diff --git a/Makefile b/Makefile
index f97f786de58dd8497db3599279d9e2c3d40e121b..06e2b73978e8fe596907d15858e8bf7d2aa6783a 100644
--- a/Makefile
+++ b/Makefile
@@ -370,7 +370,7 @@ LDFLAGS_MODULE  =
 CFLAGS_KERNEL	=
 AFLAGS_KERNEL	=
 LDFLAGS_vmlinux =
-CFLAGS_GCOV	= -fprofile-arcs -ftest-coverage -fno-tree-loop-im
+CFLAGS_GCOV	= -fprofile-arcs -ftest-coverage -fno-tree-loop-im -Wno-maybe-uninitialized
 CFLAGS_KCOV	:= $(call cc-option,-fsanitize-coverage=trace-pc,)
 
 
@@ -620,7 +620,6 @@ ARCH_CFLAGS :=
 include arch/$(SRCARCH)/Makefile
 
 KBUILD_CFLAGS	+= $(call cc-option,-fno-delete-null-pointer-checks,)
-KBUILD_CFLAGS	+= $(call cc-disable-warning,maybe-uninitialized,)
 KBUILD_CFLAGS	+= $(call cc-disable-warning,frame-address,)
 
 ifdef CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
@@ -629,15 +628,18 @@ KBUILD_CFLAGS	+= $(call cc-option,-fdata-sections,)
 endif
 
 ifdef CONFIG_CC_OPTIMIZE_FOR_SIZE
-KBUILD_CFLAGS	+= -Os
+KBUILD_CFLAGS	+= -Os $(call cc-disable-warning,maybe-uninitialized,)
 else
 ifdef CONFIG_PROFILE_ALL_BRANCHES
-KBUILD_CFLAGS	+= -O2
+KBUILD_CFLAGS	+= -O2 $(call cc-disable-warning,maybe-uninitialized,)
 else
 KBUILD_CFLAGS   += -O2
 endif
 endif
 
+KBUILD_CFLAGS += $(call cc-ifversion, -lt, 0409, \
+			$(call cc-disable-warning,maybe-uninitialized,))
+
 # Tell gcc to never replace conditional load with a non-conditional one
 KBUILD_CFLAGS	+= $(call cc-option,--param=allow-store-data-races=0)
 
diff --git a/arch/arc/Makefile b/arch/arc/Makefile
index 864adad522803cfdec31983d062514d7c50f19c3..25f81a1db9f933b853e968de8b274a9abe4d770f 100644
--- a/arch/arc/Makefile
+++ b/arch/arc/Makefile
@@ -68,7 +68,9 @@ cflags-$(CONFIG_ARC_DW2_UNWIND)		+= -fasynchronous-unwind-tables $(cfi)
 ifndef CONFIG_CC_OPTIMIZE_FOR_SIZE
 # Generic build system uses -O2, we want -O3
 # Note: No need to add to cflags-y as that happens anyways
-ARCH_CFLAGS += -O3
+#
+# Disable the false maybe-uninitialized warings gcc spits out at -O3
+ARCH_CFLAGS += -O3 $(call cc-disable-warning,maybe-uninitialized,)
 endif
 
 # small data is default for elf32 tool-chain. If not usable, disable it
diff --git a/arch/nios2/kernel/time.c b/arch/nios2/kernel/time.c
index d9563ddb337eab4e44d052ebd285206b09788f13..746bf5caaffc7989884813b16bc3fd3fce85d0ef 100644
--- a/arch/nios2/kernel/time.c
+++ b/arch/nios2/kernel/time.c
@@ -324,6 +324,7 @@ static int __init nios2_time_init(struct device_node *timer)
 		ret = nios2_clocksource_init(timer);
 		break;
 	default:
+		ret = 0;
 		break;
 	}
 
diff --git a/arch/s390/pci/pci_dma.c b/arch/s390/pci/pci_dma.c
index 7350c8bc13a290ca362ad25b69cdb050c72ab3f4..6b2f72f523b91bb6c68347602b33ca2446807229 100644
--- a/arch/s390/pci/pci_dma.c
+++ b/arch/s390/pci/pci_dma.c
@@ -423,7 +423,7 @@ static int __s390_dma_map_sg(struct device *dev, struct scatterlist *sg,
 	dma_addr_t dma_addr_base, dma_addr;
 	int flags = ZPCI_PTE_VALID;
 	struct scatterlist *s;
-	unsigned long pa;
+	unsigned long pa = 0;
 	int ret;
 
 	size = PAGE_ALIGN(size);
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 0ab5ee1c26af057d9965470d42d5a9edd65c9ae7..aa8b0672f87a451865283f5f3e9f3d2c03992870 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -888,7 +888,7 @@ static int helper_rfc4106_encrypt(struct aead_request *req)
 	unsigned long auth_tag_len = crypto_aead_authsize(tfm);
 	u8 iv[16] __attribute__ ((__aligned__(AESNI_ALIGN)));
 	struct scatter_walk src_sg_walk;
-	struct scatter_walk dst_sg_walk;
+	struct scatter_walk dst_sg_walk = {};
 	unsigned int i;
 
 	/* Assuming we are supporting rfc4106 64-bit extended */
@@ -968,7 +968,7 @@ static int helper_rfc4106_decrypt(struct aead_request *req)
 	u8 iv[16] __attribute__ ((__aligned__(AESNI_ALIGN)));
 	u8 authTag[16];
 	struct scatter_walk src_sg_walk;
-	struct scatter_walk dst_sg_walk;
+	struct scatter_walk dst_sg_walk = {};
 	unsigned int i;
 
 	if (unlikely(req->assoclen != 16 && req->assoclen != 20))
diff --git a/arch/x86/kernel/apm_32.c b/arch/x86/kernel/apm_32.c
index c7364bd633e1d8c1a346c69534ded295bc2ba48d..51287cd90bf65f4ffa6215c4dea0c112aa5f6697 100644
--- a/arch/x86/kernel/apm_32.c
+++ b/arch/x86/kernel/apm_32.c
@@ -1042,8 +1042,11 @@ static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
 
 	if (apm_info.get_power_status_broken)
 		return APM_32_UNSUPPORTED;
-	if (apm_bios_call(&call))
+	if (apm_bios_call(&call)) {
+		if (!call.err)
+			return APM_NO_ERROR;
 		return call.err;
+	}
 	*status = call.ebx;
 	*bat = call.ecx;
 	if (apm_info.get_power_status_swabinminutes) {
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 36bf50ebb187eb40195f0ede0d2d3abcc47d8ccb..89a6b05468045cbca835573fd450d4e4466f75d7 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -1094,47 +1094,47 @@ static void cma_save_ib_info(struct sockaddr *src_addr,
 	}
 }
 
-static void cma_save_ip4_info(struct sockaddr *src_addr,
-			      struct sockaddr *dst_addr,
+static void cma_save_ip4_info(struct sockaddr_in *src_addr,
+			      struct sockaddr_in *dst_addr,
 			      struct cma_hdr *hdr,
 			      __be16 local_port)
 {
-	struct sockaddr_in *ip4;
-
 	if (src_addr) {
-		ip4 = (struct sockaddr_in *)src_addr;
-		ip4->sin_family = AF_INET;
-		ip4->sin_addr.s_addr = hdr->dst_addr.ip4.addr;
-		ip4->sin_port = local_port;
+		*src_addr = (struct sockaddr_in) {
+			.sin_family = AF_INET,
+			.sin_addr.s_addr = hdr->dst_addr.ip4.addr,
+			.sin_port = local_port,
+		};
 	}
 
 	if (dst_addr) {
-		ip4 = (struct sockaddr_in *)dst_addr;
-		ip4->sin_family = AF_INET;
-		ip4->sin_addr.s_addr = hdr->src_addr.ip4.addr;
-		ip4->sin_port = hdr->port;
+		*dst_addr = (struct sockaddr_in) {
+			.sin_family = AF_INET,
+			.sin_addr.s_addr = hdr->src_addr.ip4.addr,
+			.sin_port = hdr->port,
+		};
 	}
 }
 
-static void cma_save_ip6_info(struct sockaddr *src_addr,
-			      struct sockaddr *dst_addr,
+static void cma_save_ip6_info(struct sockaddr_in6 *src_addr,
+			      struct sockaddr_in6 *dst_addr,
 			      struct cma_hdr *hdr,
 			      __be16 local_port)
 {
-	struct sockaddr_in6 *ip6;
-
 	if (src_addr) {
-		ip6 = (struct sockaddr_in6 *)src_addr;
-		ip6->sin6_family = AF_INET6;
-		ip6->sin6_addr = hdr->dst_addr.ip6;
-		ip6->sin6_port = local_port;
+		*src_addr = (struct sockaddr_in6) {
+			.sin6_family = AF_INET6,
+			.sin6_addr = hdr->dst_addr.ip6,
+			.sin6_port = local_port,
+		};
 	}
 
 	if (dst_addr) {
-		ip6 = (struct sockaddr_in6 *)dst_addr;
-		ip6->sin6_family = AF_INET6;
-		ip6->sin6_addr = hdr->src_addr.ip6;
-		ip6->sin6_port = hdr->port;
+		*dst_addr = (struct sockaddr_in6) {
+			.sin6_family = AF_INET6,
+			.sin6_addr = hdr->src_addr.ip6,
+			.sin6_port = hdr->port,
+		};
 	}
 }
 
@@ -1159,10 +1159,12 @@ static int cma_save_ip_info(struct sockaddr *src_addr,
 
 	switch (cma_get_ip_ver(hdr)) {
 	case 4:
-		cma_save_ip4_info(src_addr, dst_addr, hdr, port);
+		cma_save_ip4_info((struct sockaddr_in *)src_addr,
+				  (struct sockaddr_in *)dst_addr, hdr, port);
 		break;
 	case 6:
-		cma_save_ip6_info(src_addr, dst_addr, hdr, port);
+		cma_save_ip6_info((struct sockaddr_in6 *)src_addr,
+				  (struct sockaddr_in6 *)dst_addr, hdr, port);
 		break;
 	default:
 		return -EAFNOSUPPORT;
diff --git a/drivers/media/i2c/ir-kbd-i2c.c b/drivers/media/i2c/ir-kbd-i2c.c
index f95a6bc839d58f5f6cde8c37170f297f24ca8b3b..cede3975d04bd90441abcb29e6f169857561f935 100644
--- a/drivers/media/i2c/ir-kbd-i2c.c
+++ b/drivers/media/i2c/ir-kbd-i2c.c
@@ -118,7 +118,7 @@ static int get_key_haup_common(struct IR_i2c *ir, enum rc_type *protocol,
 			*protocol = RC_TYPE_RC6_MCE;
 			dev &= 0x7f;
 			dprintk(1, "ir hauppauge (rc6-mce): t%d vendor=%d dev=%d code=%d\n",
-						toggle, vendor, dev, code);
+						*ptoggle, vendor, dev, code);
 		} else {
 			*ptoggle = 0;
 			*protocol = RC_TYPE_RC6_6A_32;
diff --git a/drivers/media/usb/dvb-usb/dib0700_core.c b/drivers/media/usb/dvb-usb/dib0700_core.c
index 92d5408684ac1cdc33f65f578b5ee2ce525968b0..47ce9d5de4c678e78d1cd6cc075661ddaf40b0f6 100644
--- a/drivers/media/usb/dvb-usb/dib0700_core.c
+++ b/drivers/media/usb/dvb-usb/dib0700_core.c
@@ -704,7 +704,7 @@ static void dib0700_rc_urb_completion(struct urb *purb)
 	struct dvb_usb_device *d = purb->context;
 	struct dib0700_rc_response *poll_reply;
 	enum rc_type protocol;
-	u32 uninitialized_var(keycode);
+	u32 keycode;
 	u8 toggle;
 
 	deb_info("%s()\n", __func__);
@@ -745,7 +745,8 @@ static void dib0700_rc_urb_completion(struct urb *purb)
 		    poll_reply->nec.data       == 0x00 &&
 		    poll_reply->nec.not_data   == 0xff) {
 			poll_reply->data_state = 2;
-			break;
+			rc_repeat(d->rc_dev);
+			goto resubmit;
 		}
 
 		if ((poll_reply->nec.data ^ poll_reply->nec.not_data) != 0xff) {
diff --git a/drivers/pcmcia/soc_common.c b/drivers/pcmcia/soc_common.c
index 153f3122283deb9fa4260c0e1da0c443a5fde2c0..b6b316de055c7129648904cbdae92cafb593e8dd 100644
--- a/drivers/pcmcia/soc_common.c
+++ b/drivers/pcmcia/soc_common.c
@@ -107,7 +107,7 @@ int soc_pcmcia_regulator_set(struct soc_pcmcia_socket *skt,
 
 		ret = regulator_enable(r->reg);
 	} else {
-		regulator_disable(r->reg);
+		ret = regulator_disable(r->reg);
 	}
 	if (ret == 0)
 		r->on = on;
diff --git a/scripts/Makefile.extrawarn b/scripts/Makefile.extrawarn
index 53449a6ff6aa7de3c5c868f0645f6000b6f551e6..7c321a603b079d355bd127aebb04adc0294b4ba5 100644
--- a/scripts/Makefile.extrawarn
+++ b/scripts/Makefile.extrawarn
@@ -36,6 +36,7 @@ warning-2 += -Wshadow
 warning-2 += $(call cc-option, -Wlogical-op)
 warning-2 += $(call cc-option, -Wmissing-field-initializers)
 warning-2 += $(call cc-option, -Wsign-compare)
+warning-2 += $(call cc-option, -Wmaybe-uninitialized)
 
 warning-3 := -Wbad-function-cast
 warning-3 += -Wcast-qual
diff --git a/scripts/Makefile.ubsan b/scripts/Makefile.ubsan
index dd779c40c8e6af713c0ad7039bc929b0c6c2944a..3b1b13818d594f9ffa9dcb15206314ab349325a7 100644
--- a/scripts/Makefile.ubsan
+++ b/scripts/Makefile.ubsan
@@ -17,4 +17,8 @@ endif
 ifdef CONFIG_UBSAN_NULL
       CFLAGS_UBSAN += $(call cc-option, -fsanitize=null)
 endif
+
+      # -fsanitize=* options makes GCC less smart than usual and
+      # increase number of 'maybe-uninitialized false-positives
+      CFLAGS_UBSAN += $(call cc-option, -Wno-maybe-uninitialized)
 endif