Re: [Qemu-devel] [PATCH 4/6] alpha-linux-user: Fix sigaction

[Riku Voipio <riku.voipio@iki.fi>]

Hi,

This patch doesn't compile for me on ubuntu 12.04 x86_64 host:

  CC    linux-user/signal.o 
/home/voipio/test/qemu/linux-user/signal.c: In function ‘do_sigaction’:
/home/voipio/test/qemu/linux-user/signal.c:620:9: error: passing
argument 1 of ‘memcpy’ discards ‘const’ qualifier from pointer target
type [-Werror]
/usr/include/x86_64-linux-gnu/bits/string3.h:49:1: note: expected ‘void
* __restrict__’ but argument is of type ‘const long unsigned int *’
/home/voipio/test/qemu/linux-user/signal.c:620:9: error: assignment of
read-only variable ‘gu_’
/home/voipio/test/qemu/linux-user/signal.c:620:9: error: assignment of
read-only variable ‘gu_’
/home/voipio/test/qemu/linux-user/signal.c:620:9: error: assignment of
read-only variable ‘gu_’
/home/voipio/test/qemu/linux-user/signal.c:621:9: error: passing
argument 1 of ‘memcpy’ discards ‘const’ qualifier from pointer target
type [-Werror]
/usr/include/x86_64-linux-gnu/bits/string3.h:49:1: note: expected ‘void
* __restrict__’ but argument is of type ‘const long unsigned int *’
/home/voipio/test/qemu/linux-user/signal.c:621:9: error: assignment of
read-only variable ‘gu_’
/home/voipio/test/qemu/linux-user/signal.c:621:9: error: assignment of
read-only variable ‘gu_’
/home/voipio/test/qemu/linux-user/signal.c:621:9: error: assignment of
read-only variable ‘gu_’
/home/voipio/test/qemu/linux-user/signal.c:623:9: error: passing
argument 1 of ‘memcpy’ discards ‘const’ qualifier from pointer target
type [-Werror]
/usr/include/x86_64-linux-gnu/bits/string3.h:49:1: note: expected ‘void
* __restrict__’ but argument is of type ‘const long unsigned int *’
/home/voipio/test/qemu/linux-user/signal.c:623:9: error: assignment of
read-only variable ‘gu_’
/home/voipio/test/qemu/linux-user/signal.c:623:9: error: assignment of
read-only variable ‘gu_’
/home/voipio/test/qemu/linux-user/signal.c:623:9: error: assignment of
read-only variable ‘gu_’
cc1: all warnings being treated as errors
make: *** [linux-user/signal.o] Error 1


On Fri, Sep 21, 2012 at 07:17:12AM -0700, Richard Henderson wrote:
> Unconditional bswap replaced by __get_user/__put_user.
> 
> Signed-off-by: Richard Henderson <rth@twiddle.net>
> ---
>  linux-user/signal.c       | 22 ++++++++--------------
>  linux-user/syscall_defs.h |  2 +-
>  2 files changed, 9 insertions(+), 15 deletions(-)
> 
> diff --git a/linux-user/signal.c b/linux-user/signal.c
> index 7869147..bf2dfb8 100644
> --- a/linux-user/signal.c
> +++ b/linux-user/signal.c
> @@ -586,28 +586,22 @@ int do_sigaction(int sig, const struct target_sigaction *act,
>              sig, act, oact);
>  #endif
>      if (oact) {
> -        oact->_sa_handler = tswapal(k->_sa_handler);
> -#if defined(TARGET_MIPS) || defined (TARGET_ALPHA)
> -        oact->sa_flags = bswap32(k->sa_flags);
> -#else
> -        oact->sa_flags = tswapal(k->sa_flags);
> -#endif
> +        __put_user(k->_sa_handler, &oact->_sa_handler);
> +        __put_user(k->sa_flags, &oact->sa_flags);
>  #if !defined(TARGET_MIPS)
> -        oact->sa_restorer = tswapal(k->sa_restorer);
> +        __put_user(k->sa_restorer, &oact->sa_restorer);
>  #endif
> +        /* Not swapped.  */
>          oact->sa_mask = k->sa_mask;
>      }
>      if (act) {
>          /* FIXME: This is not threadsafe.  */
> -        k->_sa_handler = tswapal(act->_sa_handler);
> -#if defined(TARGET_MIPS) || defined (TARGET_ALPHA)
> -        k->sa_flags = bswap32(act->sa_flags);
> -#else
> -        k->sa_flags = tswapal(act->sa_flags);
> -#endif
> +        __get_user(k->_sa_handler, &act->_sa_handler);
> +        __get_user(k->sa_flags, &act->sa_flags);
>  #if !defined(TARGET_MIPS)
> -        k->sa_restorer = tswapal(act->sa_restorer);
> +        __get_user(k->sa_restorer, &act->sa_restorer);
>  #endif
> +        /* To be swapped in target_to_host_sigset.  */
>          k->sa_mask = act->sa_mask;
>  
>          /* we update the host linux signal state */
> diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
> index a98cbf7..8ca70b9 100644
> --- a/linux-user/syscall_defs.h
> +++ b/linux-user/syscall_defs.h
> @@ -540,7 +540,7 @@ int do_sigaction(int sig, const struct target_sigaction *act,
>  struct target_old_sigaction {
>      abi_ulong _sa_handler;
>      abi_ulong sa_mask;
> -    abi_ulong sa_flags;
> +    int32_t sa_flags;
>  };
>  
>  struct target_rt_sigaction {
> -- 
> 1.7.11.4