Create a PLT entry for R_X86_64_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
	* elf64-x86-64.c (elf_x86_64_check_relocs): Set
	pointer_equality_needed for R_X86_64_PC32 reloc in non-code
	sections.

ld/testsuite/

	PR ld/19031
	* ld-x86-64/x86-64.exp: Run PR ld/19031 test.
	* ld-x86-64/pr19031.out: New file.
	* ld-x86-64/pr19031a.c: Likewise.
	* ld-x86-64/pr19031b.S: Likewise.
	* ld-x86-64/pr19031c.c: Likewise.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 55cfa5334b02c919e1247bb8ec9effb56ad13af5..c4312c8281af13a910764a1b65aa12cd3f524129 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,10 @@
+2015-10-01  H.J. Lu  <hongjiu.lu@intel.com>
+
+       PR ld/19031
+       * elf64-x86-64.c (elf_x86_64_check_relocs): Set
+       pointer_equality_needed for R_X86_64_PC32 reloc in non-code
+       sections.
+
 2015-10-01  Renlin Li  <renlin.li@arm.com>
 
        * elfnn-aarch64.c (elfNN_aarch64_output_plt_map): Remove.

diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index cbb8cfb348431791a8fed0632832736cb4dd37a9..29639d81d53238885c3c559c22cb49611424f14f 100644 (file)
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -1961,9 +1961,16 @@ pointer:
              /* 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_X86_64_PC32
-                 && r_type != R_X86_64_PC32_BND
-                 && r_type != R_X86_64_PC64)
+             if (r_type == R_X86_64_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 if (r_type != R_X86_64_PC32_BND
+                      && r_type != R_X86_64_PC64)
                {
                  h->pointer_equality_needed = 1;
                  /* At run-time, R_X86_64_64 can be resolved for both

diff --git a/ld/testsuite/ChangeLog b/ld/testsuite/ChangeLog
index fdf4b3c21e2e9b432875e279e23e19b8b5a79b95..41be8cd9c7a2d237875520597269fecd87732d49 100644 (file)
--- a/ld/testsuite/ChangeLog
+++ b/ld/testsuite/ChangeLog
@@ -1,3 +1,12 @@
+2015-10-01  H.J. Lu  <hongjiu.lu@intel.com>
+
+       PR ld/19031
+       * ld-x86-64/x86-64.exp: Run PR ld/19031 test.
+       * ld-x86-64/pr19031.out: New file.
+       * ld-x86-64/pr19031a.c: Likewise.
+       * ld-x86-64/pr19031b.S: Likewise.
+       * ld-x86-64/pr19031c.c: Likewise.
+
 2015-10-01  Renlin Li  <renlin.li@arm.com>
 
        * ld-aarch64/aarch64-elf.exp: Run the new test.
@@ -17,10 +26,10 @@
 
        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.
+       * ld-i386/pr19031.out: New file.
+       * ld-i386/pr19031a.c: Likewise.
+       * ld-i386/pr19031b.S: Likewise.
+       * ld-i386/pr19031c.c: Likewise.
 
 2015-09-30  H.J. Lu  <hongjiu.lu@intel.com>
 

diff --git a/ld/testsuite/ld-x86-64/pr19031.out b/ld/testsuite/ld-x86-64/pr19031.out
new file mode 100644 (file)
index 0000000..d86bac9
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19031.out
@@ -0,0 +1 @@
+OK

diff --git a/ld/testsuite/ld-x86-64/pr19031a.c b/ld/testsuite/ld-x86-64/pr19031a.c
new file mode 100644 (file)
index 0000000..fa34d37
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19031a.c
@@ -0,0 +1,4 @@
+void
+f (void)
+{
+}

diff --git a/ld/testsuite/ld-x86-64/pr19031b.S b/ld/testsuite/ld-x86-64/pr19031b.S
new file mode 100644 (file)
index 0000000..ccc9125
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr19031b.S
@@ -0,0 +1,18 @@
+       .text
+       .globl g
+       .type g, @function
+g:
+       movq f@GOTPCREL(%rip), %rax
+       retq
+
+       .globl h
+       .type h, @function
+h:
+       leaq zed, %rax
+       movslq zed, %rbx
+       addq %rbx, %rax
+       retq
+
+       .data
+zed:
+        .long f - .

diff --git a/ld/testsuite/ld-x86-64/pr19031c.c b/ld/testsuite/ld-x86-64/pr19031c.c
new file mode 100644 (file)
index 0000000..60eccaf
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/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;
+}

diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index 5de67caa2da57c4731e14c4a8b344d777f0b8eb5..69728c22754434e25cf8f6ec4c1ee6a703e44d73 100644 (file)
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -503,6 +503,14 @@ if { [isnative] && [which $CC] != 0 } {
            {{readelf {-Wrd} pr18900b.rd}} \
            "pr18900b" \
        ] \
+       [list \
+           "Build pr19031.so" \
+           "-shared" \
+           "-fPIC" \
+           { pr19031a.c } \
+           "" \
+           "pr19031.so" \
+       ] \
     ]
 
     run_ld_link_exec_tests [] [list \
@@ -557,6 +565,14 @@ if { [isnative] && [which $CC] != 0 } {
            "pr18900" \
            "pr18900.out" \
        ] \
+       [list \
+           "Run pr19031" \
+           "tmpdir/pr19031.so" \
+           "" \
+           { pr19031b.S pr19031c.c } \
+           "pr19031" \
+           "pr19031.out" \
+       ] \
     ]
 
     if { [istarget "x86_64-*-linux*"] \