[Git][ghc/ghc][wip/supersven/riscv64-ncg] Fix linker issue

[Sven Tennie (@supersven)]

Sven Tennie pushed to branch wip/supersven/riscv64-ncg at Glasgow Haskell Compiler / GHC


Commits:
1bb2fd79 by Sven Tennie at 2024-04-12T07:26:50+00:00
Fix linker issue

Local symbols don't get GOT entries. Fake them with extra symbols instead. Such that R_RISCV_CALL_PLT has an address to load and jump to.

- - - - -


1 changed file:

- rts/linker/elf_reloc_riscv64.c


Changes:

=====================================
rts/linker/elf_reloc_riscv64.c
=====================================
@@ -454,9 +454,23 @@ int32_t computeAddend(ElfRelocationATable * relaTab, unsigned relNo, Elf_Rel *re
     return S + A - P;
   case R_RISCV_CALL:
   case R_RISCV_CALL_PLT: {
+    addr_t GOT_Target;
+    if (GOT_S != 0) {
+      // 1. Public symbol with GOT entry.
+      GOT_Target = GOT_S;
+    } else {
+      // 2. Fake GOT entry with symbol extra entry.
+      SymbolExtra *symbolExtra = makeSymbolExtra(oc, ELF_R_SYM(rel->r_info), S);
+      addr_t* FAKE_GOT_S = &symbolExtra->addr;
+      IF_DEBUG(linker, debugBelch("R_RISCV_CALL_PLT w/ SymbolExtra = %p , "
+                                  "entry = 0x%lx\n",
+                                  symbolExtra, FAKE_GOT_S));
+      GOT_Target = FAKE_GOT_S;
+    }
+
     if (findStub(section, (void **)&S, 0)) {
       /* did not find it. Crete a new stub. */
-      if (makeStub(section, (void **)&S, (void *)GOT_S, 0)) {
+      if (makeStub(section, (void **)&S, (void *)GOT_Target, 0)) {
         abort(/* could not find or make stub */);
       }
     }



View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1bb2fd798f14a6a8f06d3193eadebaf102469d83

-- 
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/commit/1bb2fd798f14a6a8f06d3193eadebaf102469d83
You're receiving this email because of your account on gitlab.haskell.org.


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/ghc-commits/attachments/20240412/df748a87/attachment-0001.html>