Re: [PATCH] selftests/android/ion: fix heap_type may be uninitialized

From: Pintu Kumar
Date: Fri Mar 16 2018 - 06:14:18 EST


On Thu, Mar 8, 2018 at 7:18 PM, Anders Roxell <anders.roxell@xxxxxxxxxx> wrote:
> gcc warns that 'heap_type' is not initialized if we don't come through
> any of the two 'case' statesments before:
>

OK thanks for your patch.

> ionapp_export.c:91:2: warning: âheap_typeâ may be used uninitialized in
> this function [-Wmaybe-uninitialized]
> printf("heap_type: %ld, heap_size: %ld\n", heap_type, heap_size);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> In the current code, we initialize the heap_type to -1 before the 'case'
> statements. We also change the print_usage function to state that
> heap_type and heap_size isn't optional, they are mandatory.
>

OK

> Fixes: 47a18c42d992 ("android/ion: userspace test utility for ion buffer sharing")
> Signed-off-by: Anders Roxell <anders.roxell@xxxxxxxxxx>
> ---
> .../testing/selftests/android/ion/ionapp_export.c | 23 +++++++++++++++++++---
> 1 file changed, 20 insertions(+), 3 deletions(-)
>
> diff --git a/tools/testing/selftests/android/ion/ionapp_export.c b/tools/testing/selftests/android/ion/ionapp_export.c
> index a944e72621a9..b42f803e9d2a 100644
> --- a/tools/testing/selftests/android/ion/ionapp_export.c
> +++ b/tools/testing/selftests/android/ion/ionapp_export.c
> @@ -31,16 +31,24 @@
>
> void print_usage(int argc, char *argv[])
> {
> - printf("Usage: %s [-h <help>] [-i <heap id>] [-s <size in bytes>]\n",
> + printf("Usage: %s [-h <help>] -i <heap id> -s <size in bytes>\n",
> argv[0]);
> }
>
> +void heap_type_error_text(void)
> +{
> + printf("heap_type must be specified\n");
> + printf(" need to specify -i <heap_type>\n");
> + printf(" supported heap types 0 or 1\n");
> +}
> +

I think this error function needs to be generic.
See explanation below.


> int main(int argc, char *argv[])
> {
> int opt, ret, status, heapid;
> int sockfd, client_fd, shared_fd;
> unsigned char *map_buf;
> - unsigned long map_len, heap_type, heap_size, flags;
> + unsigned long map_len, heap_size, flags;
> + long heap_type;
> struct ion_buffer_info info;
> struct socket_info skinfo;
>
> @@ -50,6 +58,7 @@ int main(int argc, char *argv[])
> }
>
> heap_size = 0;
> + heap_type = -1;
> flags = 0;
>
> while ((opt = getopt(argc, argv, "hi:s:")) != -1) {
> @@ -68,7 +77,8 @@ int main(int argc, char *argv[])
> heap_type = ION_HEAP_TYPE_SYSTEM_CONTIG;
> break;
> default:
> - printf("ERROR: heap type not supported\n");
> + heap_type_error_text();
> + print_usage(argc, argv);
> exit(1);
> }
> break;
> @@ -82,8 +92,15 @@ int main(int argc, char *argv[])
> }
> }
>
> + if (heap_type < 0) {
> + heap_type_error_text();
> + print_usage(argc, argv);
> + exit(1);
> + }
> +
> if (heap_size <= 0) {
> printf("heap_size cannot be 0\n");
> + printf(" need to specify -s <heap_size>\n");
> print_usage(argc, argv);
> exit(1);
> }

I think both heap_type and heap_size error message is almost same.
How about creating a common error handler for both ?
Also it may be possible to merge both the above.
Or, another option is to make use of print_usage function itself,
instead of one more function.


> --
> 2.11.0
>