Create a PLT entry for R_386_PC32 in non-code sections

Since something like ".long foo - ." may be used as pointer, we make
sure that PLT is used if foo is a function defined in a shared library.

bfd/

	PR ld/19031
	* elf32-i386.c (elf_i386_check_relocs): Set
	pointer_equality_needed for R_386_PC32 reloc in non-code
	sections.

ld/testsuite/

	PR ld/19031
	* ld-i386/i386.exp: Run PR ld/19031 test.
	* ld/testsuite/ld-i386/pr19031.out: New file.
	* ld/testsuite/ld-i386/pr19031a.c: Likewise.
	* ld/testsuite/ld-i386/pr19031b.S: Likewise.
	* ld/testsuite/ld-i386/pr19031c.c: Likewise.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index a218d44..3610948 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,5 +1,12 @@
 2015-09-30  H.J. Lu  <hongjiu.lu@intel.com>
 
+       PR ld/19031
+       * elf32-i386.c (elf_i386_check_relocs): Set
+       pointer_equality_needed for R_386_PC32 reloc in non-code
+       sections.
+
+2015-09-30  H.J. Lu  <hongjiu.lu@intel.com>
+
        PR ld/19013
        * elflink.c (_bfd_elf_merge_sections): Only merge input bfds
        that have the compatible ELF machine code with the output bfd.

diff --git a/bfd/elf32-i386.c b/bfd/elf32-i386.c
index 9390450..0a06191 100644 (file)
--- a/bfd/elf32-i386.c
+++ b/bfd/elf32-i386.c
@@ -1772,7 +1772,15 @@ elf_i386_check_relocs (bfd *abfd,
              /* We may need a .plt entry if the function this reloc
                 refers to is in a shared lib.  */
              h->plt.refcount += 1;
-             if (r_type != R_386_PC32)
+             if (r_type == R_386_PC32)
+               {
+                 /* Since something like ".long foo - ." may be used
+                    as pointer, make sure that PLT is used if foo is
+                    a function defined in a shared library.  */
+                 if ((sec->flags & SEC_CODE) == 0)
+                   h->pointer_equality_needed = 1;
+               }
+             else
                {
                  h->pointer_equality_needed = 1;
                  /* R_386_32 can be resolved at run-time.  */

diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index 7f1b7ac..9c77301 100644 (file)
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,5 +1,14 @@
 2015-09-30  H.J. Lu  <hongjiu.lu@intel.com>
 
+       PR ld/19031
+       * ld-i386/i386.exp: Run PR ld/19031 test.
+       * ld/testsuite/ld-i386/pr19031.out: New file.
+       * ld/testsuite/ld-i386/pr19031a.c: Likewise.
+       * ld/testsuite/ld-i386/pr19031b.S: Likewise.
+       * ld/testsuite/ld-i386/pr19031c.c: Likewise.
+
+2015-09-30  H.J. Lu  <hongjiu.lu@intel.com>
+
        PR ld/19013
        * ld-x86-64/pr19013-nacl.d: New file.
        * ld-x86-64/pr19013-x32.d: Likewise.

diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp
index 6213dbe..8cddfce 100644 (file)
--- a/ld/testsuite/ld-i386/i386.exp
+++ b/ld/testsuite/ld-i386/i386.exp
@@ -490,6 +490,14 @@ if { [isnative]
            {{readelf {-Wrd} pr18900b.rd}} \
            "pr18900b" \
        ] \
+       [list \
+           "Build pr19031.so" \
+           "-shared" \
+           "-fPIC" \
+           { pr19031a.c } \
+           "" \
+           "pr19031.so" \
+       ] \
     ]
 
     run_ld_link_exec_tests [] [list \
@@ -552,6 +560,14 @@ if { [isnative]
            "pr18900" \
            "pr18900.out" \
        ] \
+       [list \
+           "Run pr19031" \
+           "tmpdir/pr19031.so" \
+           "" \
+           { pr19031b.S pr19031c.c } \
+           "pr19031" \
+           "pr19031.out" \
+       ] \
     ]
 }
 

diff --git a/ld/testsuite/ld-i386/pr19031.out b/ld/testsuite/ld-i386/pr19031.out
new file mode 100644 (file)
index 0000000..d86bac9
--- /dev/null
+++ b/ld/testsuite/ld-i386/pr19031.out
@@ -0,0 +1 @@
+OK

diff --git a/ld/testsuite/ld-i386/pr19031a.c b/ld/testsuite/ld-i386/pr19031a.c
new file mode 100644 (file)
index 0000000..fa34d37
--- /dev/null
+++ b/ld/testsuite/ld-i386/pr19031a.c
@@ -0,0 +1,4 @@
+void
+f (void)
+{
+}

diff --git a/ld/testsuite/ld-i386/pr19031b.S b/ld/testsuite/ld-i386/pr19031b.S
new file mode 100644 (file)
index 0000000..3249652
--- /dev/null
+++ b/ld/testsuite/ld-i386/pr19031b.S
@@ -0,0 +1,23 @@
+       .text
+       .globl g
+       .type g, @function
+g:
+        calll .Lfoo
+.Lfoo:
+        popl %eax
+.Lbar:
+        addl $_GLOBAL_OFFSET_TABLE_+(.Lbar-.Lfoo), %eax
+       movl f@GOT(%eax), %eax
+       ret
+
+       .globl h
+       .type h, @function
+h:
+        leal zed, %eax
+        movl zed, %ebx
+        addl %ebx, %eax
+       ret
+
+       .data
+zed:
+        .long f - .

diff --git a/ld/testsuite/ld-i386/pr19031c.c b/ld/testsuite/ld-i386/pr19031c.c
new file mode 100644 (file)
index 0000000..60eccaf
--- /dev/null
+++ b/ld/testsuite/ld-i386/pr19031c.c
@@ -0,0 +1,14 @@
+#include <stdio.h>
+
+extern void *h (void);
+extern void *g (void);
+
+int
+main (void)
+{
+
+  if (h () == g ())
+    printf ("OK\n");
+
+  return 0;
+}