From: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Date: Thu, 16 Mar 2017 12:15:57 +0000 (-0300)
Subject: sparc: Fix .udiv plt on libc
X-Git-Tag: glibc-2.26~644
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=bdc543e338281da051b3dc06eae96c330a485ce6;p=thirdparty%2Fglibc.git

sparc: Fix .udiv plt on libc

With the removal of divdi3 object from sparcv9-linux-gnu build, its
definition came from libgcc and its functions internall calls .udiv.
Since glibc also exports these symbols for compatibility reasons, it
will end up creating PLT calls internally in libc.so.

To avoid it, this patch uses the linker option --wrap to replace all
the internal libc.so .udiv calls to the wrapper __wrap_.udiv. Along
with strong alias in the udiv implementations, it makes linker do
local calls.

Checked on sparcv9-linux-gnu.

	* sysdeps/sparc/sparc32/Makefile (libc.so-gnulib): New rule.
	* sysdeps/sparc/sparc32/sparcv8/udiv.S (.udiv): Make a strong_alias
	to __wrap_.udiv.
	* sysdeps/sparc/sparc32/sparcv9/udiv.S (.udiv): Likewise.
	* sysdeps/sparc/sparc32/udiv.S (.udiv): Likewise.
---

diff --git a/ChangeLog b/ChangeLog
index e70ecd78631..9024e62fc7e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
 2017-04-05  Adhemerval Zanella  <adhemerval.zanella@linaro.org>
 
+	* sysdeps/sparc/sparc32/Makefile (libc.so-gnulib): New rule.
+	* sysdeps/sparc/sparc32/sparcv8/udiv.S (.udiv): Make a strong_alias
+	to __wrap_.udiv.
+	* sysdeps/sparc/sparc32/sparcv9/udiv.S (.udiv): Likewise.
+	* sysdeps/sparc/sparc32/udiv.S (.udiv): Likewise.
+
 	* sysdeps/i386/symbol-hacks.h: New file.
 	* sysdeps/m68k/symbol-hacks.h: New file.
 	* sysdeps/powerpc/powerpc32/symbol-hacks.h: New file.
diff --git a/sysdeps/sparc/sparc32/Makefile b/sysdeps/sparc/sparc32/Makefile
index da205898cf6..14d6e03c6f1 100644
--- a/sysdeps/sparc/sparc32/Makefile
+++ b/sysdeps/sparc/sparc32/Makefile
@@ -47,3 +47,9 @@ $(divrem:%=$(sysdep_dir)/sparc/sparc32/%.S): $(sysdep_dir)/sparc/sparc32/divrem.
 	mv -f $@-tmp $@
 
 sysdep-realclean := $(sysdep-realclean) $(divrem:%=sysdeps/sparc/sparc32/%.S)
+
+# libgcc __divdi3 and __moddi3 uses .udiv and since it is also exported by
+# libc.so linker will create PLTs for the symbol.  To avoid it we strong alias
+# the exported libc one to __wrap_.udiv and use linker option --wrap to make any
+# call to .udiv to call the wrapper symbol.
+libc.so-gnulib += -Wl,--wrap=.udiv
diff --git a/sysdeps/sparc/sparc32/sparcv8/udiv.S b/sysdeps/sparc/sparc32/sparcv8/udiv.S
index d71954351ef..e9cab4e4ef6 100644
--- a/sysdeps/sparc/sparc32/sparcv8/udiv.S
+++ b/sysdeps/sparc/sparc32/sparcv8/udiv.S
@@ -13,3 +13,4 @@ ENTRY(.udiv)
 	 udiv	%o0, %o1, %o0
 
 END(.udiv)
+strong_alias (.udiv, __wrap_.udiv)
diff --git a/sysdeps/sparc/sparc32/sparcv9/udiv.S b/sysdeps/sparc/sparc32/sparcv9/udiv.S
index de798997568..368f85ede2c 100644
--- a/sysdeps/sparc/sparc32/sparcv9/udiv.S
+++ b/sysdeps/sparc/sparc32/sparcv9/udiv.S
@@ -15,3 +15,4 @@ ENTRY(.udiv)
 	 udiv		%o0, %o1, %o0
 
 END(.udiv)
+strong_alias (.udiv, __wrap_.udiv)
diff --git a/sysdeps/sparc/sparc32/udiv.S b/sysdeps/sparc/sparc32/udiv.S
index 8dfff661584..ade0afdf40d 100644
--- a/sysdeps/sparc/sparc32/udiv.S
+++ b/sysdeps/sparc/sparc32/udiv.S
@@ -344,3 +344,4 @@ LOC(got_result):
 	mov %o2, %o0
 
 END(.udiv)
+strong_alias (.udiv, __wrap_.udiv)