perf tools: Pass context to perf hook functions

Pass a pointer to perf hook functions so they receive context
information during setup.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Joe Stringer <joe@ovn.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/20161126070354.141764-6-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

3 files changed, 20 insertions, 10 deletions

diff --git a/tools/perf/tests/perf-hooks.c b/tools/perf/tests/perf-hooks.c
index 9338cb2c25ab..665ecc19671c 100644
--- a/tools/perf/tests/perf-hooks.c
+++ b/tools/perf/tests/perf-hooks.c
@@ -15,13 +15,13 @@ static void sigsegv_handler(int sig __maybe_unused)
         exit(-1);
 }
 
-static int hook_flags;
 
-static void the_hook(void)
+static void the_hook(void *_hook_flags)
 {
+        int *hook_flags = _hook_flags;
         int *p = NULL;
 
-        hook_flags = 1234;
+        *hook_flags = 1234;
 
         /* Generate a segfault, test perf_hooks__recover */
         *p = 0;
@@ -29,13 +29,17 @@ static void the_hook(void)
 
 int test__perf_hooks(int subtest __maybe_unused)
 {
+        int hook_flags = 0;
+
         signal(SIGSEGV, sigsegv_handler);
-        perf_hooks__set_hook("test", the_hook);
+        perf_hooks__set_hook("test", the_hook, &hook_flags);
         perf_hooks__invoke_test();
 
         /* hook is triggered? */
-        if (hook_flags != 1234)
+        if (hook_flags != 1234) {
+                pr_debug("Setting failed: %d (%p)\n", hook_flags, &hook_flags);
                 return TEST_FAIL;
+        }
 
         /* the buggy hook is removed? */
         if (perf_hooks__get_hook("test"))
diff --git a/tools/perf/util/perf-hooks.c b/tools/perf/util/perf-hooks.c
index 4ce88e37dd63..cb368306b12b 100644
--- a/tools/perf/util/perf-hooks.c
+++ b/tools/perf/util/perf-hooks.c
@@ -27,7 +27,7 @@ void perf_hooks__invoke(const struct perf_hook_desc *desc)
                 *(current_perf_hook->p_hook_func) = NULL;
         } else {
                 current_perf_hook = desc;
-                (**desc->p_hook_func)();
+                (**desc->p_hook_func)(desc->hook_ctx);
         }
         current_perf_hook = NULL;
 }
@@ -41,7 +41,9 @@ void perf_hooks__recover(void)
 #define PERF_HOOK(name)                                 \
 perf_hook_func_t __perf_hook_func_##name = NULL;        \
 struct perf_hook_desc __perf_hook_desc_##name =         \
-        {.hook_name = #name, .p_hook_func = &__perf_hook_func_##name};
+        {.hook_name = #name,                            \
+         .p_hook_func = &__perf_hook_func_##name,       \
+         .hook_ctx = NULL};
 #include "perf-hooks-list.h"
 #undef PERF_HOOK
 
@@ -54,7 +56,8 @@ static struct perf_hook_desc *perf_hooks[] = {
 #undef PERF_HOOK
 
 int perf_hooks__set_hook(const char *hook_name,
-                         perf_hook_func_t hook_func)
+                         perf_hook_func_t hook_func,
+                         void *hook_ctx)
 {
         unsigned int i;
 
@@ -65,6 +68,7 @@ int perf_hooks__set_hook(const char *hook_name,
                 if (*(perf_hooks[i]->p_hook_func))
                         pr_warning("Overwrite existing hook: %s\n", hook_name);
                 *(perf_hooks[i]->p_hook_func) = hook_func;
+                perf_hooks[i]->hook_ctx = hook_ctx;
                 return 0;
         }
         return -ENOENT;
diff --git a/tools/perf/util/perf-hooks.h b/tools/perf/util/perf-hooks.h
index 1d482b26b4b9..838d5797bc1e 100644
--- a/tools/perf/util/perf-hooks.h
+++ b/tools/perf/util/perf-hooks.h
@@ -5,10 +5,11 @@
 extern "C" {
 #endif
 
-typedef void (*perf_hook_func_t)(void);
+typedef void (*perf_hook_func_t)(void *ctx);
 struct perf_hook_desc {
         const char * const hook_name;
         perf_hook_func_t * const p_hook_func;
+        void *hook_ctx;
 };
 
 extern void perf_hooks__invoke(const struct perf_hook_desc *);
@@ -26,7 +27,8 @@ static inline void perf_hooks__invoke_##name(void)	\
 
 extern int
 perf_hooks__set_hook(const char *hook_name,
-                     perf_hook_func_t hook_func);
+                     perf_hook_func_t hook_func,
+                     void *hook_ctx);
 
 extern perf_hook_func_t
 perf_hooks__get_hook(const char *hook_name);