AFAICT, char is unsigned on s390. Relying on that is a little
subtle. The problem here is that if char happens to be signed and
e.g. card->info.mcl_level[2] contains the value -16, the formatted
output will be "fffffff0", thus overflowing card->info.mcl_level
(which has size 5). To help future readers, simply do an explicit mask
so that the value passed to sprintf is in 0-255. If char is indeed
unsigned, gcc should be able to elide the masking.
In any case, the subsequent 0-termination is redundant, since sprintf
has done that.
Signed-off-by: Rasmus Villemoes <[email protected]>
---
drivers/s390/net/qeth_core_main.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 31ac53fa5cee..84bc4b862fbb 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -2682,10 +2682,8 @@ void qeth_print_status_message(struct qeth_card *card)
* */
if (!card->info.mcl_level[0]) {
sprintf(card->info.mcl_level, "%02x%02x",
- card->info.mcl_level[2],
- card->info.mcl_level[3]);
-
- card->info.mcl_level[QETH_MCL_LENGTH] = 0;
+ card->info.mcl_level[2] & 0xff,
+ card->info.mcl_level[3] & 0xff);
break;
}
/* fallthrough */
--
2.6.1
Rasmus,
I do not see a need for your first patch proposal. Our code works fine
in our environment.
But I will pickup your second part to remove the explicit setting of the
0-termination. Thanks!
Regards, Ursula
On Sat, 2015-12-05 at 22:32 +0100, Rasmus Villemoes wrote:
> AFAICT, char is unsigned on s390. Relying on that is a little
> subtle. The problem here is that if char happens to be signed and
> e.g. card->info.mcl_level[2] contains the value -16, the formatted
> output will be "fffffff0", thus overflowing card->info.mcl_level
> (which has size 5). To help future readers, simply do an explicit mask
> so that the value passed to sprintf is in 0-255. If char is indeed
> unsigned, gcc should be able to elide the masking.
>
> In any case, the subsequent 0-termination is redundant, since sprintf
> has done that.
>
> Signed-off-by: Rasmus Villemoes <[email protected]>
> ---
> drivers/s390/net/qeth_core_main.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
> index 31ac53fa5cee..84bc4b862fbb 100644
> --- a/drivers/s390/net/qeth_core_main.c
> +++ b/drivers/s390/net/qeth_core_main.c
> @@ -2682,10 +2682,8 @@ void qeth_print_status_message(struct qeth_card *card)
> * */
> if (!card->info.mcl_level[0]) {
> sprintf(card->info.mcl_level, "%02x%02x",
> - card->info.mcl_level[2],
> - card->info.mcl_level[3]);
> -
> - card->info.mcl_level[QETH_MCL_LENGTH] = 0;
> + card->info.mcl_level[2] & 0xff,
> + card->info.mcl_level[3] & 0xff);
> break;
> }
> /* fallthrough */
On Mon, Dec 07, 2015 at 01:02:35PM +0100, Ursula Braun wrote:
> Rasmus,
>
> I do not see a need for your first patch proposal. Our code works fine
> in our environment.
>
> But I will pickup your second part to remove the explicit setting of the
> 0-termination. Thanks!
>
> Regards, Ursula
Hi Uschi,
das untenstehende habe ich schon diverse male geschrieben, um zu
verhindern, dass "wir" uns mit einfach vermeidbaren Dingen auf externen
Mailinglisten unbeliebt machen:
Just a general comment and unrelated to this patch.
Please, when replying:
- don't top-post
- use interleaved style with an empty line after each quoted block
- trim your replies to only the relevant parts
See also: https://en.wikipedia.org/wiki/Posting_style
This should make your and everybody else's life easier when your are
participating on external mailing lists.
On Mon, Dec 07, 2015 at 02:47:44PM +0100, Heiko Carstens wrote:
> On Mon, Dec 07, 2015 at 01:02:35PM +0100, Ursula Braun wrote:
> > Rasmus,
> >
> > I do not see a need for your first patch proposal. Our code works fine
> > in our environment.
> >
> > But I will pickup your second part to remove the explicit setting of the
> > 0-termination. Thanks!
> >
> > Regards, Ursula
>
> Hi Uschi,
>
> das untenstehende habe ich schon diverse male geschrieben, um zu
> verhindern, dass "wir" uns mit einfach vermeidbaren Dingen auf externen
> Mailinglisten unbeliebt machen:
Ooops, this was not supposed to go to everybody... ;)