Re: [Qemu-devel] [PATCH for 2.10 04/35] ivshmem: fix incorrect error handling in ivshmem_recv_msg()

[Markus Armbruster]

Philippe Mathieu-Daudé <address@hidden> writes:

> If qemu_chr_fe_read_all() returns -EINTR the do {} statement continues and the
> n accumulator used to complete reads upto sizeof(msg) is decremented by 4 (the
> value of EINTR on Linux).
> To avoid that, use simpler if() statements and continue if EINTR occured.
>
> hw/misc/ivshmem.c:650:14: warning: Loss of sign in implicit conversion
>     } while (n < sizeof(msg));
>              ^
>

Let's add "Screwed up in commit 3a55fc0f, v2.6.0."

> Reported-by: Clang Static Analyzer
> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> ---
> get_maintainer.pl: No maintainers found!
>
>  hw/misc/ivshmem.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
> index a58f9ee579..47a015f072 100644
> --- a/hw/misc/ivshmem.c
> +++ b/hw/misc/ivshmem.c
> @@ -642,7 +642,10 @@ static int64_t ivshmem_recv_msg(IVShmemState *s, int 
> *pfd, Error **errp)
>      do {
>          ret = qemu_chr_fe_read_all(&s->server_chr, (uint8_t *)&msg + n,
>                                     sizeof(msg) - n);
> -        if (ret < 0 && ret != -EINTR) {
> +        if (ret < 0) {
> +            if (ret == -EINTR) {
> +                continue;
> +            }
>              error_setg_errno(errp, -ret, "read from server failed");
>              return INT64_MIN;
>          }

Reviewed-by: Markus Armbruster <address@hidden>

Paolo, you taking this through your miscellaneous queue would save me
(and possibly Peter) a bit of work.  Only if you have something queued
already.  Let me know.