[binutils-gdb] x86-64: Test protected function pointers

[H.J. Lu]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=b6b42983720c2d88f680ef7679f41c3ff95daae1

commit b6b42983720c2d88f680ef7679f41c3ff95daae1
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Thu Jun 17 10:19:29 2021 -0700

    x86-64: Test protected function pointers
    
    On x86-64, function pointers in executable for external funtions may be
    resolved to their PLT entries in executable.  If it happens, function
    pointers of protected funtions in shared libraries must be resolved to
    the PLT entries in executable, not addresses of protected funtions in
    shared libraries.
    
            PR ld/27973
            * testsuite/ld-x86-64/x86-64.exp: Run protected function tests.
            * testsuite/ld-x86-64/protected-func-1.h: New file.
            * testsuite/ld-x86-64/protected-func-1a.s: Likewise.
            * testsuite/ld-x86-64/protected-func-1b.c: Likewise.

Diff:
---
 ld/ChangeLog                               |  8 +++++
 ld/testsuite/ld-x86-64/protected-func-1.h  |  6 ++++
 ld/testsuite/ld-x86-64/protected-func-1a.s | 48 ++++++++++++++++++++++++++++++
 ld/testsuite/ld-x86-64/protected-func-1b.c | 35 ++++++++++++++++++++++
 ld/testsuite/ld-x86-64/x86-64.exp          | 25 ++++++++++++++++
 5 files changed, 122 insertions(+)

diff --git a/ld/ChangeLog b/ld/ChangeLog
index 3d3cbeda377..2b46bb92b6a 100644
--- a/ld/ChangeLog
+++ b/ld/ChangeLog
@@ -1,3 +1,11 @@
+2021-06-17  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR ld/27973
+	* testsuite/ld-x86-64/x86-64.exp: Run protected function tests.
+	* testsuite/ld-x86-64/protected-func-1.h: New file.
+	* testsuite/ld-x86-64/protected-func-1a.s: Likewise.
+	* testsuite/ld-x86-64/protected-func-1b.c: Likewise.
+
 2021-06-17  Fangrui Song  <maskray@google.com>
 
 	* ldlex.h (enum option_values): Add OPTION_NO_PIE.
diff --git a/ld/testsuite/ld-x86-64/protected-func-1.h b/ld/testsuite/ld-x86-64/protected-func-1.h
new file mode 100644
index 00000000000..b5ff4e8f822
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/protected-func-1.h
@@ -0,0 +1,6 @@
+extern int protected_func_1a (void);
+extern int protected_func_1b (void);
+
+typedef int (*protected_func_type) (void);
+extern protected_func_type protected_func_1a_p (void);
+extern protected_func_type protected_func_1b_p (void);
diff --git a/ld/testsuite/ld-x86-64/protected-func-1a.s b/ld/testsuite/ld-x86-64/protected-func-1a.s
new file mode 100644
index 00000000000..eb2ed91fb52
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/protected-func-1a.s
@@ -0,0 +1,48 @@
+	.text
+	.p2align 4
+	.protected	protected_func_1a
+	.globl	protected_func_1a
+	.type	protected_func_1a, @function
+protected_func_1a:
+.LFB0:
+	.cfi_startproc
+	movl	$1, %eax
+	ret
+	.cfi_endproc
+.LFE0:
+	.size	protected_func_1a, .-protected_func_1a
+	.p2align 4
+	.protected	protected_func_1b
+	.globl	protected_func_1b
+	.type	protected_func_1b, @function
+protected_func_1b:
+.LFB1:
+	.cfi_startproc
+	movl	$2, %eax
+	ret
+	.cfi_endproc
+.LFE1:
+	.size	protected_func_1b, .-protected_func_1b
+	.p2align 4
+	.globl	protected_func_1a_p
+	.type	protected_func_1a_p, @function
+protected_func_1a_p:
+.LFB2:
+	.cfi_startproc
+	movq	protected_func_1a@GOTPCREL(%rip), %rax
+	ret
+	.cfi_endproc
+.LFE2:
+	.size	protected_func_1a_p, .-protected_func_1a_p
+	.p2align 4
+	.globl	protected_func_1b_p
+	.type	protected_func_1b_p, @function
+protected_func_1b_p:
+.LFB3:
+	.cfi_startproc
+	movq	protected_func_1b@GOTPCREL(%rip), %rax
+	ret
+	.cfi_endproc
+.LFE3:
+	.size	protected_func_1b_p, .-protected_func_1b_p
+	.section	.note.GNU-stack,"",@progbits
diff --git a/ld/testsuite/ld-x86-64/protected-func-1b.c b/ld/testsuite/ld-x86-64/protected-func-1b.c
new file mode 100644
index 00000000000..a9d728afe24
--- /dev/null
+++ b/ld/testsuite/ld-x86-64/protected-func-1b.c
@@ -0,0 +1,35 @@
+#include <stdio.h>
+
+#include "protected-func-1.h"
+
+int
+protected_func_1b (void)
+{
+  return 3;
+}
+
+int
+main (void)
+{
+  int res = 0;
+
+  /* Check if we get the same address for the protected function symbol.  */
+  if (protected_func_1a != protected_func_1a_p ())
+    {
+      puts ("'protected_func_1a' in main and shared library doesn't have same address");
+      res = 1;
+    }
+
+  /* Check if we get the different addresses for the protected function
+     symbol.  */
+  if (protected_func_1b == protected_func_1b_p ())
+    {
+      puts ("'protected_func_1b' in main and shared library has same address");
+      res = 1;
+    }
+
+  if (!res)
+    puts ("PASS");
+
+  return res;
+}
diff --git a/ld/testsuite/ld-x86-64/x86-64.exp b/ld/testsuite/ld-x86-64/x86-64.exp
index 80716668df6..5dc9a1c218e 100644
--- a/ld/testsuite/ld-x86-64/x86-64.exp
+++ b/ld/testsuite/ld-x86-64/x86-64.exp
@@ -1321,6 +1321,14 @@ if { [isnative] && [check_compiler_available] } {
 	     {readelf -rW pr22842b.rd}} \
 	    "pr22842" \
 	] \
+	[list \
+	    "Build libprotected-func-1.so" \
+	    "-shared" \
+	    "-fPIC -Wa,-mx86-used-note=yes" \
+	    { protected-func-1a.s } \
+	    {} \
+	    "libprotected-func-1.so" \
+	] \
     ]
 
     if  {[istarget "x86_64-*-linux*-gnux32"]} {
@@ -1730,6 +1738,23 @@ if { [isnative] && [check_compiler_available] } {
 	    "pr23997" \
 	    "pass.out" \
 	] \
+	[list \
+	    "Run protected-func-1 without PIE" \
+	    "-Wl,--no-as-needed tmpdir/libprotected-func-1.so" \
+	    "-Wa,-mx86-used-note=yes" \
+	    { protected-func-1b.c } \
+	    "protected-func-1a" \
+	    "pass.out" \
+	] \
+	[list \
+	    "Run protected-func-1 with PIE" \
+	    "-Wl,--no-as-needed -pie tmpdir/libprotected-func-1.so" \
+	    "-Wa,-mx86-used-note=yes" \
+	    { protected-func-1b.c } \
+	    "protected-func-1b" \
+	    "pass.out" \
+	    "-fPIE" \
+	] \
     ]
 
     # Run-time tests which require working ifunc attribute support.