Changeset 40812 in vbox

Timestamp:

Apr 7, 2012 10:13:10 AM (12 years ago)

Author:

vboxsync

Message:

SUPDrv: Corrected supdrvTracerCommonDeregisterImpl so the tracer module can be reloaded and re-register the providers of modules/drivers that aren't unloaded in the mean time. This means that we can demand-load the tracer module when needed and doesn't need to have it stick around the whole time.

Location:

trunk/src/VBox/HostDrivers/Support

Files:

• SUPDrvTracer.cpp (modified) (13 diffs)
• testcase/tstSupLoadModule.cpp (modified) (2 diffs)

trunk/src/VBox/HostDrivers/Support/SUPDrvTracer.cpp

@@ -66 +66 @@
     PSUPDRVSESSION          pSession;
 
-    /** Set when the module is unloaded or the driver deregisters its probes. */
+    /** Used to indicate that we've called pfnProviderDeregistered already and it
+     * failed because the provider was busy.  Next time we must try
+     * pfnProviderDeregisterZombie.
+     *
+     * @remarks This does not necessiarly mean the provider is in the zombie
+     *          list.  See supdrvTracerCommonDeregisterImpl. */
     bool                    fZombie;
     /** Set if the provider has been successfully registered with the
@@ -81 +86 @@
 *   Defined Constants And Macros                                               *
 *******************************************************************************/
-#if 0
+#ifdef DEBUG_bird
 # define LOG_TRACER(a_Args)  SUPR0Printf a_Args
 #else
@@ -552 +557 @@
             if (RT_SUCCESS(rc))
             {
-                if (pDevExt->pTracerOps)
+                if (   pDevExt->pTracerOps
+                    && !pDevExt->fTracerUnloading)
                     rc = pDevExt->pTracerOps->pfnProviderRegister(pDevExt->pTracerOps, &pProv->Core);
                 else
@@ -563 +569 @@
                     RTListAppend(&pDevExt->TracerProviderList, &pProv->ListEntry);
                     RTSemFastMutexRelease(pDevExt->mtxTracer);
-                    LOG_TRACER(("Registered DTrace provider '%s' in '%s' -> %p\n",
+                    LOG_TRACER(("Registered Tracer provider '%s' in '%s' -> %p\n",
                                 pProv->szName, pszModName, pProv->Core.TracerData.DTrace.idProvider));
                 }
@@ -680 +686 @@
     int             rc;
 
+    LOG_TRACER(("SUPR0TracerRegisterModule: %p\n", pVtgHdr));
+
     /*
      * Validate input and context.
@@ -702 +710 @@
 
     rc = supdrvTracerRegisterVtgObj(pDevExt, pVtgHdr, cbVtgObj, pImage, NULL, pImage->szName);
+    LOG_TRACER(("SUPR0TracerRegisterModule: rc=%d\n", rc));
 
     /*
@@ -725 +734 @@
 SUPR0DECL(int) SUPR0TracerRegisterImpl(void *hMod, PSUPDRVSESSION pSession, PCSUPDRVTRACERREG pReg, PCSUPDRVTRACERHLP *ppHlp)
 {
-    PSUPDRVLDRIMAGE pImage = (PSUPDRVLDRIMAGE)hMod;
-    PSUPDRVDEVEXT   pDevExt;
-    int             rc;
+    PSUPDRVLDRIMAGE     pImage = (PSUPDRVLDRIMAGE)hMod;
+    PSUPDRVDEVEXT       pDevExt;
+    PSUPDRVTPPROVIDER   pProv;
+    int                 rc;
 
     /*
@@ -753 +763 @@
     }
 
+    AssertReturn(pReg->u32Magic   == SUPDRVTRACERREG_MAGIC, VERR_INVALID_MAGIC);
+    AssertReturn(pReg->u32Version == SUPDRVTRACERREG_VERSION, VERR_VERSION_MISMATCH);
+    AssertReturn(pReg->uEndMagic  == SUPDRVTRACERREG_MAGIC, VERR_VERSION_MISMATCH);
     AssertPtrReturn(pReg->pfnProbeFireKernel, VERR_INVALID_POINTER);
     AssertPtrReturn(pReg->pfnProbeFireUser, VERR_INVALID_POINTER);
@@ -770 +783 @@
         if (!pDevExt->pTracerOps)
         {
+            LOG_TRACER(("SUPR0TracerRegisterImpl: pReg=%p\n", pReg));
             pDevExt->pTracerOps     = pReg;
             pDevExt->pTracerSession = pSession;
@@ -775 +789 @@
 
             *ppHlp = &pDevExt->TracerHlp;
+
             rc = VINF_SUCCESS;
+
+            /*
+             * Iterate the already loaded modules and register their providers.
+             */
+            RTListForEach(&pDevExt->TracerProviderList, pProv, SUPDRVTPPROVIDER, ListEntry)
+            {
+                Assert(!pProv->fRegistered);
+                pProv->fRegistered = true;
+                int rc2 = pDevExt->pTracerOps->pfnProviderRegister(pDevExt->pTracerOps, &pProv->Core);
+                if (RT_FAILURE(rc2))
+                {
+                    pProv->fRegistered = false;
+                    SUPR0Printf("SUPR0TracerRegisterImpl: Failed to register provider %s::%s - rc=%d\n",
+                                pProv->Core.pszModName, pProv->szName, rc2);
+                }
+            }
         }
         else
@@ -796 +827 @@
 static void supdrvTracerCommonDeregisterImpl(PSUPDRVDEVEXT pDevExt)
 {
-    supdrvTracerRemoveAllProviders(pDevExt);
+    uint32_t            i;
+    PSUPDRVTPPROVIDER   pProv;
+    PSUPDRVTPPROVIDER   pProvNext;
 
     RTSemFastMutexRequest(pDevExt->mtxTracer);
+
+    /*
+     * Disassociate the tracer implementation from all providers.
+     * We will have to wait on busy providers.
+     */
+    for (i = 0; ; i++)
+    {
+        uint32_t cZombies = 0;
+
+        /* Live providers. */
+        RTListForEachSafe(&pDevExt->TracerProviderList, pProv, pProvNext, SUPDRVTPPROVIDER, ListEntry)
+        {
+            int rc;
+            LOG_TRACER(("supdrvTracerRemoveAllProviders: Attemting to unregister '%s' / %p...\n",
+                        pProv->szName, pProv->Core.TracerData.DTrace.idProvider));
+
+            if (!pProv->fRegistered)
+                continue;
+            if (!pProv->fZombie)
+            {
+                rc = pDevExt->pTracerOps->pfnProviderDeregister(pDevExt->pTracerOps, &pProv->Core);
+                if (RT_FAILURE(rc))
+                    pProv->fZombie = true;
+            }
+            else
+                rc = pDevExt->pTracerOps->pfnProviderDeregisterZombie(pDevExt->pTracerOps, &pProv->Core);
+            if (RT_SUCCESS(rc))
+                pProv->fZombie = pProv->fRegistered = false;
+            else
+            {
+                cZombies++;
+                if (!(i & 0xf))
+                    SUPR0Printf("supdrvTracerCommonDeregisterImpl: Waiting on busy provider '%s' / %p (rc=%d)\n",
+                                pProv->szName, pProv->Core.TracerData.DTrace.idProvider, rc);
+                else
+                    LOG_TRACER(("supdrvTracerCommonDeregisterImpl: Failed to unregister provider '%s' / %p - rc=%d\n",
+                                pProv->szName, pProv->Core.TracerData.DTrace.idProvider, rc));
+            }
+        }
+
+        /* Zombies providers. */
+        RTListForEachSafe(&pDevExt->TracerProviderZombieList, pProv, pProvNext, SUPDRVTPPROVIDER, ListEntry)
+        {
+            int rc;
+            LOG_TRACER(("supdrvTracerRemoveAllProviders: Attemting to unregister '%s' / %p (zombie)...\n",
+                        pProv->szName, pProv->Core.TracerData.DTrace.idProvider));
+
+            rc = pDevExt->pTracerOps->pfnProviderDeregisterZombie(pDevExt->pTracerOps, &pProv->Core);
+            if (RT_SUCCESS(rc))
+            {
+                RTListNodeRemove(&pProv->ListEntry);
+                supdrvTracerFreeProvider(pProv);
+            }
+            else
+            {
+                cZombies++;
+                if (!(i & 0xf))
+                    SUPR0Printf("supdrvTracerRemoveAllProviders: Waiting on busy provider '%s' / %p (rc=%d)\n",
+                                pProv->szName, pProv->Core.TracerData.DTrace.idProvider, rc);
+                else
+                    LOG_TRACER(("supdrvTracerRemoveAllProviders: Failed to unregister provider '%s' / %p - rc=%d\n",
+                                pProv->szName, pProv->Core.TracerData.DTrace.idProvider, rc));
+            }
+        }
+
+        if (cZombies == 0)
+            break;
+
+        /* Delay...*/
+        RTSemFastMutexRelease(pDevExt->mtxTracer);
+        RTThreadSleep(1000);
+        RTSemFastMutexRequest(pDevExt->mtxTracer);
+    }
+
+    /*
+     * Deregister the tracer implementation.
+     */
     pDevExt->pTracerImage     = NULL;
     pDevExt->pTracerSession   = NULL;
     pDevExt->pTracerOps       = NULL;
     pDevExt->fTracerUnloading = false;
+
     RTSemFastMutexRelease(pDevExt->mtxTracer);
 }
@@ -849 +960 @@
             : pDevExt->pTracerSession == pSession)
         {
+            LOG_TRACER(("SUPR0TracerDeregisterImpl: Unloading ...\n"));
             pDevExt->fTracerUnloading = true;
             RTSemFastMutexRelease(pDevExt->mtxTracer);
             supdrvTracerCommonDeregisterImpl(pDevExt);
+            LOG_TRACER(("SUPR0TracerDeregisterImpl: ... done.\n"));
         }
         else
@@ -922 +1035 @@
     if (pDevExt->pTracerImage == pImage)
     {
+        LOG_TRACER(("supdrvTracerModuleUnloading: Unloading tracer ...\n"));
         pDevExt->fTracerUnloading = true;
         RTSemFastMutexRelease(pDevExt->mtxTracer);
         supdrvTracerCommonDeregisterImpl(pDevExt);
+        LOG_TRACER(("supdrvTracerModuleUnloading: ... done.\n"));
     }
     else

trunk/src/VBox/HostDrivers/Support/testcase/tstSupLoadModule.cpp

@@ -54 +54 @@
     static const RTGETOPTDEF s_aOptions[] =
     {
-        { "--keep",             'k', RTGETOPT_REQ_NOTHING }
+        { "--keep",             'k', RTGETOPT_REQ_NOTHING },
+        { "--no-keep",          'n', RTGETOPT_REQ_NOTHING },
     };
 
@@ -96 +97 @@
                 break;
 
+            case 'n':
+                fKeepLoaded = false;
+                break;
+
             case 'h':
                 RTPrintf("%s [mod1 [mod2...]]\n");