From 809fb493412a8e1cb27dac737f832b316e69cd45 Mon Sep 17 00:00:00 2001
From: Oliver Kunz <okunz@google.com>
Date: Mon, 21 Mar 2022 08:35:29 -0700
Subject: [PATCH] Create a convencience function to set the name of a
 thread/process

PiperOrigin-RevId: 436215084
Change-Id: I17dc8930a117fe67bd1b87e2ae3d4652875780df
---
 sandboxed_api/sandbox2/policybuilder.cc | 9 ++++++++-
 sandboxed_api/sandbox2/policybuilder.h  | 5 +++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/sandboxed_api/sandbox2/policybuilder.cc b/sandboxed_api/sandbox2/policybuilder.cc
index 622a7b1..c9c4fb6 100644
--- a/sandboxed_api/sandbox2/policybuilder.cc
+++ b/sandboxed_api/sandbox2/policybuilder.cc
@@ -15,12 +15,14 @@
 #include "sandboxed_api/sandbox2/policybuilder.h"
 
 #include <asm/ioctls.h>  // For TCGETS
-#include <fcntl.h>       // For the fcntl flags
+#include <asm/unistd_64.h>
+#include <fcntl.h>  // For the fcntl flags
 #include <linux/filter.h>
 #include <linux/futex.h>
 #include <linux/net.h>     // For SYS_CONNECT
 #include <linux/random.h>  // For GRND_NONBLOCK
 #include <sys/mman.h>      // For mmap arguments
+#include <sys/prctl.h>
 #include <sys/socket.h>
 #include <sys/statvfs.h>
 #include <syscall.h>
@@ -646,6 +648,11 @@ PolicyBuilder& PolicyBuilder::AllowRename() {
   return *this;
 }
 
+PolicyBuilder& PolicyBuilder::AllowPrctlSetName() {
+  AddPolicyOnSyscall(__NR_prctl, {ARG_32(0), JEQ(PR_SET_NAME, ALLOW)});
+  return *this;
+}
+
 PolicyBuilder& PolicyBuilder::AllowFutexOp(int op) {
   return AddPolicyOnSyscall(
       __NR_futex, {
diff --git a/sandboxed_api/sandbox2/policybuilder.h b/sandboxed_api/sandbox2/policybuilder.h
index f249462..48ddcee 100644
--- a/sandboxed_api/sandbox2/policybuilder.h
+++ b/sandboxed_api/sandbox2/policybuilder.h
@@ -379,6 +379,11 @@ class PolicyBuilder final {
   // - renameat2
   PolicyBuilder& AllowRename();
 
+  // Appends code to allow setting the name of a thread
+  // Allows the following
+  // - prctl(PR_SET_NAME, ...)
+  PolicyBuilder& AllowPrctlSetName();
+
   // Enables the syscalls necessary to start a statically linked binary
   //
   // NOTE: This will call BlockSyscallWithErrno(__NR_readlink, ENOENT). If you