From d325d7887b960627dc686d70d07682e18383f9c4 Mon Sep 17 00:00:00 2001 From: Wang Nan Date: Tue, 14 Jul 2015 06:40:02 +0000 Subject: perf tools: Auto detecting kernel build directory This patch detects kernel build directory by checking the existence of include/generated/autoconf.h. clang working directory is changed to kbuild directory if it is found, to help user use relative include path. Following patch will detect kernel include directory, which contains relative include patch so this workdir changing is needed. Users are allowed to set 'kbuild-dir = ""' manually to disable this checking. Signed-off-by: Wang Nan Acked-by: Alexei Starovoitov Cc: Brendan Gregg Cc: Daniel Borkmann Cc: David Ahern Cc: He Kuang Cc: Jiri Olsa Cc: Kaixu Xia Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Zefan Li Cc: pi3orama@163.com Link: http://lkml.kernel.org/n/tip-owyfwfbemrjn0tlj6tgk2nf5@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/llvm-utils.c | 80 +++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 79 insertions(+), 1 deletion(-) (limited to 'tools/perf/util/llvm-utils.c') diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c index 5ae11249baad..6bfcb2dd3161 100644 --- a/tools/perf/util/llvm-utils.c +++ b/tools/perf/util/llvm-utils.c @@ -4,6 +4,7 @@ */ #include +#include #include "util.h" #include "debug.h" #include "llvm-utils.h" @@ -204,6 +205,74 @@ version_notice(void) ); } +static int detect_kbuild_dir(char **kbuild_dir) +{ + const char *test_dir = llvm_param.kbuild_dir; + const char *prefix_dir = ""; + const char *suffix_dir = ""; + + char *autoconf_path; + struct utsname utsname; + + int err; + + if (!test_dir) { + err = uname(&utsname); + if (err) { + pr_warning("uname failed: %s\n", strerror(errno)); + return -EINVAL; + } + + test_dir = utsname.release; + prefix_dir = "/lib/modules/"; + suffix_dir = "/build"; + } + + err = asprintf(&autoconf_path, "%s%s%s/include/generated/autoconf.h", + prefix_dir, test_dir, suffix_dir); + if (err < 0) + return -ENOMEM; + + if (access(autoconf_path, R_OK) == 0) { + free(autoconf_path); + + err = asprintf(kbuild_dir, "%s%s%s", prefix_dir, test_dir, + suffix_dir); + if (err < 0) + return -ENOMEM; + return 0; + } + free(autoconf_path); + return -ENOENT; +} + +static inline void +get_kbuild_opts(char **kbuild_dir) +{ + int err; + + if (!kbuild_dir) + return; + + *kbuild_dir = NULL; + + if (llvm_param.kbuild_dir && !llvm_param.kbuild_dir[0]) { + pr_debug("[llvm.kbuild-dir] is set to \"\" deliberately.\n"); + pr_debug("Skip kbuild options detection.\n"); + return; + } + + err = detect_kbuild_dir(kbuild_dir); + if (err) { + pr_warning( +"WARNING:\tunable to get correct kernel building directory.\n" +"Hint:\tSet correct kbuild directory using 'kbuild-dir' option in [llvm]\n" +" \tsection of ~/.perfconfig or set it to \"\" to suppress kbuild\n" +" \tdetection.\n\n"); + return; + } +} + int llvm__compile_bpf(const char *path, void **p_obj_buf, size_t *p_obj_buf_sz) { @@ -211,6 +280,7 @@ 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; void *obj_buf = NULL; size_t obj_buf_sz; @@ -228,10 +298,16 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf, return -ENOENT; } + /* + * This is an optional work. Even it fail we can continue our + * work. Needn't to check error return. + */ + get_kbuild_opts(&kbuild_dir); + force_set_env("CLANG_EXEC", clang_path); force_set_env("CLANG_OPTIONS", clang_opt); force_set_env("KERNEL_INC_OPTIONS", NULL); - force_set_env("WORKING_DIR", "."); + force_set_env("WORKING_DIR", kbuild_dir ? : "."); /* * Since we may reset clang's working dir, path of source file @@ -253,6 +329,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf, goto errout; } + free(kbuild_dir); if (!p_obj_buf) free(obj_buf); else @@ -262,6 +339,7 @@ int llvm__compile_bpf(const char *path, void **p_obj_buf, *p_obj_buf_sz = obj_buf_sz; return 0; errout: + free(kbuild_dir); free(obj_buf); if (p_obj_buf) *p_obj_buf = NULL; -- cgit v1.2.3-55-g7522