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authorRichard Henderson <rth@twiddle.net>2014-02-12 06:54:57 -0800
committerRichard Henderson <rth@twiddle.net>2014-02-12 07:00:06 -0800
commit68b7efaadb1b6045a56277ea62d324c20ac0b633 (patch)
tree07b51c9866373430373fb90b252d46c23cc1707e /sysdeps/unix/sysv/linux/alpha/clone.S
parent8fd7b0d5591e59ed5cb3078b351bd49314a66cef (diff)
downloadglibc-68b7efaadb1b6045a56277ea62d324c20ac0b633.tar.gz
Relocate alpha from ports to libc
Also fixed the following whitespace nits to satisfy the push: sysdeps/alpha/alphaev6/memset.S:142: space before tab in indent. sysdeps/alpha/configure:1: new blank line at EOF. sysdeps/alpha/fpu/e_sqrt.c:126: space before tab in indent. sysdeps/alpha/preconfigure:1: new blank line at EOF. sysdeps/unix/sysv/linux/alpha/syscalls.list:1: new blank line at EOF.
Diffstat (limited to 'sysdeps/unix/sysv/linux/alpha/clone.S')
-rw-r--r--sysdeps/unix/sysv/linux/alpha/clone.S143
1 files changed, 143 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/alpha/clone.S b/sysdeps/unix/sysv/linux/alpha/clone.S
new file mode 100644
index 0000000000..c5c3300c47
--- /dev/null
+++ b/sysdeps/unix/sysv/linux/alpha/clone.S
@@ -0,0 +1,143 @@
+/* Copyright (C) 1996-2014 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Richard Henderson <rth@tamu.edu>, 1996.
+
+ 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/>. */
+
+/* clone() is even more special than fork() as it mucks with stacks
+ and invokes a function in the right context after its all over. */
+
+#include <sysdep.h>
+#define _ERRNO_H 1
+#include <bits/errno.h>
+
+#define CLONE_VM 0x00000100
+#define CLONE_THREAD 0x00010000
+
+/* int clone(int (*fn)(void *arg), void *child_stack, int flags,
+ void *arg, pid_t *ptid, void *tls, pid_t *ctid);
+
+ Note that everything past ARG is technically optional, based
+ on FLAGS, and that CTID is arg 7, and thus is on the stack.
+ However, since a load from top-of-stack better be legal always,
+ we don't bother checking FLAGS. */
+
+ .text
+ .align 4
+ .globl __clone
+ .ent __clone
+ .usepv __clone, USEPV_PROF
+
+ cfi_startproc
+__clone:
+#ifdef PROF
+ ldgp gp,0(pv)
+ lda AT, _mcount
+ jsr AT, (AT), _mcount
+#endif
+
+ /* Sanity check arguments. */
+ ldiq v0, EINVAL
+ beq a0, SYSCALL_ERROR_LABEL /* no NULL function pointers */
+ beq a1, SYSCALL_ERROR_LABEL /* no NULL stack pointers */
+
+ /* Save the fn ptr and arg on the new stack. */
+ subq a1, 32, a1
+ stq a0, 0(a1)
+ stq a3, 8(a1)
+#ifdef RESET_PID
+ stq a2, 16(a1)
+#endif
+
+ /* The syscall is of the form clone(flags, usp, ptid, ctid, tls).
+ Shift the flags, ptid, ctid, tls arguments into place; the
+ child_stack argument is already correct. */
+ mov a2, a0
+ mov a4, a2
+ ldq a3, 0(sp)
+ mov a5, a4
+
+ /* Do the system call. */
+ ldiq v0, __NR_clone
+ call_pal PAL_callsys
+
+ bne a3, SYSCALL_ERROR_LABEL
+ beq v0, thread_start
+
+ /* Successful return from the parent. */
+ ret
+
+PSEUDO_END(__clone)
+ cfi_endproc
+
+/* Load up the arguments to the function. Put this block of code in
+ its own function so that we can terminate the stack trace with our
+ debug info. */
+
+ .ent thread_start
+ cfi_startproc
+thread_start:
+ mov 0, fp
+ cfi_def_cfa_register(fp)
+ cfi_undefined(ra)
+
+#ifdef RESET_PID
+ /* Check and see if we need to reset the PID. */
+ ldq t0, 16(sp)
+ lda t1, CLONE_THREAD
+ and t0, t1, t2
+ beq t2, 2f
+1:
+#endif
+
+ /* Load up the arguments. */
+ ldq pv, 0(sp)
+ ldq a0, 8(sp)
+ addq sp, 32, sp
+
+ /* Call the user's function. */
+ jsr ra, (pv)
+ ldgp gp, 0(ra)
+
+ /* Call _exit rather than doing it inline for breakpoint purposes. */
+ mov v0, a0
+#ifdef PIC
+ bsr ra, HIDDEN_JUMPTARGET(_exit) !samegp
+#else
+ jsr ra, HIDDEN_JUMPTARGET(_exit)
+#endif
+
+ /* Die horribly. */
+ halt
+
+#ifdef RESET_PID
+2:
+ rduniq
+ lda t1, CLONE_VM
+ mov v0, s0
+ lda v0, -1
+ and t0, t1, t2
+ bne t2, 3f
+ lda v0, __NR_getxpid
+ callsys
+3:
+ stl v0, PID_OFFSET(s0)
+ stl v0, TID_OFFSET(s0)
+ br 1b
+#endif
+ cfi_endproc
+ .end thread_start
+
+weak_alias (__clone, clone)