summaryrefslogtreecommitdiff
path: root/libc/sysdeps/linux/ia64/clone2.S
diff options
context:
space:
mode:
Diffstat (limited to 'libc/sysdeps/linux/ia64/clone2.S')
-rw-r--r--libc/sysdeps/linux/ia64/clone2.S105
1 files changed, 105 insertions, 0 deletions
diff --git a/libc/sysdeps/linux/ia64/clone2.S b/libc/sysdeps/linux/ia64/clone2.S
new file mode 100644
index 000000000..af621662c
--- /dev/null
+++ b/libc/sysdeps/linux/ia64/clone2.S
@@ -0,0 +1,105 @@
+/* Copyright (C) 2000, 2001, 2003, 2004 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#include "sysdep.h"
+
+#include "sysdep.h"
+#include <asm/errno.h>
+
+
+/* int __clone2(int (*fn) (void *arg), void *child_stack_base, */
+/* size_t child_stack_size, int flags, void *arg, */
+/* pid_t *parent_tid, void *tls, pid_t *child_tid) */
+
+#define CHILD p8
+#define PARENT p9
+
+ENTRY(__clone2)
+ .prologue
+ alloc r2=ar.pfs,8,1,6,0
+ cmp.eq p6,p0=0,in0
+ mov r8=EINVAL
+ mov out0=in3 /* Flags are first syscall argument. */
+ mov out1=in1 /* Stack address. */
+(p6) br.cond.spnt.many __syscall_error
+ ;;
+ mov out2=in2 /* Stack size. */
+ mov out3=in5 /* Parent TID Pointer */
+ mov out4=in7 /* Child TID Pointer */
+ mov out5=in6 /* TLS pointer */
+ /*
+ * clone2() is special: the child cannot execute br.ret right
+ * after the system call returns, because it starts out
+ * executing on an empty stack. Because of this, we can't use
+ * the new (lightweight) syscall convention here. Instead, we
+ * just fall back on always using "break".
+ *
+ * Furthermore, since the child starts with an empty stack, we
+ * need to avoid unwinding past invalid memory. To that end,
+ * we'll pretend now that __clone2() is the end of the
+ * call-chain. This is wrong for the parent, but only until
+ * it returns from clone2() but it's better than the
+ * alternative.
+ */
+ mov r15=SYS_ify (clone2)
+ .save rp, r0
+ break __BREAK_SYSCALL
+ .body
+ cmp.eq p6,p0=-1,r10
+ cmp.eq CHILD,PARENT=0,r8 /* Are we the child? */
+(p6) br.cond.spnt.many __syscall_error
+ ;;
+(CHILD) mov loc0=gp
+(PARENT) ret
+ ;;
+#ifdef RESET_PID
+ tbit.nz p6,p0=in3,16 /* CLONE_THREAD */
+ tbit.z p7,p10=in3,8 /* CLONE_VM */
+(p6) br.cond.dptk 1f
+ ;;
+ mov r15=SYS_ify (getpid)
+(p10) addl r8=-1,r0
+(p7) break __BREAK_SYSCALL
+ ;;
+ add r9=PID,r13
+ add r10=TID,r13
+ ;;
+ st4 [r9]=r8
+ st4 [r10]=r8
+ ;;
+#endif
+1: ld8 out1=[in0],8 /* Retrieve code pointer. */
+ mov out0=in4 /* Pass proper argument to fn */
+ ;;
+ ld8 gp=[in0] /* Load function gp. */
+ mov b6=out1
+ br.call.dptk.many rp=b6 /* Call fn(arg) in the child */
+ ;;
+ mov out0=r8 /* Argument to _exit */
+ mov gp=loc0
+ .globl HIDDEN_JUMPTARGET(_exit)
+ br.call.dpnt.many rp=HIDDEN_JUMPTARGET(_exit)
+ /* call _exit with result from fn. */
+ ret /* Not reached. */
+PSEUDO_END(__clone2)
+
+/* For now we leave __clone undefined. This is unlikely to be a */
+/* problem, since at least the i386 __clone in glibc always failed */
+/* with a 0 sp (eventhough the kernel explicitly handled it). */
+/* Thus all such calls needed to pass an explicit sp, and as a result, */
+/* would be unlikely to work on ia64. */