[v2,3/4] or1k: Avoid R_OR1K_GOT16 overflow failures in presence of R_OR1K_GOT_AHI16

Message ID 20210501210217.2975268-4-shorne@gmail.com
State New
Headers show
Series
  • OpenRISC large binary fixes
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Commit Message

Luis Machado via Binutils May 1, 2021, 9:02 p.m.
Now that we support R_OR1K_GOT_AHI16 we can relax the R_OR1K_GOT16
overflow validation check if the section has R_OR1K_GOT_AHI16.

We cannot simple disable R_OR1K_GOT16 overflow validation as there will
still be binaries that will have only R_OR1K_GOT16.  The
R_OR1K_GOT_AHI16 relocation will only be added by GCC when building with
the option -mcmodel=large.

This assumes that R_OR1K_GOT_AHI16 will come before R_OR1K_GOT16, which
is the code pattern that will be emitted by GCC.

bfd/ChangeLog:

	PR 21464
	* elf32-or1k.c (or1k_elf_relocate_section): Relax R_OR1K_GOT16
	overflow check if we have R_OR1K_GOT_AHI16 followed by
	R_OR1K_GOT16.
---
 bfd/elf32-or1k.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

-- 
2.26.2

Patch

diff --git a/bfd/elf32-or1k.c b/bfd/elf32-or1k.c
index 1b8938df37f..5eca4300c45 100644
--- a/bfd/elf32-or1k.c
+++ b/bfd/elf32-or1k.c
@@ -1278,6 +1278,7 @@  or1k_elf_relocate_section (bfd *output_bfd,
   asection *sgot, *splt;
   bfd_vma plt_base, got_base, got_sym_value;
   bool ret_val = true;
+  bool saw_gotha = false;
 
   if (htab == NULL)
     return false;
@@ -1485,6 +1486,16 @@  or1k_elf_relocate_section (bfd *output_bfd,
 		|| r_type == R_OR1K_GOT_AHI16)
 	      relocation -= got_sym_value;
 
+	    if (r_type == R_OR1K_GOT_AHI16)
+	      saw_gotha = true;
+
+	    /* If we have a R_OR1K_GOT16 followed by a R_OR1K_GOT_AHI16
+	       relocation we assume the code is doing the right thing to avoid
+	       overflows.  Here we mask the lower 16-bit of the relocation to
+	       avoid overflow validation failures.  */
+	    if (r_type == R_OR1K_GOT16 && saw_gotha)
+	      relocation &= 0xffff;
+
 	  /* Addend should be zero.  */
 	  if (rel->r_addend != 0)
 	    {