2 * Copyright (C) 2015, Wang Nan <wangnan0@huawei.com>
3 * Copyright (C) 2015, Huawei Inc.
10 #include <linux/err.h>
12 #include "llvm-utils.h"
17 #define CLANG_BPF_CMD_DEFAULT_TEMPLATE \
18 "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\
19 "-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE " \
20 "$CLANG_OPTIONS $KERNEL_INC_OPTIONS " \
21 "-Wno-unused-value -Wno-pointer-sign " \
22 "-working-directory $WORKING_DIR " \
23 "-c \"$CLANG_SOURCE\" -target bpf -O2 -o -"
25 struct llvm_param llvm_param
= {
26 .clang_path
= "clang",
27 .clang_bpf_cmd_template
= CLANG_BPF_CMD_DEFAULT_TEMPLATE
,
31 .user_set_param
= false,
34 int perf_llvm_config(const char *var
, const char *value
)
36 if (prefixcmp(var
, "llvm."))
38 var
+= sizeof("llvm.") - 1;
40 if (!strcmp(var
, "clang-path"))
41 llvm_param
.clang_path
= strdup(value
);
42 else if (!strcmp(var
, "clang-bpf-cmd-template"))
43 llvm_param
.clang_bpf_cmd_template
= strdup(value
);
44 else if (!strcmp(var
, "clang-opt"))
45 llvm_param
.clang_opt
= strdup(value
);
46 else if (!strcmp(var
, "kbuild-dir"))
47 llvm_param
.kbuild_dir
= strdup(value
);
48 else if (!strcmp(var
, "kbuild-opts"))
49 llvm_param
.kbuild_opts
= strdup(value
);
50 else if (!strcmp(var
, "dump-obj"))
51 llvm_param
.dump_obj
= !!perf_config_bool(var
, value
);
53 pr_debug("Invalid LLVM config option: %s\n", value
);
56 llvm_param
.user_set_param
= true;
61 search_program(const char *def
, const char *name
,
64 char *env
, *path
, *tmp
= NULL
;
69 if (def
&& def
[0] != '\0') {
71 if (access(def
, F_OK
) == 0) {
72 strlcpy(output
, def
, PATH_MAX
);
75 } else if (def
[0] != '\0')
87 path
= strtok_r(env
, ":", &tmp
);
89 scnprintf(buf
, sizeof(buf
), "%s/%s", path
, name
);
90 if (access(buf
, F_OK
) == 0) {
91 strlcpy(output
, buf
, PATH_MAX
);
95 path
= strtok_r(NULL
, ":", &tmp
);
102 #define READ_SIZE 4096
104 read_from_pipe(const char *cmd
, void **p_buf
, size_t *p_read_sz
)
109 size_t read_sz
= 0, buf_sz
= 0;
110 char serr
[STRERR_BUFSIZE
];
112 file
= popen(cmd
, "r");
114 pr_err("ERROR: unable to popen cmd: %s\n",
115 str_error_r(errno
, serr
, sizeof(serr
)));
119 while (!feof(file
) && !ferror(file
)) {
121 * Make buf_sz always have obe byte extra space so we
122 * can put '\0' there.
124 if (buf_sz
- read_sz
< READ_SIZE
+ 1) {
127 buf_sz
= read_sz
+ READ_SIZE
+ 1;
128 new_buf
= realloc(buf
, buf_sz
);
131 pr_err("ERROR: failed to realloc memory\n");
138 read_sz
+= fread(buf
+ read_sz
, 1, READ_SIZE
, file
);
141 if (buf_sz
- read_sz
< 1) {
142 pr_err("ERROR: internal error\n");
148 pr_err("ERROR: error occurred when reading from pipe: %s\n",
149 str_error_r(errno
, serr
, sizeof(serr
)));
154 err
= WEXITSTATUS(pclose(file
));
162 * If buf is string, give it terminal '\0' to make our life
163 * easier. If buf is not string, that '\0' is out of space
164 * indicated by read_sz so caller won't even notice it.
166 ((char *)buf
)[read_sz
] = '\0';
174 *p_read_sz
= read_sz
;
189 force_set_env(const char *var
, const char *value
)
192 setenv(var
, value
, 1);
193 pr_debug("set env: %s=%s\n", var
, value
);
196 pr_debug("unset env: %s\n", var
);
204 " \tLLVM 3.7 or newer is required. Which can be found from http://llvm.org\n"
205 " \tYou may want to try git trunk:\n"
206 " \t\tgit clone http://llvm.org/git/llvm.git\n"
208 " \t\tgit clone http://llvm.org/git/clang.git\n\n"
209 " \tOr fetch the latest clang/llvm 3.7 from pre-built llvm packages for\n"
210 " \tdebian/ubuntu:\n"
211 " \t\thttp://llvm.org/apt\n\n"
212 " \tIf you are using old version of clang, change 'clang-bpf-cmd-template'\n"
213 " \toption in [llvm] section of ~/.perfconfig to:\n\n"
214 " \t \"$CLANG_EXEC $CLANG_OPTIONS $KERNEL_INC_OPTIONS \\\n"
215 " \t -working-directory $WORKING_DIR -c $CLANG_SOURCE \\\n"
216 " \t -emit-llvm -o - | /path/to/llc -march=bpf -filetype=obj -o -\"\n"
217 " \t(Replace /path/to/llc with path to your llc)\n\n"
221 static int detect_kbuild_dir(char **kbuild_dir
)
223 const char *test_dir
= llvm_param
.kbuild_dir
;
224 const char *prefix_dir
= "";
225 const char *suffix_dir
= "";
232 /* _UTSNAME_LENGTH is 65 */
235 err
= fetch_kernel_version(NULL
, release
,
241 prefix_dir
= "/lib/modules/";
242 suffix_dir
= "/build";
245 err
= asprintf(&autoconf_path
, "%s%s%s/include/generated/autoconf.h",
246 prefix_dir
, test_dir
, suffix_dir
);
250 if (access(autoconf_path
, R_OK
) == 0) {
253 err
= asprintf(kbuild_dir
, "%s%s%s", prefix_dir
, test_dir
,
263 static const char *kinc_fetch_script
=
264 "#!/usr/bin/env sh\n"
265 "if ! test -d \"$KBUILD_DIR\"\n"
269 "if ! test -f \"$KBUILD_DIR/include/generated/autoconf.h\"\n"
273 "TMPDIR=`mktemp -d`\n"
274 "if test -z \"$TMPDIR\"\n"
278 "cat << EOF > $TMPDIR/Makefile\n"
280 "\\$(obj)/%.o: \\$(src)/%.c\n"
281 "\t@echo -n \"\\$(NOSTDINC_FLAGS) \\$(LINUXINCLUDE) \\$(EXTRA_CFLAGS)\"\n"
283 "touch $TMPDIR/dummy.c\n"
284 "make -s -C $KBUILD_DIR M=$TMPDIR $KBUILD_OPTS dummy.o 2>/dev/null\n"
289 void llvm__get_kbuild_opts(char **kbuild_dir
, char **kbuild_include_opts
)
291 static char *saved_kbuild_dir
;
292 static char *saved_kbuild_include_opts
;
295 if (!kbuild_dir
|| !kbuild_include_opts
)
299 *kbuild_include_opts
= NULL
;
301 if (saved_kbuild_dir
&& saved_kbuild_include_opts
&&
302 !IS_ERR(saved_kbuild_dir
) && !IS_ERR(saved_kbuild_include_opts
)) {
303 *kbuild_dir
= strdup(saved_kbuild_dir
);
304 *kbuild_include_opts
= strdup(saved_kbuild_include_opts
);
306 if (*kbuild_dir
&& *kbuild_include_opts
)
310 zfree(kbuild_include_opts
);
312 * Don't fall through: it may breaks saved_kbuild_dir and
313 * saved_kbuild_include_opts if detect them again when
319 if (llvm_param
.kbuild_dir
&& !llvm_param
.kbuild_dir
[0]) {
320 pr_debug("[llvm.kbuild-dir] is set to \"\" deliberately.\n");
321 pr_debug("Skip kbuild options detection.\n");
325 err
= detect_kbuild_dir(kbuild_dir
);
328 "WARNING:\tunable to get correct kernel building directory.\n"
329 "Hint:\tSet correct kbuild directory using 'kbuild-dir' option in [llvm]\n"
330 " \tsection of ~/.perfconfig or set it to \"\" to suppress kbuild\n"
331 " \tdetection.\n\n");
335 pr_debug("Kernel build dir is set to %s\n", *kbuild_dir
);
336 force_set_env("KBUILD_DIR", *kbuild_dir
);
337 force_set_env("KBUILD_OPTS", llvm_param
.kbuild_opts
);
338 err
= read_from_pipe(kinc_fetch_script
,
339 (void **)kbuild_include_opts
,
343 "WARNING:\tunable to get kernel include directories from '%s'\n"
344 "Hint:\tTry set clang include options using 'clang-bpf-cmd-template'\n"
345 " \toption in [llvm] section of ~/.perfconfig and set 'kbuild-dir'\n"
346 " \toption in [llvm] to \"\" to suppress this detection.\n\n",
354 pr_debug("include option is set to %s\n", *kbuild_include_opts
);
356 saved_kbuild_dir
= strdup(*kbuild_dir
);
357 saved_kbuild_include_opts
= strdup(*kbuild_include_opts
);
359 if (!saved_kbuild_dir
|| !saved_kbuild_include_opts
) {
360 zfree(&saved_kbuild_dir
);
361 zfree(&saved_kbuild_include_opts
);
365 saved_kbuild_dir
= ERR_PTR(-EINVAL
);
366 saved_kbuild_include_opts
= ERR_PTR(-EINVAL
);
369 int llvm__get_nr_cpus(void)
371 static int nr_cpus_avail
= 0;
372 char serr
[STRERR_BUFSIZE
];
374 if (nr_cpus_avail
> 0)
375 return nr_cpus_avail
;
377 nr_cpus_avail
= sysconf(_SC_NPROCESSORS_CONF
);
378 if (nr_cpus_avail
<= 0) {
380 "WARNING:\tunable to get available CPUs in this system: %s\n"
381 " \tUse 128 instead.\n", str_error_r(errno
, serr
, sizeof(serr
)));
384 return nr_cpus_avail
;
387 void llvm__dump_obj(const char *path
, void *obj_buf
, size_t size
)
389 char *obj_path
= strdup(path
);
394 pr_warning("WARNING: Not enough memory, skip object dumping\n");
398 p
= strrchr(obj_path
, '.');
399 if (!p
|| (strcmp(p
, ".c") != 0)) {
400 pr_warning("WARNING: invalid llvm source path: '%s', skip object dumping\n",
406 fp
= fopen(obj_path
, "wb");
408 pr_warning("WARNING: failed to open '%s': %s, skip object dumping\n",
409 obj_path
, strerror(errno
));
413 pr_info("LLVM: dumping %s\n", obj_path
);
414 if (fwrite(obj_buf
, size
, 1, fp
) != 1)
415 pr_warning("WARNING: failed to write to file '%s': %s, skip object dumping\n",
416 obj_path
, strerror(errno
));
422 int llvm__compile_bpf(const char *path
, void **p_obj_buf
,
423 size_t *p_obj_buf_sz
)
426 void *obj_buf
= NULL
;
427 int err
, nr_cpus_avail
;
428 unsigned int kernel_version
;
429 char linux_version_code_str
[64];
430 const char *clang_opt
= llvm_param
.clang_opt
;
431 char clang_path
[PATH_MAX
], abspath
[PATH_MAX
], nr_cpus_avail_str
[64];
432 char serr
[STRERR_BUFSIZE
];
433 char *kbuild_dir
= NULL
, *kbuild_include_opts
= NULL
;
434 const char *template = llvm_param
.clang_bpf_cmd_template
;
436 if (path
[0] != '-' && realpath(path
, abspath
) == NULL
) {
438 pr_err("ERROR: problems with path %s: %s\n",
439 path
, str_error_r(err
, serr
, sizeof(serr
)));
444 template = CLANG_BPF_CMD_DEFAULT_TEMPLATE
;
446 err
= search_program(llvm_param
.clang_path
,
447 "clang", clang_path
);
450 "ERROR:\tunable to find clang.\n"
451 "Hint:\tTry to install latest clang/llvm to support BPF. Check your $PATH\n"
452 " \tand 'clang-path' option in [llvm] section of ~/.perfconfig.\n");
458 * This is an optional work. Even it fail we can continue our
459 * work. Needn't to check error return.
461 llvm__get_kbuild_opts(&kbuild_dir
, &kbuild_include_opts
);
463 nr_cpus_avail
= llvm__get_nr_cpus();
464 snprintf(nr_cpus_avail_str
, sizeof(nr_cpus_avail_str
), "%d",
467 if (fetch_kernel_version(&kernel_version
, NULL
, 0))
470 snprintf(linux_version_code_str
, sizeof(linux_version_code_str
),
471 "0x%x", kernel_version
);
473 force_set_env("NR_CPUS", nr_cpus_avail_str
);
474 force_set_env("LINUX_VERSION_CODE", linux_version_code_str
);
475 force_set_env("CLANG_EXEC", clang_path
);
476 force_set_env("CLANG_OPTIONS", clang_opt
);
477 force_set_env("KERNEL_INC_OPTIONS", kbuild_include_opts
);
478 force_set_env("WORKING_DIR", kbuild_dir
? : ".");
481 * Since we may reset clang's working dir, path of source file
482 * should be transferred into absolute path, except we want
483 * stdin to be source file (testing).
485 force_set_env("CLANG_SOURCE",
486 (path
[0] == '-') ? path
: abspath
);
488 pr_debug("llvm compiling command template: %s\n", template);
489 err
= read_from_pipe(template, &obj_buf
, &obj_buf_sz
);
491 pr_err("ERROR:\tunable to compile %s\n", path
);
492 pr_err("Hint:\tCheck error message shown above.\n");
493 pr_err("Hint:\tYou can also pre-compile it into .o using:\n");
494 pr_err(" \t\tclang -target bpf -O2 -c %s\n", path
);
495 pr_err(" \twith proper -I and -D options.\n");
500 free(kbuild_include_opts
);
505 *p_obj_buf
= obj_buf
;
508 *p_obj_buf_sz
= obj_buf_sz
;
512 free(kbuild_include_opts
);
521 int llvm__search_clang(void)
523 char clang_path
[PATH_MAX
];
525 return search_program(llvm_param
.clang_path
, "clang", clang_path
);