Index: llvm/test/tools/llvm-objcopy/ELF/mirror-permissions.test
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-objcopy/ELF/mirror-permissions.test
@@ -0,0 +1,36 @@
+# RUN: touch %t
+# RUN: chmod 0777 %t
+# RUN: ls -l %t | cut -f 1 -d ' ' > %t.0777
+# RUN: chmod 0666 %t
+# RUN: ls -l %t | cut -f 1 -d ' ' > %t.0666
+# RUN: chmod 0640 %t
+# RUN: ls -l %t | cut -f 1 -d ' ' > %t.0640
+
+## Set umask to be permissive of all permissions,
+## only test mirroring of permissions. umask(1) doesn't
+## exist on Windows.
+# RUN: if [[ "$OSTYPE" != "win32" ]]; then umask 0; fi
+
+# RUN: yaml2obj %s -o %t
+
+# RUN: chmod 0777 %t
+# RUN: llvm-objcopy %t %t1
+# RUN: ls -l %t1 | cut -f 1 -d ' ' > %t1.perms
+# RUN: cmp %t1.perms %t.0777
+
+# RUN: chmod 0666 %t
+# RUN: llvm-objcopy %t %t1
+# RUN: ls -l %t1 | cut -f 1 -d ' ' > %t1.perms
+# RUN: cmp %t1.perms %t.0666
+
+# RUN: chmod 0640 %t
+# RUN: llvm-objcopy %t %t1
+# RUN: ls -l %t1 | cut -f 1 -d ' ' > %t1.perms
+# RUN: cmp %t1.perms %t.0640
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
Index: llvm/test/tools/llvm-objcopy/ELF/respect-umask.test
===================================================================
--- /dev/null
+++ llvm/test/tools/llvm-objcopy/ELF/respect-umask.test
@@ -0,0 +1,37 @@
+# UNSUPPORTED: windows
+
+# RUN: touch %t
+# RUN: chmod 0755 %t
+# RUN: ls -l %t | cut -f 1 -d ' ' > %t.0755
+# RUN: chmod 0500 %t
+# RUN: ls -l %t | cut -f 1 -d ' ' > %t.0500
+# RUN: chmod 0555 %t
+# RUN: ls -l %t | cut -f 1 -d ' ' > %t.0555
+
+# RUN: yaml2obj %s -o %t
+
+# RUN: umask 0022
+# RUN: chmod 0777 %t
+# RUN: llvm-objcopy %t %t1
+# RUN: ls -l %t1 | cut -f 1 -d ' ' > %t1.perms
+# RUN: cmp %t1.perms %t.0755
+
+# RUN: umask 0237
+# RUN: chmod 0707 %t
+# RUN: llvm-objcopy %t %t1
+# RUN: ls -l %t1 | cut -f 1 -d ' ' > %t1.perms
+# RUN: cmp %t1.perms %t.0500
+
+# RUN: umask 0222
+# RUN: chmod 0777 %t
+# RUN: llvm-objcopy %t %t1
+# RUN: ls -l %t1 | cut -f 1 -d ' ' > %t1.perms
+# RUN: cmp %t1.perms %t.0555
+
+
+--- !ELF
+FileHeader:
+  Class:   ELFCLASS64
+  Data:    ELFDATA2LSB
+  Type:    ET_EXEC
+  Machine: EM_X86_64
Index: llvm/tools/llvm-objcopy/llvm-objcopy.cpp
===================================================================
--- llvm/tools/llvm-objcopy/llvm-objcopy.cpp
+++ llvm/tools/llvm-objcopy/llvm-objcopy.cpp
@@ -45,6 +45,10 @@
 #include <string>
 #include <system_error>
 #include <utility>
+// TODO: Remove this if D63583 lands.
+#ifndef _WIN32
+#include <sys/stat.h>
+#endif
 
 namespace llvm {
 namespace objcopy {
@@ -196,16 +200,32 @@
                           Config.DeterministicArchives, Ar.isThin());
 }
 
-static Error restoreDateOnFile(StringRef Filename,
-                               const sys::fs::file_status &Stat) {
+static Error restoreStatOnFile(StringRef Filename, sys::fs::file_status &Stat,
+                               bool PreserveDates) {
   int FD;
 
+  // Writing to stdout should not be treated as an error here, just
+  // do not set access/modification times or permissions.
+  if (Filename == "-")
+    return Error::success();
+
   if (auto EC =
           sys::fs::openFileForWrite(Filename, FD, sys::fs::CD_OpenExisting))
     return createFileError(Filename, EC);
 
-  if (auto EC = sys::fs::setLastAccessAndModificationTime(
-          FD, Stat.getLastAccessedTime(), Stat.getLastModificationTime()))
+  if (PreserveDates)
+    if (auto EC = sys::fs::setLastAccessAndModificationTime(
+            FD, Stat.getLastAccessedTime(), Stat.getLastModificationTime()))
+      return createFileError(Filename, EC);
+
+      // TODO: Rework this if D63583 lands.
+#ifndef _WIN32
+  unsigned Mask = ::umask(0);
+  (void)::umask(Mask);
+  Stat.permissions(static_cast<sys::fs::perms>(Stat.permissions & ~Mask));
+#endif
+
+  if (auto EC = sys::fs::setPermissions(Filename, Stat.permissions()))
     return createFileError(Filename, EC);
 
   if (auto EC = sys::Process::SafelyCloseFileDescriptor(FD))
@@ -219,9 +239,12 @@
 /// format-agnostic modifications, i.e. preserving dates.
 static Error executeObjcopy(const CopyConfig &Config) {
   sys::fs::file_status Stat;
-  if (Config.PreserveDates)
+  if (Config.InputFilename != "-") {
     if (auto EC = sys::fs::status(Config.InputFilename, Stat))
       return createFileError(Config.InputFilename, EC);
+  } else {
+    Stat.permissions(static_cast<sys::fs::perms>(0775));
+  }
 
   typedef Error (*ProcessRawFn)(const CopyConfig &, MemoryBuffer &, Buffer &);
   auto ProcessRaw = StringSwitch<ProcessRawFn>(Config.InputFormat)
@@ -253,12 +276,15 @@
     }
   }
 
-  if (Config.PreserveDates) {
-    if (Error E = restoreDateOnFile(Config.OutputFilename, Stat))
+  if (Error E =
+          restoreStatOnFile(Config.OutputFilename, Stat, Config.PreserveDates))
+    return E;
+
+  if (!Config.SplitDWO.empty()) {
+    Stat.permissions(static_cast<sys::fs::perms>(0664));
+    if (Error E =
+            restoreStatOnFile(Config.SplitDWO, Stat, Config.PreserveDates))
       return E;
-    if (!Config.SplitDWO.empty())
-      if (Error E = restoreDateOnFile(Config.SplitDWO, Stat))
-        return E;
   }
 
   return Error::success();