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aarch64: Consolidate NPTL/non versions of clone 

At the same time, rely on non-clobbered registers across syscall
so that we eliminate the stack frame that we previously ignored
in the unwind info.
This commit is contained in:
Richard Henderson 2014-05-23 15:44:23 -04:00
parent ccc3991113
commit 111cc71489
3 changed files with 32 additions and 55 deletions
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6
ChangeLog
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@ -1,3 +1,9 @@
2014-06-03 Richard Henderson <rth@redhat.com>
* sysdeps/unix/sysv/linux/aarch64/clone.S (__clone): Save args for
child in registers, not on the stack. Remove RESET_PID conditionals.
* sysdeps/unix/sysv/linux/aarch64/nptl/clone.S: Remove file.
2014-06-03 Marcus Shawcroft <marcus.shawcroft@arm.com>
* sysdeps/aarch64/libm-test-ulps: Regenerate.

60
sysdeps/unix/sysv/linux/aarch64/clone.S
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@ -39,47 +39,42 @@
*/
.text
ENTRY(__clone)
/* Save args for the child. */
mov x10, x0
mov x11, x2
mov x12, x3
/* Sanity check args. */
cbz x0, 1f
cbz x1, 1f
/* Insert the args onto the new stack. */
stp x0, x3, [x1, #-16]! /* Fn, arg. */
mov x0, #-EINVAL
cbz x10, .Lsyscall_error
cbz x1, .Lsyscall_error
/* Do the system call. */
/* X0:flags, x1:newsp, x2:parenttidptr, x3:newtls, x4:childtid. */
mov x0, x2 /* flags */
/* New sp is already in x1. */
mov x2, x4 /* ptid */
mov x3, x5 /* tls */
mov x4, x6 /* ctid */
#ifdef RESET_PID
/* We rely on the kernel preserving the argument regsiters across a
each system call so that we can inspect the flags against after
the clone call. */
mov x5, x0
#endif
mov x8, #SYS_ify(clone)
/* X0:flags, x1:newsp, x2:parenttidptr, x3:newtls, x4:childtid. */
svc 0x0
cfi_endproc
cmp x0, #0
beq 2f
blt 3f
RET
1: mov x0, #-EINVAL
3:
b syscall_error
2:
cmp x0, #0
beq thread_start
blt .Lsyscall_error
RET
PSEUDO_END (__clone)
.align 4
.type thread_start, %function
thread_start:
cfi_startproc
cfi_undefined (x30)
mov x29, 0
#ifdef RESET_PID
tbnz x5, #CLONE_THREAD_BIT, 3f
tbnz x11, #CLONE_THREAD_BIT, 3f
mov x0, #-1
tbnz x5, #CLONE_VM_BIT, 2f
tbnz x11, #CLONE_VM_BIT, 2f
mov x8, #SYS_ify(getpid)
svc 0x0
2:
@ -87,18 +82,15 @@ ENTRY(__clone)
sub x1, x1, #PTHREAD_SIZEOF
str w0, [x1, #PTHREAD_PID_OFFSET]
str w0, [x1, #PTHREAD_TID_OFFSET]
3:
#endif
/* Pick the function arg and call address from the stack and
execute. */
ldp x1, x0, [sp], #16
blr x1
/* Pick the function arg and execute. */
mov x0, x12
blr x10
/* We are done, pass the return value through x0. */
b HIDDEN_JUMPTARGET(_exit)
cfi_endproc
cfi_startproc
PSEUDO_END (__clone)
.size thread_start, .-thread_start
weak_alias (__clone, clone)

21
sysdeps/unix/sysv/linux/aarch64/nptl/clone.S
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@ -1,21 +0,0 @@
/* Copyright (C) 2009-2014 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, see
<http://www.gnu.org/licenses/>. */
#define RESET_PID
#include <tcb-offsets.h>
#include "../clone.S"