c51cd5fe91
Before safecopies, the IO_ENDPT and DL_ENDPT message fields were needed to know which actual process to copy data from/to, as that process may not always be the caller. Now that we have full safecopy support, these fields have become useless for that purpose: the owner of the grant is *always* the caller. Allowing the caller to supply another endpoint is in fact dangerous, because the callee may then end up using a grant from a third party. One could call this a variant of the confused deputy problem. From now on, safecopy calls should always use the caller's endpoint as grant owner. This fully obsoletes the DL_ENDPT field in the inet/ethernet protocol. IO_ENDPT has other uses besides identifying the grant owner though. This patch renames IO_ENDPT to USER_ENDPT, not only because that is a more fitting name (it should never be used for I/O after all), but also in order to intentionally break any old system source code outside the base system. If this patch breaks your code, fixing it is fairly simple: - DL_ENDPT should be replaced with m_source; - IO_ENDPT should be replaced with m_source when used for safecopies; - IO_ENDPT should be replaced with USER_ENDPT for any other use, e.g. when setting REP_ENDPT, matching requests in CANCEL calls, getting DEV_SELECT flags, and retrieving of the real user process's endpoint in DEV_OPEN. The changes in this patch are binary backward compatible.
100 lines
3.2 KiB
C
100 lines
3.2 KiB
C
#include "log.h"
|
|
|
|
/* State management variables. */
|
|
#define NR_DEVS 1 /* number of minor devices */
|
|
EXTERN struct logdevice logdevices[NR_DEVS];
|
|
|
|
/* State management helpers. */
|
|
PRIVATE int is_read_pending;
|
|
PRIVATE int is_select_callback_pending;
|
|
PRIVATE void load_state_info(void)
|
|
{
|
|
int i, found_pending;
|
|
struct logdevice *log;
|
|
|
|
/* Check if reads or select callbacks are pending. */
|
|
is_read_pending = FALSE;
|
|
is_select_callback_pending = FALSE;
|
|
found_pending = FALSE;
|
|
for (i = 0; i < NR_DEVS && !found_pending; i++) {
|
|
log = &logdevices[i];
|
|
if(log->log_source != NONE) {
|
|
is_read_pending = TRUE;
|
|
}
|
|
if(log->log_selected) {
|
|
is_select_callback_pending = TRUE;
|
|
}
|
|
|
|
found_pending = (is_read_pending && is_select_callback_pending);
|
|
}
|
|
}
|
|
|
|
/* Custom states definition. */
|
|
#define LOG_STATE_SELECT_PROTOCOL_FREE (SEF_LU_STATE_CUSTOM_BASE + 0)
|
|
#define LOG_STATE_IS_CUSTOM(s) ((s) == LOG_STATE_SELECT_PROTOCOL_FREE)
|
|
|
|
/*===========================================================================*
|
|
* sef_cb_lu_prepare *
|
|
*===========================================================================*/
|
|
PUBLIC int sef_cb_lu_prepare(int state)
|
|
{
|
|
int is_ready;
|
|
|
|
/* Load state information. */
|
|
load_state_info();
|
|
|
|
/* Check if we are ready for the target state. */
|
|
is_ready = FALSE;
|
|
switch(state) {
|
|
/* Standard states. */
|
|
case SEF_LU_STATE_REQUEST_FREE:
|
|
is_ready = (!is_read_pending);
|
|
break;
|
|
|
|
case SEF_LU_STATE_PROTOCOL_FREE:
|
|
is_ready = (!is_read_pending && !is_select_callback_pending);
|
|
break;
|
|
|
|
/* Custom states. */
|
|
case LOG_STATE_SELECT_PROTOCOL_FREE:
|
|
is_ready = (!is_select_callback_pending);
|
|
break;
|
|
}
|
|
|
|
/* Tell SEF if we are ready. */
|
|
return is_ready ? OK : ENOTREADY;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* sef_cb_lu_state_isvalid *
|
|
*===========================================================================*/
|
|
PUBLIC int sef_cb_lu_state_isvalid(int state)
|
|
{
|
|
return SEF_LU_STATE_IS_STANDARD(state) || LOG_STATE_IS_CUSTOM(state);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* sef_cb_lu_state_dump *
|
|
*===========================================================================*/
|
|
PUBLIC void sef_cb_lu_state_dump(int state)
|
|
{
|
|
/* Load state information. */
|
|
load_state_info();
|
|
|
|
sef_lu_dprint("log: live update state = %d\n", state);
|
|
sef_lu_dprint("log: is_read_pending = %d\n", is_read_pending);
|
|
sef_lu_dprint("log: is_select_callback_pending = %d\n",
|
|
is_select_callback_pending);
|
|
|
|
sef_lu_dprint("log: SEF_LU_STATE_WORK_FREE(%d) reached = %d\n",
|
|
SEF_LU_STATE_WORK_FREE, TRUE);
|
|
sef_lu_dprint("log: SEF_LU_STATE_REQUEST_FREE(%d) reached = %d\n",
|
|
SEF_LU_STATE_REQUEST_FREE, (!is_read_pending));
|
|
sef_lu_dprint("log: SEF_LU_STATE_PROTOCOL_FREE(%d) reached = %d\n",
|
|
SEF_LU_STATE_PROTOCOL_FREE, (!is_read_pending
|
|
&& !is_select_callback_pending));
|
|
sef_lu_dprint("log: LOG_STATE_SELECT_PROTOCOL_FREE(%d) reached = %d\n",
|
|
LOG_STATE_SELECT_PROTOCOL_FREE, (!is_select_callback_pending));
|
|
}
|
|
|