Commit 099d6b0f authored by Riku Voipio's avatar Riku Voipio Committed by Riku Voipio
Browse files

linux-user: implement pipe2 [v3] 



implement pipe2 syscall.

[v2] fix do_pipe on mips and sh4
[v3] use pipe2 to ensure atomicity, but only when it is available.

Signed-off-by: default avatarRiku Voipio <riku.voipio@iki.fi>
parent 4b627a23

configure

+21 −0
Original line number Diff line number Diff line
@@ -1304,6 +1304,24 @@ if $cc $ARCH_CFLAGS -o $TMPE $TMPC 2> /dev/null ; then 
  utimens=yes

fi



# check if pipe2 is there

pipe2=no

cat > $TMPC << EOF

#define _GNU_SOURCE

#include <unistd.h>

#include <fcntl.h>



int main(void)

{

    int pipefd[2];

    pipe2(pipefd, O_CLOEXEC);

    return 0;

}

EOF

if $cc $ARCH_CFLAGS -o $TMPE $TMPC 2> /dev/null ; then

  pipe2=yes

fi



# Check if tools are available to build documentation.

if test "$build_docs" = "yes" -a \( ! -x "`which texi2html 2>/dev/null`" -o ! -x "`which pod2man 2>/dev/null`" \) ; then

  build_docs="no"
@@ -1704,6 +1722,9 @@ fi 
if test "$utimens" = "yes" ; then

  echo "#define CONFIG_UTIMENSAT 1" >> $config_h

fi

if test "$pipe2" = "yes" ; then

  echo "#define CONFIG_PIPE2 1" >> $config_h

fi

if test "$inotify" = "yes" ; then

  echo "#define CONFIG_INOTIFY 1" >> $config_h

fi

linux-user/syscall.c

+37 −18
Original line number Diff line number Diff line
@@ -944,6 +944,37 @@ static abi_long do_select(int n, 
    return ret;

}



static abi_long do_pipe2(int host_pipe[], int flags)

{

#ifdef CONFIG_PIPE2

    return pipe2(host_pipe, flags);

#else

    return -ENOSYS;

#endif

}



static abi_long do_pipe(void *cpu_env, int pipedes, int flags)

{

    int host_pipe[2];

    abi_long ret;

    ret = flags ? do_pipe2(host_pipe, flags) : pipe(host_pipe);



    if (is_error(ret))

        return get_errno(ret);

#if defined(TARGET_MIPS)

    ((CPUMIPSState*)cpu_env)->active_tc.gpr[3] = host_pipe[1];

    ret = host_pipe[0];

#elif defined(TARGET_SH4)

    ((CPUSH4State*)cpu_env)->gregs[1] = host_pipe[1];

    ret = host_pipe[0];

#else

    if (put_user_s32(host_pipe[0], pipedes)

        || put_user_s32(host_pipe[1], pipedes + sizeof(host_pipe[0])))

        return -TARGET_EFAULT;

#endif

    return get_errno(ret);

}



static inline abi_long target_to_host_ip_mreq(struct ip_mreqn *mreqn,

                                              abi_ulong target_addr,

                                              socklen_t len)
@@ -4529,25 +4560,13 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1, 
        ret = get_errno(dup(arg1));

        break;

    case TARGET_NR_pipe:

        {

            int host_pipe[2];

            ret = get_errno(pipe(host_pipe));

            if (!is_error(ret)) {

#if defined(TARGET_MIPS)

                CPUMIPSState *env = (CPUMIPSState*)cpu_env;

		env->active_tc.gpr[3] = host_pipe[1];

		ret = host_pipe[0];

#elif defined(TARGET_SH4)

		((CPUSH4State*)cpu_env)->gregs[1] = host_pipe[1];

		ret = host_pipe[0];

#else

                if (put_user_s32(host_pipe[0], arg1)

                    || put_user_s32(host_pipe[1], arg1 + sizeof(host_pipe[0])))

                    goto efault;

#endif

            }

        }

        ret = do_pipe(cpu_env, arg1, 0);

        break;

#ifdef TARGET_NR_pipe2

    case TARGET_NR_pipe2:

        ret = do_pipe(cpu_env, arg1, arg2);

        break;

#endif

    case TARGET_NR_times:

        {

            struct target_tms *tmsp;