Fix PR gdb/20948: --write option to GDB causes segmentation fault

[deliverable/binutils-gdb.git] / bfd / elf64-s390.c

diff --git a/bfd/elf64-s390.c b/bfd/elf64-s390.c
index 16a62a3d7c8cb038a3e5e49c8ee1b70098af1702..c2a2955b36bc521d68ec68353acb6f973cc09e09 100644 (file)
--- a/bfd/elf64-s390.c
+++ b/bfd/elf64-s390.c
@@ -2341,6 +2341,9 @@ elf_s390_relocate_section (bfd *output_bfd,
                           && SYMBOL_REFERENCES_LOCAL (info, h))
                       || resolved_to_zero)
                {
+                 Elf_Internal_Sym *isym;
+                 asection *sym_sec;
+
                  /* This is actually a static link, or it is a
                     -Bsymbolic link and the symbol is defined
                     locally, or the symbol was forced to be local
@@ -2362,6 +2365,10 @@ elf_s390_relocate_section (bfd *output_bfd,
                      h->got.offset |= 1;
                    }
 
+                 /* When turning a GOT slot dereference into a direct
+                    reference using larl we have to make sure that
+                    the symbol is 1. properly aligned and 2. it is no
+                    ABS symbol or will become one.  */
                  if ((h->def_regular
                       && bfd_link_pic (info)
                       && SYMBOL_REFERENCES_LOCAL (info, h))
@@ -2376,8 +2383,17 @@ elf_s390_relocate_section (bfd *output_bfd,
                                              contents + rel->r_offset - 2)
                                  & 0xff00f000) == 0xe300c000
                              && bfd_get_8 (input_bfd,
-                                           contents + rel->r_offset + 3) == 0x04)))
-
+                                           contents + rel->r_offset + 3) == 0x04))
+                     && (isym = bfd_sym_from_r_symndx (&htab->sym_cache,
+                                                       input_bfd, r_symndx))
+                     && isym->st_shndx != SHN_ABS
+                     && h != htab->elf.hdynamic
+                     && h != htab->elf.hgot
+                     && h != htab->elf.hplt
+                     && !(isym->st_value & 1)
+                     && (sym_sec = bfd_section_from_elf_index (input_bfd,
+                                                               isym->st_shndx))
+                     && sym_sec->alignment_power)
                    {
                      unsigned short new_insn =
                        (0xc000 | (bfd_get_8 (input_bfd,
@@ -3787,7 +3803,7 @@ elf_s390_write_core_note (bfd *abfd, char *buf, int *bufsiz,
        strncpy (data + 40, fname, 16);
 #if GCC_VERSION == 8000 || GCC_VERSION == 8001
        DIAGNOSTIC_PUSH;
-       /* GCC 8.1 warns about 80 equals destination size with
+       /* GCC 8.0 and 8.1 warn about 80 equals destination size with
           -Wstringop-truncation:
           https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85643
         */