nptl: Remove vfork IFUNC-based forwarder from libpthread [BZ #20188]

With commit f0b2132b35248c1f4a80f62a2c38cddcc802aa8c ("ld.so:
Support moving versioned symbols between sonames [BZ #24741]"), the
dynamic linker will find the definition of vfork in libc and binds
a vfork reference to that symbol, even if the soname in the version
reference says that the symbol should be located in libpthread.

As a result, the forwarder (whether it's IFUNC-based or a duplicate
of the libc implementation) is no longer necessary.

On older architectures, a placeholder symbol is required, to make sure
that the GLIBC_2.1.2 symbol version does not go away, or is turned in
to a weak symbol definition by the link editor.  (The symbol version
needs to preserved so that the symbol coverage check in
elf/dl-version.c does not fail for old binaries.)

mips32 is an outlier: It defined __vfork@@GLIBC_2.2, but the
baseline is GLIBC_2.0.  Since there are other @@GLIBC_2.2 symbols,
the placeholder symbol is not needed there.

1 files changed, 0 insertions, 1 deletions

diff --git a/sysdeps/unix/sysv/linux/csky/pt-vfork.S b/sysdeps/unix/sysv/linux/csky/pt-vfork.S
deleted file mode 100644
index 1cc8931700..0000000000
--- a/sysdeps/unix/sysv/linux/csky/pt-vfork.S
+++ /dev/null
@@ -1 +0,0 @@
-/* Not needed.  */