Re: [Qemu-devel] [PATCH] linux-user: remove all traces of qemu from /proc/self/cmdline

[Riku Voipio]

On Mon, Mar 20, 2017 at 12:31:55PM +0100, Andreas Schwab wrote:
> Instead of post-processing the real contents use the remembered target
> argv.  That removes all traces of qemu, including command line options,
> and handles QEMU_ARGV0.

Applied to Linux-user, thanks

Riku
 
> Signed-off-by: Andreas Schwab <address@hidden>
> ---
>  linux-user/syscall.c | 47 +++++++----------------------------------------
>  1 file changed, 7 insertions(+), 40 deletions(-)
> 
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index cec8428589..ec1fd20386 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -7358,52 +7358,19 @@ int host_to_target_waitstatus(int status)
>  
>  static int open_self_cmdline(void *cpu_env, int fd)
>  {
> -    int fd_orig = -1;
> -    bool word_skipped = false;
> -
> -    fd_orig = open("/proc/self/cmdline", O_RDONLY);
> -    if (fd_orig < 0) {
> -        return fd_orig;
> -    }
> +    CPUState *cpu = ENV_GET_CPU((CPUArchState *)cpu_env);
> +    struct linux_binprm *bprm = ((TaskState *)cpu->opaque)->bprm;
> +    int i;
>  
> -    while (true) {
> -        ssize_t nb_read;
> -        char buf[128];
> -        char *cp_buf = buf;
> +    for (i = 0; i < bprm->argc; i++) {
> +        size_t len = strlen(bprm->argv[i]) + 1;
>  
> -        nb_read = read(fd_orig, buf, sizeof(buf));
> -        if (nb_read < 0) {
> -            int e = errno;
> -            fd_orig = close(fd_orig);
> -            errno = e;
> +        if (write(fd, bprm->argv[i], len) != len) {
>              return -1;
> -        } else if (nb_read == 0) {
> -            break;
> -        }
> -
> -        if (!word_skipped) {
> -            /* Skip the first string, which is the path to qemu-*-static
> -               instead of the actual command. */
> -            cp_buf = memchr(buf, 0, nb_read);
> -            if (cp_buf) {
> -                /* Null byte found, skip one string */
> -                cp_buf++;
> -                nb_read -= cp_buf - buf;
> -                word_skipped = true;
> -            }
> -        }
> -
> -        if (word_skipped) {
> -            if (write(fd, cp_buf, nb_read) != nb_read) {
> -                int e = errno;
> -                close(fd_orig);
> -                errno = e;
> -                return -1;
> -            }
>          }
>      }
>  
> -    return close(fd_orig);
> +    return 0;
>  }
>  
>  static int open_self_maps(void *cpu_env, int fd)
> -- 
> 2.12.0
> 
> 
> -- 
> Andreas Schwab, SUSE Labs, address@hidden
> GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE  1748 E4D4 88E3 0EEA B9D7
> "And now for something completely different."