Allow using gpgrt_lock_init on an unitialized variable.

* src/posix-lock.c (gpgrt_lock_init): Detect unitialized lock var.
* src/w32-lock.c (gpgrt_lock_init): Ditto.
--

gpgrt_lock_init may be used for dynamically allocated locks.  For
example

   gpgrt_lock_t *lock = xcalloc (1, sizeof *lock);
   gpgrt_lock_init (lock);
   gpgrt_lock_lock (lock);
   foo ();
   gpgrt_lock_unlock (lock);
   gpgrt_lock_destroy (lock);
   free (lock);

This patch actually allows for this.

Signed-off-by: Werner Koch <[email protected]>

3 files changed, 33 insertions, 6 deletions

diff --git a/src/gpg-error.h.in b/src/gpg-error.h.in
index adb796b..4bd28bf 100644
--- a/src/gpg-error.h.in
+++ b/src/gpg-error.h.in
@@ -291,7 +291,8 @@ gpg_error_from_syserror (void)
 #define GPGRT_LOCK_DEFINE(name) \
   static gpgrt_lock_t name  = GPGRT_LOCK_INITIALIZER
 
-
+/* NB: If GPGRT_LOCK_DEFINE is not used, zero out the lock variable
+   before passing it to gpgrt_lock_init.  */
 gpg_err_code_t gpgrt_lock_init (gpgrt_lock_t *lockhd);
 gpg_err_code_t gpgrt_lock_lock (gpgrt_lock_t *lockhd);
 gpg_err_code_t gpgrt_lock_unlock (gpgrt_lock_t *lockhd);
diff --git a/src/posix-lock.c b/src/posix-lock.c
index 363cc09..5b0cab5 100644
--- a/src/posix-lock.c
+++ b/src/posix-lock.c
@@ -116,9 +116,21 @@ get_lock_object (gpgrt_lock_t *lockhd)
 gpg_err_code_t
 gpgrt_lock_init (gpgrt_lock_t *lockhd)
 {
-  _gpgrt_lock_t *lock = get_lock_object (lockhd);
+  _gpgrt_lock_t *lock = (_gpgrt_lock_t*)lockhd;
   int rc;
 
+  /* If VERS is zero we assume that no static initialization has been
+     done, so we setup our ABI version right here.  The caller might
+     have called us to test whether lock support is at all available. */
+  if (!lock->vers)
+    {
+      if (sizeof (gpgrt_lock_t) < sizeof (_gpgrt_lock_t))
+        abort ();
+      lock->vers = LOCK_ABI_VERSION;
+    }
+  else /* Run the usual check.  */
+    lock = get_lock_object (lockhd);
+
 #if USE_POSIX_THREADS
   if (use_pthread_p())
     {
@@ -198,7 +210,7 @@ gpgrt_lock_destroy (gpgrt_lock_t *lockhd)
         rc = gpg_err_code_from_errno (rc);
       else
         {
-          /* Re-init the the mutex so that it can be re-used.  */
+          /* Re-init the mutex so that it can be re-used.  */
           gpgrt_lock_t tmp = GPGRT_LOCK_INITIALIZER;
           memcpy (lockhd, &tmp, sizeof tmp);
         }
diff --git a/src/w32-lock.c b/src/w32-lock.c
index 0ad9409..56a0ed5 100644
--- a/src/w32-lock.c
+++ b/src/w32-lock.c
@@ -52,10 +52,24 @@ get_lock_object (gpgrt_lock_t *lockhd)
 gpg_err_code_t
 gpgrt_lock_init (gpgrt_lock_t *lockhd)
 {
-  _gpgrt_lock_t *lock = get_lock_object (lockhd);
+  _gpgrt_lock_t *lock = (_gpgrt_lock_t*)lockhd;
+
+  /* If VERS is zero we assume that no static initialization has been
+     done, so we setup our ABI version right here.  The caller might
+     have called us to test whether lock support is at all available. */
+  if (!lock->vers)
+    {
+      if (sizeof (gpgrt_lock_t) < sizeof (_gpgrt_lock_t))
+        abort ();
+      lock->vers = LOCK_ABI_VERSION;
+    }
+  else /* Run the usual check.  */
+    {
+      lock = get_lock_object (lockhd);
+      if (sizeof (gpgrt_lock_t) < sizeof (_gpgrt_lock_t))
+        abort ();
+    }
 
-  if (sizeof (gpgrt_lock_t) < sizeof (_gpgrt_lock_t))
-    abort ();
   InitializeCriticalSection (&lock->csec);
   lock->initdone = 1;
 }