[RFC PATCH v7 25/37] perf tests: Add LLVM test for eBPF on-the-fly compiling

Wang Nan
2015-06-12T05:40:46Z

Previous patch introduces llvm__compile_bpf() to compile source file to
eBPF object. This patch adds testcase to test it. It also test libbpf
by opening generated object.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
---
tools/perf/tests/Build | 1 +
tools/perf/tests/builtin-test.c | 4 ++
tools/perf/tests/llvm.c | 85 +++++++++++++++++++++++++++++++++++++++++
tools/perf/tests/tests.h | 1 +
4 files changed, 91 insertions(+)
create mode 100644 tools/perf/tests/llvm.c

diff --git a/tools/perf/tests/Build b/tools/perf/tests/Build
index ee41e70..5d74604 100644
--- a/tools/perf/tests/Build
+++ b/tools/perf/tests/Build
@@ -31,6 +31,7 @@ perf-y += code-reading.o
perf-y += sample-parsing.o
perf-y += parse-no-sample-id-all.o
perf-y += kmod-path.o
+perf-y += llvm.o

perf-$(CONFIG_X86) += perf-time-to-tsc.o

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index 87b9961..4d28fd9 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -171,6 +171,10 @@ static struct test {
.func = test__kmod_path__parse,
},
{
+ .desc = "Test LLVM searching and compiling",
+ .func = test__llvm,
+ },
+ {
.func = NULL,
},
};
diff --git a/tools/perf/tests/llvm.c b/tools/perf/tests/llvm.c
new file mode 100644
index 0000000..272be1b
--- /dev/null
+++ b/tools/perf/tests/llvm.c
@@ -0,0 +1,85 @@
+#include <stdio.h>
+#include <bpf/libbpf.h>
+#include <util/llvm-utils.h>
+#include <util/cache.h>
+#include "tests.h"
+#include "debug.h"
+
+static int perf_config_cb(const char *var, const char *val,
+ void *arg __maybe_unused)
+{
+ return perf_default_config(var, val, arg);
+}
+
+/*
+ * Randomly give it a "version" section since we don't really load it
+ * into kernel
+ */
+static const char test_bpf_prog[] =
+ "__attribute__((section(\"do_fork\"), used)) "
+ "int fork(void *ctx) {return 0;} "
+ "char _license[] __attribute__((section(\"license\"), used)) = \"GPL\";"
+ "int _version __attribute__((section(\"version\"), used)) = 0x40100;";
+
+#ifdef HAVE_LIBBPF_SUPPORT
+static int test__bpf_parsing(void *obj_buf, size_t obj_buf_sz)
+{
+ struct bpf_object *obj;
+
+ obj = bpf_object__open_buffer(obj_buf, obj_buf_sz);
+ if (!obj)
+ return -1;
+ bpf_object__close(obj);
+ return 0;
+}
+#else
+static int test__bpf_parsing(void *obj_buf __maybe_unused,
+ size_t obj_buf_sz __maybe_unused)
+{
+ fprintf(stderr, " (skip bpf parsing)");
+ return 0;
+}
+#endif
+
+#define new_string(n, fmt, ...) \
+do { \
+ n##_sz = snprintf(NULL, 0, fmt, __VA_ARGS__);\
+ if (n##_sz == 0) \
+ return -1; \
+ n##_new = malloc(n##_sz + 1); \
+ if (!n##_new) \
+ return -1; \
+ snprintf(n##_new, n##_sz + 1, fmt, __VA_ARGS__);\
+ n##_new[n##_sz] = '\0'; \
+} while(0)
+
+int test__llvm(void)
+{
+ char *tmpl_new, *clang_opt_new;
+ size_t tmpl_sz, clang_opt_sz;
+ void *obj_buf;
+ size_t obj_buf_sz;
+ int err;
+
+ perf_config(perf_config_cb, NULL);
+
+ if (!llvm_param.clang_bpf_cmd_template)
+ return -1;
+
+ if (!llvm_param.clang_opt)
+ llvm_param.clang_opt = strdup("");
+
+ new_string(tmpl, "echo '%s' | %s", test_bpf_prog,
+ llvm_param.clang_bpf_cmd_template);
+ new_string(clang_opt, "-xc %s", llvm_param.clang_opt);
+
+ llvm_param.clang_bpf_cmd_template = tmpl_new;
+ llvm_param.clang_opt = clang_opt_new;
+ err = llvm__compile_bpf("-", &obj_buf, &obj_buf_sz);
+ if (err)
+ return -1;
+
+ err = test__bpf_parsing(obj_buf, obj_buf_sz);
+ free(obj_buf);
+ return err;
+}
diff --git a/tools/perf/tests/tests.h b/tools/perf/tests/tests.h
index 8e5038b..5b29796 100644
--- a/tools/perf/tests/tests.h
+++ b/tools/perf/tests/tests.h
@@ -61,6 +61,7 @@ int test__switch_tracking(void);
int test__fdarray__filter(void);
int test__fdarray__add(void);
int test__kmod_path__parse(void);
+int test__llvm(void);

#if defined(__x86_64__) || defined(__i386__) || defined(__arm__) || defined(__aarch64__)
#ifdef HAVE_DWARF_UNWIND_SUPPORT
--
1.8.3.4