Miloslav Trmac wrote: > ----- "Stefan Richter" <stefanr@xxxxxxxxxxxxxxxxx> wrote: >> Miloslav Trmač wrote: >>> --- /dev/null >>> +++ b/crypto/userspace/utils.c >> [...] >>> +#ifdef CONFIG_COMPAT >>> +/* max() is too clever for compile-time constants */ >>> +#define CONST_MAX(A, B) ((A) > (B) ? (A) : (B)) >>> + >>> +#define MAX_SESSION_INPUT_DATA_SIZE \ >>> + (CONST_MAX(sizeof(struct ncr_session_input_data), \ >>> + sizeof(struct compat_ncr_session_input_data))) >>> +#define MAX_SESSION_OUTPUT_BUFFER_SIZE \ >>> + (CONST_MAX(sizeof(struct ncr_session_output_buffer), \ >>> + sizeof(struct compat_ncr_session_output_buffer))) >>> + >>> +#else /* !CONFIG_COMPAT */ >>> + >>> +#define MAX_SESSION_INPUT_DATA_SIZE (sizeof(struct ncr_session_input_data)) >>> +#define MAX_SESSION_OUTPUT_BUFFER_SIZE \ >>> + (sizeof(struct ncr_session_output_buffer)) >>> + >>> +#endif /* !CONFIG_COMPAT */ >> >> struct compat_xyz cannot be bigger than struct xyz, can it? > > Perhaps not, but the code has been written and it's easier to keep it than to > speculate :) What's there to speculate? :-) COMPAT = 32bit user on 64bit kernel. The latter has larger long and pointers and possibly different alignment of 64bit data. > It also helps document the fact that the data format depends on properties of > the userspace. Since it is a new ABI, it can be written to not need COMPAT ifdef'ery nor compat handlers. -- Stefan Richter -=====-==-=- =--- =-=-= http://arcgraph.de/sr/ -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
