diff options
Diffstat (limited to 'tools/perf/util/llvm-utils.c')
| -rw-r--r-- | tools/perf/util/llvm-utils.c | 612 |
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); +} |