Remove unnecessary NULL checks before freeing memory blocks.

The following functions check for NULL internally:
 free, kfree, xfree, free_xenheap_page[s]

Signed-off-by: Keir Fraser <keir@xensource.com>

linux-2.6-xen-sparse/drivers/char/tpm/tpm_xen.c

@@ -97,9 +97,7 @@ static inline unsigned char *
 transmission_set_buffer(struct transmission *t,
                         unsigned char *buffer, unsigned int len)
 {
-	if (NULL != t->request) {
-		kfree(t->request);
-	}
+	kfree(t->request);
 	t->request = kmalloc(len, GFP_KERNEL);
 	if (t->request) {
 		memcpy(t->request,
@@ -113,12 +111,8 @@ transmission_set_buffer(struct transmission *t,
 static inline void
 transmission_free(struct transmission *t)
 {
-	if (t->request) {
-		kfree(t->request);
-	}
-	if (t->rcv_buffer) {
-		kfree(t->rcv_buffer);
-	}
+	kfree(t->request);
+	kfree(t->rcv_buffer);
 	kfree(t);
 }
 

linux-2.6-xen-sparse/drivers/xen/blkback/xenbus.c

@@ -48,8 +48,7 @@ static int blkback_remove(struct xenbus_device *dev)
 	unregister_xenbus_watch(&be->backend_watch);
 	if (be->blkif)
 		blkif_put(be->blkif);
-	if (be->frontpath)
-		kfree(be->frontpath);
+	kfree(be->frontpath);
 	kfree(be);
 	return 0;
 }
@@ -274,8 +273,7 @@ static int blkback_probe(struct xenbus_device *dev,
  free_be:
 	if (be->backend_watch.node)
 		unregister_xenbus_watch(&be->backend_watch);
-	if (frontend)
-		kfree(frontend);
+	kfree(frontend);
 	kfree(be);
 	return err;
 }

linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c

@@ -607,8 +607,7 @@ again:
  destroy_blkring:
 	blkif_free(info);
  out:
-	if (backend)
-		kfree(backend);
+	kfree(backend);
 	return err;
 }
 

linux-2.6-xen-sparse/drivers/xen/blktap/xenbus.c

@@ -52,8 +52,7 @@ static int blkback_remove(struct xenbus_device *dev)
 	unregister_xenbus_watch(&be->backend_watch);
 	if (be->blkif)
 		blkif_put(be->blkif);
-	if (be->frontpath)
-		kfree(be->frontpath);
+	kfree(be->frontpath);
 	kfree(be);
 	return 0;
 }
@@ -201,8 +200,7 @@ static int blkback_probe(struct xenbus_device *dev,
  free_be:
 	if (be->backend_watch.node)
 		unregister_xenbus_watch(&be->backend_watch);
-	if (frontend)
-		kfree(frontend);
+	kfree(frontend);
 	kfree(be);
 	return err;
 }

linux-2.6-xen-sparse/drivers/xen/netback/loopback.c

@@ -160,10 +160,8 @@ static int __init make_loopback(int i)
 	return 0;
 
  fail:
-	if (dev1 != NULL)
-		kfree(dev1);
-	if (dev2 != NULL)
-		kfree(dev2);
+	kfree(dev1);
+	kfree(dev2);
 	return err;
 }
 

linux-2.6-xen-sparse/drivers/xen/netback/xenbus.c

@@ -46,8 +46,7 @@ static int netback_remove(struct xenbus_device *dev)
 	unregister_xenbus_watch(&be->backend_watch);
 	if (be->netif)
 		netif_disconnect(be->netif);
-	if (be->frontpath)
-		kfree(be->frontpath);
+	kfree(be->frontpath);
 	kfree(be);
 	return 0;
 }
@@ -253,8 +252,7 @@ static int netback_probe(struct xenbus_device *dev,
  free_be:
 	if (be->backend_watch.node)
 		unregister_xenbus_watch(&be->backend_watch);
-	if (frontend)
-		kfree(frontend);
+	kfree(frontend);
 	kfree(be);
 	return err;
 }

linux-2.6-xen-sparse/drivers/xen/netfront/netfront.c

@@ -917,7 +917,7 @@ static int create_netdev(int handle, struct xenbus_device *dev,
 	np->netdev = netdev;
 
  exit:
-	if ((err != 0) && (netdev != NULL))
+	if (err != 0)
 		kfree(netdev);
 	else if (val != NULL)
 		*val = netdev;

linux-2.6-xen-sparse/drivers/xen/tpmback/tpmback.c

@@ -167,9 +167,7 @@ static void inline
 packet_free(struct packet *pak)
 {
 	del_singleshot_timer_sync(&pak->processing_timer);
-	if (pak->data_buffer) {
-		kfree(pak->data_buffer);
-	}
+	kfree(pak->data_buffer);
 	/*
 	 * cannot do tpmif_put(pak->tpmif); bad things happen
 	 * on the last tpmif_put()

linux-2.6-xen-sparse/drivers/xen/tpmback/xenbus.c

@@ -41,19 +41,16 @@ static int tpmback_remove(struct xenbus_device *dev)
 {
 	struct backend_info *be = dev->data;
 
-	if (be->watch.node) {
+	if (be->watch.node)
 		unregister_xenbus_watch(&be->watch);
-	}
 	unregister_xenbus_watch(&be->backend_watch);
 
 	tpmif_vtpm_close(be->instance);
 
-	if (be->tpmif) {
+	if (be->tpmif)
 		tpmif_put(be->tpmif);
-	}
 
-	if (be->frontpath)
-		kfree(be->frontpath);
+	kfree(be->frontpath);
 	kfree(be);
 	return 0;
 }
@@ -258,8 +255,7 @@ static int tpmback_probe(struct xenbus_device *dev,
 free_be:
 	if (be->backend_watch.node)
 		unregister_xenbus_watch(&be->backend_watch);
-	if (frontend)
-		kfree(frontend);
+	kfree(frontend);
 	kfree(be);
 	return err;
 }

linux-2.6-xen-sparse/drivers/xen/tpmfront/tpmfront.c

@@ -387,8 +387,7 @@ abort_transaction:
 destroy_tpmring:
 	destroy_tpmring(info, &my_private);
 out:
-	if (backend)
-		kfree(backend);
+	kfree(backend);
 	return err;
 }
 

tools/blktap/blkif.c

@@ -108,8 +108,7 @@ void free_blkif(blkif_t *blkif)
         }
         pblkif = &curs->hash_next;
     }
-    if (blkif != NULL)
-        free(blkif);
+    free(blkif);
 }
 
 void blkif_register_request_hook(blkif_t *blkif, char *name, 

tools/blktap/parallax/blockstore.c

@@ -604,8 +604,7 @@ void *readblock_indiv(int server, uint64_t id) {
     return block;
 
     err:
-    if (qe->block)
-        free(qe->block);
+    free(qe->block);
     free((void *)qe);
     return NULL;
 }
@@ -1072,7 +1071,7 @@ uint64_t allocblock_hint(void *block, uint64_t hint) {
  *
  *   @return: pointer to new block, NULL on error
  */
-void *newblock() {
+void *newblock(void) {
     void *block = malloc(BLOCK_SIZE);
     if (block == NULL) {
         perror("newblock");
@@ -1089,7 +1088,6 @@ void *newblock() {
  *   @block: block to be freed
  */
 void freeblock(void *block) {
-    if (block != NULL)
         free(block);
 }
 

tools/blktap/parallax/blockstored.c

@@ -232,7 +232,7 @@ uint64_t allocblock(void *block) {
  *
  *   @return: pointer to new block, NULL on error
  */
-void *newblock() {
+void *newblock(void) {
     void *block = malloc(BLOCK_SIZE);
     if (block == NULL) {
         perror("newblock");
@@ -249,7 +249,6 @@ void *newblock() {
  *   @block: block to be freed
  */
 void freeblock(void *block) {
-    if (block != NULL)
         free(block);
 }
 

tools/blktap/parallax/requests-async.c

@@ -715,7 +715,7 @@ static void write_cb(struct io_ret r, void *param)
         r.u.i  = -1;
         /* free any saved node vals. */
         for (i=0; i<3; i++)
-            if (req->radix[i] != 0) free(req->radix[i]);
+            free(req->radix[i]);
         free(req);
         cb(r, req_param);
     }

tools/blktap/xenbus.c

@@ -339,10 +339,8 @@ static int backend_remove(struct xs_handle *h, struct backend_info *be)
     /* Free everything else. */
     if (be->blkif)
         free_blkif(be->blkif);
-    if (be->frontpath)
-        free(be->frontpath);
-    if (be->backpath)
-        free(be->backpath);
+    free(be->frontpath);
+    free(be->backpath);
     free(be);
     return 0;
 }
@@ -406,8 +404,7 @@ static void frontend_changed(struct xs_handle *h, struct xenbus_watch *w,
     return;
 
  fail:
-    if (fepath)
-        free(fepath);
+    free(fepath);
 }
 
 
@@ -460,9 +457,7 @@ static void backend_changed(struct xs_handle *h, struct xenbus_watch *w,
     }
 
  fail:
-    if (path)
-        free(path);
-
+    free(path);
 }
 
 static void blkback_probe(struct xs_handle *h, struct xenbus_watch *w, 
@@ -537,12 +532,10 @@ static void blkback_probe(struct xs_handle *h, struct xenbus_watch *w,
 	return;
 
  free_be:
-	if ((be) && (be->backend_watch.node))
+	if (be && (be->backend_watch.node))
             unregister_xenbus_watch(h, &be->backend_watch);
-	if (frontend)
-            free(frontend);
-        if (bepath)
-            free(bepath);
+        free(frontend);
+        free(bepath);
 	free(be);
 	return;
 }

tools/console/daemon/io.c

@@ -344,8 +344,7 @@ static struct domain *create_domain(int domid)
 
 	return dom;
  out:
-	if (dom->conspath)
-		free(dom->conspath);
+	free(dom->conspath);
 	free(dom);
 	return NULL;
 }
@@ -380,20 +379,16 @@ static void cleanup_domain(struct domain *d)
 	if (!buffer_empty(&d->buffer))
 		return;
 
-	if (d->buffer.data) {
-		free(d->buffer.data);
-		d->buffer.data = NULL;
-	}
-
 	if (d->tty_fd != -1) {
 		close(d->tty_fd);
 		d->tty_fd = -1;
 	}
 
-	if (d->conspath) {
-		free(d->conspath);
-		d->conspath = NULL;
-	}
+	free(d->buffer.data);
+	d->buffer.data = NULL;
+
+	free(d->conspath);
+	d->conspath = NULL;
 
 	remove_domain(d);
 }

tools/ioemu/hw/magic-load.c

@@ -196,10 +196,8 @@ static void load_symbols(struct elfhdr *ehdr, int fd)
 	goto error_freesyms;
 
     /* Commit */
-    if (disas_symtab)
-	qemu_free(disas_symtab); /* XXX Merge with old symbols? */
-    if (disas_strtab)
-	qemu_free(disas_strtab);
+    qemu_free(disas_symtab); /* XXX Merge with old symbols? */
+    qemu_free(disas_strtab);
     disas_symtab = syms;
     disas_num_syms = nsyms;
     disas_strtab = str;

tools/ioemu/vnc.c

@@ -187,8 +187,7 @@ static void mouse_find_bounding_box_of_difference(int* x,int* y,int* w,int* h) {
 
 static void start_mouse_calibration() {
 	int size = screen->height*screen->paddedWidthInBytes;
-	if(mouse_magic->calibration)
-		free(mouse_magic->calibration);
+	free(mouse_magic->calibration);
 	mouse_magic->calibration = malloc(size);
 	memcpy(mouse_magic->calibration, screen->frameBuffer, size);
 	calibration_step=0;
@@ -198,8 +197,7 @@ static void start_mouse_calibration() {
 }
 
 static void stop_mouse_calibration() {
-	if(mouse_magic->calibration)
-		free(mouse_magic->calibration);
+	free(mouse_magic->calibration);
 	mouse_magic->calibration = 0;
 }
 

tools/libxc/xc_ia64_stubs.c

@@ -77,7 +77,7 @@ int xc_ia64_copy_to_domain_pages(int xc_handle, uint32_t domid,
 {
     // N.B. gva should be page aligned
     
-    unsigned long *page_array=NULL;
+    unsigned long *page_array = NULL;
     int i;
 
     if ( (page_array = malloc(nr_pages * sizeof(unsigned long))) == NULL ){
@@ -99,8 +99,7 @@ int xc_ia64_copy_to_domain_pages(int xc_handle, uint32_t domid,
     return 0;
     
 error_out:
-    if (page_array)
-        free(page_array);
+    free(page_array);
     return -1;
 }
 
@@ -657,8 +656,7 @@ int xc_vmx_build(int xc_handle,
         goto error_out;
     }
 
-    if ( image != NULL )
-        free(image);
+    free(image);
 
     ctxt->flags = VGCF_VMX_GUEST;
     ctxt->regs.cr_iip = 0x80000000ffffffb0UL;
@@ -675,9 +673,7 @@ int xc_vmx_build(int xc_handle,
     return rc;
 
  error_out:
-    if ( image != NULL )
-        free(image);
-
+    free(image);
     return -1;
 }
 

tools/libxc/xc_linux_build.c

@@ -670,10 +670,8 @@ static int setup_guest(int xc_handle,
     return 0;
 
  error_out:
-    if ( mmu != NULL )
-        free(mmu);
-    if ( page_array != NULL )
-        free(page_array);
+    free(mmu);
+    free(page_array);
     return -1;
 }
 #endif
@@ -768,8 +766,7 @@ int xc_linux_build(int xc_handle,
         close(initrd_fd);
     if ( initrd_gfd )
         gzclose(initrd_gfd);
-    if ( image != NULL )
-        free(image);
+    free(image);
 
 #ifdef __ia64__
     /* based on new_thread in xen/arch/ia64/domain.c */
@@ -858,9 +855,7 @@ int xc_linux_build(int xc_handle,
         gzclose(initrd_gfd);
     else if ( initrd_fd >= 0 )
         close(initrd_fd);
-    if ( image != NULL )
-        free(image);
-
+    free(image);
     return -1;
 }
 

tools/libxc/xc_vmx_build.c

@@ -565,10 +565,8 @@ static int setup_guest(int xc_handle,
     return 0;
 
  error_out:
-    if ( mmu != NULL )
-        free(mmu);
-    if ( page_array != NULL )
-        free(page_array);
+    free(mmu);
+    free(page_array);
     return -1;
 }
 
@@ -663,8 +661,7 @@ int xc_vmx_build(int xc_handle,
         goto error_out;
     }
 
-    if ( image != NULL )
-        free(image);
+    free(image);
 
     ctxt->flags = VGCF_VMX_GUEST;
     /* FPU is set up to default initial state. */
@@ -710,9 +707,7 @@ int xc_vmx_build(int xc_handle,
     return rc;
 
  error_out:
-    if ( image != NULL )
-        free(image);
-
+    free(image);
     return -1;
 }
 

tools/python/xen/lowlevel/xs/xs.c

@@ -114,8 +114,7 @@ static PyObject *xspy_read(PyObject *self, PyObject *args, PyObject *kwds)
     }
     val = PyString_FromStringAndSize(xsval, xsval_n);
  exit:
-    if (xsval)
-        free(xsval);
+    free(xsval);
     return val;
 }
 
@@ -427,8 +426,7 @@ static PyObject *xspy_set_permissions(PyObject *self, PyObject *args,
     val = Py_None;
  exit:
     Py_XDECREF(tuple0);
-    if (xsperms)
-        free(xsperms);
+    free(xsperms);
     return val;
 }
 
@@ -541,8 +539,7 @@ again:
     /* Create tuple (path, token). */
     val = Py_BuildValue("(sO)", xsval[XS_WATCH_PATH], token);
  exit:
-    if (xsval)
-        free(xsval);
+    free(xsval);
     return val;
 }
 

tools/vtpm_manager/manager/securestorage.c

@@ -393,8 +393,7 @@ TPM_RESULT VTPM_LoadService(void) {
   vtpmlogerror(VTPM_LOG_VTPM, "Failed to load service data with error = %s\n", tpm_get_error_name(status));
  egress:
   
-  if (flat_global)
-    free(flat_global);
+  free(flat_global);
   close(fh);
   
   return status;

tools/vtpm_manager/util/bsg.c

@@ -616,8 +616,7 @@ static void BSG_Destroy_private(BSG_Type type, BSG_BYTE** src) {
   else if (format == __FMT_SIZE || format == __FMT_HSIZE) {
     s += size;
     BSG_BYTE* ptr = *(BSG_BYTE**) s;
-    if (ptr)
-      free(ptr);
+    free(ptr);
     s += sizeof(void*);
   } else if (format == __FMT_PACKED) {
 

tools/xenstat/libxenstat/src/xenstat.c

@@ -284,10 +284,8 @@ void xenstat_free_node(xenstat_node * node)
 
 	if (node) {
 		if (node->domains) {
-			for (i = 0; i < node->num_domains; i++) {
-				if (node->domains[i].name)
-					free(node->domains[i].name);
-			}
+			for (i = 0; i < node->num_domains; i++)
+				free(node->domains[i].name);
 
 			for (i = 0; i < NUM_COLLECTORS; i++)
 				if((node->flags & collectors[i].flag)

tools/xenstore/xenstored_core.c

@@ -1411,8 +1411,6 @@ static void manual_node(const char *name, const char *child)
 	talloc_free(node);
 }
 
-#
-
 static void setup_structure(void)
 {
 	char *tdbname;

xen/acm/acm_chinesewall_hooks.c

@@ -117,8 +117,7 @@ static int chwall_init_domain_ssid(void **chwall_ssid, ssidref_t ssidref)
 static void chwall_free_domain_ssid(void *chwall_ssid)
 {
     traceprintk("%s.\n", __func__);
-    if (chwall_ssid != NULL)
-        xfree(chwall_ssid);
+    xfree(chwall_ssid);
     return;
 }
 
@@ -344,14 +343,10 @@ static int chwall_set_policy(u8 * buf, u32 buf_size)
     chwall_bin_pol.max_types = chwall_buf->chwall_max_types;
     chwall_bin_pol.max_ssidrefs = chwall_buf->chwall_max_ssidrefs;
     chwall_bin_pol.max_conflictsets = chwall_buf->chwall_max_conflictsets;
-    if (chwall_bin_pol.ssidrefs != NULL)
-        xfree(chwall_bin_pol.ssidrefs);
-    if (chwall_bin_pol.conflict_aggregate_set != NULL)
-        xfree(chwall_bin_pol.conflict_aggregate_set);
-    if (chwall_bin_pol.running_types != NULL)
-        xfree(chwall_bin_pol.running_types);
-    if (chwall_bin_pol.conflict_sets != NULL)
-        xfree(chwall_bin_pol.conflict_sets);
+    xfree(chwall_bin_pol.ssidrefs);
+    xfree(chwall_bin_pol.conflict_aggregate_set);
+    xfree(chwall_bin_pol.running_types);
+    xfree(chwall_bin_pol.conflict_sets);
     chwall_bin_pol.ssidrefs = ssids;
     chwall_bin_pol.conflict_aggregate_set = conflict_aggregate_set;
     chwall_bin_pol.running_types = running_types;
@@ -360,14 +355,10 @@ static int chwall_set_policy(u8 * buf, u32 buf_size)
 
  error_free:
     printk("%s: ERROR setting policy.\n", __func__);
-    if (ssids != NULL)
-        xfree(ssids);
-    if (conflict_sets != NULL)
-        xfree(conflict_sets);
-    if (running_types != NULL)
-        xfree(running_types);
-    if (conflict_aggregate_set != NULL)
-        xfree(conflict_aggregate_set);
+    xfree(ssids);
+    xfree(conflict_sets);
+    xfree(running_types);
+    xfree(conflict_aggregate_set);
     return -EFAULT;
 }
 

xen/acm/acm_simple_type_enforcement_hooks.c

@@ -130,8 +130,7 @@ static void
 ste_free_domain_ssid(void *ste_ssid)
 {
     traceprintk("%s.\n", __func__);
-    if (ste_ssid != NULL)
-        xfree(ste_ssid);
+    xfree(ste_ssid);
     return;
 }
 
@@ -320,8 +319,7 @@ ste_set_policy(u8 *buf, u32 buf_size)
     /* 3. replace old policy (activate new policy) */
     ste_bin_pol.max_types = ste_buf->ste_max_types;
     ste_bin_pol.max_ssidrefs = ste_buf->ste_max_ssidrefs;
-    if (ste_bin_pol.ssidrefs) 
-        xfree(ste_bin_pol.ssidrefs);
+    xfree(ste_bin_pol.ssidrefs);
     ste_bin_pol.ssidrefs = (domaintype_t *)ssidrefsbuf;
 
     /* clear all ste caches */
@@ -338,7 +336,7 @@ ste_set_policy(u8 *buf, u32 buf_size)
 
  error_free:
     printk("%s: ERROR setting policy.\n", __func__);
-    if (ssidrefsbuf != NULL) xfree(ssidrefsbuf);
+    xfree(ssidrefsbuf);
     return -EFAULT;
 }
 

xen/arch/ia64/xen/grant_table.c

@@ -1348,8 +1348,7 @@ grant_table_create(
     if ( t != NULL )
     {
         xfree(t->active);
-        if ( t->maptrack != NULL )
-            free_xenheap_page(t->maptrack);
+        free_xenheap_page(t->maptrack);
         xfree(t);
     }
     return -ENOMEM;

xen/arch/x86/mm.c

@@ -3369,10 +3369,8 @@ int ptwr_init(struct domain *d)
 
     if ( (x == NULL) || (y == NULL) )
     {
-        if ( x != NULL )
-            free_xenheap_page(x);
-        if ( y != NULL )
-            free_xenheap_page(y);
+        free_xenheap_page(x);
+        free_xenheap_page(y);
         return -ENOMEM;
     }
 

xen/arch/x86/mtrr/generic.c

@@ -71,8 +71,7 @@ void __init get_mtrr_state(void)
 /*  Free resources associated with a struct mtrr_state  */
 void __init finalize_mtrr_state(void)
 {
-	if (mtrr_state.var_ranges)
-		xfree(mtrr_state.var_ranges);
+	xfree(mtrr_state.var_ranges);
 	mtrr_state.var_ranges = NULL;
 }
 

xen/arch/x86/vmx_vmcs.c

@@ -564,19 +564,14 @@ err_out:
 
 void destroy_vmcs(struct arch_vmx_struct *arch_vmx)
 {
-    if(arch_vmx->vmcs != NULL)
-        free_vmcs(arch_vmx->vmcs);
-    if(arch_vmx->io_bitmap_a != 0) {
-        free_xenheap_pages(
-            arch_vmx->io_bitmap_a, get_order_from_bytes(0x1000));
-        arch_vmx->io_bitmap_a = 0;
-    }
-    if(arch_vmx->io_bitmap_b != 0) {
-        free_xenheap_pages(
-            arch_vmx->io_bitmap_b, get_order_from_bytes(0x1000));
-        arch_vmx->io_bitmap_b = 0;
-    }
-    arch_vmx->vmcs = 0;
+    free_vmcs(arch_vmx->vmcs);
+    arch_vmx->vmcs = NULL;
+
+    free_xenheap_pages(arch_vmx->io_bitmap_a, get_order_from_bytes(0x1000));
+    arch_vmx->io_bitmap_a = NULL;
+
+    free_xenheap_pages(arch_vmx->io_bitmap_b, get_order_from_bytes(0x1000));
+    arch_vmx->io_bitmap_b = NULL;
 }
 
 /*

xen/common/event_channel.c

@@ -621,8 +621,7 @@ void evtchn_destroy(struct domain *d)
             (void)__evtchn_close(d, i);
 
     for ( i = 0; i < NR_EVTCHN_BUCKETS; i++ )
-        if ( d->evtchn[i] != NULL )
-            xfree(d->evtchn[i]);
+        xfree(d->evtchn[i]);
 }
 
 /*

xen/common/grant_table.c

@@ -1107,8 +1107,7 @@ grant_table_create(
     if ( t != NULL )
     {
         xfree(t->active);
-        if ( t->maptrack != NULL )
-            free_xenheap_page(t->maptrack);
+        free_xenheap_page(t->maptrack);
         xfree(t);
     }
     return -ENOMEM;

xen/common/page_alloc.c

@@ -470,6 +470,9 @@ void free_xenheap_pages(void *v, unsigned int order)
 {
     unsigned long flags;
 
+    if ( v == NULL )
+        return;
+
     memguard_guard_range(v, 1 << (order + PAGE_SHIFT));    
 
     local_irq_save(flags);