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Message-ID: <20161126070354.141764-23-wangnan0@huawei.com>
Date: Sat, 26 Nov 2016 07:03:46 +0000
From: Wang Nan <wangnan0@...wei.com>
To: <acme@...hat.com>, <ast@...com>
CC: <lizefan@...wei.com>, <hekuang@...wei.com>,
<linux-kernel@...r.kernel.org>, <pi3orama@....com>, <joe@....org>,
Wang Nan <wangnan0@...wei.com>, Jiri Olsa <jolsa@...nel.org>
Subject: [PATCH v3 22/30] perf clang jit: Actually JIT and hook in bpf loader
Makes perf_clang__compile_bpf() actually uses clang jit to compile perf
hooks. Returns a map through perf_clang__compile_bpf(), and set hooks
after bpf_object is created.
After this path jitting takes actions for bpf loader. For example:
$ cat ./test.c
/******************************************************/
#define SEC(name) __attribute__((section(name), used))
SEC("dofork=_do_fork")
int dofork(void *ctx)
{
return 0;
}
extern int printf(const char *fmt, ...);
SEC("perfhook:record_start")
void record_start(void)
{
printf("Welcom to perf record\n");
}
SEC("perfhook:record_end")
void record_end(void)
{
printf("Goodbye, perf record\n");
}
char _license[] SEC("license") = "GPL";
int _version SEC("version") = LINUX_VERSION_CODE;
/******************************************************/
$ perf record -e ./test.c sleep 1
Welcom to perf record
[ perf record: Woken up 1 times to write data ]
Goodbye, perf record
[ perf record: Captured and wrote 0.014 MB perf.data ]
Signed-off-by: Wang Nan <wangnan0@...wei.com>
Cc: Arnaldo Carvalho de Melo <acme@...hat.com>
Cc: Alexei Starovoitov <ast@...com>
Cc: He Kuang <hekuang@...wei.com>
Cc: Jiri Olsa <jolsa@...nel.org>
Cc: Zefan Li <lizefan@...wei.com>
Cc: pi3orama@....com
---
tools/perf/util/bpf-loader.c | 11 ++++++++++-
tools/perf/util/c++/clang-c.h | 18 ++++++++++++++++--
tools/perf/util/c++/clang.cpp | 28 +++++++++++++++++++++++++++-
3 files changed, 53 insertions(+), 4 deletions(-)
diff --git a/tools/perf/util/bpf-loader.c b/tools/perf/util/bpf-loader.c
index a0ea334f..e50045f 100644
--- a/tools/perf/util/bpf-loader.c
+++ b/tools/perf/util/bpf-loader.c
@@ -85,9 +85,11 @@ struct bpf_object *bpf__prepare_load(const char *filename, bool source)
int err;
void *obj_buf;
size_t obj_buf_sz;
+ jitted_funcs_map_t jitted_funcs_map;
perf_clang__init();
- err = perf_clang__compile_bpf(filename, &obj_buf, &obj_buf_sz);
+ err = perf_clang__compile_bpf(filename, &obj_buf,
+ &obj_buf_sz, &jitted_funcs_map);
perf_clang__cleanup();
if (err) {
pr_warning("bpf: builtin compiling failed: %d, try external compiler\n", err);
@@ -101,6 +103,13 @@ struct bpf_object *bpf__prepare_load(const char *filename, bool source)
if (!IS_ERR(obj) && llvm_param.dump_obj)
llvm__dump_obj(filename, obj_buf, obj_buf_sz);
+ /*
+ * Call perf_clang__hook_jitted_func even IS_ERR(obj) to make sure
+ * the C++ map pointer is deleted.
+ */
+ if (jitted_funcs_map)
+ perf_clang__hook_jitted_func(jitted_funcs_map, obj, IS_ERR(obj));
+
free(obj_buf);
} else
obj = bpf_object__open(filename);
diff --git a/tools/perf/util/c++/clang-c.h b/tools/perf/util/c++/clang-c.h
index 9f75e41..021b1ad 100644
--- a/tools/perf/util/c++/clang-c.h
+++ b/tools/perf/util/c++/clang-c.h
@@ -8,6 +8,7 @@
extern "C" {
#endif
+typedef void *jitted_funcs_map_t;
#ifdef HAVE_LIBCLANGLLVM_SUPPORT
extern void perf_clang__init(void);
extern void perf_clang__cleanup(void);
@@ -20,7 +21,11 @@ extern void test__clang_callback(int x);
extern int perf_clang__compile_bpf(const char *filename,
void **p_obj_buf,
- size_t *p_obj_buf_sz);
+ size_t *p_obj_buf_sz,
+ jitted_funcs_map_t *p_funcs_map);
+
+extern int
+perf_clang__hook_jitted_func(jitted_funcs_map_t map, void *ctx, bool is_err);
#else
@@ -34,7 +39,16 @@ static inline int test__clang_jit(void) { return -1;}
static inline int
perf_clang__compile_bpf(const char *filename __maybe_unused,
void **p_obj_buf __maybe_unused,
- size_t *p_obj_buf_sz __maybe_unused)
+ size_t *p_obj_buf_sz __maybe_unused,
+ jitted_funcs_map_t *p_funcs_map __maybe_unused)
+{
+ return -ENOTSUP;
+}
+
+static inline int
+perf_clang__hook_jitted_func(jitted_funcs_map_t map __maybe_unused,
+ void *ctx __maybe_unused,
+ bool is_err __maybe_unused)
{
return -ENOTSUP;
}
diff --git a/tools/perf/util/c++/clang.cpp b/tools/perf/util/c++/clang.cpp
index 325fbe4..f2608f5 100644
--- a/tools/perf/util/c++/clang.cpp
+++ b/tools/perf/util/c++/clang.cpp
@@ -388,7 +388,8 @@ void perf_clang__cleanup(void)
int perf_clang__compile_bpf(const char *_filename,
void **p_obj_buf,
- size_t *p_obj_buf_sz)
+ size_t *p_obj_buf_sz,
+ jitted_funcs_map_t *p_funcs_map)
{
using namespace perf;
@@ -415,6 +416,31 @@ int perf_clang__compile_bpf(const char *_filename,
memcpy(buffer, O->data(), size);
*p_obj_buf = buffer;
*p_obj_buf_sz = size;
+
+ if (M->doJIT())
+ return -1;
+
+ if (p_funcs_map)
+ *p_funcs_map = (jitted_funcs_map_t)(M->copyJITResult());
+ return 0;
+}
+
+int perf_clang__hook_jitted_func(jitted_funcs_map_t map, void *ctx, bool is_err)
+{
+ std::unique_ptr<perf::PerfModule::HookMap>
+ hook_map((perf::PerfModule::HookMap *)map);
+
+ /* Do nothing but ensure map is deleted */
+ if (is_err)
+ return -1;
+
+ for (auto i : *hook_map) {
+ const char *hook_name = i.first.c_str();
+ perf_hook_func_t hook_func = i.second;
+
+ if (perf_hooks__set_hook(hook_name, hook_func, ctx))
+ return -1;
+ }
return 0;
}
}
--
2.10.1
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