This is the first patch of libbpf. The goal of libbpf is to create a
standard way for accessing eBPF object files. This patch creates
'Makefile' and 'Build' for it, allows 'make' to build libbpf.a and
libbpf.so, 'make install' to put them into proper directories.
Most part of Makefile is borrowed from traceevent.
Before building, it checks the existence of libelf in Makefile, and deny
to build if not found. Instead of throwing an error if libelf not found,
the error raises in a phony target "elfdep". This design is to ensure
'make clean' still workable even if libelf is not found.
Because libbpf requires 'kern_version' field set for 'union bpf_attr'
(bpfdep" is used for that dependency), Kernel BPF API is also checked
by intruducing a new feature check 'bpf' into tools/build/feature,
which checks the existence and version of linux/bpf.h. When building
libbpf, it searches that file from include/uapi/linux in kernel source
tree (controlled by FEATURE_CHECK_CFLAGS-bpf). Since it searches kernel
source tree it reside, installing of newest kernel headers is not
required, except we are trying to port these files to an old kernel.
To avoid checking that file when perf building, the newly introduced
'bpf' feature check doesn't added into FEATURE_TESTS and
FEATURE_DISPLAY by default in tools/build/Makefile.feature, but added
into libbpf's specific.
Signed-off-by: Wang Nan <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Cc: Brendan Gregg <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: David Ahern <[email protected]>
Cc: He Kuang <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kaixu Xia <[email protected]>
Cc: Masami Hiramatsu <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Zefan Li <[email protected]>
Bcc: [email protected]
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Pull perf fixes from Ingo Molnar:
"These are the left over fixes from the v4.1 cycle"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf tools: Fix build breakage if prefix= is specified
perf/x86: Honor the architectural performance monitoring version
perf/x86/intel: Fix PMI handling for Intel PT
perf/x86/intel/bts: Fix DS area sharing with x86_pmu events
perf/x86: Add more Broadwell model numbers
perf: Fix ring_buffer_attach() RCU sync, again
Invoking Makefile.perf with prefix= breaks the build since Makefile.perf
hands that variable down to Makefile.build where it overrides
prefix := $(subst ./,,$(OUTPUT)$(dir)/)
leading to errors like this:
No rule to make target '/usrabspath.o', needed by '/usrlibperf-in.o'
Signed-off-by: Lukas Wunner <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Cc: David Ahern <[email protected]>
Fixes: c819e2cf2e
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Allow nesting into directories without Build file. Currently we force
include of the Build file, which fails the build when the Build file is
missing.
We already support empty *-in.o' objects if there's nothing in the
directory to be compiled, so we can just use it for missing Build file
cases.
Also adding this case under tests.
Reported-by: Rabin Vincent <[email protected]>
Signed-off-by: Jiri Olsa <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Rabin Vincent <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Adding new build framework into 'tools/build' to be used by tools.
There's no change for actual building at this point, it comes in the
next patches.
The idea and more details are explained in the
'tools/build/Documentation/Build.txt' file.
I adopted everything from the kernel build system, with some changes to
allow for multiple binaries build definitions.
While the kernel's build output is single image (forget modules) we need
to be able to build several binaries/libraries.
The basic idea is that sser provides 'Build' files with objects
definitions like:
perf-y += a.o
perf-y += b.o
libperf-y += c.o
libperf-y += d.o
and the build framework outputs files:
perf-in.o # a.o, b.o compiled in
libperf-in.o # c.o, d.o compiled in
Signed-off-by: Jiri Olsa <[email protected]>
Tested-by: Sukadev Bhattiprolu <[email protected]>
Tested-by: Will Deacon <[email protected]>
Cc: Alexis Berlemont <[email protected]>
Cc: Borislav Petkov <[email protected]>
Cc: Corey Ashford <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
Wang Nan