[flat|nested] 8+ messages in thread

* Re: [PATCH v2 bpf-next 1/3] bpftool: only build bpftool-prog-profile if supported by clang
  2020-03-11 22:18 ` [PATCH v2 bpf-next 1/3] bpftool: only build bpftool-prog-profile if supported by clang Song Liu
@ 2020-03-12 11:46   ` Quentin Monnet
  0 siblings, 0 replies; 8+ messages in thread
From: Quentin Monnet @ 2020-03-12 11:46 UTC (permalink / raw)
  To: Song Liu, netdev, bpf
  Cc: john.fastabend, kernel-team, ast, daniel, arnaldo.melo, jolsa

2020-03-11 15:18 UTC-0700 ~ Song Liu <songliubraving@fb.com>
> bpftoo-prog-profile requires clang to generate BTF for global variables.

Typo: bpftool (missing "l")

> When compared with older clang, skip this command. This is achieved by
> adding a new feature, clang-bpf-global-var, to tools/build/feature.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>

Works great when clang is either too old or missing, thanks!

> diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
> index 576ddd82bc96..03b1979dfad8 100644
> --- a/tools/bpf/bpftool/prog.c
> +++ b/tools/bpf/bpftool/prog.c
> @@ -1545,6 +1545,8 @@ static int do_loadall(int argc, char **argv)
>  
>  static int do_profile(int argc, char **argv)
>  {
> +	fprintf(stdout, "bpftool prog profile command is not supported.\n"
> +		"Please build bpftool with clang >= 10.0.0\n");

Nit: Can we use p_err() instead of fprintf(), and a single-line error
message please? To remain consistent and work with JSON output.

Thanks,
Quentin

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v2 bpf-next 2/3] bpftool: skeleton should depend on libbpf
  2020-03-11 22:18 ` [PATCH v2 bpf-next 2/3] bpftool: skeleton should depend on libbpf Song Liu
@ 2020-03-12 11:46   ` Quentin Monnet
  2020-03-12 12:34     ` Quentin Monnet
  0 siblings, 1 reply; 8+ messages in thread
From: Quentin Monnet @ 2020-03-12 11:46 UTC (permalink / raw)
  To: Song Liu, netdev, bpf
  Cc: john.fastabend, kernel-team, ast, daniel, arnaldo.melo, jolsa

2020-03-11 15:18 UTC-0700 ~ Song Liu <songliubraving@fb.com>
> Add the dependency to libbpf, to fix build errors like:
> 
>   In file included from skeleton/profiler.bpf.c:5:
>   .../bpf_helpers.h:5:10: fatal error: 'bpf_helper_defs.h' file not found
>   #include "bpf_helper_defs.h"
>            ^~~~~~~~~~~~~~~~~~~
>   1 error generated.
>   make: *** [skeleton/profiler.bpf.o] Error 1
>   make: *** Waiting for unfinished jobs....
> 
> Fixes: 47c09d6a9f67 ("bpftool: Introduce "prog profile" command")
> Acked-by: John Fastabend <john.fastabend@gmail.com>
> Signed-off-by: Song Liu <songliubraving@fb.com>

Reviewed-by: Quentin Monnet <quentin@isovalent.com>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v2 bpf-next 3/3] bpftool: add _bpftool and profiler.skel.h to .gitignore
  2020-03-11 22:18 ` [PATCH v2 bpf-next 3/3] bpftool: add _bpftool and profiler.skel.h to .gitignore Song Liu
@ 2020-03-12 11:47   ` Quentin Monnet
  0 siblings, 0 replies; 8+ messages in thread
From: Quentin Monnet @ 2020-03-12 11:47 UTC (permalink / raw)
  To: Song Liu, netdev, bpf
  Cc: john.fastabend, kernel-team, ast, daniel, arnaldo.melo, jolsa

2020-03-11 15:18 UTC-0700 ~ Song Liu <songliubraving@fb.com>
> These files are generated, so ignore them.
> 
> Signed-off-by: Song Liu <songliubraving@fb.com>

Reviewed-by: Quentin Monnet <quentin@isovalent.com>

^ permalink raw reply	[flat|nested] 8+ messages in thread

* Re: [PATCH v2 bpf-next 2/3] bpftool: skeleton should depend on libbpf
  2020-03-12 11:46   ` Quentin Monnet
@ 2020-03-12 12:34     ` Quentin Monnet
  0 siblings, 0 replies; 8+ messages in thread
From: Quentin Monnet @ 2020-03-12 12:34 UTC (permalink / raw)
  To: Song Liu, netdev, bpf
  Cc: john.fastabend, kernel-team, ast, daniel, arnaldo.melo, jolsa

2020-03-12 11:46 UTC+0000 ~ Quentin Monnet <quentin@isovalent.com>
> 2020-03-11 15:18 UTC-0700 ~ Song Liu <songliubraving@fb.com>
>> Add the dependency to libbpf, to fix build errors like:
>>
>>   In file included from skeleton/profiler.bpf.c:5:
>>   .../bpf_helpers.h:5:10: fatal error: 'bpf_helper_defs.h' file not found
>>   #include "bpf_helper_defs.h"
>>            ^~~~~~~~~~~~~~~~~~~
>>   1 error generated.
>>   make: *** [skeleton/profiler.bpf.o] Error 1
>>   make: *** Waiting for unfinished jobs....
>>
>> Fixes: 47c09d6a9f67 ("bpftool: Introduce "prog profile" command")
>> Acked-by: John Fastabend <john.fastabend@gmail.com>
>> Signed-off-by: Song Liu <songliubraving@fb.com>
> 
> Reviewed-by: Quentin Monnet <quentin@isovalent.com>
> 

Sorry, I gave the tag too fast. This one is not solved on my machine,
I still observe the same error when building out of tree, e.g. if I
compile with e.g. "make O=/tmp/foo". This is because make does not
know where to find bpf_helper_defs.h in that case.

I could solve it with the additional diff:

----
diff --git a/tools/bpf/bpftool/Makefile b/tools/bpf/bpftool/Makefile
index 45a37e2fb6e6..8b765993598b 100644
--- a/tools/bpf/bpftool/Makefile
+++ b/tools/bpf/bpftool/Makefile
@@ -127,7 +127,7 @@ $(OUTPUT)_bpftool: $(_OBJS) $(LIBBPF)
        $(QUIET_LINK)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(_OBJS) $(LIBS)
 
 skeleton/profiler.bpf.o: skeleton/profiler.bpf.c $(LIBBPF)
-       $(QUIET_CLANG)$(CLANG) -I$(srctree)/tools/lib -g -O2 -target bpf -c $< -o $@
+       $(QUIET_CLANG)$(CLANG) -I$(srctree)/tools/lib -I$(LIBBPF_PATH) -g -O2 -target bpf -c $< -o $@
 
 profiler.skel.h: $(OUTPUT)_bpftool skeleton/profiler.bpf.o
        $(QUIET_GEN)$(OUTPUT)./_bpftool gen skeleton skeleton/profiler.bpf.o > $@
----

tools/testing/selftests/bpf/test_bpftool_build.sh seems happy on my
setup with the above.

Best regards,
Quentin

^ permalink raw reply related	[flat|nested] 8+ messages in thread

end of thread, other threads:[~2020-03-12 12:34 UTC | newest]

Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-03-11 22:18 [PATCH v2 bpf-next 0/3] Fixes for bpftool-prog-profile Song Liu
2020-03-11 22:18 ` [PATCH v2 bpf-next 1/3] bpftool: only build bpftool-prog-profile if supported by clang Song Liu
2020-03-12 11:46   ` Quentin Monnet
2020-03-11 22:18 ` [PATCH v2 bpf-next 2/3] bpftool: skeleton should depend on libbpf Song Liu
2020-03-12 11:46   ` Quentin Monnet
2020-03-12 12:34     ` Quentin Monnet
2020-03-11 22:18 ` [PATCH v2 bpf-next 3/3] bpftool: add _bpftool and profiler.skel.h to .gitignore Song Liu
2020-03-12 11:47   ` Quentin Monnet

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