Update from https://crrev.com/327068

sandbox/linux/services/credentials.cc

Index: sandbox/linux/services/credentials.cc
diff --git a/sandbox/linux/services/credentials.cc b/sandbox/linux/services/credentials.cc
index 2e66d97cf53a45895d0ea7caeb1e8315f0a510a8..35bb4dcbd73fe99882deaf362dae473b9efd8c56 100644
--- a/sandbox/linux/services/credentials.cc
+++ b/sandbox/linux/services/credentials.cc
@@ -6,13 +6,13 @@
 
 #include <errno.h>
 #include <signal.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
-#include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
@@ -27,6 +27,7 @@
 #include "sandbox/linux/services/syscall_wrappers.h"
 #include "sandbox/linux/services/thread_helpers.h"
 #include "sandbox/linux/system_headers/capability.h"
+#include "sandbox/linux/system_headers/linux_signal.h"
 
 namespace sandbox {
 
@@ -40,8 +41,8 @@ bool IsRunningOnValgrind() { return RUNNING_ON_VALGRIND; }
 bool GetRESIds(uid_t* resuid, gid_t* resgid) {
   uid_t ruid, euid, suid;
   gid_t rgid, egid, sgid;
-  PCHECK(getresuid(&ruid, &euid, &suid) == 0);
-  PCHECK(getresgid(&rgid, &egid, &sgid) == 0);
+  PCHECK(sys_getresuid(&ruid, &euid, &suid) == 0);
+  PCHECK(sys_getresgid(&rgid, &egid, &sgid) == 0);
   const bool uids_are_equal = (ruid == euid) && (ruid == suid);
   const bool gids_are_equal = (rgid == egid) && (rgid == sgid);
   if (!uids_are_equal || !gids_are_equal) return false;
@@ -53,7 +54,7 @@ bool GetRESIds(uid_t* resuid, gid_t* resgid) {
 const int kExitSuccess = 0;
 
 int ChrootToSelfFdinfo(void*) {
-  RAW_CHECK(chroot("/proc/self/fdinfo/") == 0);
+  RAW_CHECK(sys_chroot("/proc/self/fdinfo/") == 0);
 
   // CWD is essentially an implicit file descriptor, so be careful to not
   // leave it behind.
@@ -89,9 +90,10 @@ bool ChrootToSafeEmptyDir() {
 #else
 #error "Unsupported architecture"
 #endif
+
   pid = clone(ChrootToSelfFdinfo, stack,
-              CLONE_VM | CLONE_VFORK | CLONE_FS | SIGCHLD, nullptr, nullptr,
-              nullptr, nullptr);
+              CLONE_VM | CLONE_VFORK | CLONE_FS | LINUX_SIGCHLD, nullptr,
+              nullptr, nullptr, nullptr);
   PCHECK(pid != -1);
 
   int status = -1;
@@ -110,23 +112,24 @@ void CheckCloneNewUserErrno(int error) {
          error == ENOSYS);
 }
 
-// Converts a LinuxCapability to the corresponding Linux CAP_XXX value.
-int LinuxCapabilityToKernelValue(LinuxCapability cap) {
+// Converts a Capability to the corresponding Linux CAP_XXX value.
+int CapabilityToKernelValue(Credentials::Capability cap) {
   switch (cap) {
-    case LinuxCapability::kCapSysChroot:
+    case Credentials::Capability::SYS_CHROOT:
       return CAP_SYS_CHROOT;
-    case LinuxCapability::kCapSysAdmin:
+    case Credentials::Capability::SYS_ADMIN:
       return CAP_SYS_ADMIN;
   }
 
-  LOG(FATAL) << "Invalid LinuxCapability: " << static_cast<int>(cap);
+  LOG(FATAL) << "Invalid Capability: " << static_cast<int>(cap);
   return 0;
 }
 
 }  // namespace.
 
+// static
 bool Credentials::DropAllCapabilities(int proc_fd) {
-  if (!SetCapabilities(proc_fd, std::vector<LinuxCapability>())) {
+  if (!SetCapabilities(proc_fd, std::vector<Capability>())) {
     return false;
   }
 
@@ -134,30 +137,28 @@ bool Credentials::DropAllCapabilities(int proc_fd) {
   return true;
 }
 
+// static
 bool Credentials::DropAllCapabilities() {
   base::ScopedFD proc_fd(ProcUtil::OpenProc());
   return Credentials::DropAllCapabilities(proc_fd.get());
 }
 
 // static
-bool Credentials::SetCapabilities(int proc_fd,
-                                  const std::vector<LinuxCapability>& caps) {
-  DCHECK_LE(0, proc_fd);
-
-#if !defined(THREAD_SANITIZER)
-  // With TSAN, accept to break the security model as it is a testing
-  // configuration.
-  CHECK(ThreadHelpers::IsSingleThreaded(proc_fd));
-#endif
+bool Credentials::DropAllCapabilitiesOnCurrentThread() {
+  return SetCapabilitiesOnCurrentThread(std::vector<Capability>());
+}
 
+// static
+bool Credentials::SetCapabilitiesOnCurrentThread(
+    const std::vector<Capability>& caps) {
   struct cap_hdr hdr = {};
   hdr.version = _LINUX_CAPABILITY_VERSION_3;
   struct cap_data data[_LINUX_CAPABILITY_U32S_3] = {{}};
 
   // Initially, cap has no capability flags set. Enable the effective and
   // permitted flags only for the requested capabilities.
-  for (const LinuxCapability cap : caps) {
-    const int cap_num = LinuxCapabilityToKernelValue(cap);
+  for (const Capability cap : caps) {
+    const int cap_num = CapabilityToKernelValue(cap);
     const size_t index = CAP_TO_INDEX(cap_num);
     const uint32_t mask = CAP_TO_MASK(cap_num);
     data[index].effective |= mask;
@@ -167,6 +168,20 @@ bool Credentials::SetCapabilities(int proc_fd,
   return sys_capset(&hdr, data) == 0;
 }
 
+// static
+bool Credentials::SetCapabilities(int proc_fd,
+                                  const std::vector<Capability>& caps) {
+  DCHECK_LE(0, proc_fd);
+
+#if !defined(THREAD_SANITIZER)
+  // With TSAN, accept to break the security model as it is a testing
+  // configuration.
+  CHECK(ThreadHelpers::IsSingleThreaded(proc_fd));
+#endif
+
+  return SetCapabilitiesOnCurrentThread(caps);
+}
+
 bool Credentials::HasAnyCapability() {
   struct cap_hdr hdr = {};
   hdr.version = _LINUX_CAPABILITY_VERSION_3;
@@ -183,14 +198,14 @@ bool Credentials::HasAnyCapability() {
   return false;
 }
 
-bool Credentials::HasCapability(LinuxCapability cap) {
+bool Credentials::HasCapability(Capability cap) {
   struct cap_hdr hdr = {};
   hdr.version = _LINUX_CAPABILITY_VERSION_3;
   struct cap_data data[_LINUX_CAPABILITY_U32S_3] = {{}};
 
   PCHECK(sys_capget(&hdr, data) == 0);
 
-  const int cap_num = LinuxCapabilityToKernelValue(cap);
+  const int cap_num = CapabilityToKernelValue(cap);
   const size_t index = CAP_TO_INDEX(cap_num);
   const uint32_t mask = CAP_TO_MASK(cap_num);
 
@@ -247,7 +262,7 @@ bool Credentials::MoveToNewUserNS() {
     DVLOG(1) << "uids or gids differ!";
     return false;
   }
-  int ret = unshare(CLONE_NEWUSER);
+  int ret = sys_unshare(CLONE_NEWUSER);
   if (ret) {
     const int unshare_errno = errno;
     VLOG(1) << "Looks like unprivileged CLONE_NEWUSER may not be available "