Detect unbalanced lock/unlock

[urcu.git] / urcu-checker.c

diff --git a/urcu-checker.c b/urcu-checker.c
index cd4721d3cd95f1a1a4f2454dd5c19b99c5807ff6..97220ab73a9745684f1b4640d2662b5f5121cef4 100644 (file)
--- a/urcu-checker.c
+++ b/urcu-checker.c
@@ -67,7 +67,7 @@ static inline pid_t gettid(void)
                (long) getpid(), (long) gettid(), ## args)
 
 struct urcu_debug_entry {
-       void *ip;
+       char *func;
        int depth;
 };
 
@@ -145,16 +145,32 @@ void print_bt(struct backtrace *bt)
 void rcu_read_lock_debug(void)
 {
        struct urcu_debug_stack *r = &URCU_TLS(rcu_debug_stack);
+       char *func = get_symbol(__builtin_return_address(0));
 
-       r->stack[r->stackend++].ip = __builtin_return_address(0);
+       r->stack[r->stackend++].func = func;
 }
 
 void rcu_read_unlock_debug(void)
 {
        struct urcu_debug_stack *r = &URCU_TLS(rcu_debug_stack);
+       char *func = get_symbol(__builtin_return_address(0));
 
        assert(r->stackend != 0);
-       r->stack[--r->stackend].ip = NULL;
+       if (r->stack[r->stackend - 1].func && func &&
+                       strcmp(r->stack[r->stackend - 1].func,
+                               func) != 0) {
+               struct backtrace bt;
+
+               err_printf("URCU lock/unlock caller mismatch: lock by <%s> unlock by <%s>\n",
+                       r->stack[r->stackend - 1].func, func);
+               save_backtrace(&bt);
+               print_bt(&bt);
+               free_backtrace(&bt);
+       }
+       r->stackend--;
+       free(r->stack[r->stackend].func);
+       r->stack[r->stackend].func = NULL;
+       free(func);
 }
 
 void rcu_read_ongoing_check_debug(const char *func)
@@ -163,12 +179,13 @@ void rcu_read_ongoing_check_debug(const char *func)
 
        if (r->stackend == 0) {
                struct backtrace bt;
+               char *func = get_symbol(__builtin_return_address(0));
 
                err_printf("rcu_dereference() used outside of critical section at %p <%s>\n",
-                       __builtin_return_address(0),
-                       get_symbol(__builtin_return_address(0)));
+                       __builtin_return_address(0), func);
                save_backtrace(&bt);
                print_bt(&bt);
                free_backtrace(&bt);
+               free(func);
        }
 }