On Thu, 2009-04-09 at 22:17 -0700, Andrew Morton wrote: > On Fri, 10 Apr 2009 05:08:54 +0000 Andrew Patterson <andrew.patterson@xxxxxx> wrote: > > > > > + char model[MODEL_LEN + 1]; > > > > ... > > > > + return snprintf(buf, MODEL_LEN + 2, "%s\n", drv->model); > > > > > > Isn't the buffer sizing wrong here? Should be MODEL_LEN+1. > > > > > > > Don't we need space for the '\0' and the '\n'? > > The second arg to snprintf() tells snprintf() how large the buffer is. > That buffer should be sized to allow room for the trailing \0. > > So if MODEL_LEN represents the maximum number of characters in a string > then you want: > > char model[MODEL_LEN + 2]; /* Room for the \n and the \0 */ > ... > return snprintf(buf, sizeof(model), "%s\n", drv->model); Note that I don't want the '\n" in the source string. I just want it output to the dest string (buf). I could do: return snprintf(buf, sizeof(model) + 1, "%s\n", drv->model); if that is preferable. Perhaps what is confusing is using: #define MODEL_LEN 16 char model[MODEL_LEN + 1]; /* SCSI model string */ So MODEL_LEN is not accounting for the '\0'. I am not sure what the convention is here. It have seen SCSI code that uses the above, e.g., include/scsi/scsi_transport_sas.h. But I am happy to have *_LEN account for the '\0' if that makes it less confusing. Andrew -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
