RISC-V: Allow pcrel_lo addends, error on addend overflow.

	bfd/
	* elfnn-riscv.c (riscv_resolve_pcrel_lo_relocs): Add check for reloc
	overflow with addend.  Use reloc_dangerous instead of reloc_overflow.
	Add strings for the two errors handled here.
	(riscv_elf_relocate_section) In case R_RISCV_PCREL_LO12_I, rewrite
	comment.  Only give error with addend when used with section symbol.
	In case bfd_reloc_dangerous, update error string.

	ld/
	* testsuite/ld-riscv-elf/ld-riscv-elf.exp: Run pcrel-lo-addend-2.
	* testsuite/ld-riscv/elf/ld-riscv-elf/pcrel-lo-addend-2.d: New.
	* testsuite/ld-riscv/elf/ld-riscv-elf/pcrel-lo-addend-2.s: New.
	* testsuite/ld-riscv/elf/ld-riscv-elf/pcrel-lo-addend.d: Update name
	and error string.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 382df33..d14cca0 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,12 @@
+2018-09-24  Jim Wilson  <jimw@sifive.com>
+
+       * elfnn-riscv.c (riscv_resolve_pcrel_lo_relocs): Add check for reloc
+       overflow with addend.  Use reloc_dangerous instead of reloc_overflow.
+       Add strings for the two errors handled here.
+       (riscv_elf_relocate_section) In case R_RISCV_PCREL_LO12_I, rewrite
+       comment.  Only give error with addend when used with section symbol.
+       In case bfd_reloc_dangerous, update error string.
+
 2018-09-24  Jozef Lawrynowicz  <jozef.l@mittosystems.com>
 
        PR gdb/20948

diff --git a/bfd/elfnn-riscv.c b/bfd/elfnn-riscv.c
index 4be3ece..63ff07e 100644 (file)
--- a/bfd/elfnn-riscv.c
+++ b/bfd/elfnn-riscv.c
@@ -1651,11 +1651,16 @@ riscv_resolve_pcrel_lo_relocs (riscv_pcrel_relocs *p)
 
       riscv_pcrel_hi_reloc search = {r->addr, 0};
       riscv_pcrel_hi_reloc *entry = htab_find (p->hi_relocs, &search);
-      if (entry == NULL)
+      if (entry == NULL
+         /* Check for overflow into bit 11 when adding reloc addend.  */
+         || (! (entry->value & 0x800)
+             && ((entry->value + r->reloc->r_addend) & 0x800)))
        {
-         ((*r->info->callbacks->reloc_overflow)
-          (r->info, NULL, r->name, r->howto->name, (bfd_vma) 0,
-           input_bfd, r->input_section, r->reloc->r_offset));
+         char *string = (entry == NULL
+                         ? "%pcrel_lo missing matching %pcrel_hi"
+                         : "%pcrel_lo overflow with an addend");
+         (*r->info->callbacks->reloc_dangerous)
+           (r->info, string, input_bfd, r->input_section, r->reloc->r_offset);
          return TRUE;
        }
 
@@ -2026,11 +2031,12 @@ riscv_elf_relocate_section (bfd *output_bfd,
 
        case R_RISCV_PCREL_LO12_I:
        case R_RISCV_PCREL_LO12_S:
-         /* Addends are not allowed, because then riscv_relax_delete_bytes
-            would have to search through all relocs to update the addends.
-            Also, riscv_resolve_pcrel_lo_relocs does not support addends
-            when searching for a matching hi reloc.  */
-         if (rel->r_addend)
+         /* We don't allow section symbols plus addends as the auipc address,
+            because then riscv_relax_delete_bytes would have to search through
+            all relocs to update these addends.  This is also ambiguous, as
+            we do allow offsets to be added to the target address, which are
+            not to be used to find the auipc address.  */
+         if ((ELF_ST_TYPE (sym->st_info) == STT_SECTION) && rel->r_addend)
            {
              r = bfd_reloc_dangerous;
              break;
@@ -2288,8 +2294,8 @@ riscv_elf_relocate_section (bfd *output_bfd,
 
        case bfd_reloc_dangerous:
          info->callbacks->reloc_dangerous
-           (info, "%pcrel_lo with addend", input_bfd, input_section,
-            rel->r_offset);
+           (info, "%pcrel_lo section symbol with an addend", input_bfd,
+            input_section, rel->r_offset);
          break;
 
        default:

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 466c80a..9cdf22d 100644 (file)
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,11 @@
+2018-09-24  Jim Wilson  <jimw@sifive.com>
+
+       * testsuite/ld-riscv-elf/ld-riscv-elf.exp: Run pcrel-lo-addend-2.
+       * testsuite/ld-riscv/elf/ld-riscv-elf/pcrel-lo-addend-2.d: New.
+       * testsuite/ld-riscv/elf/ld-riscv-elf/pcrel-lo-addend-2.s: New.
+       * testsuite/ld-riscv/elf/ld-riscv-elf/pcrel-lo-addend.d: Update name
+       and error string.
+
 2018-09-21  Alan Modra  <amodra@gmail.com>
 
        * testsuite/ld-avr/gc-section-debugline.d: Update.

diff --git a/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp b/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
index c06b618..071f3a2 100644 (file)
--- a/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
+++ b/ld/testsuite/ld-riscv-elf/ld-riscv-elf.exp
@@ -23,6 +23,7 @@ if [istarget "riscv*-*-*"] {
     run_dump_test "c-lui"
     run_dump_test "disas-jalr"
     run_dump_test "pcrel-lo-addend"
+    run_dump_test "pcrel-lo-addend-2"
     run_ld_link_tests {
        { "Weak reference 32" "-T weakref.ld -melf32lriscv" ""
            "-march=rv32i -mabi=ilp32" {weakref32.s}

diff --git a/ld/testsuite/ld-riscv-elf/pcrel-lo-addend-2.d b/ld/testsuite/ld-riscv-elf/pcrel-lo-addend-2.d
new file mode 100644 (file)
index 0000000..9e94c5c
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/pcrel-lo-addend-2.d
@@ -0,0 +1,5 @@
+#name: %pcrel_lo overflow with an addend
+#source: pcrel-lo-addend-2.s
+#as: -march=rv32ic
+#ld: -melf32lriscv
+#error: .*dangerous relocation: %pcrel_lo overflow with an addend

diff --git a/ld/testsuite/ld-riscv-elf/pcrel-lo-addend-2.s b/ld/testsuite/ld-riscv-elf/pcrel-lo-addend-2.s
new file mode 100644 (file)
index 0000000..b7f8212
--- /dev/null
+++ b/ld/testsuite/ld-riscv-elf/pcrel-lo-addend-2.s
@@ -0,0 +1,16 @@
+       .text
+       .globl _start
+       .align 3
+_start:
+       nop
+       .LA0: auipc     a5,%pcrel_hi(ll)
+       lw      a0,%pcrel_lo(.LA0)(a5)
+       lw      a0,%pcrel_lo(.LA0+4)(a5)
+       ret
+       .globl ll
+       .data
+       .align 3
+       .zero 2024
+ll:
+       .word 0
+       .word 0

diff --git a/ld/testsuite/ld-riscv-elf/pcrel-lo-addend.d b/ld/testsuite/ld-riscv-elf/pcrel-lo-addend.d
index bd61b4b..ad658be 100644 (file)
--- a/ld/testsuite/ld-riscv-elf/pcrel-lo-addend.d
+++ b/ld/testsuite/ld-riscv-elf/pcrel-lo-addend.d
@@ -1,5 +1,5 @@
-#name: %pcrel_lo with an addend
+#name: %pcrel_lo section symbol with an addend
 #source: pcrel-lo-addend.s
 #as: -march=rv32ic
 #ld: -melf32lriscv
-#error: .*dangerous relocation: %pcrel_lo with addend
+#error: .*dangerous relocation: %pcrel_lo section symbol with an addend