-/* Copyright (C) 1996, 1997, 2000 Free Software Foundation, Inc.
+/* Copyright (C) 1996-2019 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.
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. */
+ 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>
-
-/* int clone(int (*fn)(void *arg), void *child_stack, int flags, void *arg) */
+#include <tcb-offsets.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)
- /* FIXME: I have no idea how profiling works on hppa. */
+ /* Prologue */
+ stwm %r4, 64(%sp)
+ .cfi_def_cfa_offset -64
+ .cfi_offset 4, 0
+ stw %sp, -4(%sp)
+#ifdef PIC
+ stw %r19, -32(%sp)
+ .cfi_offset 19, 32
+#endif
/* Sanity check arguments. */
- comib,= 0,%arg0,.Lerror /* no NULL function pointers */
- ldi -EINVAL,%ret0
- comib,= 0,%arg1,.Lerror /* no NULL stack pointers */
- nop
-
- /* Save the fn ptr and arg on the new stack. */
- stwm %arg0,64(%arg1)
- stw %arg3,-60(%arg1)
+ 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
- stw %r19,-32(%sr0, %sp) /* parent */
+ copy %r19, %r4 /* parent */
#endif
/* Do the system call */
- copy %arg2,%arg0
- ble 0x100(%sr2,%r0)
- ldi __NR_clone,%r20
+ ble 0x100(%sr2, %r0)
+ ldi __NR_clone, %r20
- ldi -4096,%r1
- comclr,>>= %r1,%ret0,%r0 /* Note: unsigned compare. */
- b,n .Lerror
+ ldi -4096, %r1
+ comclr,>>= %r1, %ret0, %r0 /* Note: unsigned compare. */
+ b,n .LerrorRest
- comib,=,n 0,%ret0,thread_start
+ /* 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,
+ No need to restore the PIC register,
since we return immediately. */
+ ldw -84(%sp), %rp
bv %r0(%rp)
- nop
+ ldwm -64(%sp), %r4
+.LerrorRest:
/* Something bad happened -- no child created */
-.Lerror:
-
- /* Restore the PIC register on error */
-#ifdef PIC
- ldw -32(%sr0, %sp), %r19 /* parent */
-#endif
-
- b __syscall_error
- sub %r0,%ret0,%arg0
+ 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
-thread_start:
+.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:
/* Load up the arguments. */
- ldw -60(%sr0, %sp),%arg0
- ldw -64(%sr0, %sp),%r22
+ ldw -60(%sp), %arg0
+ ldw -64(%sp), %r22
- /* $$dyncall fixes childs PIC register */
+ /* $$dyncall fixes child's PIC register */
/* Call the user's function */
- bl $$dyncall,%r31
- copy %r31,%rp
-
- bl _exit,%rp
- copy %ret0,%arg0
+#ifdef PIC
+ copy %r19, %r4
+#endif
+ bl $$dyncall, %r31
+ copy %r31, %rp
+#ifdef PIC
+ copy %r4, %r19
+#endif
+ copy %r28, %r26
+ ble 0x100(%sr2, %r0)
+ ldi __NR_exit, %r20
- /* Die horribly. */
- iitlbp %r0,(%r0)
+ /* 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)
+libc_hidden_def (__clone)
+weak_alias (__clone, clone)
projects / thirdparty / glibc.git / blobdiff