IBM zSystems: Issue error for *DBL relocs on misaligned symbols

Relocs like PC32DBL require a right shift of the symbol value.  There
is no situation where dropping symbol value bits with the right shift
is a good thing.  Hence we now issue an error to detect such problems.

diff --git a/bfd/elf64-s390.c b/bfd/elf64-s390.c
index c1ed3d619d6661866634b8c90b1c09006c571883..fa4497181feb6229097ba325da65c6644c31654e 100644 (file)
--- a/bfd/elf64-s390.c
+++ b/bfd/elf64-s390.c
@@ -3056,6 +3056,24 @@ elf_s390_relocate_section (bfd *output_bfd,
          || r_type == R_390_PLT24DBL)
        rel->r_offset--;
 
+      /* Issue an error if the right shift implied by the relocation
+        would drop bits from the symbol value.  */
+      if (howto->rightshift
+         && (relocation & (((bfd_vma)1 << howto->rightshift) - 1)))
+       {
+         _bfd_error_handler
+           /* xgettext:c-format */
+           (_("%pB(%pA+%#" PRIx64 "): "
+              "misaligned symbol `%s' (%#" PRIx64 ") for relocation %s"),
+            input_bfd,
+            input_section,
+            (uint64_t) rel->r_offset,
+            h->root.root.string,
+            (uint64_t)relocation,
+            howto->name);
+         return false;
+       }
+
       if (r_type == R_390_20
          || r_type == R_390_GOT20
          || r_type == R_390_GOTPLT20

diff --git a/ld/testsuite/ld-s390/reloccheck-1.d b/ld/testsuite/ld-s390/reloccheck-1.d
new file mode 100644 (file)
index 0000000..4696dcb
--- /dev/null
+++ b/ld/testsuite/ld-s390/reloccheck-1.d
@@ -0,0 +1,3 @@
+#as: -m64 -mzarch -march=z900
+#ld: -m elf64_s390 -e start -static
+#error: .*misaligned symbol.*

diff --git a/ld/testsuite/ld-s390/reloccheck-1.s b/ld/testsuite/ld-s390/reloccheck-1.s
new file mode 100644 (file)
index 0000000..6c932bd
--- /dev/null
+++ b/ld/testsuite/ld-s390/reloccheck-1.s
@@ -0,0 +1,14 @@
+        .machinemode zarch
+        .machine "z900"
+.text
+        .align  8
+.globl start
+        .type   start, @function
+start:
+       larl    %r1, test
+.globl test
+.data
+       .align  4
+       .byte   23
+test:
+       .zero   4