diff options
Diffstat (limited to 'ports/sysdeps/unix/sysv/linux/tile/nptl/clone.S')
| -rw-r--r-- | ports/sysdeps/unix/sysv/linux/tile/nptl/clone.S | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/ports/sysdeps/unix/sysv/linux/tile/nptl/clone.S b/ports/sysdeps/unix/sysv/linux/tile/nptl/clone.S new file mode 100644 index 0000000000..de4fa136d3 --- /dev/null +++ b/ports/sysdeps/unix/sysv/linux/tile/nptl/clone.S @@ -0,0 +1,220 @@ +/* Copyright (C) 2011-2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Chris Metcalf <cmetcalf@tilera.com>, 2011. + + 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 it's all over. */ + +#include <sysdep.h> +#define _ERRNO_H 1 +#include <bits/errno.h> + +#include <asm/unistd.h> +#include <arch/abi.h> +#include <tls.h> +#include <linux/sched.h> + +/* What we save where in the stack frame; must include all callee-saves. */ +#define FRAME_NEXT_LR (0 * REGSIZE) /* reserved by ABI; not used here */ +#define FRAME_SP (1 * REGSIZE) +#define FRAME_R30 (2 * REGSIZE) +#define FRAME_R31 (3 * REGSIZE) +#define FRAME_R32 (4 * REGSIZE) +#define FRAME_SIZE (5 * REGSIZE) + +/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg, + pid_t *ptid, struct user_desc *tls, pid_t *ctid); */ + + .text +ENTRY (__clone) + /* sanity check arguments */ + BEQZ r0, .Linvalid + BEQZ r1, .Linvalid + + /* Create a stack frame so we can pass callee-saves to new task. */ + { + move r10, sp + ST sp, lr + ADDI_PTR sp, sp, -FRAME_SIZE + } + cfi_offset (lr, 0) + cfi_def_cfa_offset (FRAME_SIZE) + ADDI_PTR r11, sp, FRAME_SP + { + ST r11, r10 + ADDI_PTR r11, sp, FRAME_R30 + } + { + ST r11, r30 + ADDI_PTR r11, sp, FRAME_R31 + } + cfi_offset (r30, FRAME_R30 - FRAME_SIZE) + { + ST r11, r31 + ADDI_PTR r11, sp, FRAME_R32 + } + cfi_offset (r31, FRAME_R31 - FRAME_SIZE) + ST r11, r32 + cfi_offset (r32, FRAME_R32 - FRAME_SIZE) + + /* Make sure child stack is properly aligned, and set up the + top frame so that we can call out of it immediately in the + child. Setting it up here means we fault in the parent if + it's bogus, which is probably cleaner than faulting first + thing in the child. */ + ADDI_PTR r1, r1, -C_ABI_SAVE_AREA_SIZE + andi r1, r1, -C_ABI_SAVE_AREA_SIZE + ADDI_PTR r9, r1, REGSIZE /* sp of this frame on entry, i.e. zero */ + ST r9, zero + + /* We need to switch the argument convention around from + libc to kernel: + + libc: + r0 fn + r1 child_stack + r2 flags + r3 arg + r4 ptid + r5 tls + r6 ctid + + kernel: + r0 flags + r1 child_stack [same as libc] + r2 ptid + r3 ctid + r4 tls + + Plus the callee-saves as described at .Lthread_start, below. */ + { + move r32, r0 + move r0, r2 + } + { + move r31, r3 + move r3, r6 + } + { + move r30, r2 + move r2, r4 + } + { + move r4, r5 + moveli TREG_SYSCALL_NR_NAME, __NR_clone + } + swint1 + BEQZ r0, .Lthread_start /* If in child task. */ + + /* Restore the callee-saved registers and return. */ + ADDLI_PTR lr, sp, FRAME_SIZE + { + LD lr, lr + ADDLI_PTR r30, sp, FRAME_R30 + } + { + LD r30, r30 + ADDLI_PTR r31, sp, FRAME_R31 + } + { + LD r31, r31 + ADDLI_PTR r32, sp, FRAME_R32 + } + { + LD r32, r32 + ADDI_PTR sp, sp, FRAME_SIZE + } + cfi_def_cfa_offset (0) + + BNEZ r1, .Lerror + jrp lr + +.Lerror: + j SYSCALL_ERROR_NAME + +.Linvalid: + { + movei r1, EINVAL + j SYSCALL_ERROR_NAME + } + +/* This function expects to receive: + + sp: the top of a valid stack area + r30: clone() flags + r31: the argument to pass to the user function + r32: the user function pointer */ + +.Lthread_start: + /* Check and see if we need to reset the PID, which we do if + CLONE_THREAD isn't set, i.e. we're not staying in the thread group. + If CLONE_VM is set, we're doing some kind of thread-like clone, + so we set the tid/pid to -1 to disable using the cached values + in getpid(). Otherwise (if CLONE_VM isn't set), it's a + fork-like clone, and we go ahead and write the cached values + from the true system pid (retrieved via __NR_getpid syscall). */ + cfi_def_cfa_offset (FRAME_SIZE) +#ifdef __tilegx__ + { + moveli r0, hw1_last(CLONE_VM) + moveli r1, hw1_last(CLONE_THREAD) + } + { + shl16insli r0, r0, hw0(CLONE_VM) + shl16insli r1, r1, hw0(CLONE_THREAD) + } +#else + { + moveli r0, lo16(CLONE_VM) + moveli r1, lo16(CLONE_THREAD) + } + { + auli r0, r0, ha16(CLONE_VM) + auli r1, r1, ha16(CLONE_THREAD) + } +#endif + { + and r0, r30, r0 + and r1, r30, r1 + } + BNEZ r1, .Lno_reset_pid /* CLONE_THREAD is set */ + { + movei r0, -1 + BNEZ r0, .Lgotpid /* CLONE_VM is set */ + } + moveli TREG_SYSCALL_NR_NAME, __NR_getpid + swint1 +.Lgotpid: + ADDLI_PTR r2, tp, PID_OFFSET + { + ST4 r2, r0 + ADDLI_PTR r2, tp, TID_OFFSET + } + ST4 r2, r0 +.Lno_reset_pid: + { + /* Invoke user function with specified argument. */ + move r0, r31 + jalr r32 + } + { + j HIDDEN_JUMPTARGET(_exit) + info INFO_OP_CANNOT_BACKTRACE /* Notify backtracer to stop. */ + } +PSEUDO_END (__clone) + +weak_alias (__clone, clone) |