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.

diff --git a/ChangeLog b/ChangeLog
index d00c7d4979778af88dac79f142c593612f88e3c7..2b30915f6d5f8a2c9cb4374f32d5c09b6e0c99a9 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -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.

diff --git a/sysdeps/unix/sysv/linux/aarch64/clone.S b/sysdeps/unix/sysv/linux/aarch64/clone.S
index f2964f48716c3bfbc428b9c69b65e2568edff40b..a2b5a2bc24cea84292340b704bb2b9b5594b5b93 100644 (file)
--- a/sysdeps/unix/sysv/linux/aarch64/clone.S
+++ b/sysdeps/unix/sysv/linux/aarch64/clone.S
@@ -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
+       beq     thread_start
+       blt     .Lsyscall_error
        RET
-1:     mov     x0, #-EINVAL
-3:
-       b       syscall_error
+PSEUDO_END (__clone)
 
-2:
+       .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)

diff --git a/sysdeps/unix/sysv/linux/aarch64/nptl/clone.S b/sysdeps/unix/sysv/linux/aarch64/nptl/clone.S
deleted file mode 100644 (file)
index 281be3b..0000000
--- a/sysdeps/unix/sysv/linux/aarch64/nptl/clone.S
+++ /dev/null
@@ -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"