[v3,17/21] nptl: riscv: Fix Race conditions in pthread cancellation (BZ#12683)

  This patch adds the riscv modifications required for the BZ#12683 fix
by adding the arch-specific cancellation syscall bridge.
---
 .../unix/sysv/linux/riscv/syscall_cancel.S    | 68 +++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 sysdeps/unix/sysv/linux/riscv/syscall_cancel.S
  

The riscv changes look fine to me (but I didn't do any testing).


On Mon, Oct 14, 2019 at 2:00 PM Adhemerval Zanella
<adhemerval.zanella@linaro.org> wrote:
>
> This patch adds the riscv modifications required for the BZ#12683 fix
> by adding the arch-specific cancellation syscall bridge.
> ---
>  .../unix/sysv/linux/riscv/syscall_cancel.S    | 68 +++++++++++++++++++
>  1 file changed, 68 insertions(+)
>  create mode 100644 sysdeps/unix/sysv/linux/riscv/syscall_cancel.S
>
> diff --git a/sysdeps/unix/sysv/linux/riscv/syscall_cancel.S b/sysdeps/unix/sysv/linux/riscv/syscall_cancel.S
> new file mode 100644
> index 0000000000..38fd630c6d
> --- /dev/null
> +++ b/sysdeps/unix/sysv/linux/riscv/syscall_cancel.S
> @@ -0,0 +1,68 @@
> +/* Cancellable syscall wrapper.  Linux/riscv version.
> +   Copyright (C) 2019 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/>.  */
> +
> +#include <sysdep.h>
> +
> +/* long int __syscall_cancel_arch (int *cancelhandling,
> +                                  __syscall_arg_t nr,
> +                                  __syscall_arg_t arg1,
> +                                  __syscall_arg_t arg2,
> +                                  __syscall_arg_t arg3,
> +                                  __syscall_arg_t arg4,
> +                                  __syscall_arg_t arg5,
> +                                  __syscall_arg_t arg6)  */
> +
> +#ifdef SHARED
> +       .option pic
> +#else
> +       .option nopic
> +#endif
> +
> +ENTRY (__syscall_cancel_arch)
> +       mv      t1, a7
> +
> +       .globl __syscall_cancel_arch_start
> +       .type  __syscall_cancel_arch_start,@function
> +__syscall_cancel_arch_start:
> +       lw      a7, 0(a0)
> +       andi    a7, a7, 4       /* if (*ch & CANCELED_BITMASK)  */
> +       bnez    a7, 1f
> +
> +       mv      a7,a1
> +       mv      a0,a2
> +       mv      a1,a3
> +       mv      a2,a4
> +       mv      a3,a5
> +       mv      a4,a6
> +       mv      a5,t1
> +       scall
> +
> +       .globl __syscall_cancel_arch_end
> +       .type  __syscall_cancel_arch_end,@function
> +__syscall_cancel_arch_end:
> +       ret
> +
> +1:
> +       addi    sp, sp, -16
> +       cfi_def_cfa_offset (16)
> +       sd      ra, 8(sp)
> +       cfi_offset (ra, -8)
> +       call    __syscall_do_cancel
> +
> +END (__syscall_cancel_arch)
> +libc_hidden_def (__syscall_cancel_arch)
> --
> 2.17.1
>