Index: lld/trunk/ELF/SyntheticSections.cpp
===================================================================
--- lld/trunk/ELF/SyntheticSections.cpp
+++ lld/trunk/ELF/SyntheticSections.cpp
@@ -872,7 +872,13 @@
     if (tryMergeGots(MergedGots.front(), SrcGot, true)) {
       File->MipsGotIndex = 0;
     } else {
-      if (!tryMergeGots(MergedGots.back(), SrcGot, false)) {
+      // If this is the first time we failed to merge with the primary GOT,
+      // MergedGots.back() will also be the primary GOT. We must make sure not
+      // to try to merge again with IsPrimary=false, as otherwise, if the
+      // inputs are just right, we could allow the primary GOT to become 1 or 2
+      // words too big due to ignoring the header size.
+      if (MergedGots.size() == 1 ||
+          !tryMergeGots(MergedGots.back(), SrcGot, false)) {
         MergedGots.emplace_back();
         std::swap(MergedGots.back(), SrcGot);
       }
Index: lld/trunk/test/ELF/Inputs/mips-64-got-load.s
===================================================================
--- lld/trunk/test/ELF/Inputs/mips-64-got-load.s
+++ lld/trunk/test/ELF/Inputs/mips-64-got-load.s
@@ -0,0 +1,8 @@
+  .text
+  .global foo1
+foo1:
+  ld $2, %got_disp(local1)($gp)
+
+  .bss
+local1:
+  .word 0
Index: lld/trunk/test/ELF/mips-64-got-overflow.s
===================================================================
--- lld/trunk/test/ELF/mips-64-got-overflow.s
+++ lld/trunk/test/ELF/mips-64-got-overflow.s
@@ -0,0 +1,80 @@
+# REQUIRES: mips
+# Check the primary GOT cannot be made to overflow
+
+# RUN: llvm-mc -filetype=obj -triple=mips64-unknown-linux \
+# RUN:         %p/Inputs/mips-64-got-load.s -o %t1.so.o
+# RUN: llvm-mc -filetype=obj -triple=mips64-unknown-linux %s -o %t2.so.o
+# RUN: ld.lld -shared -mips-got-size 32 %t1.so.o %t2.so.o -o %t-sgot.so
+# RUN: ld.lld -shared -mips-got-size 24 %t1.so.o %t2.so.o -o %t-mgot.so
+# RUN: llvm-readobj -r -dt -mips-plt-got %t-sgot.so | FileCheck -check-prefix=SGOT %s
+# RUN: llvm-readobj -r -dt -mips-plt-got %t-mgot.so | FileCheck -check-prefix=MGOT %s
+
+# SGOT:      Primary GOT {
+# SGOT-NEXT:   Canonical gp value: 0x27FF0
+# SGOT-NEXT:   Reserved entries [
+# SGOT-NEXT:     Entry {
+# SGOT-NEXT:       Address:
+# SGOT-NEXT:       Access: -32752
+# SGOT-NEXT:       Initial: 0x0
+# SGOT-NEXT:       Purpose: Lazy resolver
+# SGOT-NEXT:     }
+# SGOT-NEXT:     Entry {
+# SGOT-NEXT:       Address:
+# SGOT-NEXT:       Access: -32744
+# SGOT-NEXT:       Initial: 0x80000000
+# SGOT-NEXT:       Purpose: Module pointer (GNU extension)
+# SGOT-NEXT:     }
+# SGOT-NEXT:   ]
+# SGOT-NEXT:   Local entries [
+# SGOT-NEXT:     Entry {
+# SGOT-NEXT:       Address:
+# SGOT-NEXT:       Access: -32736
+# SGOT-NEXT:       Initial: 0x20020
+# SGOT-NEXT:     }
+# SGOT-NEXT:     Entry {
+# SGOT-NEXT:       Address:
+# SGOT-NEXT:       Access: -32728
+# SGOT-NEXT:       Initial: 0x20030
+# SGOT-NEXT:     }
+# SGOT-NEXT:   ]
+# SGOT-NEXT:   Global entries [
+# SGOT-NEXT:   ]
+# SGOT-NEXT:   Number of TLS and multi-GOT entries: 0
+# SGOT-NEXT: }
+
+# MGOT:      Primary GOT {
+# MGOT-NEXT:   Canonical gp value: 0x27FF0
+# MGOT-NEXT:   Reserved entries [
+# MGOT-NEXT:     Entry {
+# MGOT-NEXT:       Address:
+# MGOT-NEXT:       Access: -32752
+# MGOT-NEXT:       Initial: 0x0
+# MGOT-NEXT:       Purpose: Lazy resolver
+# MGOT-NEXT:     }
+# MGOT-NEXT:     Entry {
+# MGOT-NEXT:       Address:
+# MGOT-NEXT:       Access: -32744
+# MGOT-NEXT:       Initial: 0x80000000
+# MGOT-NEXT:       Purpose: Module pointer (GNU extension)
+# MGOT-NEXT:     }
+# MGOT-NEXT:   ]
+# MGOT-NEXT:   Local entries [
+# MGOT-NEXT:     Entry {
+# MGOT-NEXT:       Address:
+# MGOT-NEXT:       Access: -32736
+# MGOT-NEXT:       Initial: 0x20020
+# MGOT-NEXT:     }
+# MGOT-NEXT:   ]
+# MGOT-NEXT:   Global entries [
+# MGOT-NEXT:   ]
+# MGOT-NEXT:   Number of TLS and multi-GOT entries: 1
+# MGOT-NEXT: }
+
+  .text
+  .global foo2
+foo2:
+  ld $2, %got_disp(local2)($gp)
+
+  .bss
+local2:
+  .word 0