diff --git a/fs/proc/base.c b/fs/proc/base.c
index 837469a..5ac6ece 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -255,32 +255,47 @@ static int proc_pid_cmdline(struct task_struct *task, char * buffer)
 	int res = 0;
 	unsigned int len;
 	struct mm_struct *mm = get_task_mm(task);
+	unsigned seq;
+
 	if (!mm)
 		goto out;
+
+	/* The process was not constructed yet? */
 	if (!mm->arg_end)
-		goto out_mm;	/* Shh! No looking before we're done */
+		goto out_mm;
 
- 	len = mm->arg_end - mm->arg_start;
- 
-	if (len > PAGE_SIZE)
-		len = PAGE_SIZE;
- 
-	res = access_process_vm(task, mm->arg_start, buffer, len, 0);
-
-	// If the nul at the end of args has been overwritten, then
-	// assume application is using setproctitle(3).
-	if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
-		len = strnlen(buffer, res);
-		if (len < res) {
-		    res = len;
-		} else {
-			len = mm->env_end - mm->env_start;
-			if (len > PAGE_SIZE - res)
-				len = PAGE_SIZE - res;
-			res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
+	do {
+		seq = read_seqbegin(&mm->arg_lock);
+
+		len = mm->arg_end - mm->arg_start;
+		if (len > PAGE_SIZE)
+			len = PAGE_SIZE;
+
+		res = access_process_vm(task, mm->arg_start, buffer, len, 0);
+
+		if (mm->arg_end != mm->env_start)
+			/* PR_SET_PROCTITLE_AREA used */
 			res = strnlen(buffer, res);
+		else if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
+			/*
+			 * If the nul at the end of args has been overwritten,
+			 * then assume application is using sendmail's
+			 * SPT_REUSEARGV style argv override.
+			 */
+			len = strnlen(buffer, res);
+			if (len < res) {
+				res = len;
+			} else {
+				len = mm->env_end - mm->env_start;
+				if (len > PAGE_SIZE - res)
+					len = PAGE_SIZE - res;
+				res += access_process_vm(task, mm->env_start,
+							 buffer+res, len, 0);
+				res = strnlen(buffer, res);
+			}
 		}
-	}
+	} while (read_seqretry(&mm->arg_lock, seq));
+
 out_mm:
 	mmput(mm);
 out:
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 84a524a..279d620 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -12,6 +12,7 @@
 #include <linux/completion.h>
 #include <linux/cpumask.h>
 #include <linux/page-debug-flags.h>
+#include <linux/seqlock.h>
 #include <asm/page.h>
 #include <asm/mmu.h>
 
@@ -236,6 +237,7 @@ struct mm_struct {
 	unsigned long stack_vm, reserved_vm, def_flags, nr_ptes;
 	unsigned long start_code, end_code, start_data, end_data;
 	unsigned long start_brk, brk, start_stack;
+	seqlock_t arg_lock;
 	unsigned long arg_start, arg_end, env_start, env_end;
 
 	unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
diff --git a/include/linux/prctl.h b/include/linux/prctl.h
index 9311505..e80a11b 100644
--- a/include/linux/prctl.h
+++ b/include/linux/prctl.h
@@ -90,4 +90,8 @@
 
 #define PR_MCE_KILL	33
 
+
+/* Set process title memory area for setproctitle() */
+#define PR_SET_PROCTITLE_AREA 34
+
 #endif /* _LINUX_PRCTL_H */
diff --git a/kernel/fork.c b/kernel/fork.c
index 266c6af..13089e3 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -459,6 +459,7 @@ static struct mm_struct * mm_init(struct mm_struct * mm, struct task_struct *p)
 	mm->cached_hole_size = ~0UL;
 	mm_init_aio(mm);
 	mm_init_owner(mm, p);
+	seqlock_init(&mm->arg_lock);
 
 	if (likely(!mm_alloc_pgd(mm))) {
 		mm->def_flags = 0;
diff --git a/kernel/sys.c b/kernel/sys.c
index 255475d..83724d2 100644
--- a/kernel/sys.c
+++ b/kernel/sys.c
@@ -1563,7 +1563,29 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3,
 			}
 			error = 0;
 			break;
+ 		case PR_SET_PROCTITLE_AREA: {
+			struct mm_struct *mm = current->mm;
+			unsigned long addr = arg2;
+			unsigned long len = arg3;
+			unsigned long end = arg2 + arg3;
 
+			if (len > PAGE_SIZE)
+				return -EINVAL;
+
+			if (addr >= end)
+				return -EINVAL;
+
+			if (!access_ok(VERIFY_READ, addr, len)) {
+				return -EFAULT;
+			}
+
+			write_seqlock(&mm->arg_lock);
+			mm->arg_start = addr;
+			mm->arg_end = addr + len;
+			write_sequnlock(&mm->arg_lock);
+
+			return 0;
+		}
 		default:
 			error = -EINVAL;
 			break;