diff options
Diffstat (limited to 'sysdeps/unix/sysv/linux/hppa/clone.S')
| -rw-r--r-- | sysdeps/unix/sysv/linux/hppa/clone.S | 179 |
1 files changed, 179 insertions, 0 deletions
diff --git a/sysdeps/unix/sysv/linux/hppa/clone.S b/sysdeps/unix/sysv/linux/hppa/clone.S new file mode 100644 index 0000000000..1a3c6c800d --- /dev/null +++ b/sysdeps/unix/sysv/linux/hppa/clone.S @@ -0,0 +1,179 @@ +/* Copyright (C) 1996-2014 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by David Huggins-Daines <dhd@debian.org>, 2000. + Based on the Alpha version 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 <asm/unistd.h> +#include <sysdep.h> +#define _ERRNO_H 1 +#include <bits/errno.h> + +/* Non-thread code calls __clone with the following parameters: + int clone(int (*fn)(void *arg), + void *child_stack, + int flags, + void *arg) + + NPTL Code will call __clone with the following parameters: + int clone(int (*fn)(void *arg), + void *child_stack, + int flags, + void *arg, + int *parent_tidptr, + struct user_desc *newtls, + int *child_pidptr) + + The code should not mangle the extra input registers. + Syscall expects: Input to __clone: + 4(r25) - function pointer (r26, arg0) + 0(r25) - argument (r23, arg3) + r26 - clone flags. (r24, arg2) + r25+64 - user stack pointer. (r25, arg1) + r24 - parent tid pointer. (stack - 52) + r23 - struct user_desc newtls pointer. (stack - 56) + r22 - child tid pointer. (stack - 60) + r20 - clone syscall number (constant) + + Return: + + On success the thread ID of the child process is returend in + the callers context. + On error return -1, and set errno to the value returned by + the syscall. + */ + + .text +ENTRY(__clone) + /* Prologue */ + stwm %r4, 64(%sp) + stw %sp, -4(%sp) +#ifdef PIC + stw %r19, -32(%sp) +#endif + + /* Sanity check arguments. */ + comib,=,n 0, %arg0, .LerrorSanity /* no NULL function pointers */ + comib,=,n 0, %arg1, .LerrorSanity /* no NULL stack pointers */ + + /* Save the function pointer, arg, and flags on the new stack. */ + stwm %r26, 64(%r25) + stw %r23, -60(%r25) + stw %r24, -56(%r25) + /* Clone arguments are (int flags, void * child_stack) */ + copy %r24, %r26 /* flags are first */ + /* User stack pointer is in the correct register already */ + + /* Load args from stack... */ + ldw -116(%sp), %r24 /* Load parent_tidptr */ + ldw -120(%sp), %r23 /* Load newtls */ + ldw -124(%sp), %r22 /* Load child_tidptr */ + + /* Save the PIC register. */ +#ifdef PIC + copy %r19, %r4 /* parent */ +#endif + + /* Do the system call */ + ble 0x100(%sr2, %r0) + ldi __NR_clone, %r20 + + ldi -4096, %r1 + comclr,>>= %r1, %ret0, %r0 /* Note: unsigned compare. */ + b,n .LerrorRest + + /* Restore the PIC register. */ +#ifdef PIC + copy %r4, %r19 /* parent */ +#endif + + comib,=,n 0, %ret0, .LthreadStart + + /* Successful return from the parent + No need to restore the PIC register, + since we return immediately. */ + + ldw -84(%sp), %rp + bv %r0(%rp) + ldwm -64(%sp), %r4 + +.LerrorRest: + /* Something bad happened -- no child created */ + bl __syscall_error, %rp + sub %r0, %ret0, %arg0 + ldw -84(%sp), %rp + /* Return after setting errno, ret0 is set to -1 by __syscall_error. */ + bv %r0(%rp) + ldwm -64(%sp), %r4 + +.LerrorSanity: + /* Sanity checks failed, return -1, and set errno to EINVAL. */ + bl __syscall_error, %rp + ldi EINVAL, %arg0 + ldw -84(%sp), %rp + bv %r0(%rp) + ldwm -64(%sp), %r4 + +.LthreadStart: +#ifdef RESET_PID +# define CLONE_VM_BIT 23 /* 0x00000100 */ +# define CLONE_THREAD_BIT 15 /* 0x00010000 */ + /* Load original clone flags. + If CLONE_THREAD was passed, don't reset the PID/TID. + If CLONE_VM was passed, we need to store -1 to PID/TID. + If CLONE_VM and CLONE_THREAD were not set store the result + of getpid to PID/TID. */ + ldw -56(%sp), %r26 + bb,<,n %r26, CLONE_THREAD_BIT, 1f + bb,< %r26, CLONE_VM_BIT, 2f + ldi -1, %ret0 + ble 0x100(%sr2, %r0) + ldi __NR_getpid, %r20 +2: + mfctl %cr27, %r26 + stw %ret0, PID_THREAD_OFFSET(%r26) + stw %ret0, TID_THREAD_OFFSET(%r26) +1: +#endif + /* Load up the arguments. */ + ldw -60(%sp), %arg0 + ldw -64(%sp), %r22 + + /* $$dyncall fixes child's PIC register */ + + /* Call the user's function */ +#ifdef PIC + copy %r19, %r4 +#endif + bl $$dyncall, %r31 + copy %r31, %rp +#ifdef PIC + copy %r4, %r19 +#endif + /* The call to _exit needs saved r19. */ + bl _exit, %rp + copy %ret0, %arg0 + + /* We should not return from _exit. + We do not restore r4, or the stack state. */ + iitlbp %r0, (%sr0, %r0) + +PSEUDO_END(__clone) + +weak_alias (__clone, clone) |