S390: Do not call memcpy, memcmp, memset within libc.so via ifunc-plt.

On s390, the memcpy, memcmp, memset functions are IFUNC symbols,
which are created with s390_libc_ifunc-macro.
This macro creates a __GI_ symbol which is set to the
ifunced symbol. Thus calls within libc.so to e.g. memcpy
result in a call to *ABS*+0x954c0@plt stub and afterwards
to the resolved memcpy-ifunc-variant.

This patch sets the __GI_ symbol to the default-ifunc-variant
to avoid the plt call. The __GI_ symbols are now created at the
default variant of ifunced function.

ChangeLog:

	* sysdeps/s390/multiarch/ifunc-resolve.h (s390_libc_ifunc):
	Remove __GI_ symbol.
	* sysdeps/s390/s390-32/multiarch/memcmp-s390.S: Add __GI_memcmp symbol.
	* sysdeps/s390/s390-64/multiarch/memcmp-s390x.S: Likewise.
	* sysdeps/s390/s390-32/multiarch/memcpy-s390.S: Add __GI_memcpy symbol.
	* sysdeps/s390/s390-64/multiarch/memcpy-s390x.S: Likewise.
	* sysdeps/s390/s390-32/multiarch/memset-s390.S: Add __GI_memset symbol.
	* sysdeps/s390/s390-64/multiarch/memset-s390x.S: Likewise.

8 files changed, 32 insertions, 5 deletions

diff --git a/ChangeLog b/ChangeLog
index 1bacd7172e..1054ca771f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,16 @@
 2016-05-24  Stefan Liebler  <stli@linux.vnet.ibm.com>
 
+	* sysdeps/s390/multiarch/ifunc-resolve.h (s390_libc_ifunc):
+	Remove __GI_ symbol.
+	* sysdeps/s390/s390-32/multiarch/memcmp-s390.S: Add __GI_memcmp symbol.
+	* sysdeps/s390/s390-64/multiarch/memcmp-s390x.S: Likewise.
+	* sysdeps/s390/s390-32/multiarch/memcpy-s390.S: Add __GI_memcpy symbol.
+	* sysdeps/s390/s390-64/multiarch/memcpy-s390x.S: Likewise.
+	* sysdeps/s390/s390-32/multiarch/memset-s390.S: Add __GI_memset symbol.
+	* sysdeps/s390/s390-64/multiarch/memset-s390x.S: Likewise.
+
+2016-05-24  Stefan Liebler  <stli@linux.vnet.ibm.com>
+
 	* sysdeps/s390/s390-64/memcpy.S (memcpy):
 	Use cghi instead of chi to compare 64bit value.
 
diff --git a/sysdeps/s390/multiarch/ifunc-resolve.h b/sysdeps/s390/multiarch/ifunc-resolve.h
index 744a0d8d6d..26e097ad6e 100644
--- a/sysdeps/s390/multiarch/ifunc-resolve.h
+++ b/sysdeps/s390/multiarch/ifunc-resolve.h
@@ -44,9 +44,7 @@
 #define s390_libc_ifunc(FUNC)						\
   __asm__ (".globl " #FUNC "\n\t"					\
 	   ".type  " #FUNC ",@gnu_indirect_function\n\t"		\
-	   ".set   " #FUNC ",__resolve_" #FUNC "\n\t"			\
-	   ".globl __GI_" #FUNC "\n\t"					\
-	   ".set   __GI_" #FUNC "," #FUNC "\n");			\
+	   ".set   " #FUNC ",__resolve_" #FUNC "\n\t");			\
 									\
   /* Make the declarations of the optimized functions hidden in order
      to prevent GOT slots being generated for them. */			\
diff --git a/sysdeps/s390/s390-32/multiarch/memcmp-s390.S b/sysdeps/s390/s390-32/multiarch/memcmp-s390.S
index e9ee6d2270..a01f3b748d 100644
--- a/sysdeps/s390/s390-32/multiarch/memcmp-s390.S
+++ b/sysdeps/s390/s390-32/multiarch/memcmp-s390.S
@@ -101,4 +101,7 @@ END(__memcmp_z10)
 .set     memcmp,__memcmp_default
 .weak    bcmp
 .set	 bcmp,__memcmp_default
+#elif defined SHARED && IS_IN (libc)
+.globl   __GI_memcmp
+.set     __GI_memcmp,__memcmp_default
 #endif
diff --git a/sysdeps/s390/s390-32/multiarch/memcpy-s390.S b/sysdeps/s390/s390-32/multiarch/memcpy-s390.S
index 4e30cdf6c6..92ffaea5ed 100644
--- a/sysdeps/s390/s390-32/multiarch/memcpy-s390.S
+++ b/sysdeps/s390/s390-32/multiarch/memcpy-s390.S
@@ -92,7 +92,10 @@ END(__memcpy_z10)
 
 #include "../memcpy.S"
 
-#if !defined SHARED || !IS_IN (libc)
+#if defined SHARED && IS_IN (libc)
+.globl   __GI_memcpy
+.set     __GI_memcpy,__memcpy_default
+#else
 .globl   memcpy
 .set     memcpy,__memcpy_default
 #endif
diff --git a/sysdeps/s390/s390-32/multiarch/memset-s390.S b/sysdeps/s390/s390-32/multiarch/memset-s390.S
index 47277c13a6..a2ddd98afe 100644
--- a/sysdeps/s390/s390-32/multiarch/memset-s390.S
+++ b/sysdeps/s390/s390-32/multiarch/memset-s390.S
@@ -110,4 +110,7 @@ END(__memset_mvcle)
 #if !IS_IN (libc)
 .globl   memset
 .set     memset,__memset_default
+#elif defined SHARED && IS_IN (libc)
+.globl   __GI_memset
+.set     __GI_memset,__memset_default
 #endif
diff --git a/sysdeps/s390/s390-64/multiarch/memcmp-s390x.S b/sysdeps/s390/s390-64/multiarch/memcmp-s390x.S
index 2a4c0ae9a6..b28ccaf3b1 100644
--- a/sysdeps/s390/s390-64/multiarch/memcmp-s390x.S
+++ b/sysdeps/s390/s390-64/multiarch/memcmp-s390x.S
@@ -98,4 +98,7 @@ END(__memcmp_z10)
 .set     memcmp,__memcmp_default
 .weak    bcmp
 .set	 bcmp,__memcmp_default
+#elif defined SHARED && IS_IN (libc)
+.globl   __GI_memcmp
+.set     __GI_memcmp,__memcmp_default
 #endif
diff --git a/sysdeps/s390/s390-64/multiarch/memcpy-s390x.S b/sysdeps/s390/s390-64/multiarch/memcpy-s390x.S
index 69fa562060..8f54526b76 100644
--- a/sysdeps/s390/s390-64/multiarch/memcpy-s390x.S
+++ b/sysdeps/s390/s390-64/multiarch/memcpy-s390x.S
@@ -88,7 +88,10 @@ END(__memcpy_z10)
 
 #include "../memcpy.S"
 
-#if !defined SHARED || !IS_IN (libc)
+#if defined SHARED && IS_IN (libc)
+.globl   __GI_memcpy
+.set     __GI_memcpy,__memcpy_default
+#else
 .globl   memcpy
 .set     memcpy,__memcpy_default
 #endif
diff --git a/sysdeps/s390/s390-64/multiarch/memset-s390x.S b/sysdeps/s390/s390-64/multiarch/memset-s390x.S
index 05e068279d..a77e798a04 100644
--- a/sysdeps/s390/s390-64/multiarch/memset-s390x.S
+++ b/sysdeps/s390/s390-64/multiarch/memset-s390x.S
@@ -106,4 +106,7 @@ END(__memset_mvcle)
 #if !IS_IN (libc)
 .globl   memset
 .set     memset,__memset_default
+#elif defined SHARED && IS_IN (libc)
+.globl   __GI_memset
+.set     __GI_memset,__memset_default
 #endif