[PPC64] Add offset to local entry point when calling functions without plt

PPC64 V2 ABI describes two entry points to a function. The global entry point
sets up the TOC base pointer. When calling a local function, the call should
branch to the local entry point rather than the global entry point.
Section 3.4.1 describes using the 3 most significant bits of the st_other
field to find out how many instructions there are between the local and global
entry point. This patch adds the correct offset required to branch to the local
entry point of a function.

Differential Revision: https://reviews.llvm.org/D45729

1 files changed, 12 insertions, 1 deletions

diff --git a/lld/ELF/InputSection.cpp b/lld/ELF/InputSection.cpp
index 4717914d914..871832a4ef7 100644
--- a/lld/ELF/InputSection.cpp
+++ b/lld/ELF/InputSection.cpp
@@ -584,7 +584,18 @@ static uint64_t getRelocTargetVA(RelType Type, int64_t A, uint64_t P,
       if (InOpd)
         SymVA = read64be(&Out::OpdBuf[SymVA - OpdStart]);
     }
-    return SymVA - P;
+
+    // PPC64 V2 ABI describes two entry points to a function. The global entry
+    // point sets up the TOC base pointer. When calling a local function, the
+    // call should branch to the local entry point rather than the global entry
+    // point. Section 3.4.1 describes using the 3 most significant bits of the
+    // st_other field to find out how many instructions there are between the
+    // local and global entry point.
+    uint8_t StOther = (Sym.StOther >> 5) & 7;
+    if (StOther == 0 || StOther == 1)
+      return SymVA - P;
+
+    return SymVA - P + (1 << StOther);
   }
   case R_PPC_TOC:
     return getPPC64TocBase() + A;