2021-05-08 20:51:18

by Jiri Olsa

Subject: [PATCH] perf tools: Fix dynamic libbpf link

Justin reported broken build with LIBBPF_DYNAMIC=1.

When linking libbpf dynamically we need to use perf's
hashmap object, because it's not exported in libbpf.so
(only in libbpf.a).

Following build is now passing:

$ make LIBBPF_DYNAMIC=1
BUILD: Doing 'make -j8' parallel build
...
$ ldd perf | grep libbpf
libbpf.so.0 => /lib64/libbpf.so.0 (0x00007fa7630db000)

Fixes: eee19501926d ("perf tools: Grab a copy of libbpf's hashmap")
Cc: Ian Rogers <[email protected]>
Reported-by: Justin M. Forbes <[email protected]>
Signed-off-by: Jiri Olsa <[email protected]>
---
tools/perf/Makefile.config | 1 +
tools/perf/util/Build | 7 +++++++
2 files changed, 8 insertions(+)

diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
index 7b195e16040e..dacd16874d3d 100644
--- a/tools/perf/Makefile.config
+++ b/tools/perf/Makefile.config
@@ -546,6 +546,7 @@ ifndef NO_LIBELF
ifdef LIBBPF_DYNAMIC
ifeq ($(feature-libbpf), 1)
EXTLIBS += -lbpf
+ $(call detected,CONFIG_LIBBPF_DYNAMIC)
else
dummy := $(error Error: No libbpf devel library found, please install libbpf-devel);
endif
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index e27a551acd3a..95e15d1035ab 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -145,7 +145,14 @@ perf-$(CONFIG_LIBELF) += symbol-elf.o
perf-$(CONFIG_LIBELF) += probe-file.o
perf-$(CONFIG_LIBELF) += probe-event.o

+ifdef CONFIG_LIBBPF_DYNAMIC
+ hashmap := 1
+endif
ifndef CONFIG_LIBBPF
+ hashmap := 1
+endif
+
+ifdef hashmap
perf-y += hashmap.o
endif

--
2.31.1

2021-05-09 12:52:44

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH] perf tools: Fix dynamic libbpf link

Em Sat, May 08, 2021 at 10:50:20PM +0200, Jiri Olsa escreveu:
> Justin reported broken build with LIBBPF_DYNAMIC=1.
>
> When linking libbpf dynamically we need to use perf's
> hashmap object, because it's not exported in libbpf.so
> (only in libbpf.a).
>
> Following build is now passing:
>
> $ make LIBBPF_DYNAMIC=1
> BUILD: Doing 'make -j8' parallel build
> ...
> $ ldd perf | grep libbpf
> libbpf.so.0 => /lib64/libbpf.so.0 (0x00007fa7630db000)

Thanks, applied.

- Arnaldo


> Fixes: eee19501926d ("perf tools: Grab a copy of libbpf's hashmap")
> Cc: Ian Rogers <[email protected]>
> Reported-by: Justin M. Forbes <[email protected]>
> Signed-off-by: Jiri Olsa <[email protected]>
> ---
> tools/perf/Makefile.config | 1 +
> tools/perf/util/Build | 7 +++++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 7b195e16040e..dacd16874d3d 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -546,6 +546,7 @@ ifndef NO_LIBELF
> ifdef LIBBPF_DYNAMIC
> ifeq ($(feature-libbpf), 1)
> EXTLIBS += -lbpf
> + $(call detected,CONFIG_LIBBPF_DYNAMIC)
> else
> dummy := $(error Error: No libbpf devel library found, please install libbpf-devel);
> endif
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index e27a551acd3a..95e15d1035ab 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -145,7 +145,14 @@ perf-$(CONFIG_LIBELF) += symbol-elf.o
> perf-$(CONFIG_LIBELF) += probe-file.o
> perf-$(CONFIG_LIBELF) += probe-event.o
>
> +ifdef CONFIG_LIBBPF_DYNAMIC
> + hashmap := 1
> +endif
> ifndef CONFIG_LIBBPF
> + hashmap := 1
> +endif
> +
> +ifdef hashmap
> perf-y += hashmap.o
> endif
>
> --
> 2.31.1
>

--

- Arnaldo

2021-05-10 21:36:23

by Justin Forbes

Subject: Re: [PATCH] perf tools: Fix dynamic libbpf link

On Sat, May 8, 2021 at 3:50 PM Jiri Olsa <[email protected]> wrote:
>
> Justin reported broken build with LIBBPF_DYNAMIC=1.
>
> When linking libbpf dynamically we need to use perf's
> hashmap object, because it's not exported in libbpf.so
> (only in libbpf.a).
>
> Following build is now passing:
>
> $ make LIBBPF_DYNAMIC=1
> BUILD: Doing 'make -j8' parallel build
> ...
> $ ldd perf | grep libbpf
> libbpf.so.0 => /lib64/libbpf.so.0 (0x00007fa7630db000)
>
> Fixes: eee19501926d ("perf tools: Grab a copy of libbpf's hashmap")
> Cc: Ian Rogers <[email protected]>
> Reported-by: Justin M. Forbes <[email protected]>
> Signed-off-by: Jiri Olsa <[email protected]>
> ---

This patch fixes it for me.

Tested-by: Justin M. Forbes <[email protected]>

> tools/perf/Makefile.config | 1 +
> tools/perf/util/Build | 7 +++++++
> 2 files changed, 8 insertions(+)
>
> diff --git a/tools/perf/Makefile.config b/tools/perf/Makefile.config
> index 7b195e16040e..dacd16874d3d 100644
> --- a/tools/perf/Makefile.config
> +++ b/tools/perf/Makefile.config
> @@ -546,6 +546,7 @@ ifndef NO_LIBELF
> ifdef LIBBPF_DYNAMIC
> ifeq ($(feature-libbpf), 1)
> EXTLIBS += -lbpf
> + $(call detected,CONFIG_LIBBPF_DYNAMIC)
> else
> dummy := $(error Error: No libbpf devel library found, please install libbpf-devel);
> endif
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index e27a551acd3a..95e15d1035ab 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -145,7 +145,14 @@ perf-$(CONFIG_LIBELF) += symbol-elf.o
> perf-$(CONFIG_LIBELF) += probe-file.o
> perf-$(CONFIG_LIBELF) += probe-event.o
>
> +ifdef CONFIG_LIBBPF_DYNAMIC
> + hashmap := 1
> +endif
> ifndef CONFIG_LIBBPF
> + hashmap := 1
> +endif
> +
> +ifdef hashmap
> perf-y += hashmap.o
> endif
>
> --
> 2.31.1
>