Replace explicit rcu_read_lock/unlock with lttng::urcu::read_lock_guard

[lttng-tools.git] / src / bin / lttng-sessiond / lttng-syscall.cpp

diff --git a/src/bin/lttng-sessiond/lttng-syscall.cpp b/src/bin/lttng-sessiond/lttng-syscall.cpp
index dd042fd361aa752862e9dba5bb0c75de569ee86d..821bbaa34f80b6e1c6d572192909c0ec0257aab2 100644 (file)
--- a/src/bin/lttng-sessiond/lttng-syscall.cpp
+++ b/src/bin/lttng-sessiond/lttng-syscall.cpp
@@ -13,6 +13,7 @@
 
 #include <common/common.hpp>
 #include <common/kernel-ctl/kernel-ctl.hpp>
+#include <common/urcu.hpp>
 
 #include <stdbool.h>
 
@@ -150,28 +151,31 @@ error_ioctl:
  * syscall hashtable used to track duplicate between 32 and 64 bit arch.
  *
  * This empty the hash table and destroys it after. After this, the pointer is
- * unsuable. RCU read side lock MUST be acquired before calling this.
+ * unsuable. RCU read side lock MUST NOT be acquired before calling this.
  */
 static void destroy_syscall_ht(struct lttng_ht *ht)
 {
        struct lttng_ht_iter iter;
        struct syscall *ksyscall;
 
-       ASSERT_RCU_READ_LOCKED();
-
        DBG3("Destroying syscall hash table.");
 
        if (!ht) {
                return;
        }
 
-       cds_lfht_for_each_entry (ht->ht, &iter.iter, ksyscall, node.node) {
-               int ret;
+       {
+               lttng::urcu::read_lock_guard read_lock;
+
+               cds_lfht_for_each_entry (ht->ht, &iter.iter, ksyscall, node.node) {
+                       int ret;
 
-               ret = lttng_ht_del(ht, &iter);
-               LTTNG_ASSERT(!ret);
-               free(ksyscall);
+                       ret = lttng_ht_del(ht, &iter);
+                       LTTNG_ASSERT(!ret);
+                       free(ksyscall);
+               }
        }
+
        lttng_ht_destroy(ht);
 }
 
@@ -197,6 +201,8 @@ static int init_syscall_ht(struct lttng_ht **ht)
 /*
  * Lookup a syscall in the given hash table by name.
  *
+ * RCU read lock MUST be acquired by the callers of this function.
+ *
  * Return syscall object if found or else NULL.
  */
 static struct syscall *lookup_syscall(struct lttng_ht *ht, const char *name)
@@ -283,8 +289,6 @@ ssize_t syscall_table_list(struct lttng_event **_events)
 
        DBG("Syscall table listing.");
 
-       rcu_read_lock();
-
        /*
         * Allocate at least the number of total syscall we have even if some of
         * them might not be valid. The count below will make sure to return the
@@ -303,17 +307,20 @@ ssize_t syscall_table_list(struct lttng_event **_events)
        }
 
        for (i = 0; i < syscall_table_nb_entry; i++) {
-               struct syscall *ksyscall;
-
                /* Skip empty syscalls. */
                if (*syscall_table[i].name == '\0') {
                        continue;
                }
 
-               ksyscall = lookup_syscall(syscalls_ht, syscall_table[i].name);
-               if (ksyscall) {
-                       update_event_syscall_bitness(events, i, ksyscall->index);
-                       continue;
+               {
+                       lttng::urcu::read_lock_guard read_lock;
+                       struct syscall *ksyscall;
+
+                       ksyscall = lookup_syscall(syscalls_ht, syscall_table[i].name);
+                       if (ksyscall) {
+                               update_event_syscall_bitness(events, i, ksyscall->index);
+                               continue;
+                       }
                }
 
                ret = add_syscall_to_ht(syscalls_ht, i, index);
@@ -332,12 +339,10 @@ ssize_t syscall_table_list(struct lttng_event **_events)
 
        destroy_syscall_ht(syscalls_ht);
        *_events = events;
-       rcu_read_unlock();
        return index;
 
 error:
        destroy_syscall_ht(syscalls_ht);
        free(events);
-       rcu_read_unlock();
        return ret;
 }