compile: Fix GNU-IFUNC funcs called from injected code

One could not call IFUNCs (=indirect functions) from the compiled injected
code.  Either it errored with:
	gdb command line:1:1: error: function return type cannot be function

or it just called the IFUNC dispatcher in normal way, returning real function
implementation address instead of the function return value (and thus no
function was called).

gdb/ChangeLog
2015-02-26  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* compile/compile-c-symbols.c (convert_one_symbol, convert_symbol_bmsym)
	(gcc_symbol_address): Call gnu_ifunc_resolve_addr.

gdb/testsuite/ChangeLog
2015-02-26  Jan Kratochvil  <jan.kratochvil@redhat.com>

	* gdb.compile/compile-ifunc.c: New file.
	* gdb.compile/compile-ifunc.exp: New file.

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 5c4138ef7578a36165c6a265635cb7409ee2f17a..3b21d8c3729777df2401e2af0ad86ff81194acd7 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,8 @@
+2015-02-26  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+       * compile/compile-c-symbols.c (convert_one_symbol, convert_symbol_bmsym)
+       (gcc_symbol_address): Call gnu_ifunc_resolve_addr.
+
 2015-02-26  Antoine Tremblay  <antoine.tremblay@ericsson.com>
 
        * gdb/infcmd.c (print_return_value): use type_to_string to print type.

diff --git a/gdb/compile/compile-c-symbols.c b/gdb/compile/compile-c-symbols.c
index 6562f05ec8a8f8b0f11333bb693eda831e30bc29..75c093ff5910e0bb0a55170b4bbd9a8abb10ba15 100644 (file)
--- a/gdb/compile/compile-c-symbols.c
+++ b/gdb/compile/compile-c-symbols.c
@@ -187,6 +187,8 @@ convert_one_symbol (struct compile_c_instance *context,
        case LOC_BLOCK:
          kind = GCC_C_SYMBOL_FUNCTION;
          addr = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
+         if (is_global && TYPE_GNU_IFUNC (SYMBOL_TYPE (sym)))
+           addr = gnu_ifunc_resolve_addr (target_gdbarch (), addr);
          break;
 
        case LOC_CONST:
@@ -365,6 +367,8 @@ convert_symbol_bmsym (struct compile_c_instance *context,
   gcc_decl decl;
   CORE_ADDR addr;
 
+  addr = MSYMBOL_VALUE_ADDRESS (objfile, msym);
+
   /* Conversion copied from write_exp_msymbol.  */
   switch (MSYMBOL_TYPE (msym))
     {
@@ -376,8 +380,11 @@ convert_symbol_bmsym (struct compile_c_instance *context,
       break;
 
     case mst_text_gnu_ifunc:
-      type = objfile_type (objfile)->nodebug_text_gnu_ifunc_symbol;
+      /* nodebug_text_gnu_ifunc_symbol would cause:
+        function return type cannot be function  */
+      type = objfile_type (objfile)->nodebug_text_symbol;
       kind = GCC_C_SYMBOL_FUNCTION;
+      addr = gnu_ifunc_resolve_addr (target_gdbarch (), addr);
       break;
 
     case mst_data:
@@ -400,7 +407,6 @@ convert_symbol_bmsym (struct compile_c_instance *context,
     }
 
   sym_type = convert_type (context, type);
-  addr = MSYMBOL_VALUE_ADDRESS (objfile, msym);
   decl = C_CTX (context)->c_ops->build_decl (C_CTX (context),
                                             MSYMBOL_NATURAL_NAME (msym),
                                             kind, sym_type, NULL, addr,
@@ -497,6 +503,8 @@ gcc_symbol_address (void *datum, struct gcc_c_context *gcc_context,
                                "gcc_symbol_address \"%s\": full symbol\n",
                                identifier);
          result = BLOCK_START (SYMBOL_BLOCK_VALUE (sym));
+         if (TYPE_GNU_IFUNC (SYMBOL_TYPE (sym)))
+           result = gnu_ifunc_resolve_addr (target_gdbarch (), result);
          found = 1;
        }
       else
@@ -512,6 +520,8 @@ gcc_symbol_address (void *datum, struct gcc_c_context *gcc_context,
                                    "symbol\n",
                                    identifier);
              result = BMSYMBOL_VALUE_ADDRESS (msym);
+             if (MSYMBOL_TYPE (msym.minsym) == mst_text_gnu_ifunc)
+               result = gnu_ifunc_resolve_addr (target_gdbarch (), result);
              found = 1;
            }
        }

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index b578053825391051f0c46b01b3242b6430c9b50f..183644f6949e244a97865ca52f6d3829ffa3829d 100644 (file)
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2015-02-26  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+       * gdb.compile/compile-ifunc.c: New file.
+       * gdb.compile/compile-ifunc.exp: New file.
+
 2015-02-26  Antoine Tremblay  <antoine.tremblay@ericsson.com>
 
        * gdb.base/structs.exp: Check for correct struct on finish.

diff --git a/gdb/testsuite/gdb.compile/compile-ifunc.c b/gdb/testsuite/gdb.compile/compile-ifunc.c
new file mode 100644 (file)
index 0000000..e5cee77
--- /dev/null
+++ b/gdb/testsuite/gdb.compile/compile-ifunc.c
@@ -0,0 +1,46 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2015 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include <stdlib.h>
+
+typedef int (*final_t) (int arg);
+
+int
+final (int arg)
+{
+  return arg + 1;
+}
+
+asm (".type gnu_ifunc, %gnu_indirect_function");
+
+final_t
+gnu_ifunc (void)
+{
+  return final;
+}
+
+extern int gnu_ifunc_alias (int arg) __attribute__ ((alias ("gnu_ifunc")));
+
+static int resultvar;
+
+int
+main (void)
+{
+  if (gnu_ifunc_alias (10) != 11)
+    abort ();
+  return resultvar;
+}

diff --git a/gdb/testsuite/gdb.compile/compile-ifunc.exp b/gdb/testsuite/gdb.compile/compile-ifunc.exp
new file mode 100644 (file)
index 0000000..026c62f
--- /dev/null
+++ b/gdb/testsuite/gdb.compile/compile-ifunc.exp
@@ -0,0 +1,54 @@
+# Copyright 2015 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+standard_testfile
+
+with_test_prefix "nodebug" {
+
+    if { [prepare_for_testing ${testfile}.exp "$testfile-nodebug" $srcfile {}] } {
+       return -1
+    }
+
+    if ![runto_main] {
+       return -1
+    }
+
+    if {[skip_compile_feature_tests]} {
+       untested "compile command not supported (could not find libcc1 shared library?)"
+       return -1
+    }
+
+    gdb_test_no_output "compile code resultvar = gnu_ifunc (10);"
+
+    gdb_test "p resultvar" " = 11"
+
+}
+
+with_test_prefix "debug" {
+
+    if { [prepare_for_testing ${testfile}.exp "$testfile-debug" $srcfile] } {
+       return -1
+    }
+
+    if ![runto_main] {
+       return -1
+    }
+
+    # gnu_ifunc (10): error: too many arguments to function 'gnu_ifunc'
+    gdb_test_no_output "compile code resultvar = gnu_ifunc_alias (10);"
+
+    gdb_test "p resultvar" " = 11"
+
+}