Add PTHREAD_PRIO_INHERIT to POSIX Locks

sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc

Index: sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc
diff --git a/sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc b/sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc
index f5cbef00855d2945e7340e51444d2bba3fccaa88..3a09a4f5e5b282221a817e1a9197128e86d60454 100644
--- a/sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc
+++ b/sandbox/linux/seccomp-bpf-helpers/syscall_parameters_restrictions.cc
@@ -22,8 +22,10 @@
 
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/synchronization/lock.h"
 #include "build/build_config.h"
 #include "sandbox/linux/bpf_dsl/bpf_dsl.h"
+#include "sandbox/linux/bpf_dsl/bpf_dsl_impl.h"
 #include "sandbox/linux/bpf_dsl/seccomp_macros.h"
 #include "sandbox/linux/seccomp-bpf-helpers/sigsys_handlers.h"
 #include "sandbox/linux/seccomp-bpf/sandbox_bpf.h"
@@ -65,6 +67,19 @@
 #if defined(__mips__) && !defined(MAP_STACK)
 #define MAP_STACK 0x40000
 #endif
+
+#define CASES SANDBOX_BPF_DSL_CASES
+
+using sandbox::bpf_dsl::Allow;
+using sandbox::bpf_dsl::Arg;
+using sandbox::bpf_dsl::BoolExpr;
+using sandbox::bpf_dsl::Error;
+using sandbox::bpf_dsl::If;
+using sandbox::bpf_dsl::Kill;
+using sandbox::bpf_dsl::ResultExpr;
+
+namespace sandbox {
+
 namespace {
 
 inline bool IsArchitectureX86_64() {
@@ -99,30 +114,21 @@ inline bool IsArchitectureMips() {
 #endif
 }
 
+// Default case for futexes since they occur twice, once when priority
+// inheritance is disallowed and again for the disallowed futex op.
+inline sandbox::bpf_dsl::ResultExpr DisallowFutexOp() {
 // Ubuntu's version of glibc has a race condition in sem_post that can cause
 // it to call futex(2) with bogus op arguments. To workaround this, we need
 // to allow those futex(2) calls to fail with EINVAL, instead of crashing the
 // process. See crbug.com/598471.
-inline bool IsBuggyGlibcSemPost() {
 #if defined(LIBC_GLIBC) && !defined(OS_CHROMEOS)
-  return true;
+  return Error(EINVAL);
 #else
-  return false;
+  return CrashSIGSYSFutex();
 #endif
 }
 
-}  // namespace.
-
-#define CASES SANDBOX_BPF_DSL_CASES
-
-using sandbox::bpf_dsl::Allow;
-using sandbox::bpf_dsl::Arg;
-using sandbox::bpf_dsl::BoolExpr;
-using sandbox::bpf_dsl::Error;
-using sandbox::bpf_dsl::If;
-using sandbox::bpf_dsl::ResultExpr;
-
-namespace sandbox {
+}  // namespace
 
 #if !defined(OS_NACL_NONSFI)
 // Allow Glibc's and Android pthread creation flags, crash on any other
@@ -266,9 +272,15 @@ ResultExpr RestrictFutex() {
   const Arg<int> op(1);
   return Switch(op & ~kAllowedFutexFlags)
       .CASES((FUTEX_WAIT, FUTEX_WAKE, FUTEX_REQUEUE, FUTEX_CMP_REQUEUE,
-              FUTEX_WAKE_OP, FUTEX_WAIT_BITSET, FUTEX_WAKE_BITSET),
-             Allow())
-      .Default(IsBuggyGlibcSemPost() ? Error(EINVAL) : CrashSIGSYSFutex());
+              FUTEX_WAKE_OP, FUTEX_WAIT_BITSET, FUTEX_WAKE_BITSET), Allow())
+#if PRIORITY_INHERITANCE_LOCKS_POSSIBLE()
+      .CASES((FUTEX_LOCK_PI, FUTEX_UNLOCK_PI, FUTEX_WAIT_REQUEUE_PI,
+              FUTEX_CMP_REQUEUE_PI),
+             base::Lock::PriorityInheritanceAvailable()
+                 ? Allow()
+                 : DisallowFutexOp())
+#endif
+      .Default(DisallowFutexOp());
 }
 
 ResultExpr RestrictGetSetpriority(pid_t target_pid) {