x86: Properly handle PLT expression in directive

For PLT expressions, we should subtract the PLT relocation size only for
jump instructions.  Since PLT relocations are PC relative, we only allow
"symbol@PLT" in PLT expression.

gas/

	PR gas/23997
	* config/tc-i386.c (x86_cons): Check for invalid PLT expression.
	(md_apply_fix): Subtract the PLT relocation size only for jump
	instructions.
	* testsuite/gas/i386/reloc32.s: Add test for invalid PLT
	expression.
	* testsuite/gas/i386/reloc64.s: Likewise.
	* testsuite/gas/i386/ilp32/reloc64.s: Likewise.
	* testsuite/gas/i386/reloc32.l: Updated.
	* testsuite/gas/i386/reloc64.l: Likewise.
	* testsuite/gas/i386/ilp32/reloc64.l: Likewise.

ld/

	PR gas/23997
	* testsuite/ld-i386/i386.exp: Run PR gas/23997 test.
	* testsuite/ld-x86-64/x86-64.exp: Likewise.
	* testsuite/ld-x86-64/pr23997a.s: New file.
	* testsuite/ld-x86-64/pr23997b.c: Likewise.
	* testsuite/ld-x86-64/pr23997c.c: Likewise.

6 files changed, 64 insertions, 0 deletions

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 17a2e45..c7d4a0c 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,5 +1,14 @@
 2018-12-19  H.J. Lu  <hongjiu.lu@intel.com>
 
+	PR gas/23997
+	* testsuite/ld-i386/i386.exp: Run PR gas/23997 test.
+	* testsuite/ld-x86-64/x86-64.exp: Likewise.
+	* testsuite/ld-x86-64/pr23997a.s: New file.
+	* testsuite/ld-x86-64/pr23997b.c: Likewise.
+	* testsuite/ld-x86-64/pr23997c.c: Likewise.
+
+2018-12-19  H.J. Lu  <hongjiu.lu@intel.com>
+
 	* testsuite/ld-x86-64/x86-64.exp: Rename PR ld/22842 run-time
 	test to "Run pr22842".
 
diff --git a/ld/testsuite/ld-i386/i386.exp b/ld/testsuite/ld-i386/i386.exp
index f86a54d..b3c489a 100644
--- a/ld/testsuite/ld-i386/i386.exp
+++ b/ld/testsuite/ld-i386/i386.exp
@@ -1420,6 +1420,15 @@ if { [isnative]
 	    "pr22842" \
 	    "pass.out" \
 	] \
+	[list \
+	    "Run pr23997" \
+	    "" \
+	    "" \
+	    { ../ld-x86-64/pr23997a.s ../ld-x86-64/pr23997b.c \
+	      ../ld-x86-64/pr23997c.c } \
+	    "pr23997" \
+	    "pass.out" \
+	] \
     ]
 
     if { [at_least_gcc_version 5 0] } {
diff --git a/ld/testsuite/ld-x86-64/pr23997a.s b/ld/testsuite/ld-x86-64/pr23997a.s
new file mode 100644
index 0000000..8d72c62
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr23997a.s
@@ -0,0 +1,6 @@
+	.text
+	.p2align 3
+	.globl foo_p
+foo_p:
+	.long foo@plt
+	.section	.note.GNU-stack,"",@progbits
diff --git a/ld/testsuite/ld-x86-64/pr23997b.c b/ld/testsuite/ld-x86-64/pr23997b.c
new file mode 100644
index 0000000..02cb8f8
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr23997b.c
@@ -0,0 +1,25 @@
+#include <stdio.h>
+
+typedef void (*func_t) (void);
+
+extern func_t get_foo (void);
+
+void
+foo (void)
+{
+}
+
+int
+main ()
+{
+  func_t p;
+
+  foo ();
+  p = get_foo ();
+  p ();
+
+  if (foo == p)
+    printf ("PASS\n");
+
+  return 0;
+}
diff --git a/ld/testsuite/ld-x86-64/pr23997c.c b/ld/testsuite/ld-x86-64/pr23997c.c
new file mode 100644
index 0000000..3573157
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/pr23997c.c
@@ -0,0 +1,7 @@
+extern int foo_p;
+
+void *
+get_foo (void)
+{
+  return (void *) ((long) &foo_p + foo_p);
+}
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index 75e2546..c9e8ecb 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -1594,6 +1594,14 @@ if { [isnative] && [which $CC] != 0 } {
 	    "pr22842" \
 	    "pass.out" \
 	] \
+	[list \
+	    "Run pr23997" \
+	    "" \
+	    "" \
+	    { pr23997a.s pr23997b.c pr23997c.c } \
+	    "pr23997" \
+	    "pass.out" \
+	] \
     ]
 
     # Run-time tests which require working ifunc attribute support.