Fix remaining return type of ifunc resolver declaration

Since Martin Sebor's commit

commit ee4e992ebe5f9712faedeefe8958b67d61eaa0f2
Author: Martin Sebor <msebor@redhat.com>
Date:   Tue Aug 22 09:35:23 2017 -0600

    Declare ifunc resolver to return a pointer to the same type as the target
    function to help GCC detect incompatibilities between the two when it's
    enhanced to do so.

builds for powerpc64le fail in the declaration of some ifunc resolvers,
because the ifunc is declared with unmatching return types.  One of the
declarations comes from the __ifunc_resolver macro, which was patched by
the aforementioned commit:

    /* Helper / base  macros for indirect function symbols.  */
    #define __ifunc_resolver(type_name, name, expr, arg, init, classifier) \
      classifier inhibit_stack_protector                                   \
      __typeof (type_name) *name##_ifunc (arg)                             \

whereas the other comes from the unpatched __ifunc macro when
HAVE_GCC_IFUNC is not defined:

    # define __ifunc(type_name, name, expr, arg, init)                     \
      extern __typeof (type_name) name;                                    \
      void *name##_ifunc (arg) __asm__ (#name);                            \

This patch changes the return type of the ifunc resolver in the __ifunc
macro, so that it matches the return type of the target function,
similarly to what the aforementioned commit does.

Tested for powerpc64le and s390x with unpatched GCC.

	* include/libc-symbols.h: [!defined HAVE_GCC_IFUNC] (__ifunc):
	Change the return type of the ifunc resolver to match the return
	type of the target function.

(cherry picked from commit b513da7e80febbbfb8e58282075018652b6f7273)

diff --git a/ChangeLog b/ChangeLog
index ec9b9f5edbe8f6977a9d0f1fd71e88b7987556ee..6b09c61d5a3d94322598e012e6f5d8a627757620 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2017-08-22  Gabriel F. T. Gomes  <gftg@linux.vnet.ibm.com>
+
+       * include/libc-symbols.h: [!defined HAVE_GCC_IFUNC] (__ifunc):
+       Change the return type of the ifunc resolver to match the return
+       type of the target function.
+
 2017-08-22  Martin Sebor  <msebor@redhat.com>
 
        * include/libc-symbols.h (__ifunc_resolver): Declare resolver

diff --git a/include/libc-symbols.h b/include/libc-symbols.h
index c50f9adec2475a46e2343e5bbe6649eaccb6503f..5bf57703a98ecea381246873baefb837481db6a0 100644 (file)
--- a/include/libc-symbols.h
+++ b/include/libc-symbols.h
@@ -810,7 +810,7 @@ for linking")
 
 # define __ifunc(type_name, name, expr, arg, init)                     \
   extern __typeof (type_name) name;                                    \
-  void *name##_ifunc (arg) __asm__ (#name);                            \
+  __typeof (type_name) *name##_ifunc (arg) __asm__ (#name);            \
   __ifunc_resolver (type_name, name, expr, arg, init,)                 \
  __asm__ (".type " #name ", %gnu_indirect_function");