Add a 'llvm.dump-obj' config option to enable perf dump BPF object files
compiled by LLVM.
This option is useful when using BPF objects in embedded platforms.
LLVM compiler won't be deployed in these platforms, and currently we
don't support dynamic compiling library.
Before this patch users have to explicitly issue llvm commands to
compile BPF scripts, and can't use helpers (like include path detection
and default macros) in perf. With this option, user is allowed to use
perf to compile their BPF objects then copy them into their embedded
platforms.
Committer notice:
Testing it:
# cat ~/.perfconfig
[llvm]
dump-obj = true
#
# ls -la filter.o
ls: cannot access filter.o: No such file or directory
# cat filter.c
#include <uapi/linux/bpf.h>
#define SEC(NAME) __attribute__((section(NAME), used))
SEC("func=hrtimer_nanosleep rqtp->tv_nsec")
int func(void *ctx, int err, long nsec)
{
return nsec > 1000;
}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
# trace -e nanosleep --event filter.c usleep 6
LLVM: dumping filter.o
0.007 ( 0.007 ms): usleep/13976 nanosleep(rqtp: 0x7ffc5847f640 ) ...
0.007 ( ): perf_bpf_probe:func:(ffffffff811137d0) tv_nsec=6000)
0.070 ( 0.070 ms): usleep/13976 ... [continued]: nanosleep()) = 0
# ls -la filter.o
-rw-r--r--. 1 root root 776 Jun 20 17:01 filter.o
# readelf -SW filter.o
There are 7 section headers, starting at offset 0x148:
Section Headers:
[Nr] Name Type Address Off Size ES Flg Lk Inf Al
[ 0] NULL 0000000000000000 000000 000000 00 0 0 0
[ 1] .strtab STRTAB 0000000000000000 0000e8 00005a 00 0 0 1
[ 2] .text PROGBITS 0000000000000000 000040 000000 00 AX 0 0 4
[ 3] func=hrtimer_nanosleep rqtp->tv_nsec PROGBITS 0000000000000000 000040 000028 00 AX 0 0 8
[ 4] license PROGBITS 0000000000000000 000068 000004 00 WA 0 0 1
[ 5] version PROGBITS 0000000000000000 00006c 000004 00 WA 0 0 4
[ 6] .symtab SYMTAB 0000000000000000 000070 000078 18 1 2 8
Key to Flags:
W (write), A (alloc), X (execute), M (merge), S (strings)
I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown)
O (extra OS processing required) o (OS specific), p (processor specific)
#
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1466064161-48553-2-git-send-email-wangnan0@huawei.com
[ s/dumpping/dumping/g ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-w246stf7ponfamclsai6b9zo@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Previous patches introduce llvm__compile_bpf() to compile source file to
eBPF object. This patch adds testcase to test it. It also tests libbpf
by opening generated object after applying next patch which introduces
HAVE_LIBBPF_SUPPORT option.
Since llvm__compile_bpf() prints long messages which users who don't
explicitly test llvm doesn't care, this patch set verbose to -1 to
suppress all debug, warning and error message, and hint user use 'perf
test -v' to see the full output.
For the same reason, if clang is not found in PATH and there's no [llvm]
section in .perfconfig, skip this test.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/n/1436445342-1402-17-git-send-email-wangnan0@huawei.com
[ Add tools/lib/bpf/ to tools/perf/MANIFEST, so that the tarball targets build ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This is the core patch for supporting eBPF on-the-fly compiling, does
the following work:
1. Search clang compiler using search_program().
2. Run command template defined in llvm-bpf-cmd-template option in
[llvm] config section using read_from_pipe(). Patch of clang and
source code path is injected into shell command using environment
variable using force_set_env().
Commiter notice:
When building with DEBUG=1 we get a compiler error that gets fixed with
the same approach described in commit b236512280fb:
perf kmem: Fix compiler warning about may be accessing uninitialized variable
The last argument to strtok_r doesn't need to be initialized, its
just a placeholder to make this routine reentrant, but gcc doesn't know
about that and complains, breaking the build, fix it by setting it to
NULL.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/n/1436445342-1402-14-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This patch introduces [llvm] config section with 5 options. Following
patches will use then to config llvm dynamica compiling.
'llvm-utils.[ch]' is introduced in this patch for holding all
llvm/clang related stuffs.
Example:
[llvm]
# Path to clang. If omit, search it from $PATH.
clang-path = "/path/to/clang"
# Cmdline template. Following line shows its default value.
# Environment variable is used to passing options.
#
# *NOTE*: -D__KERNEL__ MUST appears before $CLANG_OPTIONS,
# so user have a chance to use -U__KERNEL__ in $CLANG_OPTIONS
# to cancel it.
clang-bpf-cmd-template = "$CLANG_EXEC -D__KERNEL__ $CLANG_OPTIONS \
$KERNEL_INC_OPTIONS -Wno-unused-value \
-Wno-pointer-sign -working-directory \
$WORKING_DIR -c $CLANG_SOURCE -target \
bpf -O2 -o -"
# Options passed to clang, will be passed to cmdline by
# $CLANG_OPTIONS.
clang-opt = "-Wno-unused-value -Wno-pointer-sign"
# kbuild directory. If not set, use /lib/modules/`uname -r`/build.
# If set to "" deliberately, skip kernel header auto-detector.
kbuild-dir = "/path/to/kernel/build"
# Options passed to 'make' when detecting kernel header options.
kbuild-opts = "ARCH=x86_64"
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1437477214-149684-1-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Wang Nan