diff --git a/benchmarks/kms_vblank.c b/benchmarks/kms_vblank.c
index f9dbe3d..3d2f977 100644
--- a/benchmarks/kms_vblank.c
+++ b/benchmarks/kms_vblank.c
@@ -41,6 +41,7 @@
 #include <drm.h>
 #include <xf86drm.h>
 #include "drmtest.h"
+#include "assert.h"
 
 static double elapsed(const struct timespec *start,
 		      const struct timespec *end,
@@ -89,7 +90,7 @@ static void vblank_query(int fd, int busy)
 
 	printf("%f\n", 1e6/elapsed(&start, &end, count));
 	if (busy)
-		read(fd, &event, sizeof(event));
+		assert(read(fd, &event, sizeof(event)) != -1);
 }
 
 static void vblank_event(int fd, int busy)
@@ -118,14 +119,14 @@ static void vblank_event(int fd, int busy)
 		vbl.request.sequence = 0;
 		drmIoctl(fd, DRM_IOCTL_WAIT_VBLANK, &vbl);
 
-		read(fd, &event, sizeof(event));
+		assert(read(fd, &event, sizeof(event)) != -1);
 		count++;
 	} while ((event.sequence - seq) <= 120);
 	clock_gettime(CLOCK_MONOTONIC, &end);
 
 	printf("%f\n", 1e6/elapsed(&start, &end, count));
 	if (busy)
-		read(fd, &event, sizeof(event));
+		assert(read(fd, &event, sizeof(event)) != -1);
 }
 
 int main(int argc, char **argv)
diff --git a/debugger/eudb.c b/debugger/eudb.c
index 39c5cca..275a27e 100644
--- a/debugger/eudb.c
+++ b/debugger/eudb.c
@@ -147,7 +147,9 @@ dump_debug(void *buf, size_t count) {
 	if (!debug_fd)
 		debug_fd = open(debug_file, O_CREAT | O_WRONLY | O_TRUNC, S_IRWXO);
 
-	write(debug_fd, buf, count);
+	if (write(debug_fd, buf, count) == -1)
+		fprintf(stderr, "Error writing to debug file: %s\n",
+			strerror(errno));
 }
 
 static volatile void *
diff --git a/lib/igt_aux.c b/lib/igt_aux.c
index c26d167..e77392c 100644
--- a/lib/igt_aux.c
+++ b/lib/igt_aux.c
@@ -767,8 +767,12 @@ static void igt_module_param_exit_handler(int sig)
 
 		fd = open(file_path, O_RDWR);
 		if (fd >= 0) {
-			write(fd, data->original_value,
-			      strlen(data->original_value));
+			int size = strlen (data->original_value);
+
+			if (size != write(fd, data->original_value, size))
+				igt_warn("%s may not have been reset to its"
+					 " original value\n", file_path);
+
 			close(fd);
 		}
 	}
diff --git a/overlay/gpu-top.c b/overlay/gpu-top.c
index d1f5ec8..4097cd0 100644
--- a/overlay/gpu-top.c
+++ b/overlay/gpu-top.c
@@ -29,6 +29,7 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <errno.h>
+#include <assert.h>
 
 #include "perf.h"
 #include "igfx.h"
@@ -260,7 +261,8 @@ static void mmio_init(struct gpu_top *gt)
 		mmio_ring_emit(&render_ring, 1000, payload);
 		mmio_ring_emit(&bsd_ring, 1000, payload);
 		mmio_ring_emit(&blt_ring, 1000, payload);
-		write(fd[1], payload, sizeof(payload));
+		assert(write(fd[1], payload, sizeof(payload))
+		       == sizeof(payload));
 	}
 }
 
diff --git a/overlay/overlay.c b/overlay/overlay.c
index 035e02c..3c0dbb4 100644
--- a/overlay/overlay.c
+++ b/overlay/overlay.c
@@ -910,8 +910,8 @@ int main(int argc, char **argv)
 	if (daemonize && daemon(0, 0))
 		return EINVAL;
 
-	if (renice)
-		nice(renice);
+	if (renice && (nice(renice) == -1))
+		fprintf(stderr, "Could not renice: %s\n", strerror(errno));
 
 	signal(SIGUSR1, signal_snapshot);
 
diff --git a/tools/intel_l3_udev_listener.c b/tools/intel_l3_udev_listener.c
index 261630e..0b94c1c 100644
--- a/tools/intel_l3_udev_listener.c
+++ b/tools/intel_l3_udev_listener.c
@@ -113,10 +113,10 @@ again:
 
 	udev_device_unref(udev_dev);
 
-	asprintf(&err_msg, "Parity error detected on: %d,%d,%d,%d. "
+	assert(asprintf(&err_msg, "Parity error detected on: %d,%d,%d,%d. "
 			"Try to run intel_l3_parity -r %d -b %d -s %d -w %d -d",
 			loc->slice, loc->row, loc->bank, loc->subbank,
-			loc->row, loc->bank, loc->subbank, loc->slice);
+			loc->row, loc->bank, loc->subbank, loc->slice) != -1);
 	if (daemon) {
 		syslog(LOG_INFO, "%s\n", err_msg);
 		goto again;
diff --git a/tools/intel_reg.c b/tools/intel_reg.c
index 95760db..bef3287 100644
--- a/tools/intel_reg.c
+++ b/tools/intel_reg.c
@@ -506,7 +506,8 @@ static int intel_reg_snapshot(struct config *config, int argc, char *argv[])
 	intel_mmio_use_pci_bar(config->pci_dev);
 
 	/* XXX: error handling */
-	write(1, igt_global_mmio, config->pci_dev->regions[mmio_bar].size);
+	if (write(1, igt_global_mmio, config->pci_dev->regions[mmio_bar].size) == -1)
+		fprintf(stderr, "Error writing snapshot: %s", strerror(errno));
 
 	if (config->verbosity > 0)
 		printf("use this with --mmio=FILE --devid=0x%04X\n",
