diff --git a/fs_mgr/fs_mgr.c b/fs_mgr/fs_mgr.c
index c47a585..02aff55 100644
--- a/fs_mgr/fs_mgr.c
+++ b/fs_mgr/fs_mgr.c
@@ -600,7 +600,7 @@
                   fstab->recs[top_idx].fs_type);
             if (fs_mgr_is_encryptable(&fstab->recs[top_idx]) &&
                 strcmp(fstab->recs[top_idx].key_loc, KEY_IN_FOOTER)) {
-                int fd = open(fstab->recs[top_idx].key_loc, O_WRONLY, 0644);
+                int fd = open(fstab->recs[top_idx].key_loc, O_WRONLY);
                 if (fd >= 0) {
                     INFO("%s(): also wipe %s\n", __func__, fstab->recs[top_idx].key_loc);
                     wipe_block_device(fd, get_file_size(fd));
diff --git a/fs_mgr/fs_mgr_format.c b/fs_mgr/fs_mgr_format.c
index 853bf0b..c63ff67 100644
--- a/fs_mgr/fs_mgr_format.c
+++ b/fs_mgr/fs_mgr_format.c
@@ -36,7 +36,7 @@
     uint64_t dev_sz;
     int fd, rc = 0;
 
-    if ((fd = open(fs_blkdev, O_WRONLY, 0644)) < 0) {
+    if ((fd = open(fs_blkdev, O_WRONLY)) < 0) {
         ERROR("Cannot open block device.  %s\n", strerror(errno));
         return -1;
     }
diff --git a/gatekeeperd/gatekeeperd.cpp b/gatekeeperd/gatekeeperd.cpp
index b4fdab0..7254cf2 100644
--- a/gatekeeperd/gatekeeperd.cpp
+++ b/gatekeeperd/gatekeeperd.cpp
@@ -76,7 +76,7 @@
 
     void store_sid(uint32_t uid, uint64_t sid) {
         char filename[21];
-        sprintf(filename, "%u", uid);
+        snprintf(filename, sizeof(filename), "%u", uid);
         int fd = open(filename, O_WRONLY | O_TRUNC | O_CREAT, S_IRUSR | S_IWUSR);
         if (fd < 0) {
             ALOGE("could not open file: %s: %s", filename, strerror(errno));
@@ -102,7 +102,7 @@
 
     void maybe_store_sid(uint32_t uid, uint64_t sid) {
         char filename[21];
-        sprintf(filename, "%u", uid);
+        snprintf(filename, sizeof(filename), "%u", uid);
         if (access(filename, F_OK) == -1) {
             store_sid(uid, sid);
         }
@@ -111,7 +111,7 @@
     uint64_t read_sid(uint32_t uid) {
         char filename[21];
         uint64_t sid;
-        sprintf(filename, "%u", uid);
+        snprintf(filename, sizeof(filename), "%u", uid);
         int fd = open(filename, O_RDONLY);
         if (fd < 0) return 0;
         read(fd, &sid, sizeof(sid));
@@ -121,7 +121,7 @@
 
     void clear_sid(uint32_t uid) {
         char filename[21];
-        sprintf(filename, "%u", uid);
+        snprintf(filename, sizeof(filename), "%u", uid);
         if (remove(filename) < 0) {
             ALOGE("%s: could not remove file [%s], attempting 0 write", __func__, strerror(errno));
             store_sid(uid, 0);
diff --git a/init/parser.cpp b/init/parser.cpp
index 8193729..ae103ec 100644
--- a/init/parser.cpp
+++ b/init/parser.cpp
@@ -12,7 +12,7 @@
     char buf[128];
     int off;
 
-    snprintf(buf, 128, "%s: %d: ", state->filename, state->line);
+    snprintf(buf, sizeof(buf), "%s: %d: ", state->filename, state->line);
     buf[127] = 0;
     off = strlen(buf);
 
diff --git a/libsync/sync_test.c b/libsync/sync_test.c
index ee9ea3c..9a5f7d8 100644
--- a/libsync/sync_test.c
+++ b/libsync/sync_test.c
@@ -92,7 +92,7 @@
 
         for (j = 0; j < 2; j++) {
             unsigned val = i + j * 3 + 1;
-            sprintf(str, "test_fence%d-%d", i, j);
+            snprintf(str, sizeof(str), "test_fence%d-%d", i, j);
             int fd = sw_sync_fence_create(sync_timeline_fd, str, val);
             if (fd < 0) {
                 printf("can't create sync pt %d: %s", val, strerror(errno));
@@ -106,7 +106,7 @@
 
     sync_data[3].thread_no = 3;
     for (j = 0; j < 2; j++) {
-        sprintf(str, "merged_fence%d", j);
+        snprintf(str, sizeof(str), "merged_fence%d", j);
         sync_data[3].fd[j] = sync_merge(str, sync_data[0].fd[j], sync_data[1].fd[j]);
         if (sync_data[3].fd[j] < 0) {
             printf("can't merge sync pts %d and %d: %s\n",
diff --git a/libutils/RefBase.cpp b/libutils/RefBase.cpp
index 02907ad..ea1e4db 100644
--- a/libutils/RefBase.cpp
+++ b/libutils/RefBase.cpp
@@ -190,17 +190,22 @@
         {
             Mutex::Autolock _l(mMutex);
             char buf[128];
-            sprintf(buf, "Strong references on RefBase %p (weakref_type %p):\n", mBase, this);
+            snprintf(buf, sizeof(buf),
+                     "Strong references on RefBase %p (weakref_type %p):\n",
+                     mBase, this);
             text.append(buf);
             printRefsLocked(&text, mStrongRefs);
-            sprintf(buf, "Weak references on RefBase %p (weakref_type %p):\n", mBase, this);
+            snprintf(buf, sizeof(buf),
+                     "Weak references on RefBase %p (weakref_type %p):\n",
+                     mBase, this);
             text.append(buf);
             printRefsLocked(&text, mWeakRefs);
         }
 
         {
             char name[100];
-            snprintf(name, 100, DEBUG_REFS_CALLSTACK_PATH "/%p.stack", this);
+            snprintf(name, sizeof(name), DEBUG_REFS_CALLSTACK_PATH "/%p.stack",
+                     this);
             int rc = open(name, O_RDWR | O_CREAT | O_APPEND, 644);
             if (rc >= 0) {
                 write(rc, text.string(), text.length());
@@ -293,8 +298,8 @@
         char buf[128];
         while (refs) {
             char inc = refs->ref >= 0 ? '+' : '-';
-            sprintf(buf, "\t%c ID %p (ref %d):\n", 
-                    inc, refs->id, refs->ref);
+            snprintf(buf, sizeof(buf), "\t%c ID %p (ref %d):\n",
+                     inc, refs->id, refs->ref);
             out->append(buf);
 #if DEBUG_REFS_CALLSTACK_ENABLED
             out->append(refs->stack.toString("\t\t"));
diff --git a/toolbox/newfs_msdos.c b/toolbox/newfs_msdos.c
index 5b98a01..27ea9e8 100644
--- a/toolbox/newfs_msdos.c
+++ b/toolbox/newfs_msdos.c
@@ -695,7 +695,7 @@
                                                     (u_int)tm->tm_min));
                 mk4(bsx->volid, x);
                 mklabel(bsx->label, opt_L ? opt_L : "NO NAME");
-                sprintf(buf, "FAT%u", fat);
+                snprintf(buf, sizeof(buf), "FAT%u", fat);
                 setstr(bsx->type, buf, sizeof(bsx->type));
                 if (!opt_B) {
                     x1 += sizeof(struct bsx);
diff --git a/toolbox/ps.c b/toolbox/ps.c
index 7e70c71..d366f3e 100644
--- a/toolbox/ps.c
+++ b/toolbox/ps.c
@@ -57,16 +57,16 @@
     int prio, nice, rtprio, sched, psr;
     struct passwd *pw;
 
-    sprintf(statline, "/proc/%d", tid ? tid : pid);
+    snprintf(statline, sizeof(statline), "/proc/%d", tid ? tid : pid);
     stat(statline, &stats);
 
     if(tid) {
-        sprintf(statline, "/proc/%d/task/%d/stat", pid, tid);
+        snprintf(statline, sizeof(statline), "/proc/%d/task/%d/stat", pid, tid);
         cmdline[0] = 0;
         snprintf(macline, sizeof(macline), "/proc/%d/task/%d/attr/current", pid, tid);
     } else {
-        sprintf(statline, "/proc/%d/stat", pid);
-        sprintf(cmdline, "/proc/%d/cmdline", pid);
+        snprintf(statline, sizeof(statline), "/proc/%d/stat", pid);
+        snprintf(cmdline, sizeof(cmdline), "/proc/%d/cmdline", pid);
         snprintf(macline, sizeof(macline), "/proc/%d/attr/current", pid);
         int fd = open(cmdline, O_RDONLY);
         if(fd == 0) {
@@ -149,7 +149,7 @@
 
     pw = getpwuid(stats.st_uid);
     if(pw == 0 || (display_flags & SHOW_NUMERIC_UID)) {
-        sprintf(user,"%d",(int)stats.st_uid);
+        snprintf(user,sizeof(user),"%d",(int)stats.st_uid);
     } else {
         strcpy(user,pw->pw_name);
     }
@@ -208,7 +208,7 @@
     int fd, r;
     char exeline[1024];
 
-    sprintf(exeline, "/proc/%d/exe", pid);
+    snprintf(exeline, sizeof(exeline), "/proc/%d/exe", pid);
     fd = open(exeline, O_RDONLY);
     if(fd == 0) {
         printf("    ");
@@ -243,7 +243,7 @@
     DIR *d;
     struct dirent *de;
 
-    sprintf(tmp,"/proc/%d/task",pid);
+    snprintf(tmp,sizeof(tmp),"/proc/%d/task",pid);
     d = opendir(tmp);
     if(d == 0) return;
 
diff --git a/toolbox/top.c b/toolbox/top.c
index 6fda132..003f4c9 100644
--- a/toolbox/top.c
+++ b/toolbox/top.c
@@ -258,29 +258,29 @@
 
             proc->pid = proc->tid = pid;
 
-            sprintf(filename, "/proc/%d/stat", pid);
+            snprintf(filename, sizeof(filename), "/proc/%d/stat", pid);
             read_stat(filename, proc);
 
-            sprintf(filename, "/proc/%d/cmdline", pid);
+            snprintf(filename, sizeof(filename), "/proc/%d/cmdline", pid);
             read_cmdline(filename, proc);
 
-            sprintf(filename, "/proc/%d/status", pid);
+            snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
             read_status(filename, proc);
 
             read_policy(pid, proc);
 
             proc->num_threads = 0;
         } else {
-            sprintf(filename, "/proc/%d/cmdline", pid);
+            snprintf(filename, sizeof(filename), "/proc/%d/cmdline", pid);
             read_cmdline(filename, &cur_proc);
 
-            sprintf(filename, "/proc/%d/status", pid);
+            snprintf(filename, sizeof(filename), "/proc/%d/status", pid);
             read_status(filename, &cur_proc);
 
             proc = NULL;
         }
 
-        sprintf(filename, "/proc/%d/task", pid);
+        snprintf(filename, sizeof(filename), "/proc/%d/task", pid);
         task_dir = opendir(filename);
         if (!task_dir) continue;
 
@@ -295,7 +295,7 @@
 
                 proc->pid = pid; proc->tid = tid;
 
-                sprintf(filename, "/proc/%d/task/%d/stat", pid, tid);
+                snprintf(filename, sizeof(filename), "/proc/%d/task/%d/stat", pid, tid);
                 read_stat(filename, proc);
 
                 read_policy(tid, proc);
@@ -484,7 +484,7 @@
         if (user && user->pw_name) {
             user_str = user->pw_name;
         } else {
-            snprintf(user_buf, 20, "%d", proc->uid);
+            snprintf(user_buf, sizeof(user_buf), "%d", proc->uid);
             user_str = user_buf;
         }
         if (!threads) {