minix/lib/libsys/sys_eniop.c

#include "syslib.h"

/*===========================================================================*
 *                               sys_enable_iop				     *    
 *===========================================================================*/
int sys_enable_iop(proc_ep)
endpoint_t proc_ep;			/* number of process to allow I/O */
{
    message m_iop;
    m_iop.IOP_ENDPT = proc_ep;
    return _kernel_call(SYS_IOPENABLE, &m_iop);
}
Resurrected sys_eniop. 2005-11-09 18:14:14 +01:00			`#include "syslib.h"`

			`/===========================================================================`
			`* sys_enable_iop *`
			`===========================================================================/`
retire PUBLIC, PRIVATE and FORWARD 2012-03-25 20:25:53 +02:00			`int sys_enable_iop(proc_ep)`
endpoint_t in syslib - headers use the endpoint_t in syslib.h and the implmentation was using int instead. Both uses endpoint_t now - every variable named like proc, proc_nr or proc_nr_e of type endpoint_t has name proc_ep now - endpoint_t defined as u32_t not int 2009-09-22 23:42:02 +02:00			`endpoint_t proc_ep; /* number of process to allow I/O */`
Resurrected sys_eniop. 2005-11-09 18:14:14 +01:00			`{`
			`message m_iop;`
Server/driver protocols: no longer allow third-party copies. 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. 2011-04-11 19:35:05 +02:00			`m_iop.IOP_ENDPT = proc_ep;`
Removal of the system task * Userspace change to use the new kernel calls - _taskcall(SYSTASK...) changed to _kernel_call(...) - int 32 reused for the kernel calls - _do_kernel_call() to make the trap to kernel - kernel_call() to make the actuall kernel call from C using _do_kernel_call() - unlike ipc call the kernel call always succeeds as kernel is always available, however, kernel may return an error * Kernel side implementation of kernel calls - the SYSTEm task does not run, only the proc table entry is preserved - every data_copy(SYSTEM is no data_copy(KERNEL - "locking" is an empty operation now as everything runs in kernel - sys_task() is replaced by kernel_call() which copies the message into kernel, dispatches the call to its handler and finishes by either copying the results back to userspace (if need be) or by suspending the process because of VM - suspended processes are later made runnable once the memory issue is resolved, picked up by the scheduler and only at this time the call is resumed (in fact restarted) which does not need to copy the message from userspace as the message is already saved in the process structure. - no ned for the vmrestart queue, the scheduler will restart the system calls - no special case in do_vmctl(), all requests remove the RTS_VMREQUEST flag 2010-02-09 16:20:09 +01:00			`return _kernel_call(SYS_IOPENABLE, &m_iop);`
Resurrected sys_eniop. 2005-11-09 18:14:14 +01:00			`}`