LoongArch: Fix linker generate PLT entry for data symbol

With old "medium" code model, we call a function with a pair of PCALAU12I
and JIRL instructions. The assembler produces something like:

   8:	1a00000c 	pcalau12i   	$t0, 0
			8: R_LARCH_PCALA_HI20	g
   c:	4c000181 	jirl        	$ra, $t0, 0
			c: R_LARCH_PCALA_LO12	g

The linker generates a "PLT entry" for data without any diagnostic.
If "g" is a data symbol and ld with -shared option, it may load two
instructions in the PLT.

Without -shared option, loongarch_elf_adjust_dynamic_symbol can delete PLT
entry.

For R_LARCH_PCALA_HI20 relocation, linker only generate PLT entry for STT_FUNC
and STT_GNU_IFUNC symbols.

diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
index add916e..2a79e00 100644 (file)
--- a/bfd/elfnn-loongarch.c
+++ b/bfd/elfnn-loongarch.c
@@ -891,8 +891,12 @@ loongarch_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
            h->non_got_ref = 1;
          break;
 
+       /* For normal cmodel, pcalau12i + addi.d/w used to data.
+          For first version medium cmodel, pcalau12i + jirl are used to
+          function call, it need to creat PLT entry for STT_FUNC and
+          STT_GNU_IFUNC type symbol.  */
        case R_LARCH_PCALA_HI20:
-         if (h != NULL)
+         if (h != NULL && (STT_FUNC == h->type || STT_GNU_IFUNC == h->type))
            {
              /* For pcalau12i + jirl.  */
              h->needs_plt = 1;

diff --git a/ld/testsuite/ld-loongarch-elf/data-plt.s b/ld/testsuite/ld-loongarch-elf/data-plt.s
new file mode 100644 (file)
index 0000000..faff052
--- /dev/null
+++ b/ld/testsuite/ld-loongarch-elf/data-plt.s
@@ -0,0 +1,20 @@
+# The first version medium codel model function call is: pcalau12i + jirl.
+# R_LARCH_PCALA_HI20 only need to generate PLT entry for function symbols.
+       .text
+       .globl  a
+
+       .data
+       .align  2
+       .type   a, @object
+       .size   a, 4
+a:
+       .word   1
+
+       .text
+       .align  2
+       .globl  test
+       .type   test, @function
+test:
+       pcalau12i       $r12,%pc_hi20(a)
+       ld.w    $r12,$r12,%pc_lo12(a)
+       .size   test, .-test

diff --git a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
index 8dc04fe..64e644d 100644 (file)
--- a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
+++ b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
@@ -59,6 +59,30 @@ if [istarget "loongarch64-*-*"] {
        ]
   }
 
+  # loongarch*-elf target do not support -shared option
+  if [check_shared_lib_support] {
+    run_ld_link_tests \
+       [list \
+            [list \
+                 "data plt" \
+                 "-shared" "" \
+                 "" \
+                 {data-plt.s} \
+                 {} \
+                 "data-plt.so" \
+            ] \
+       ]
+
+    if [file exist "tmpdir/data-plt.so"] {
+      set objdump_output [run_host_cmd "objdump" "-d tmpdir/data-plt.so"]
+      if { [ regexp "<a@plt>" $objdump_output] } {
+       fail "data plt"
+      } {
+       pass "data plt"
+      }
+    }
+  }
+
   run_ld_link_tests \
       [list \
          [list \

diff --git a/ld/testsuite/ld-loongarch-elf/libjirl.s b/ld/testsuite/ld-loongarch-elf/libjirl.s
index 4d96387..de028c5 100644 (file)
--- a/ld/testsuite/ld-loongarch-elf/libjirl.s
+++ b/ld/testsuite/ld-loongarch-elf/libjirl.s
@@ -1,2 +1,3 @@
+.type func @function
 pcalau12i $r12, %pc_hi20(func)
 jirl $r1,$r12, %pc_lo12(func)