[PATCH] D71517: [ELF][PPC64] Fix IPLT entry in .glink

[Fangrui Song via Phabricator via llvm-commits]

MaskRay created this revision.
Herald added subscribers: llvm-commits, jsji, kbarton, arichardson, nemanjai, emaste.
Herald added a reviewer: espindola.
Herald added a project: LLVM.

Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D71517

Files:
  lld/ELF/Arch/PPC64.cpp
  lld/ELF/SyntheticSections.cpp


Index: lld/ELF/SyntheticSections.cpp
===================================================================
--- lld/ELF/SyntheticSections.cpp
+++ lld/ELF/SyntheticSections.cpp
@@ -2481,7 +2481,8 @@
     unsigned relOff = relSec->entsize * i + pltOff;
     uint64_t got = b->getGotPltVA();
     uint64_t plt = this->getVA() + off;
-    target->writePlt(buf + off, got, plt, b->pltIndex, relOff);
+    int index = isIplt ? -1 : (int)b->pltIndex;
+    target->writePlt(buf + off, got, plt, index, relOff);
     off += target->pltEntrySize;
   }
 }
@@ -2492,6 +2493,8 @@
 }
 
 size_t PltSection::getSize() const {
+  if (config->emachine == EM_PPC64 && isIplt)
+    return entries.size() * 16;
   return headerSize + entries.size() * target->pltEntrySize;
 }
 
Index: lld/ELF/Arch/PPC64.cpp
===================================================================
--- lld/ELF/Arch/PPC64.cpp
+++ lld/ELF/Arch/PPC64.cpp
@@ -671,9 +671,20 @@
 void PPC64::writePlt(uint8_t *buf, uint64_t gotPltEntryAddr,
                      uint64_t pltEntryAddr, int32_t index,
                      unsigned relOff) const {
-  int32_t offset = pltHeaderSize + index * pltEntrySize;
-  // bl __glink_PLTresolve
-  write32(buf, 0x48000000 | ((-offset) & 0x03FFFFFc));
+  if (index < 0) {
+    int64_t offset = gotPltEntryAddr - getPPC64TocBase();
+    uint16_t offHa = (offset + 0x8000) >> 16;
+    uint16_t offLo = offset & 0xffff;
+
+    write32(buf + 0, 0x3d820000 | offHa); // addis r12, r2, OffHa
+    write32(buf + 4, 0xe98c0000 | offLo); // ld    r12, OffLo(r12)
+    write32(buf + 8, 0x7d8903a6);         // mtctr r12
+    write32(buf + 12, 0x4e800420);        // bctr
+  } else {
+    int32_t offset = pltHeaderSize + index * pltEntrySize;
+    // bl __glink_PLTresolve
+    write32(buf, 0x48000000 | ((-offset) & 0x03FFFFFc));
+  }
 }
 
 static std::pair<RelType, uint64_t> toAddr16Rel(RelType type, uint64_t val) {


-------------- next part --------------
A non-text attachment was scrubbed...
Name: D71517.233943.patch
Type: text/x-patch
Size: 1896 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20191214/ad32f96e/attachment.bin>