[FIX] syscall features installing

correct processing errors and set/unset/_features() synchronization

Change-Id: Id3b7d812a7050cba2c21a3254d12379f66142fa4
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>

diff --git a/ks_features/features_data.c b/ks_features/features_data.c
index 4f50fac..ec47f66 100644 (file)
--- a/ks_features/features_data.c
+++ b/ks_features/features_data.c
@@ -24,11 +24,14 @@
 
 
 #include "syscall_list.h"
+#include <linux/mutex.h>
 
 struct feature {
        size_t cnt;
        enum syscall_id *feature_list;
        int sub_type;
+
+       unsigned enable:1;
 };
 
 #define X(name, args) id_##name
@@ -257,7 +260,8 @@ static enum syscall_id id_desc[] = {
 {                                                              \
        .cnt = sizeof(x) / sizeof(enum syscall_id),             \
        .feature_list = x,                                      \
-       .sub_type = subtype                                     \
+       .sub_type = subtype,                                    \
+       .enable = 0                                             \
 }
 
 static struct feature features[] = {
@@ -273,3 +277,8 @@ static struct feature features[] = {
 enum {
        feature_cnt = sizeof(features) / sizeof(struct feature)
 };
+
+static int feature_index(struct feature *f)
+{
+       return f - features;
+}

diff --git a/ks_features/ks_features.c b/ks_features/ks_features.c
index 3eb19b8..9f8d038 100644 (file)
--- a/ks_features/ks_features.c
+++ b/ks_features/ks_features.c
@@ -250,8 +250,38 @@ static void unset_pst(struct feature *f, size_t id)
        ksp[id].sub_type &= !f->sub_type;
 }
 
-static int install_features(struct feature *f)
+static void do_uninstall_features(struct feature *f, size_t i)
+{
+       int ret;
+       size_t id;
+       const size_t end = ((size_t) 0) - 1;
+
+       for (; i != end; --i) {
+               id = f->feature_list[i];
+
+               if (get_counter(id) == 0) {
+                       printk("syscall %s not installed\n",
+                              get_sys_name(id));
+                       BUG();
+               }
+
+               dec_counter(id);
+
+               if (get_counter(id) == 0) {
+                       ret = unregister_syscall(id);
+                       if (ret)
+                               printk("syscall %s uninstall error, ret=%d\n",
+                                      get_sys_name(id), ret);
+
+               }
+
+               unset_pst(f, id);
+       }
+}
+
+static int do_install_features(struct feature *f)
 {
+       int ret;
        size_t i, id;
 
        for (i = 0; i < f->cnt; ++i) {
@@ -259,10 +289,12 @@ static int install_features(struct feature *f)
                set_pst(f, id);
 
                if (get_counter(id) == 0) {
-                       int ret = register_syscall(id);
+                       ret = register_syscall(id);
                        if (ret) {
-                               printk("syscall %d install error, ret = %d\n",
-                                      id, ret);
+                               printk("syscall %s install error, ret=%d\n",
+                                      get_sys_name(id), ret);
+
+                               do_uninstall_features(f, --i);
                                return ret;
                        }
                }
@@ -273,32 +305,44 @@ static int install_features(struct feature *f)
        return 0;
 }
 
-static int uninstall_features(struct feature *f)
+static DEFINE_MUTEX(mutex_features);
+
+static int install_features(struct feature *f)
 {
-       size_t i, id;
+       int ret = 0;
 
-       for (i = 0; i < f->cnt; ++i) {
-               id = f->feature_list[i];
+       mutex_lock(&mutex_features);
+       if (f->enable) {
+               printk("energy profiling is already run!\n");
+               ret = -EINVAL;
+               goto unlock;
+       }
 
-               if (get_counter(id) == 0) {
-                       /* TODO: error */
-                       return -EINVAL;
-               }
+       ret = do_install_features(f);
 
-               dec_counter(id);
+       f->enable = 1;
+unlock:
+       mutex_unlock(&mutex_features);
+       return ret;
+}
 
-               if (get_counter(id) == 0) {
-                       int ret = unregister_syscall(id);
-                       if (ret) {
-                               /* TODO: error */
-                               return ret;
-                       }
-               }
+static int uninstall_features(struct feature *f)
+{
+       int ret = 0;
 
-               unset_pst(f, id);
+       mutex_lock(&mutex_features);
+       if (f->enable == 0) {
+               printk("feature[%d] is not running!\n", feature_index(f));
+               ret = -EINVAL;
+               goto unlock;
        }
 
-       return 0;
+       do_uninstall_features(f, f->cnt - 1);
+
+       f->enable = 0;
+unlock:
+       mutex_unlock(&mutex_features);
+       return ret;
 }
 
 static struct feature *get_feature(enum feature_id id)
@@ -341,15 +385,11 @@ int unset_feature(enum feature_id id)
 }
 EXPORT_SYMBOL_GPL(unset_feature);
 
-static int __init init_ks_feature(void)
+static int init_syscall_features(void)
 {
-       int i, ret;
+       size_t i;
        unsigned long addr, ni_syscall;
-       char *name;
-
-       ret = init_switch_context();
-       if (ret)
-               return ret;
+       const char *name;
 
        ni_syscall = swap_ksyms("sys_ni_syscall");
 
@@ -362,25 +402,44 @@ static int __init init_ks_feature(void)
                }
 
                if (ni_syscall == addr) {
-                       printk("INFO: %s is not install\n", get_sys_name(i));
+                       printk("INFO: %s is not install\n", name);
                        addr = 0;
                }
 
-               ksp[i].rp.kp.addr = addr;
+               ksp[i].rp.kp.addr = (kprobe_opcode_t *)addr;
        }
 
        return 0;
 }
 
-static void __exit exit_ks_feature(void)
+static void uninit_syscall_features(void)
 {
-       int id;
+       size_t id;
 
        for (id = 0; id < syscall_name_cnt; ++id) {
                if (get_counter(id) > 0)
                        unregister_syscall(id);
        }
+}
+
+static int __init init_ks_feature(void)
+{
+       int ret;
+
+       ret = init_switch_context();
+       if (ret)
+               return ret;
 
+       ret = init_syscall_features();
+       if (ret)
+               exit_switch_context();
+
+       return ret;
+}
+
+static void __exit exit_ks_feature(void)
+{
+       uninit_syscall_features();
        exit_switch_context();
 }