From: Wang Nan <wangnan0@huawei.com>
To: <acme@kernel.org>, <ast@plumgrid.com>
Cc: <linux-kernel@vger.kernel.org>, <lizefan@huawei.com>,
<hekuang@huawei.com>, <xiakaixu@huawei.com>, <pi3orama@163.com>
Subject: [PATCH 13/39] perf tools: Call clang to compile C source to object code
Date: Thu, 9 Jul 2015 12:35:16 +0000 [thread overview]
Message-ID: <1436445342-1402-14-git-send-email-wangnan0@huawei.com> (raw)
In-Reply-To: <1436445342-1402-1-git-send-email-wangnan0@huawei.com>
This is the core patch for supporting eBPF on-the-fly compiling, does
the following work:
1. Search clang compiler using search_program().
2. Run command template defined in llvm-bpf-cmd-template option in
[llvm] config section using read_from_pipe(). Patch of clang and
source code path is injected into shell command using environment
variable using force_set_env().
Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/util/llvm-utils.c | 225 +++++++++++++++++++++++++++++++++++++++++++
tools/perf/util/llvm-utils.h | 3 +
2 files changed, 228 insertions(+)
diff --git a/tools/perf/util/llvm-utils.c b/tools/perf/util/llvm-utils.c
index fd5b1bc..dca16e7 100644
--- a/tools/perf/util/llvm-utils.c
+++ b/tools/perf/util/llvm-utils.c
@@ -43,3 +43,228 @@ int perf_llvm_config(const char *var, const char *value)
return -1;
return 0;
}
+
+static int
+search_program(const char *def, const char *name,
+ char *output)
+{
+ char *env, *path, *tmp;
+ 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;
+}
+
+#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;
+
+ file = popen(cmd, "r");
+ if (!file) {
+ pr_err("ERROR: unable to popen cmd: %s\n",
+ strerror(errno));
+ 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",
+ strerror(errno));
+ 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\thttp://llvm.org/apt\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 \\\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"
+);
+}
+
+int llvm__compile_bpf(const char *path, void **p_obj_buf,
+ size_t *p_obj_buf_sz)
+{
+ int err;
+ char clang_path[PATH_MAX];
+ const char *clang_opt = llvm_param.clang_opt;
+ const char *template = llvm_param.clang_bpf_cmd_template;
+ void *obj_buf = NULL;
+ size_t obj_buf_sz;
+
+ if (!template)
+ template = CLANG_BPF_CMD_DEFAULT_TEMPLATE;
+
+ err = search_program(llvm_param.clang_path,
+ "clang", clang_path);
+ if (err) {
+ pr_err(
+"ERROR:\tunable to find clang.\n"
+"Hint:\tTry to install latest clang/llvm to support BPF. Check your $PATH\n"
+" \tand 'clang-path' option in [llvm] section of ~/.perfconfig.\n");
+ version_notice();
+ return -ENOENT;
+ }
+
+ 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", ".");
+
+ /*
+ * 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 :
+ make_nonrelative_path(path));
+
+ pr_debug("llvm compiling command template: %s\n", template);
+ 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");
+ version_notice();
+ pr_err("Hint:\tYou can also pre-compile it into .o\n");
+ goto errout;
+ }
+
+ 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(obj_buf);
+ if (p_obj_buf)
+ *p_obj_buf = NULL;
+ if (p_obj_buf_sz)
+ *p_obj_buf_sz = 0;
+ return err;
+}
diff --git a/tools/perf/util/llvm-utils.h b/tools/perf/util/llvm-utils.h
index 504b799..d23adbc 100644
--- a/tools/perf/util/llvm-utils.h
+++ b/tools/perf/util/llvm-utils.h
@@ -33,4 +33,7 @@ struct llvm_param {
extern struct llvm_param llvm_param;
extern int perf_llvm_config(const char *var, const char *value);
+
+extern int llvm__compile_bpf(const char *path, void **p_obj_buf,
+ size_t *p_obj_buf_sz);
#endif
--
1.8.3.4
next prev parent reply other threads:[~2015-07-09 12:48 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-07-09 12:35 [GIT PULL 00/39] perf tools: filtering events using eBPF programs Wang Nan
2015-07-09 12:35 ` [PATCH 01/39] bpf tools: Collect symbol table from SHT_SYMTAB section Wang Nan
2015-07-09 12:35 ` [PATCH 02/39] bpf tools: Collect eBPF programs from their own sections Wang Nan
2015-07-09 15:58 ` Arnaldo Carvalho de Melo
2015-07-10 3:07 ` Wangnan (F)
2015-07-13 19:51 ` Arnaldo Carvalho de Melo
2015-07-14 3:58 ` Wangnan (F)
2015-07-09 12:35 ` [PATCH 03/39] bpf tools: Collect relocation sections from SHT_REL sections Wang Nan
2015-07-09 12:35 ` [PATCH 04/39] bpf tools: Record map accessing instructions for each program Wang Nan
2015-07-09 12:35 ` [PATCH 05/39] bpf tools: Add bpf.c/h for common bpf operations Wang Nan
2015-07-09 12:35 ` [PATCH 06/39] bpf tools: Create eBPF maps defined in an object file Wang Nan
2015-07-13 19:54 ` Arnaldo Carvalho de Melo
2015-07-14 3:59 ` Wangnan (F)
2015-07-09 12:35 ` [PATCH 07/39] bpf tools: Relocate eBPF programs Wang Nan
2015-07-09 12:35 ` [PATCH 08/39] bpf tools: Introduce bpf_load_program() to bpf.c Wang Nan
2015-07-09 12:35 ` [PATCH 09/39] bpf tools: Load eBPF programs in object files into kernel Wang Nan
2015-07-09 12:35 ` [PATCH 10/39] bpf tools: Introduce accessors for struct bpf_program Wang Nan
2015-07-09 12:35 ` [PATCH 11/39] bpf tools: Link all bpf objects onto a list Wang Nan
2015-07-09 12:35 ` [PATCH 12/39] perf tools: Introduce llvm config options Wang Nan
2015-07-21 11:13 ` [PATCH 12/39 update] " Wang Nan
2015-08-08 8:16 ` [tip:perf/core] " tip-bot for Wang Nan
2015-07-09 12:35 ` Wang Nan [this message]
2015-07-09 12:35 ` [PATCH 14/39] perf tools: Auto detecting kernel build directory Wang Nan
2015-07-13 21:46 ` Arnaldo Carvalho de Melo
2015-07-14 6:56 ` Wangnan (F)
2015-07-14 7:16 ` Wangnan (F)
2015-07-09 12:35 ` [PATCH 15/39] perf tools: Auto detecting kernel include options Wang Nan
2015-08-08 8:17 ` [tip:perf/core] " tip-bot for Wang Nan
2015-07-09 12:35 ` [PATCH 16/39] perf tests: Add LLVM test for eBPF on-the-fly compiling Wang Nan
2015-07-15 10:54 ` [PATCH updated " Wang Nan
2015-07-22 4:46 ` [PATCH 16/39 RESEND] " Wang Nan
2015-07-09 12:35 ` [PATCH 17/39] perf tools: Make perf depend on libbpf Wang Nan
2015-07-09 12:35 ` [PATCH 18/39] perf record: Enable passing bpf object file to --event Wang Nan
2015-07-09 12:35 ` [PATCH 19/39] perf record: Compile scriptlets if pass '.c' " Wang Nan
2015-07-09 12:35 ` [PATCH 20/39] perf tools: Parse probe points of eBPF programs during preparation Wang Nan
2015-07-09 12:35 ` [PATCH 21/39] perf probe: Attach trace_probe_event with perf_probe_event Wang Nan
2015-07-09 12:35 ` [PATCH 22/39] perf record: Probe at kprobe points Wang Nan
2015-07-09 12:35 ` [PATCH 23/39] perf record: Load all eBPF object into kernel Wang Nan
2015-07-09 12:35 ` [PATCH 24/39] perf tools: Add bpf_fd field to evsel and config it Wang Nan
2015-07-09 12:35 ` [PATCH 25/39] perf tools: Attach eBPF program to perf event Wang Nan
2015-07-09 12:35 ` [PATCH 26/39] perf tools: Suppress probing messages when probing by BPF loading Wang Nan
2015-07-09 12:35 ` [PATCH 27/39] perf record: Add clang options for compiling BPF scripts Wang Nan
2015-07-09 12:35 ` [PATCH 28/39] bpf tools: Load a program with different instances using preprocessor Wang Nan
2015-07-13 5:44 ` Wangnan (F)
2015-07-09 12:35 ` [PATCH 29/39] perf tools: Fix probe-event.h include Wang Nan
2015-07-09 12:35 ` [PATCH 30/39] perf probe: Reset args and nargs for probe_trace_event when failure Wang Nan
2015-07-09 12:35 ` [PATCH 31/39] perf tools: Move linux/filter.h to tools/include Wang Nan
2015-07-09 12:35 ` [PATCH 32/39] perf tools: Add BPF_PROLOGUE config options for further patches Wang Nan
2015-07-09 12:35 ` [PATCH 33/39] perf tools: Introduce arch_get_reg_info() for x86 Wang Nan
2015-07-09 12:35 ` [PATCH 34/39] perf tools: Add prologue for BPF programs for fetching arguments Wang Nan
2015-07-09 12:35 ` [PATCH 35/39] perf tools: Generate prologue for BPF programs Wang Nan
2015-07-09 12:35 ` [PATCH 36/39] perf tools: Use same BPF program if arguments are identical Wang Nan
2015-07-09 12:35 ` [PATCH 37/39] perf record: Support custom vmlinux path Wang Nan
2015-07-09 12:35 ` [PATCH 38/39] perf probe: Init symbol as kprobe if any event is kprobe Wang Nan
2015-07-09 12:35 ` [PATCH 39/39] perf tools: Support attach BPF program on uprobe events Wang Nan
2015-07-14 15:36 ` perf test LLVM was: Re: [GIT PULL 00/39] perf tools: filtering events using eBPF programs Arnaldo Carvalho de Melo
2015-07-15 10:49 ` Wangnan (F)
2015-07-15 11:20 ` Arnaldo Carvalho de Melo
2015-07-17 2:34 ` Wangnan (F)
[not found] ` <CA+JHD93=ZMFP0gB1NqTXGBjTfSyYC-53Uj7r11gQJnKtQRKcDg@mail.gmail.com>
2015-07-21 11:09 ` Wangnan (F)
2015-07-21 11:41 ` Arnaldo Carvalho de Melo
2015-07-22 4:40 ` Wangnan (F)
2015-07-31 15:35 ` perf eBPF patch ordering. was: " Arnaldo Carvalho de Melo
2015-07-31 20:31 ` Arnaldo Carvalho de Melo
2015-08-03 2:37 ` Wangnan (F)
2015-08-03 15:07 ` Arnaldo Carvalho de Melo
2015-08-03 15:19 ` Arnaldo Carvalho de Melo
2015-08-03 15:53 ` pi3orama
2015-08-03 16:11 ` Arnaldo Carvalho de Melo
2015-08-03 19:49 ` Arnaldo Carvalho de Melo
2015-08-04 5:28 ` Wangnan (F)
2015-08-04 10:39 ` Wangnan (F)
2015-08-04 15:55 ` Arnaldo Carvalho de Melo
2015-08-04 16:11 ` Arnaldo Carvalho de Melo
2015-08-04 16:13 ` pi3orama
2015-08-06 1:44 ` Wangnan (F)
2015-08-06 14:46 ` Arnaldo Carvalho de Melo
2015-08-06 15:58 ` Arnaldo Carvalho de Melo
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