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-rw-r--r--tools/perf/util/llvm-utils.c612
1 files changed, 612 insertions, 0 deletions
diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c
new file mode 100644
index 000000000..a9e18bb16
--- /dev/null
+++ b/tools/perf/util/llvm-utils.c
@@ -0,0 +1,612 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2015, Wang Nan <wangnan0@huawei.com>
+ * Copyright (C) 2015, Huawei Inc.
+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <linux/err.h>
+#include <linux/string.h>
+#include <linux/zalloc.h>
+#include "debug.h"
+#include "llvm-utils.h"
+#include "config.h"
+#include "util.h"
+#include <sys/wait.h>
+#include <subcmd/exec-cmd.h>
+
+#define CLANG_BPF_CMD_DEFAULT_TEMPLATE \
+ "$CLANG_EXEC -D__KERNEL__ -D__NR_CPUS__=$NR_CPUS "\
+ "-DLINUX_VERSION_CODE=$LINUX_VERSION_CODE " \
+ "$CLANG_OPTIONS $PERF_BPF_INC_OPTIONS $KERNEL_INC_OPTIONS " \
+ "-Wno-unused-value -Wno-pointer-sign " \
+ "-working-directory $WORKING_DIR " \
+ "-c \"$CLANG_SOURCE\" -target bpf $CLANG_EMIT_LLVM -g -O2 -o - $LLVM_OPTIONS_PIPE"
+
+struct llvm_param llvm_param = {
+ .clang_path = "clang",
+ .llc_path = "llc",
+ .clang_bpf_cmd_template = CLANG_BPF_CMD_DEFAULT_TEMPLATE,
+ .clang_opt = NULL,
+ .opts = NULL,
+ .kbuild_dir = NULL,
+ .kbuild_opts = NULL,
+ .user_set_param = false,
+};
+
+static void version_notice(void);
+
+int perf_llvm_config(const char *var, const char *value)
+{
+ if (!strstarts(var, "llvm."))
+ return 0;
+ var += sizeof("llvm.") - 1;
+
+ if (!strcmp(var, "clang-path"))
+ llvm_param.clang_path = strdup(value);
+ else if (!strcmp(var, "clang-bpf-cmd-template"))
+ llvm_param.clang_bpf_cmd_template = strdup(value);
+ else if (!strcmp(var, "clang-opt"))
+ llvm_param.clang_opt = strdup(value);
+ else if (!strcmp(var, "kbuild-dir"))
+ llvm_param.kbuild_dir = strdup(value);
+ else if (!strcmp(var, "kbuild-opts"))
+ llvm_param.kbuild_opts = strdup(value);
+ else if (!strcmp(var, "dump-obj"))
+ llvm_param.dump_obj = !!perf_config_bool(var, value);
+ else if (!strcmp(var, "opts"))
+ llvm_param.opts = strdup(value);
+ else {
+ pr_debug("Invalid LLVM config option: %s\n", value);
+ return -1;
+ }
+ llvm_param.user_set_param = true;
+ return 0;
+}
+
+static int
+search_program(const char *def, const char *name,
+ char *output)
+{
+ char *env, *path, *tmp = NULL;
+ char buf[PATH_MAX];
+ int ret;
+
+ output[0] = '\0';
+ if (def && def[0] != '\0') {
+ if (def[0] == '/') {
+ if (access(def, F_OK) == 0) {
+ strlcpy(output, def, PATH_MAX);
+ return 0;
+ }
+ } else if (def[0] != '\0')
+ name = def;
+ }
+
+ env = getenv("PATH");
+ if (!env)
+ return -1;
+ env = strdup(env);
+ if (!env)
+ return -1;
+
+ ret = -ENOENT;
+ path = strtok_r(env, ":", &tmp);
+ while (path) {
+ scnprintf(buf, sizeof(buf), "%s/%s", path, name);
+ if (access(buf, F_OK) == 0) {
+ strlcpy(output, buf, PATH_MAX);
+ ret = 0;
+ break;
+ }
+ path = strtok_r(NULL, ":", &tmp);
+ }
+
+ free(env);
+ return ret;
+}
+
+static int search_program_and_warn(const char *def, const char *name,
+ char *output)
+{
+ int ret = search_program(def, name, output);
+
+ if (ret) {
+ pr_err("ERROR:\tunable to find %s.\n"
+ "Hint:\tTry to install latest clang/llvm to support BPF. Check your $PATH\n"
+ " \tand '%s-path' option in [llvm] section of ~/.perfconfig.\n",
+ name, name);
+ version_notice();
+ }
+ return ret;
+}
+
+#define READ_SIZE 4096
+static int
+read_from_pipe(const char *cmd, void **p_buf, size_t *p_read_sz)
+{
+ int err = 0;
+ void *buf = NULL;
+ FILE *file = NULL;
+ size_t read_sz = 0, buf_sz = 0;
+ char serr[STRERR_BUFSIZE];
+
+ file = popen(cmd, "r");
+ if (!file) {
+ pr_err("ERROR: unable to popen cmd: %s\n",
+ str_error_r(errno, serr, sizeof(serr)));
+ return -EINVAL;
+ }
+
+ while (!feof(file) && !ferror(file)) {
+ /*
+ * Make buf_sz always have obe byte extra space so we
+ * can put '\0' there.
+ */
+ if (buf_sz - read_sz < READ_SIZE + 1) {
+ void *new_buf;
+
+ buf_sz = read_sz + READ_SIZE + 1;
+ new_buf = realloc(buf, buf_sz);
+
+ if (!new_buf) {
+ pr_err("ERROR: failed to realloc memory\n");
+ err = -ENOMEM;
+ goto errout;
+ }
+
+ buf = new_buf;
+ }
+ read_sz += fread(buf + read_sz, 1, READ_SIZE, file);
+ }
+
+ if (buf_sz - read_sz < 1) {
+ pr_err("ERROR: internal error\n");
+ err = -EINVAL;
+ goto errout;
+ }
+
+ if (ferror(file)) {
+ pr_err("ERROR: error occurred when reading from pipe: %s\n",
+ str_error_r(errno, serr, sizeof(serr)));
+ err = -EIO;
+ goto errout;
+ }
+
+ err = WEXITSTATUS(pclose(file));
+ file = NULL;
+ if (err) {
+ err = -EINVAL;
+ goto errout;
+ }
+
+ /*
+ * If buf is string, give it terminal '\0' to make our life
+ * easier. If buf is not string, that '\0' is out of space
+ * indicated by read_sz so caller won't even notice it.
+ */
+ ((char *)buf)[read_sz] = '\0';
+
+ if (!p_buf)
+ free(buf);
+ else
+ *p_buf = buf;
+
+ if (p_read_sz)
+ *p_read_sz = read_sz;
+ return 0;
+
+errout:
+ if (file)
+ pclose(file);
+ free(buf);
+ if (p_buf)
+ *p_buf = NULL;
+ if (p_read_sz)
+ *p_read_sz = 0;
+ return err;
+}
+
+static inline void
+force_set_env(const char *var, const char *value)
+{
+ if (value) {
+ setenv(var, value, 1);
+ pr_debug("set env: %s=%s\n", var, value);
+ } else {
+ unsetenv(var);
+ pr_debug("unset env: %s\n", var);
+ }
+}
+
+static void
+version_notice(void)
+{
+ pr_err(
+" \tLLVM 3.7 or newer is required. Which can be found from http://llvm.org\n"
+" \tYou may want to try git trunk:\n"
+" \t\tgit clone http://llvm.org/git/llvm.git\n"
+" \t\t and\n"
+" \t\tgit clone http://llvm.org/git/clang.git\n\n"
+" \tOr fetch the latest clang/llvm 3.7 from pre-built llvm packages for\n"
+" \tdebian/ubuntu:\n"
+" \t\thttps://apt.llvm.org/\n\n"
+" \tIf you are using old version of clang, change 'clang-bpf-cmd-template'\n"
+" \toption in [llvm] section of ~/.perfconfig to:\n\n"
+" \t \"$CLANG_EXEC $CLANG_OPTIONS $KERNEL_INC_OPTIONS $PERF_BPF_INC_OPTIONS \\\n"
+" \t -working-directory $WORKING_DIR -c $CLANG_SOURCE \\\n"
+" \t -emit-llvm -o - | /path/to/llc -march=bpf -filetype=obj -o -\"\n"
+" \t(Replace /path/to/llc with path to your llc)\n\n"
+);
+}
+
+static int detect_kbuild_dir(char **kbuild_dir)
+{
+ const char *test_dir = llvm_param.kbuild_dir;
+ const char *prefix_dir = "";
+ const char *suffix_dir = "";
+
+ /* _UTSNAME_LENGTH is 65 */
+ char release[128];
+
+ char *autoconf_path;
+
+ int err;
+
+ if (!test_dir) {
+ err = fetch_kernel_version(NULL, release,
+ sizeof(release));
+ if (err)
+ return -EINVAL;
+
+ test_dir = release;
+ prefix_dir = "/lib/modules/";
+ suffix_dir = "/build";
+ }
+
+ err = asprintf(&autoconf_path, "%s%s%s/include/generated/autoconf.h",
+ prefix_dir, test_dir, suffix_dir);
+ if (err < 0)
+ return -ENOMEM;
+
+ if (access(autoconf_path, R_OK) == 0) {
+ free(autoconf_path);
+
+ err = asprintf(kbuild_dir, "%s%s%s", prefix_dir, test_dir,
+ suffix_dir);
+ if (err < 0)
+ return -ENOMEM;
+ return 0;
+ }
+ pr_debug("%s: Couldn't find \"%s\", missing kernel-devel package?.\n",
+ __func__, autoconf_path);
+ free(autoconf_path);
+ return -ENOENT;
+}
+
+static const char *kinc_fetch_script =
+"#!/usr/bin/env sh\n"
+"if ! test -d \"$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"
+"\t\\$(CC) -c -o \\$@ \\$<\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";
+
+void llvm__get_kbuild_opts(char **kbuild_dir, char **kbuild_include_opts)
+{
+ static char *saved_kbuild_dir;
+ static char *saved_kbuild_include_opts;
+ int err;
+
+ if (!kbuild_dir || !kbuild_include_opts)
+ return;
+
+ *kbuild_dir = NULL;
+ *kbuild_include_opts = NULL;
+
+ if (saved_kbuild_dir && saved_kbuild_include_opts &&
+ !IS_ERR(saved_kbuild_dir) && !IS_ERR(saved_kbuild_include_opts)) {
+ *kbuild_dir = strdup(saved_kbuild_dir);
+ *kbuild_include_opts = strdup(saved_kbuild_include_opts);
+
+ if (*kbuild_dir && *kbuild_include_opts)
+ return;
+
+ zfree(kbuild_dir);
+ zfree(kbuild_include_opts);
+ /*
+ * Don't fall through: it may breaks saved_kbuild_dir and
+ * saved_kbuild_include_opts if detect them again when
+ * memory is low.
+ */
+ return;
+ }
+
+ 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");
+ goto errout;
+ }
+
+ 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");
+ goto errout;
+ }
+
+ 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);
+
+ zfree(kbuild_dir);
+ goto errout;
+ }
+
+ pr_debug("include option is set to %s\n", *kbuild_include_opts);
+
+ saved_kbuild_dir = strdup(*kbuild_dir);
+ saved_kbuild_include_opts = strdup(*kbuild_include_opts);
+
+ if (!saved_kbuild_dir || !saved_kbuild_include_opts) {
+ zfree(&saved_kbuild_dir);
+ zfree(&saved_kbuild_include_opts);
+ }
+ return;
+errout:
+ saved_kbuild_dir = ERR_PTR(-EINVAL);
+ saved_kbuild_include_opts = ERR_PTR(-EINVAL);
+}
+
+int llvm__get_nr_cpus(void)
+{
+ static int nr_cpus_avail = 0;
+ char serr[STRERR_BUFSIZE];
+
+ if (nr_cpus_avail > 0)
+ return nr_cpus_avail;
+
+ nr_cpus_avail = sysconf(_SC_NPROCESSORS_CONF);
+ if (nr_cpus_avail <= 0) {
+ pr_err(
+"WARNING:\tunable to get available CPUs in this system: %s\n"
+" \tUse 128 instead.\n", str_error_r(errno, serr, sizeof(serr)));
+ nr_cpus_avail = 128;
+ }
+ return nr_cpus_avail;
+}
+
+void llvm__dump_obj(const char *path, void *obj_buf, size_t size)
+{
+ char *obj_path = strdup(path);
+ FILE *fp;
+ char *p;
+
+ if (!obj_path) {
+ pr_warning("WARNING: Not enough memory, skip object dumping\n");
+ return;
+ }
+
+ p = strrchr(obj_path, '.');
+ if (!p || (strcmp(p, ".c") != 0)) {
+ pr_warning("WARNING: invalid llvm source path: '%s', skip object dumping\n",
+ obj_path);
+ goto out;
+ }
+
+ p[1] = 'o';
+ fp = fopen(obj_path, "wb");
+ if (!fp) {
+ pr_warning("WARNING: failed to open '%s': %s, skip object dumping\n",
+ obj_path, strerror(errno));
+ goto out;
+ }
+
+ pr_debug("LLVM: dumping %s\n", obj_path);
+ if (fwrite(obj_buf, size, 1, fp) != 1)
+ pr_debug("WARNING: failed to write to file '%s': %s, skip object dumping\n", obj_path, strerror(errno));
+ fclose(fp);
+out:
+ free(obj_path);
+}
+
+int llvm__compile_bpf(const char *path, void **p_obj_buf,
+ size_t *p_obj_buf_sz)
+{
+ size_t obj_buf_sz;
+ void *obj_buf = NULL;
+ int err, nr_cpus_avail;
+ unsigned int kernel_version;
+ char linux_version_code_str[64];
+ const char *clang_opt = llvm_param.clang_opt;
+ char clang_path[PATH_MAX], llc_path[PATH_MAX], abspath[PATH_MAX], nr_cpus_avail_str[64];
+ char serr[STRERR_BUFSIZE];
+ char *kbuild_dir = NULL, *kbuild_include_opts = NULL,
+ *perf_bpf_include_opts = NULL;
+ const char *template = llvm_param.clang_bpf_cmd_template;
+ char *pipe_template = NULL;
+ const char *opts = llvm_param.opts;
+ char *command_echo = NULL, *command_out;
+ char *perf_include_dir = system_path(PERF_INCLUDE_DIR);
+
+ if (path[0] != '-' && realpath(path, abspath) == NULL) {
+ err = errno;
+ pr_err("ERROR: problems with path %s: %s\n",
+ path, str_error_r(err, serr, sizeof(serr)));
+ return -err;
+ }
+
+ if (!template)
+ template = CLANG_BPF_CMD_DEFAULT_TEMPLATE;
+
+ err = search_program_and_warn(llvm_param.clang_path,
+ "clang", clang_path);
+ if (err)
+ return -ENOENT;
+
+ /*
+ * This is an optional work. Even it fail we can continue our
+ * work. Needn't check error return.
+ */
+ llvm__get_kbuild_opts(&kbuild_dir, &kbuild_include_opts);
+
+ nr_cpus_avail = llvm__get_nr_cpus();
+ snprintf(nr_cpus_avail_str, sizeof(nr_cpus_avail_str), "%d",
+ nr_cpus_avail);
+
+ if (fetch_kernel_version(&kernel_version, NULL, 0))
+ kernel_version = 0;
+
+ snprintf(linux_version_code_str, sizeof(linux_version_code_str),
+ "0x%x", kernel_version);
+ if (asprintf(&perf_bpf_include_opts, "-I%s/bpf", perf_include_dir) < 0)
+ goto errout;
+ force_set_env("NR_CPUS", nr_cpus_avail_str);
+ force_set_env("LINUX_VERSION_CODE", linux_version_code_str);
+ force_set_env("CLANG_EXEC", clang_path);
+ force_set_env("CLANG_OPTIONS", clang_opt);
+ force_set_env("KERNEL_INC_OPTIONS", kbuild_include_opts);
+ force_set_env("PERF_BPF_INC_OPTIONS", perf_bpf_include_opts);
+ force_set_env("WORKING_DIR", kbuild_dir ? : ".");
+
+ if (opts) {
+ err = search_program_and_warn(llvm_param.llc_path, "llc", llc_path);
+ if (err)
+ goto errout;
+
+ err = -ENOMEM;
+ if (asprintf(&pipe_template, "%s -emit-llvm | %s -march=bpf %s -filetype=obj -o -",
+ template, llc_path, opts) < 0) {
+ pr_err("ERROR:\tnot enough memory to setup command line\n");
+ goto errout;
+ }
+
+ template = pipe_template;
+
+ }
+
+ /*
+ * Since we may reset clang's working dir, path of source file
+ * should be transferred into absolute path, except we want
+ * stdin to be source file (testing).
+ */
+ force_set_env("CLANG_SOURCE",
+ (path[0] == '-') ? path : abspath);
+
+ pr_debug("llvm compiling command template: %s\n", template);
+
+ /*
+ * Below, substitute control characters for values that can cause the
+ * echo to misbehave, then substitute the values back.
+ */
+ err = -ENOMEM;
+ if (asprintf(&command_echo, "echo -n \a%s\a", template) < 0)
+ goto errout;
+
+#define SWAP_CHAR(a, b) do { if (*p == a) *p = b; } while (0)
+ for (char *p = command_echo; *p; p++) {
+ SWAP_CHAR('<', '\001');
+ SWAP_CHAR('>', '\002');
+ SWAP_CHAR('"', '\003');
+ SWAP_CHAR('\'', '\004');
+ SWAP_CHAR('|', '\005');
+ SWAP_CHAR('&', '\006');
+ SWAP_CHAR('\a', '"');
+ }
+ err = read_from_pipe(command_echo, (void **) &command_out, NULL);
+ if (err)
+ goto errout;
+
+ for (char *p = command_out; *p; p++) {
+ SWAP_CHAR('\001', '<');
+ SWAP_CHAR('\002', '>');
+ SWAP_CHAR('\003', '"');
+ SWAP_CHAR('\004', '\'');
+ SWAP_CHAR('\005', '|');
+ SWAP_CHAR('\006', '&');
+ }
+#undef SWAP_CHAR
+ pr_debug("llvm compiling command : %s\n", command_out);
+
+ err = read_from_pipe(template, &obj_buf, &obj_buf_sz);
+ if (err) {
+ pr_err("ERROR:\tunable to compile %s\n", path);
+ pr_err("Hint:\tCheck error message shown above.\n");
+ pr_err("Hint:\tYou can also pre-compile it into .o using:\n");
+ pr_err(" \t\tclang -target bpf -O2 -c %s\n", path);
+ pr_err(" \twith proper -I and -D options.\n");
+ goto errout;
+ }
+
+ free(command_echo);
+ free(command_out);
+ free(kbuild_dir);
+ free(kbuild_include_opts);
+ free(perf_bpf_include_opts);
+ free(perf_include_dir);
+
+ if (!p_obj_buf)
+ free(obj_buf);
+ else
+ *p_obj_buf = obj_buf;
+
+ if (p_obj_buf_sz)
+ *p_obj_buf_sz = obj_buf_sz;
+ return 0;
+errout:
+ free(command_echo);
+ free(kbuild_dir);
+ free(kbuild_include_opts);
+ free(obj_buf);
+ free(perf_bpf_include_opts);
+ free(perf_include_dir);
+ free(pipe_template);
+ if (p_obj_buf)
+ *p_obj_buf = NULL;
+ if (p_obj_buf_sz)
+ *p_obj_buf_sz = 0;
+ return err;
+}
+
+int llvm__search_clang(void)
+{
+ char clang_path[PATH_MAX];
+
+ return search_program_and_warn(llvm_param.clang_path, "clang", clang_path);
+}