From e64ac02c24b43659048622714afdc92fedf561fa Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Sun, 1 Jul 2012 13:06:41 +0000 Subject: Move all files into ports/ subdirectory in preparation for merge with glibc --- ports/sysdeps/unix/sysv/linux/hppa/nptl/pt-vfork.S | 106 +++++++++++++++++++++ 1 file changed, 106 insertions(+) create mode 100644 ports/sysdeps/unix/sysv/linux/hppa/nptl/pt-vfork.S (limited to 'ports/sysdeps/unix/sysv/linux/hppa/nptl/pt-vfork.S') diff --git a/ports/sysdeps/unix/sysv/linux/hppa/nptl/pt-vfork.S b/ports/sysdeps/unix/sysv/linux/hppa/nptl/pt-vfork.S new file mode 100644 index 0000000000..83c789c774 --- /dev/null +++ b/ports/sysdeps/unix/sysv/linux/hppa/nptl/pt-vfork.S @@ -0,0 +1,106 @@ +/* Copyright (C) 2005, 2010 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 + . */ + +#include +#define _ERRNO_H 1 +#include +#include + +/* 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. */ + +/* Load the thread register. + Load the saved PID value. + Negate the value. + Store the temporary PID. */ +#define SAVE_PID \ + mfctl %cr27, %r26 ASM_LINE_SEP \ + ldw PID_THREAD_OFFSET(%r26),%r1 ASM_LINE_SEP \ + sub %r0,%r1,%r1 ASM_LINE_SEP \ + stw %r1,PID_THREAD_OFFSET(%r26) ASM_LINE_SEP +/* If we are the parent... + Get the thread pointer. + Load the saved PID. + Negate the value (got back original) + Restore the PID. */ +#define RESTORE_PID \ + cmpb,=,n %r0,%ret0,.Lthread_start ASM_LINE_SEP \ + mfctl %cr27, %r26 ASM_LINE_SEP \ + ldw PID_THREAD_OFFSET(%r26),%r1 ASM_LINE_SEP \ + sub %r0,%r1,%r1 ASM_LINE_SEP \ + stw %r1,PID_THREAD_OFFSET(%r26) ASM_LINE_SEP \ +.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 + + /* Save the process PID */ + SAVE_PID + + /* Syscall saves and restores all register states */ + ble 0x100(%sr2,%r0) + ldi __NR_vfork,%r20 + + /* Conditionally restore the PID */ + RESTORE_PID + + /* 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) + stwm %r3, 64(%sp) + 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) + -- cgit v1.2.3