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.
This commit is contained in:
Adhemerval Zanella 2017-03-16 09:15:57 -03:00
parent db3d848e15
commit bdc543e338
5 changed files with 15 additions and 0 deletions

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@ -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.

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@ -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

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@ -13,3 +13,4 @@ ENTRY(.udiv)
udiv %o0, %o1, %o0
END(.udiv)
strong_alias (.udiv, __wrap_.udiv)

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@ -15,3 +15,4 @@ ENTRY(.udiv)
udiv %o0, %o1, %o0
END(.udiv)
strong_alias (.udiv, __wrap_.udiv)

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@ -344,3 +344,4 @@ LOC(got_result):
mov %o2, %o0
END(.udiv)
strong_alias (.udiv, __wrap_.udiv)