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perf tools: Auto detecting kernel include options 

To help user find correct kernel include options, this patch extracts
them from kbuild system by an embedded script kinc_fetch_script, which
creates a temporary directory, generates Makefile and an empty dummy.o
then use the Makefile to fetch $(NOSTDINC_FLAGS), $(LINUXINCLUDE) and
$(EXTRA_CFLAGS) options. The result is passed to compiler script using
'KERNEL_INC_OPTIONS' environment variable.

Because options from kbuild contains relative path like
'Iinclude/generated/uapi', the work directory must be changed. This is
done by previous patch.

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/1436445342-1402-16-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
hifive-unleashed-5.1
Wang Nan 2015-06-11 11:25:49 +00:00 committed by Arnaldo Carvalho de Melo
parent d325d7887b
commit 0c6d18bfd5
1 changed files with 55 additions and 5 deletions
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60
tools/perf/util/llvm-utils.c
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@ -246,15 +246,42 @@ static int detect_kbuild_dir(char **kbuild_dir)
return -ENOENT;
}
static const char *kinc_fetch_script =
"#!/usr/bin/env sh\n"
"if ! test -d \"$KBUILD_DIR\"\n"
"then\n"
" exit -1\n"
"fi\n"
"if ! test -f \"$KBUILD_DIR/include/generated/autoconf.h\"\n"
"then\n"
" exit -1\n"
"fi\n"
"TMPDIR=`mktemp -d`\n"
"if test -z \"$TMPDIR\"\n"
"then\n"
" exit -1\n"
"fi\n"
"cat << EOF > $TMPDIR/Makefile\n"
"obj-y := dummy.o\n"
"\\$(obj)/%.o: \\$(src)/%.c\n"
"\t@echo -n \"\\$(NOSTDINC_FLAGS) \\$(LINUXINCLUDE) \\$(EXTRA_CFLAGS)\"\n"
"EOF\n"
"touch $TMPDIR/dummy.c\n"
"make -s -C $KBUILD_DIR M=$TMPDIR $KBUILD_OPTS dummy.o 2>/dev/null\n"
"RET=$?\n"
"rm -rf $TMPDIR\n"
"exit $RET\n";
static inline void
get_kbuild_opts(char **kbuild_dir)
get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
{
int err;
if (!kbuild_dir)
if (!kbuild_dir || !kbuild_include_opts)
return;
*kbuild_dir = NULL;
*kbuild_include_opts = NULL;
if (llvm_param.kbuild_dir && !llvm_param.kbuild_dir[0]) {
pr_debug("[llvm.kbuild-dir] is set to \"\" deliberately.\n");
@ -271,6 +298,27 @@ get_kbuild_opts(char **kbuild_dir)
" \tdetection.\n\n");
return;
}
pr_debug("Kernel build dir is set to %s\n", *kbuild_dir);
force_set_env("KBUILD_DIR", *kbuild_dir);
force_set_env("KBUILD_OPTS", llvm_param.kbuild_opts);
err = read_from_pipe(kinc_fetch_script,
(void **)kbuild_include_opts,
NULL);
if (err) {
pr_warning(
"WARNING:\tunable to get kernel include directories from '%s'\n"
"Hint:\tTry set clang include options using 'clang-bpf-cmd-template'\n"
" \toption in [llvm] section of ~/.perfconfig and set 'kbuild-dir'\n"
" \toption in [llvm] to \"\" to suppress this detection.\n\n",
*kbuild_dir);
free(*kbuild_dir);
*kbuild_dir = NULL;
return;
}
pr_debug("include option is set to %s\n", *kbuild_include_opts);
}
int llvm__compile_bpf(const char *path, void **p_obj_buf,
@ -280,7 +328,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
char clang_path[PATH_MAX];
const char *clang_opt = llvm_param.clang_opt;
const char *template = llvm_param.clang_bpf_cmd_template;
char *kbuild_dir = NULL;
char *kbuild_dir = NULL, *kbuild_include_opts = NULL;
void *obj_buf = NULL;
size_t obj_buf_sz;
@ -302,11 +350,11 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
* This is an optional work. Even it fail we can continue our
* work. Needn't to check error return.
*/
get_kbuild_opts(&kbuild_dir);
get_kbuild_opts(&kbuild_dir, &kbuild_include_opts);
force_set_env("CLANG_EXEC", clang_path);
force_set_env("CLANG_OPTIONS", clang_opt);
force_set_env("KERNEL_INC_OPTIONS", NULL);
force_set_env("KERNEL_INC_OPTIONS", kbuild_include_opts);
force_set_env("WORKING_DIR", kbuild_dir ? : ".");
/*
@ -330,6 +378,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
}
free(kbuild_dir);
free(kbuild_include_opts);
if (!p_obj_buf)
free(obj_buf);
else
@ -340,6 +389,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf,
return 0;
errout:
free(kbuild_dir);
free(kbuild_include_opts);
free(obj_buf);
if (p_obj_buf)
*p_obj_buf = NULL;