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.

3 files changed, 0 insertions, 85 deletions

diff --git a/sysdeps/unix/sysv/linux/hppa/libpthread.abilist b/sysdeps/unix/sysv/linux/hppa/libpthread.abilist
index bcba07f575..e9b3be6ac8 100644
--- a/sysdeps/unix/sysv/linux/hppa/libpthread.abilist
+++ b/sysdeps/unix/sysv/linux/hppa/libpthread.abilist
@@ -46,7 +46,6 @@ GLIBC_2.2 __read F
 GLIBC_2.2 __res_state F
 GLIBC_2.2 __send F
 GLIBC_2.2 __sigaction F
-GLIBC_2.2 __vfork F
 GLIBC_2.2 __wait F
 GLIBC_2.2 __write F
 GLIBC_2.2 _pthread_cleanup_pop F
@@ -192,7 +191,6 @@ GLIBC_2.2 siglongjmp F
 GLIBC_2.2 sigwait F
 GLIBC_2.2 system F
 GLIBC_2.2 tcdrain F
-GLIBC_2.2 vfork F
 GLIBC_2.2 wait F
 GLIBC_2.2 waitpid F
 GLIBC_2.2 write F
diff --git a/sysdeps/unix/sysv/linux/hppa/localplt.data b/sysdeps/unix/sysv/linux/hppa/localplt.data
index 5f3475de19..867413f0c5 100644
--- a/sysdeps/unix/sysv/linux/hppa/localplt.data
+++ b/sysdeps/unix/sysv/linux/hppa/localplt.data
@@ -10,7 +10,6 @@ libc.so: __sigsetjmp
 libc.so: _IO_funlockfile
 libc.so: __errno_location
 libm.so: matherr
-libpthread.so: __errno_location
 # The main malloc is interposed into the dynamic linker, for
 # allocations after the initial link (when dlopen is used).
 ld.so: malloc
diff --git a/sysdeps/unix/sysv/linux/hppa/pt-vfork.S b/sysdeps/unix/sysv/linux/hppa/pt-vfork.S
deleted file mode 100644
index 9d7dda8b63..0000000000
--- a/sysdeps/unix/sysv/linux/hppa/pt-vfork.S
+++ /dev/null
@@ -1,82 +0,0 @@
-/* Copyright (C) 2005-2019 Free Software Foundation, Inc.
-   This file is part of the GNU C Library.
-
-   The GNU C Library is free software; you can redistribute it and/or
-   modify it under the terms of the GNU Lesser General Public
-   License as published by the Free Software Foundation; either
-   version 2.1 of the License, or (at your option) any later version.
-
-   The GNU C Library is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
-   Lesser General Public License for more details.
-
-   You should have received a copy of the GNU Lesser General Public
-   License along with the GNU C Library.  If not, see
-   <http://www.gnu.org/licenses/>.  */
-
-#include <sysdep.h>
-#define _ERRNO_H        1
-#include <bits/errno.h>
-#include <tcb-offsets.h>
-
-/* Clone the calling process, but without copying the whole address space.
-   The calling process is suspended until the new process exits or is
-   replaced by a call to `execve'.  Return -1 for errors, 0 to the new process,
-   and the process ID of the new process to the old process.  */
-
-.Lthread_start:						ASM_LINE_SEP
-
-	/* r26, r25, r24, r23 are free since vfork has no arguments */
-ENTRY(__vfork)
-	/* We must not create a frame. When the child unwinds to call
-	   exec it will clobber the same frame that the parent
-	   needs to unwind.  */
-
-	/* Save the PIC register. */
-#ifdef PIC
-	copy	%r19, %r25	/* parent */
-#endif
-
-	/* Syscall saves and restores all register states */
-	ble	0x100(%sr2,%r0)
-	ldi	__NR_vfork,%r20
-
-	/* Check for error */
-	ldi	-4096,%r1
-	comclr,>>= %r1,%ret0,%r0        /* Note: unsigned compare. */
-	b,n	.Lerror
-
-	/* Return, and DO NOT restore rp. The child may have called
-	   functions that updated the frame's rp. This works because
-	   the kernel ensures rp is preserved across the vfork
-	   syscall.  */
-	bv,n	%r0(%rp)
-
-.Lerror:
-	/* Now we need a stack to call a function. We are assured
-	   that there is no child now, so it's safe to create
-	   a frame.  */
-	stw	%rp, -20(%sp)
-	.cfi_offset 2, -20
-	stwm	%r3, 64(%sp)
-	.cfi_def_cfa_offset -64
-	.cfi_offset 3, 0
-	stw	%sp, -4(%sp)
-
-	sub	%r0,%ret0,%r3
-	SYSCALL_ERROR_HANDLER
-	/* Restore the PIC register (in delay slot) on error */
-#ifdef PIC
-	copy	%r25, %r19    /* parent */
-#else
-	nop
-#endif
-	/* Write syscall return into errno location */
-	stw	%r3, 0(%ret0)
-	ldw	-84(%sp), %rp
-	bv	%r0(%rp)
-	ldwm	-64(%sp), %r3
-PSEUDO_END (__vfork)
-libc_hidden_def (__vfork)
-weak_alias (__vfork, vfork)