x86-64: Convert load to mov only for GOTPCRELX relocations

Since converting load to mov needs to rewrite the REX byte and we don't
know if there is a REX byte with GOTPCREL relocation, do it only for
GOTPCRELX relocations.

bfd/

	PR ld/27016
	* elf64-x86-64.c (elf_x86_64_convert_load_reloc): Convert load
	to mov only for GOTPCRELX relocations.

ld/

	PR ld/27016
	* testsuite/ld-x86-64/x86-64.exp: Run pr27016a and pr27016b.
	* testsuite/ld-x86-64/pr27016a.d: New file.
	* testsuite/ld-x86-64/pr27016a.s: Likewise.
	* testsuite/ld-x86-64/pr27016b.d: Likewise.
	* testsuite/ld-x86-64/pr27016b.s: Likewise.

(cherry picked from commit 7e45e7a9ab38ee904ca62ed9934e933fdb1d6e9c)

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index 2bca0948f6ea09be89dbf34e3f54fb5af5631a49..6114b73a052686bec7d11323f477cb22cf3e7edb 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,9 @@
+2020-12-04  H.J. Lu  <hongjiu.lu@intel.com>
+
+       PR ld/27016
+       * elf64-x86-64.c (elf_x86_64_convert_load_reloc): Convert load
+       to mov only for GOTPCRELX relocations.
+
 2020-10-09  Alan Modra  <amodra@gmail.com>
 
        * elf64-ppc.c (write_plt_relocs_for_local_syms): Don't do local

diff --git a/bfd/elf64-x86-64.c b/bfd/elf64-x86-64.c
index 311fb28a905df619c2538ffa6308bdeeae67eca7..7eb1afe61444a0c9b20bc2220e43bfbe8dfcae06 100644 (file)
--- a/bfd/elf64-x86-64.c
+++ b/bfd/elf64-x86-64.c
@@ -1731,7 +1731,7 @@ elf_x86_64_convert_load_reloc (bfd *abfd,
 
       if (opcode == 0x8b)
        {
-         if (abs_symbol && local_ref)
+         if (abs_symbol && local_ref && relocx)
            to_reloc_pc32 = FALSE;
 
          if (to_reloc_pc32)

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 66f6e2811004c479e89ffe4560b7dc80afa55e54..89ec0798dbe705bf1b8a9775f054fb90ff2ce60a 100644 (file)
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,12 @@
+2020-12-04  H.J. Lu  <hongjiu.lu@intel.com>
+
+       PR ld/27016
+       * testsuite/ld-x86-64/x86-64.exp: Run pr27016a and pr27016b.
+       * testsuite/ld-x86-64/pr27016a.d: New file.
+       * testsuite/ld-x86-64/pr27016a.s: Likewise.
+       * testsuite/ld-x86-64/pr27016b.d: Likewise.
+       * testsuite/ld-x86-64/pr27016b.s: Likewise.
+
 2020-11-16  H.J. Lu  <hongjiu.lu@intel.com>
 
        PR ld/26869

diff --git a/ld/testsuite/ld-x86-64/pr27016a.d b/ld/testsuite/ld-x86-64/pr27016a.d
new file mode 100644 (file)
index 0000000..13200e3
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr27016a.d
@@ -0,0 +1,23 @@
+#source: pr27016a.s
+#source: pr27016b.s
+#as: --64 -mx86-used-note=no -mrelax-relocations=no
+#ld: -m elf_x86_64 -z max-page-size=0x200000 -z noseparate-code -e main
+#objdump: -dw
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+4000e8 <main>:
+ +[a-f0-9]+:   55                      push   %rbp
+ +[a-f0-9]+:   48 89 e5                mov    %rsp,%rbp
+ +[a-f0-9]+:   4c 8d 1d 39 3f 00 00    lea    0x3f39\(%rip\),%r11        # 40402c <thesym>
+ +[a-f0-9]+:   41 8b 03                mov    \(%r11\),%eax
+ +[a-f0-9]+:   8d 50 01                lea    0x1\(%rax\),%edx
+ +[a-f0-9]+:   4c 8d 1d 2c 3f 00 00    lea    0x3f2c\(%rip\),%r11        # 40402c <thesym>
+ +[a-f0-9]+:   41 89 13                mov    %edx,\(%r11\)
+ +[a-f0-9]+:   b8 00 00 00 00          mov    \$0x0,%eax
+ +[a-f0-9]+:   5d                      pop    %rbp
+ +[a-f0-9]+:   c3                      retq   
+#pass

diff --git a/ld/testsuite/ld-x86-64/pr27016a.s b/ld/testsuite/ld-x86-64/pr27016a.s
new file mode 100644 (file)
index 0000000..b64851a
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr27016a.s
@@ -0,0 +1,23 @@
+        .text
+        .comm   global_int,4,4
+        .globl  main
+        .type   main, @function
+main:
+        .cfi_startproc
+        pushq   %rbp
+        .cfi_def_cfa_offset 16
+        .cfi_offset 6, -16
+        movq    %rsp, %rbp
+        .cfi_def_cfa_register 6
+        movq    thesym@GOTPCREL(%rip), %r11
+        movl    (%r11), %eax
+        leal    1(%rax), %edx
+        movq    thesym@GOTPCREL(%rip), %r11
+        movl    %edx, (%r11)
+        movl    $0, %eax
+        popq    %rbp
+        .cfi_def_cfa 7, 8
+        ret
+        .cfi_endproc
+        .size   main, .-main
+        .section        .note.GNU-stack,"",@progbits

diff --git a/ld/testsuite/ld-x86-64/pr27016b.d b/ld/testsuite/ld-x86-64/pr27016b.d
new file mode 100644 (file)
index 0000000..d1b144b
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr27016b.d
@@ -0,0 +1,23 @@
+#source: pr27016a.s
+#source: pr27016b.s
+#as: --64 -mx86-used-note=no -mrelax-relocations=yes
+#ld: -m elf_x86_64 -z max-page-size=0x200000 -z noseparate-code -e main
+#objdump: -dw
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+4000e8 <main>:
+ +[a-f0-9]+:   55                      push   %rbp
+ +[a-f0-9]+:   48 89 e5                mov    %rsp,%rbp
+ +[a-f0-9]+:   49 c7 c3 2c 40 40 00    mov    \$0x40402c,%r11
+ +[a-f0-9]+:   41 8b 03                mov    \(%r11\),%eax
+ +[a-f0-9]+:   8d 50 01                lea    0x1\(%rax\),%edx
+ +[a-f0-9]+:   49 c7 c3 2c 40 40 00    mov    \$0x40402c,%r11
+ +[a-f0-9]+:   41 89 13                mov    %edx,\(%r11\)
+ +[a-f0-9]+:   b8 00 00 00 00          mov    \$0x0,%eax
+ +[a-f0-9]+:   5d                      pop    %rbp
+ +[a-f0-9]+:   c3                      retq   
+#pass

diff --git a/ld/testsuite/ld-x86-64/pr27016b.s b/ld/testsuite/ld-x86-64/pr27016b.s
new file mode 100644 (file)
index 0000000..ded8d7a
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr27016b.s
@@ -0,0 +1,4 @@
+       .globl thesym
+thesym = 0x40402c
+
+       .section        .note.GNU-stack,"",@progbits

diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index 3d48f860a3200d01bc3598a32ab9e6ff2d1470ff..91410304ea09bb6b062ca7c120f1adbc69bccfe7 100644 (file)
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -647,6 +647,8 @@ run_dump_test "pr20253-5b"
 run_dump_test "tlsdesc2"
 run_dump_test "pr22048"
 run_dump_test "pr22929"
+run_dump_test "pr27016a"
+run_dump_test "pr27016b"
 
 proc undefined_weak {cflags ldflags} {
     set testname "Undefined weak symbol"