From 3c3de29b048bca6b4aa4235c647b9328e71801b6 Mon Sep 17 00:00:00 2001 From: Stafford Horne Date: Thu, 6 May 2021 20:51:25 +0900 Subject: [PATCH] or1k: Avoid R_OR1K_GOT16 overflow failures in presence of R_OR1K_GOT_AHI16 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/ChangeLog | 7 +++++++ bfd/elf32-or1k.c | 11 +++++++++++ 2 files changed, 18 insertions(+) diff --git a/bfd/ChangeLog b/bfd/ChangeLog index c4a83dfe4f7..8293e9d7952 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,3 +1,10 @@ +2021-05-06 Stafford Horne + + 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. + 2021-05-06 Stafford Horne PR 21464 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) { -- 2.30.2