Re: [Qemu-devel] [PATCH RESEND 3/3] qga: fix compiler warnings (clang 5)

[Michael Roth]

Quoting Philippe Mathieu-Daudé (2017-03-22 15:48:44)
> static code analyzer complain:
> 
> qga/commands-posix.c:2127:9: warning: Null pointer passed as an argument to a 
> 'nonnull' parameter
>         closedir(dp);
>         ^~~~~~~~~~~~
> 
> Reported-by: Clang Static Analyzer
> Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> Reviewed-by: Marc-André Lureau <address@hidden>
> ---
>  qga/commands-posix.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> index 73d93eb5ce..8028141534 100644
> --- a/qga/commands-posix.c
> +++ b/qga/commands-posix.c
> @@ -2122,9 +2122,11 @@ static void transfer_memory_block(GuestMemoryBlock 
> *mem_blk, bool sys2memblk,
>           * we think this VM does not support online/offline memory block,
>           * any other solution?
>           */
> -        if (!dp && errno == ENOENT) {
> -            result->response =
> -                GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_NOT_SUPPORTED;
> +        if (!dp) {
> +            if (errno == ENOENT) {
> +                result->response =
> +                    GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_NOT_SUPPORTED;
> +            }
>              goto out1;
>          }

I think this should be:

    if (!dp) {
        if (errno == ENOENT) {
            result->response =
                GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_NOT_SUPPORTED;
        } else {
            result->response =
                GUEST_MEMORY_BLOCK_RESPONSE_TYPE_OPERATION_FAILED;
        }
        goto out1;
    }

otherwise we might set result->error_code while still indicating
success for the operation. That wasn't handled properly before your
patch either, it's just more apparent now.

>          closedir(dp);
> -- 
> 2.11.0
>