[AArch64] Fix off by one error in instruction relaxation mask.

The AArch64 TLSDESC to IE relaxation code uses a bit mask intended to
ensure that destination register in a relaxed ldr instruction is
always X0.  The mask has an off by one error resulting in the most
significant bit of the destination register being retained in the
relaxed instruction.  The issue generally appears when the compiler
emits TLS accesses code under high register pressure resulting in a
broken code sequence.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 93314775b468a51ff708044d8fb9c10ad91227bd..55d4828cc6a8866b83cf9b54c847c065af958b93 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,7 @@
+2014-04-15  Marcus Shawcroft  <marcus.shawcroft@arm.com>
+
+       * (elfNN_aarch64_tls_relax): Fix instruction mask.
+
 2014-04-14  Alan Modra  <amodra@gmail.com>
 
        * elf32-ppc.c (BA): Define

diff --git a/bfd/elfnn-aarch64.c b/bfd/elfnn-aarch64.c
index 638938d880a419fd5ffa4f31275ac1c2e2196f22..a251698d9d8cfeab7da2b3d72b83c84ee6c156f2 100644 (file)
--- a/bfd/elfnn-aarch64.c
+++ b/bfd/elfnn-aarch64.c
@@ -3957,7 +3957,7 @@ elfNN_aarch64_tls_relax (struct elf_aarch64_link_hash_table *globals,
             ldr xd, [x0, #:tlsdesc_lo12:var] => ldr x0, [x0, #:gottprel_lo12:var]
           */
          insn = bfd_getl32 (contents + rel->r_offset);
-         insn &= 0xfffffff0;
+         insn &= 0xffffffe0;
          bfd_putl32 (insn, contents + rel->r_offset);
          return bfd_reloc_continue;
        }

diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index e239ce8d7b4f83da02672a21c63d0731c0d6cb50..ae0fa8952954c94cfff4b3b5e4ceaa7387948a52 100644 (file)
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2014-04-15  Marcus Shawcroft  <marcus.shawcroft@arm.com>
+
+       * ld-aarch64/tls-relax-gdesc-ie.s (var): Adjust test case
+       to include all 5 bits of LDR destination register.
+
 2014-04-10  Senthil Kumar Selvaraj  <senthil_kumar.selvaraj@atmel.com>
 
        * ld-avr/norelax_diff.d: New testcase.

diff --git a/ld/testsuite/ld-aarch64/tls-relax-gdesc-ie.s b/ld/testsuite/ld-aarch64/tls-relax-gdesc-ie.s
index c20690c117c1f395da68e99c2c8c7012b503e928..38b372132f49c926be8d6527bce9d203b794a4b5 100644 (file)
--- a/ld/testsuite/ld-aarch64/tls-relax-gdesc-ie.s
+++ b/ld/testsuite/ld-aarch64/tls-relax-gdesc-ie.s
@@ -4,7 +4,7 @@ var:
        .word   2
        .text
        adrp    x0, :tlsdesc:var
-       ldr     x1, [x0, #:tlsdesc_lo12:var]
+       ldr     x17, [x0, #:tlsdesc_lo12:var]
        add     x0, x0, :tlsdesc_lo12:var
        .tlsdesccall    var
        blr     x1