1250 lines
40 KiB
C
Executable file
1250 lines
40 KiB
C
Executable file
/* This file contains essentially all of the process and message handling.
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* Together with "mpx.s" it forms the lowest layer of the MINIX kernel.
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* There is one entry point from the outside:
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*
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* sys_call: a system call, i.e., the kernel is trapped with an INT
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*
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* As well as several entry points used from the interrupt and task level:
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*
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* lock_notify: notify a process of a system event
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* lock_send: send a message to a process
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* lock_enqueue: put a process on one of the scheduling queues
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* lock_dequeue: remove a process from the scheduling queues
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*
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* Changes:
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* Aug 19, 2005 rewrote scheduling code (Jorrit N. Herder)
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* Jul 25, 2005 rewrote system call handling (Jorrit N. Herder)
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* May 26, 2005 rewrote message passing functions (Jorrit N. Herder)
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* May 24, 2005 new notification system call (Jorrit N. Herder)
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* Oct 28, 2004 nonblocking send and receive calls (Jorrit N. Herder)
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*
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* The code here is critical to make everything work and is important for the
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* overall performance of the system. A large fraction of the code deals with
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* list manipulation. To make this both easy to understand and fast to execute
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* pointer pointers are used throughout the code. Pointer pointers prevent
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* exceptions for the head or tail of a linked list.
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*
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* node_t *queue, *new_node; // assume these as global variables
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* node_t **xpp = &queue; // get pointer pointer to head of queue
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* while (*xpp != NULL) // find last pointer of the linked list
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* xpp = &(*xpp)->next; // get pointer to next pointer
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* *xpp = new_node; // now replace the end (the NULL pointer)
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* new_node->next = NULL; // and mark the new end of the list
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*
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* For example, when adding a new node to the end of the list, one normally
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* makes an exception for an empty list and looks up the end of the list for
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* nonempty lists. As shown above, this is not required with pointer pointers.
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*/
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#include <minix/com.h>
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#include <minix/callnr.h>
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#include <minix/endpoint.h>
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#include "debug.h"
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#include "kernel.h"
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#include "proc.h"
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#include <stddef.h>
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#include <signal.h>
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#include <minix/portio.h>
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#include <minix/u64.h>
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/* Scheduling and message passing functions. The functions are available to
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* other parts of the kernel through lock_...(). The lock temporarily disables
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* interrupts to prevent race conditions.
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*/
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FORWARD _PROTOTYPE( int mini_send, (struct proc *caller_ptr, int dst_e,
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message *m_ptr, unsigned flags));
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FORWARD _PROTOTYPE( int mini_receive, (struct proc *caller_ptr, int src,
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message *m_ptr, unsigned flags));
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FORWARD _PROTOTYPE( int mini_notify, (struct proc *caller_ptr, int dst));
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FORWARD _PROTOTYPE( int mini_senda, (struct proc *caller_ptr,
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asynmsg_t *table, size_t size));
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FORWARD _PROTOTYPE( int deadlock, (int function,
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register struct proc *caller, int src_dst));
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FORWARD _PROTOTYPE( int try_async, (struct proc *caller_ptr));
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FORWARD _PROTOTYPE( int try_one, (struct proc *src_ptr, struct proc *dst_ptr));
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FORWARD _PROTOTYPE( void enqueue, (struct proc *rp));
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FORWARD _PROTOTYPE( void dequeue, (struct proc *rp));
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FORWARD _PROTOTYPE( void sched, (struct proc *rp, int *queue, int *front));
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FORWARD _PROTOTYPE( void pick_proc, (void));
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#define BuildMess(m_ptr, src, dst_ptr) \
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(m_ptr)->m_source = proc_addr(src)->p_endpoint; \
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(m_ptr)->m_type = NOTIFY_FROM(src); \
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(m_ptr)->NOTIFY_TIMESTAMP = get_uptime(); \
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switch (src) { \
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case HARDWARE: \
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(m_ptr)->NOTIFY_ARG = priv(dst_ptr)->s_int_pending; \
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priv(dst_ptr)->s_int_pending = 0; \
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break; \
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case SYSTEM: \
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(m_ptr)->NOTIFY_ARG = priv(dst_ptr)->s_sig_pending; \
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priv(dst_ptr)->s_sig_pending = 0; \
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break; \
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}
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#define CopyMess(s,sp,sm,dp,dm) \
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cp_mess(proc_addr(s)->p_endpoint, \
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(sp)->p_memmap[D].mem_phys, \
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(vir_bytes)sm, (dp)->p_memmap[D].mem_phys, (vir_bytes)dm)
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/*===========================================================================*
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* sys_call *
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*===========================================================================*/
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PUBLIC int sys_call(call_nr, src_dst_e, m_ptr, bit_map)
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int call_nr; /* system call number and flags */
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int src_dst_e; /* src to receive from or dst to send to */
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message *m_ptr; /* pointer to message in the caller's space */
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long bit_map; /* notification event set or flags */
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{
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/* System calls are done by trapping to the kernel with an INT instruction.
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* The trap is caught and sys_call() is called to send or receive a message
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* (or both). The caller is always given by 'proc_ptr'.
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*/
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register struct proc *caller_ptr = proc_ptr; /* get pointer to caller */
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int mask_entry; /* bit to check in send mask */
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int group_size; /* used for deadlock check */
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int result; /* the system call's result */
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int src_dst_p; /* Process slot number */
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vir_clicks vlo, vhi; /* virtual clicks containing message to send */
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.total= add64u(ipc_stats.total, 1);
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#if 1
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if (RTS_ISSET(caller_ptr, SLOT_FREE))
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{
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kprintf("called by the dead?!?\n");
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.deadproc++;
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return EINVAL;
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}
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#endif
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/* Check destination. SENDA is special because its argument is a table and
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* not a single destination. RECEIVE is the only call that accepts ANY (in
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* addition to a real endpoint). The other calls (SEND, SENDNB, SENDREC,
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* and NOTIFY) require an endpoint to corresponds to a process. In addition,
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* it is necessary to check whether a process is allow to send to a given
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* destination. For SENDREC we check s_ipc_sendrec, and for SEND, SENDNB,
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* and NOTIFY we check s_ipc_to.
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*/
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if (call_nr == SENDA)
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{
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/* No destination argument */
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}
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else if (src_dst_e == ANY)
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{
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if (call_nr != RECEIVE)
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{
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#if DEBUG_ENABLE_IPC_WARNINGS
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kprintf("sys_call: trap %d by %d with bad endpoint %d\n",
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call_nr, proc_nr(caller_ptr), src_dst_e);
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#endif
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.bad_endpoint++;
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return EINVAL;
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}
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src_dst_p = src_dst_e;
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}
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else
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{
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/* Require a valid source and/or destination process. */
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if(!isokendpt(src_dst_e, &src_dst_p)) {
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if (src_dst_e == 0) panic("sys_call: no PM", NO_NUM);
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#if DEBUG_ENABLE_IPC_WARNINGS
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kprintf("sys_call: trap %d by %d with bad endpoint %d\n",
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call_nr, proc_nr(caller_ptr), src_dst_e);
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#endif
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.bad_endpoint++;
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return EDEADSRCDST;
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}
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/* If the call is to send to a process, i.e., for SEND, SENDNB,
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* SENDREC or NOTIFY, verify that the caller is allowed to send to
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* the given destination.
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*/
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if (call_nr == SENDREC)
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{
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if (! get_sys_bit(priv(caller_ptr)->s_ipc_sendrec,
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nr_to_id(src_dst_p))) {
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#if DEBUG_ENABLE_IPC_WARNINGS
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kprintf(
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"sys_call: ipc sendrec mask denied trap %d from %d ('%s') to %d\n",
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call_nr, proc_nr(caller_ptr),
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caller_ptr->p_name, src_dst_p);
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#endif
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.dst_not_allowed++;
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return(ECALLDENIED); /* call denied by ipc mask */
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}
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}
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else if (call_nr == SEND || call_nr == SENDNB || call_nr == NOTIFY)
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{
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if (! get_sys_bit(priv(caller_ptr)->s_ipc_to,
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nr_to_id(src_dst_p))) {
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#if DEBUG_ENABLE_IPC_WARNINGS
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kprintf(
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"sys_call: ipc mask denied trap %d from %d to %d\n",
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call_nr, proc_nr(caller_ptr), src_dst_p);
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#endif
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.dst_not_allowed++;
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return(ECALLDENIED); /* call denied by ipc mask */
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}
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}
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}
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/* Only allow non-negative call_nr values less than 32 */
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if (call_nr < 0 || call_nr >= 32)
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{
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#if DEBUG_ENABLE_IPC_WARNINGS
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kprintf("sys_call: trap %d not allowed, caller %d, src_dst %d\n",
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call_nr, proc_nr(caller_ptr), src_dst_p);
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#endif
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.bad_call++;
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return(ETRAPDENIED); /* trap denied by mask or kernel */
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}
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/* Check if the process has privileges for the requested call. Calls to the
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* kernel may only be SENDREC, because tasks always reply and may not block
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* if the caller doesn't do receive().
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*/
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if (!(priv(caller_ptr)->s_trap_mask & (1 << call_nr))) {
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#if DEBUG_ENABLE_IPC_WARNINGS
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kprintf("sys_call: trap %d not allowed, caller %d, src_dst %d\n",
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call_nr, proc_nr(caller_ptr), src_dst_p);
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#endif
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.call_not_allowed++;
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return(ETRAPDENIED); /* trap denied by mask or kernel */
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}
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if ((iskerneln(src_dst_p) && _function != SENDREC
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&& _function != RECEIVE)) {
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#if DEBUG_ENABLE_IPC_WARNINGS
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kprintf("sys_call: trap %d not allowed, caller %d, src_dst %d\n",
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function, proc_nr(caller_ptr), src_dst);
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#endif
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.call_not_allowed++;
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return(ETRAPDENIED); /* trap denied by mask or kernel */
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}
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/* If the call involves a message buffer, i.e., for SEND, SENDNB, SENDREC,
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* or RECEIVE, check the message pointer. This check allows a message to be
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* anywhere in data or stack or gap. It will have to be made more elaborate
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* for machines which don't have the gap mapped.
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*/
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if (call_nr == SEND || call_nr == SENDNB || call_nr == SENDREC ||
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call_nr == RECEIVE) {
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vlo = (vir_bytes) m_ptr >> CLICK_SHIFT;
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vhi = ((vir_bytes) m_ptr + MESS_SIZE - 1) >> CLICK_SHIFT;
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if (vlo < caller_ptr->p_memmap[D].mem_vir || vlo > vhi ||
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vhi >= caller_ptr->p_memmap[S].mem_vir +
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caller_ptr->p_memmap[S].mem_len) {
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#if DEBUG_ENABLE_IPC_WARNINGS
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kprintf(
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"sys_call: invalid message pointer, trap %d, caller %d\n",
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call_nr, proc_nr(caller_ptr));
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#endif
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.bad_buffer++;
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return(EFAULT); /* invalid message pointer */
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}
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}
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/* Check for a possible deadlock for blocking SEND(REC) and RECEIVE. */
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if (call_nr == SEND || call_nr == SENDREC || call_nr == RECEIVE) {
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if (group_size = deadlock(call_nr, caller_ptr, src_dst_p)) {
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#if DEBUG_ENABLE_IPC_WARNINGS
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kprintf("sys_call: trap %d from %d to %d deadlocked, group size %d\n",
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call_nr, proc_nr(caller_ptr), src_dst_p, group_size);
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#endif
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.deadlock++;
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return(ELOCKED);
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}
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}
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/* Now check if the call is known and try to perform the request. The only
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* system calls that exist in MINIX are sending and receiving messages.
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* - SENDREC: combines SEND and RECEIVE in a single system call
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* - SEND: sender blocks until its message has been delivered
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* - RECEIVE: receiver blocks until an acceptable message has arrived
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* - NOTIFY: asynchronous call; deliver notification or mark pending
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* - SENDNB: nonblocking send
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* - SENDA: list of asynchronous send requests
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*/
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switch(call_nr) {
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case SENDREC:
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/* A flag is set so that notifications cannot interrupt SENDREC. */
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caller_ptr->p_misc_flags |= REPLY_PENDING;
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/* fall through */
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case SEND:
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result = mini_send(caller_ptr, src_dst_e, m_ptr, 0 /*flags*/);
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if (call_nr == SEND || result != OK)
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break; /* done, or SEND failed */
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/* fall through for SENDREC */
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case RECEIVE:
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if (call_nr == RECEIVE)
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caller_ptr->p_misc_flags &= ~REPLY_PENDING;
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result = mini_receive(caller_ptr, src_dst_e, m_ptr, 0 /*flags*/);
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break;
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case NOTIFY:
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result = mini_notify(caller_ptr, src_dst_p);
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break;
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case SENDNB:
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result = mini_send(caller_ptr, src_dst_e, m_ptr, NON_BLOCKING);
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break;
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case SENDA:
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result = mini_senda(caller_ptr, (asynmsg_t *)m_ptr, (size_t)src_dst_e);
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break;
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default:
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result = EBADCALL; /* illegal system call */
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}
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/* Now, return the result of the system call to the caller. */
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return(result);
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}
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/*===========================================================================*
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* deadlock *
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*===========================================================================*/
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PRIVATE int deadlock(function, cp, src_dst)
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int function; /* trap number */
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register struct proc *cp; /* pointer to caller */
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int src_dst; /* src or dst process */
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{
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/* Check for deadlock. This can happen if 'caller_ptr' and 'src_dst' have
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* a cyclic dependency of blocking send and receive calls. The only cyclic
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* depency that is not fatal is if the caller and target directly SEND(REC)
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* and RECEIVE to each other. If a deadlock is found, the group size is
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* returned. Otherwise zero is returned.
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*/
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register struct proc *xp; /* process pointer */
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int group_size = 1; /* start with only caller */
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int trap_flags;
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while (src_dst != ANY) { /* check while process nr */
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int src_dst_e;
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xp = proc_addr(src_dst); /* follow chain of processes */
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group_size ++; /* extra process in group */
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/* Check whether the last process in the chain has a dependency. If it
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* has not, the cycle cannot be closed and we are done.
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*/
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if (RTS_ISSET(xp, RECEIVING)) { /* xp has dependency */
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if(xp->p_getfrom_e == ANY) src_dst = ANY;
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else okendpt(xp->p_getfrom_e, &src_dst);
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} else if (RTS_ISSET(xp, SENDING)) { /* xp has dependency */
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okendpt(xp->p_sendto_e, &src_dst);
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} else {
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return(0); /* not a deadlock */
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}
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/* Now check if there is a cyclic dependency. For group sizes of two,
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* a combination of SEND(REC) and RECEIVE is not fatal. Larger groups
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* or other combinations indicate a deadlock.
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*/
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if (src_dst == proc_nr(cp)) { /* possible deadlock */
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if (group_size == 2) { /* caller and src_dst */
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/* The function number is magically converted to flags. */
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if ((xp->p_rts_flags ^ (function << 2)) & SENDING) {
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return(0); /* not a deadlock */
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}
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}
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return(group_size); /* deadlock found */
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}
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}
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return(0); /* not a deadlock */
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}
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|
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/*===========================================================================*
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* mini_send *
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*===========================================================================*/
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PRIVATE int mini_send(caller_ptr, dst_e, m_ptr, flags)
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register struct proc *caller_ptr; /* who is trying to send a message? */
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int dst_e; /* to whom is message being sent? */
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message *m_ptr; /* pointer to message buffer */
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unsigned flags; /* system call flags */
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{
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/* Send a message from 'caller_ptr' to 'dst'. If 'dst' is blocked waiting
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* for this message, copy the message to it and unblock 'dst'. If 'dst' is
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* not waiting at all, or is waiting for another source, queue 'caller_ptr'.
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*/
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register struct proc *dst_ptr;
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register struct proc **xpp;
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int dst_p;
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dst_p = _ENDPOINT_P(dst_e);
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dst_ptr = proc_addr(dst_p);
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if (RTS_ISSET(dst_ptr, NO_ENDPOINT))
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{
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.dst_died++;
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return EDSTDIED;
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}
|
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|
|
/* Check if 'dst' is blocked waiting for this message. The destination's
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* SENDING flag may be set when its SENDREC call blocked while sending.
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*/
|
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if ( (RTS_ISSET(dst_ptr, RECEIVING) && !RTS_ISSET(dst_ptr, SENDING)) &&
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(dst_ptr->p_getfrom_e == ANY
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|| dst_ptr->p_getfrom_e == caller_ptr->p_endpoint)) {
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/* Destination is indeed waiting for this message. */
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CopyMess(caller_ptr->p_nr, caller_ptr, m_ptr, dst_ptr,
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dst_ptr->p_messbuf);
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RTS_UNSET(dst_ptr, RECEIVING);
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} else if ( ! (flags & NON_BLOCKING)) {
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/* Destination is not waiting. Block and dequeue caller. */
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caller_ptr->p_messbuf = m_ptr;
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RTS_SET(caller_ptr, SENDING);
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caller_ptr->p_sendto_e = dst_e;
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/* Process is now blocked. Put in on the destination's queue. */
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xpp = &dst_ptr->p_caller_q; /* find end of list */
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while (*xpp != NIL_PROC) xpp = &(*xpp)->p_q_link;
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*xpp = caller_ptr; /* add caller to end */
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caller_ptr->p_q_link = NIL_PROC; /* mark new end of list */
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} else {
|
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if (caller_ptr->p_endpoint == ipc_stats_target)
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ipc_stats.not_ready++;
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return(ENOTREADY);
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}
|
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return(OK);
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}
|
|
|
|
/*===========================================================================*
|
|
* mini_receive *
|
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*===========================================================================*/
|
|
PRIVATE int mini_receive(caller_ptr, src_e, m_ptr, flags)
|
|
register struct proc *caller_ptr; /* process trying to get message */
|
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int src_e; /* which message source is wanted */
|
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message *m_ptr; /* pointer to message buffer */
|
|
unsigned flags; /* system call flags */
|
|
{
|
|
/* A process or task wants to get a message. If a message is already queued,
|
|
* acquire it and deblock the sender. If no message from the desired source
|
|
* is available block the caller, unless the flags don't allow blocking.
|
|
*/
|
|
register struct proc **xpp;
|
|
register struct notification **ntf_q_pp;
|
|
message m;
|
|
int bit_nr;
|
|
sys_map_t *map;
|
|
bitchunk_t *chunk;
|
|
int i, r, src_id, src_proc_nr, src_p;
|
|
|
|
if(src_e == ANY) src_p = ANY;
|
|
else
|
|
{
|
|
okendpt(src_e, &src_p);
|
|
if (RTS_ISSET(proc_addr(src_p), NO_ENDPOINT))
|
|
{
|
|
if (caller_ptr->p_endpoint == ipc_stats_target)
|
|
ipc_stats.src_died++;
|
|
return ESRCDIED;
|
|
}
|
|
}
|
|
|
|
|
|
/* Check to see if a message from desired source is already available.
|
|
* The caller's SENDING flag may be set if SENDREC couldn't send. If it is
|
|
* set, the process should be blocked.
|
|
*/
|
|
if (!RTS_ISSET(caller_ptr, SENDING)) {
|
|
|
|
/* Check if there are pending notifications, except for SENDREC. */
|
|
if (! (caller_ptr->p_misc_flags & REPLY_PENDING)) {
|
|
|
|
map = &priv(caller_ptr)->s_notify_pending;
|
|
for (chunk=&map->chunk[0]; chunk<&map->chunk[NR_SYS_CHUNKS]; chunk++) {
|
|
|
|
/* Find a pending notification from the requested source. */
|
|
if (! *chunk) continue; /* no bits in chunk */
|
|
for (i=0; ! (*chunk & (1<<i)); ++i) {} /* look up the bit */
|
|
src_id = (chunk - &map->chunk[0]) * BITCHUNK_BITS + i;
|
|
if (src_id >= NR_SYS_PROCS) break; /* out of range */
|
|
src_proc_nr = id_to_nr(src_id); /* get source proc */
|
|
#if DEBUG_ENABLE_IPC_WARNINGS
|
|
if(src_proc_nr == NONE) {
|
|
kprintf("mini_receive: sending notify from NONE\n");
|
|
}
|
|
#endif
|
|
if (src_e!=ANY && src_p != src_proc_nr) continue;/* source not ok */
|
|
*chunk &= ~(1 << i); /* no longer pending */
|
|
|
|
/* Found a suitable source, deliver the notification message. */
|
|
BuildMess(&m, src_proc_nr, caller_ptr); /* assemble message */
|
|
CopyMess(src_proc_nr, proc_addr(HARDWARE), &m, caller_ptr, m_ptr);
|
|
return(OK); /* report success */
|
|
}
|
|
}
|
|
|
|
/* Check caller queue. Use pointer pointers to keep code simple. */
|
|
xpp = &caller_ptr->p_caller_q;
|
|
while (*xpp != NIL_PROC) {
|
|
if (src_e == ANY || src_p == proc_nr(*xpp)) {
|
|
#if 1
|
|
if (RTS_ISSET(*xpp, SLOT_FREE))
|
|
{
|
|
kprintf("listening to the dead?!?\n");
|
|
if (caller_ptr->p_endpoint == ipc_stats_target)
|
|
ipc_stats.deadproc++;
|
|
return EINVAL;
|
|
}
|
|
#endif
|
|
|
|
/* Found acceptable message. Copy it and update status. */
|
|
CopyMess((*xpp)->p_nr, *xpp, (*xpp)->p_messbuf, caller_ptr, m_ptr);
|
|
RTS_UNSET(*xpp, SENDING);
|
|
*xpp = (*xpp)->p_q_link; /* remove from queue */
|
|
return(OK); /* report success */
|
|
}
|
|
xpp = &(*xpp)->p_q_link; /* proceed to next */
|
|
}
|
|
|
|
if (caller_ptr->p_misc_flags & MF_ASYNMSG)
|
|
{
|
|
if (src_e != ANY)
|
|
{
|
|
#if 0
|
|
kprintf("mini_receive: should try async from %d\n", src_e);
|
|
#endif
|
|
r= EAGAIN;
|
|
}
|
|
else
|
|
{
|
|
caller_ptr->p_messbuf = m_ptr;
|
|
r= try_async(caller_ptr);
|
|
}
|
|
if (r == OK)
|
|
return OK; /* Got a message */
|
|
}
|
|
}
|
|
|
|
/* No suitable message is available or the caller couldn't send in SENDREC.
|
|
* Block the process trying to receive, unless the flags tell otherwise.
|
|
*/
|
|
if ( ! (flags & NON_BLOCKING)) {
|
|
caller_ptr->p_getfrom_e = src_e;
|
|
caller_ptr->p_messbuf = m_ptr;
|
|
RTS_SET(caller_ptr, RECEIVING);
|
|
return(OK);
|
|
} else {
|
|
if (caller_ptr->p_endpoint == ipc_stats_target)
|
|
ipc_stats.not_ready++;
|
|
return(ENOTREADY);
|
|
}
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* mini_notify *
|
|
*===========================================================================*/
|
|
PRIVATE int mini_notify(caller_ptr, dst)
|
|
register struct proc *caller_ptr; /* sender of the notification */
|
|
int dst; /* which process to notify */
|
|
{
|
|
register struct proc *dst_ptr = proc_addr(dst);
|
|
int src_id; /* source id for late delivery */
|
|
message m; /* the notification message */
|
|
|
|
/* Check to see if target is blocked waiting for this message. A process
|
|
* can be both sending and receiving during a SENDREC system call.
|
|
*/
|
|
if ( (RTS_ISSET(dst_ptr, RECEIVING) && !RTS_ISSET(dst_ptr, SENDING)) &&
|
|
! (dst_ptr->p_misc_flags & REPLY_PENDING) &&
|
|
(dst_ptr->p_getfrom_e == ANY ||
|
|
dst_ptr->p_getfrom_e == caller_ptr->p_endpoint)) {
|
|
|
|
/* Destination is indeed waiting for a message. Assemble a notification
|
|
* message and deliver it. Copy from pseudo-source HARDWARE, since the
|
|
* message is in the kernel's address space.
|
|
*/
|
|
BuildMess(&m, proc_nr(caller_ptr), dst_ptr);
|
|
CopyMess(proc_nr(caller_ptr), proc_addr(HARDWARE), &m,
|
|
dst_ptr, dst_ptr->p_messbuf);
|
|
RTS_UNSET(dst_ptr, RECEIVING);
|
|
return(OK);
|
|
}
|
|
|
|
/* Destination is not ready to receive the notification. Add it to the
|
|
* bit map with pending notifications. Note the indirectness: the system id
|
|
* instead of the process number is used in the pending bit map.
|
|
*/
|
|
src_id = priv(caller_ptr)->s_id;
|
|
set_sys_bit(priv(dst_ptr)->s_notify_pending, src_id);
|
|
return(OK);
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* mini_senda *
|
|
*===========================================================================*/
|
|
PRIVATE int mini_senda(caller_ptr, table, size)
|
|
struct proc *caller_ptr;
|
|
asynmsg_t *table;
|
|
size_t size;
|
|
{
|
|
int i, dst_p, done, do_notify;
|
|
unsigned flags;
|
|
phys_bytes tab_phys;
|
|
struct proc *dst_ptr;
|
|
struct priv *privp;
|
|
message *m_ptr;
|
|
asynmsg_t tabent;
|
|
|
|
privp= priv(caller_ptr);
|
|
if (!(privp->s_flags & SYS_PROC))
|
|
{
|
|
kprintf(
|
|
"mini_senda: warning caller has no privilege structure\n");
|
|
if (caller_ptr->p_endpoint == ipc_stats_target)
|
|
ipc_stats.no_priv++;
|
|
return EPERM;
|
|
}
|
|
|
|
/* Clear table */
|
|
privp->s_asyntab= -1;
|
|
privp->s_asynsize= 0;
|
|
|
|
if (size == 0)
|
|
{
|
|
/* Nothing to do, just return */
|
|
return OK;
|
|
}
|
|
|
|
/* Limit size to something reasonable. An arbitrary choice is 16
|
|
* times the number of process table entries.
|
|
*/
|
|
if (size > 16*(NR_TASKS + NR_PROCS))
|
|
{
|
|
if (caller_ptr->p_endpoint == ipc_stats_target)
|
|
ipc_stats.bad_size++;
|
|
return EDOM;
|
|
}
|
|
|
|
/* Map table */
|
|
tab_phys= umap_local(caller_ptr, D, (vir_bytes)table,
|
|
size*sizeof(table[0]));
|
|
if (tab_phys == 0)
|
|
{
|
|
kprintf("mini_senda: got bad table pointer/size\n");
|
|
if (caller_ptr->p_endpoint == ipc_stats_target)
|
|
ipc_stats.bad_buffer++;
|
|
return EFAULT;
|
|
}
|
|
|
|
/* Scan the table */
|
|
do_notify= FALSE;
|
|
done= TRUE;
|
|
for (i= 0; i<size; i++)
|
|
{
|
|
/* Read status word */
|
|
phys_copy(tab_phys + i*sizeof(table[0]) +
|
|
offsetof(struct asynmsg, flags),
|
|
vir2phys(&tabent.flags), sizeof(tabent.flags));
|
|
flags= tabent.flags;
|
|
|
|
/* Skip empty entries */
|
|
if (flags == 0)
|
|
continue;
|
|
|
|
/* Check for reserved bits in the flags field */
|
|
if (flags & ~(AMF_VALID|AMF_DONE|AMF_NOTIFY) ||
|
|
!(flags & AMF_VALID))
|
|
{
|
|
if (caller_ptr->p_endpoint == ipc_stats_target)
|
|
ipc_stats.bad_senda++;
|
|
return EINVAL;
|
|
}
|
|
|
|
/* Skip entry is AMF_DONE is already set */
|
|
if (flags & AMF_DONE)
|
|
continue;
|
|
|
|
/* Get destination */
|
|
phys_copy(tab_phys + i*sizeof(table[0]) +
|
|
offsetof(struct asynmsg, dst),
|
|
vir2phys(&tabent.dst), sizeof(tabent.dst));
|
|
|
|
if (!isokendpt(tabent.dst, &dst_p))
|
|
{
|
|
/* Bad destination, report the error */
|
|
tabent.result= EDEADSRCDST;
|
|
phys_copy(vir2phys(&tabent.result),
|
|
tab_phys + i*sizeof(table[0]) +
|
|
offsetof(struct asynmsg, result),
|
|
sizeof(tabent.result));
|
|
tabent.flags= flags | AMF_DONE;
|
|
phys_copy(vir2phys(&tabent.flags),
|
|
tab_phys + i*sizeof(table[0]) +
|
|
offsetof(struct asynmsg, flags),
|
|
sizeof(tabent.flags));
|
|
|
|
if (flags & AMF_NOTIFY)
|
|
do_notify= 1;
|
|
continue;
|
|
}
|
|
|
|
#if 0
|
|
kprintf("mini_senda: entry[%d]: flags 0x%x dst %d/%d\n",
|
|
i, tabent.flags, tabent.dst, dst_p);
|
|
#endif
|
|
|
|
dst_ptr = proc_addr(dst_p);
|
|
|
|
/* NO_ENDPOINT should be removed */
|
|
if (dst_ptr->p_rts_flags & NO_ENDPOINT)
|
|
{
|
|
tabent.result= EDSTDIED;
|
|
phys_copy(vir2phys(&tabent.result),
|
|
tab_phys + i*sizeof(table[0]) +
|
|
offsetof(struct asynmsg, result),
|
|
sizeof(tabent.result));
|
|
tabent.flags= flags | AMF_DONE;
|
|
phys_copy(vir2phys(&tabent.flags),
|
|
tab_phys + i*sizeof(table[0]) +
|
|
offsetof(struct asynmsg, flags),
|
|
sizeof(tabent.flags));
|
|
|
|
if (flags & AMF_NOTIFY)
|
|
do_notify= TRUE;
|
|
continue;
|
|
}
|
|
|
|
/* Check if 'dst' is blocked waiting for this message. The
|
|
* destination's SENDING flag may be set when its SENDREC call
|
|
* blocked while sending.
|
|
*/
|
|
if ( (dst_ptr->p_rts_flags & (RECEIVING | SENDING)) ==
|
|
RECEIVING &&
|
|
(dst_ptr->p_getfrom_e == ANY ||
|
|
dst_ptr->p_getfrom_e == caller_ptr->p_endpoint))
|
|
{
|
|
/* Destination is indeed waiting for this message. */
|
|
m_ptr= &table[i].msg; /* Note: pointer in the
|
|
* caller's address space.
|
|
*/
|
|
CopyMess(caller_ptr->p_nr, caller_ptr, m_ptr, dst_ptr,
|
|
dst_ptr->p_messbuf);
|
|
|
|
if ((dst_ptr->p_rts_flags &= ~RECEIVING) == 0)
|
|
enqueue(dst_ptr);
|
|
|
|
tabent.result= OK;
|
|
phys_copy(vir2phys(&tabent.result),
|
|
tab_phys + i*sizeof(table[0]) +
|
|
offsetof(struct asynmsg, result),
|
|
sizeof(tabent.result));
|
|
tabent.flags= flags | AMF_DONE;
|
|
phys_copy(vir2phys(&tabent.flags),
|
|
tab_phys + i*sizeof(table[0]) +
|
|
offsetof(struct asynmsg, flags),
|
|
sizeof(tabent.flags));
|
|
|
|
if (flags & AMF_NOTIFY)
|
|
do_notify= 1;
|
|
continue;
|
|
}
|
|
else
|
|
{
|
|
/* Should inform receiver that something is pending */
|
|
dst_ptr->p_misc_flags |= MF_ASYNMSG;
|
|
done= FALSE;
|
|
continue;
|
|
}
|
|
}
|
|
if (do_notify)
|
|
kprintf("mini_senda: should notifiy caller\n");
|
|
if (!done)
|
|
{
|
|
privp->s_asyntab= (vir_bytes)table;
|
|
privp->s_asynsize= size;
|
|
}
|
|
return OK;
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* try_async *
|
|
*===========================================================================*/
|
|
PRIVATE int try_async(caller_ptr)
|
|
struct proc *caller_ptr;
|
|
{
|
|
int r;
|
|
struct priv *privp;
|
|
struct proc *src_ptr;
|
|
|
|
/* Try all privilege structures */
|
|
for (privp = BEG_PRIV_ADDR; privp < END_PRIV_ADDR; ++privp)
|
|
{
|
|
if (privp->s_proc_nr == NONE || privp->s_id == USER_PRIV_ID)
|
|
continue;
|
|
if (privp->s_asynsize == 0)
|
|
continue;
|
|
#if 0
|
|
kprintf("try_async: found asyntable for proc %d\n",
|
|
privp->s_proc_nr);
|
|
#endif
|
|
src_ptr= proc_addr(privp->s_proc_nr);
|
|
r= try_one(src_ptr, caller_ptr);
|
|
if (r == OK)
|
|
return r;
|
|
}
|
|
|
|
/* Nothing found, clear MF_ASYNMSG */
|
|
caller_ptr->p_misc_flags &= ~MF_ASYNMSG;
|
|
|
|
return ESRCH;
|
|
}
|
|
|
|
|
|
/*===========================================================================*
|
|
* try_one *
|
|
*===========================================================================*/
|
|
PRIVATE int try_one(src_ptr, dst_ptr)
|
|
struct proc *src_ptr;
|
|
struct proc *dst_ptr;
|
|
{
|
|
int i, do_notify, done;
|
|
unsigned flags;
|
|
size_t size;
|
|
endpoint_t dst_e;
|
|
phys_bytes tab_phys;
|
|
asynmsg_t *table_ptr;
|
|
message *m_ptr;
|
|
struct priv *privp;
|
|
asynmsg_t tabent;
|
|
|
|
privp= priv(src_ptr);
|
|
size= privp->s_asynsize;
|
|
|
|
dst_e= dst_ptr->p_endpoint;
|
|
|
|
/* Map table */
|
|
tab_phys= umap_local(src_ptr, D, privp->s_asyntab,
|
|
size*sizeof(tabent));
|
|
if (tab_phys == 0)
|
|
{
|
|
kprintf("try_one: got bad table pointer/size\n");
|
|
privp->s_asynsize= 0;
|
|
if (src_ptr->p_endpoint == ipc_stats_target)
|
|
ipc_stats.bad_buffer++;
|
|
return EFAULT;
|
|
}
|
|
|
|
/* Scan the table */
|
|
do_notify= FALSE;
|
|
done= TRUE;
|
|
for (i= 0; i<size; i++)
|
|
{
|
|
/* Read status word */
|
|
phys_copy(tab_phys + i*sizeof(tabent) +
|
|
offsetof(struct asynmsg, flags),
|
|
vir2phys(&tabent.flags), sizeof(tabent.flags));
|
|
flags= tabent.flags;
|
|
|
|
/* Skip empty entries */
|
|
if (flags == 0)
|
|
{
|
|
continue;
|
|
}
|
|
|
|
/* Check for reserved bits in the flags field */
|
|
if (flags & ~(AMF_VALID|AMF_DONE|AMF_NOTIFY) ||
|
|
!(flags & AMF_VALID))
|
|
{
|
|
kprintf("try_one: bad bits in table\n");
|
|
privp->s_asynsize= 0;
|
|
if (src_ptr->p_endpoint == ipc_stats_target)
|
|
ipc_stats.bad_senda++;
|
|
return EINVAL;
|
|
}
|
|
|
|
/* Skip entry is AMF_DONE is already set */
|
|
if (flags & AMF_DONE)
|
|
{
|
|
continue;
|
|
}
|
|
|
|
/* Clear done. We are done when all entries are either empty
|
|
* or done at the start of the call.
|
|
*/
|
|
done= FALSE;
|
|
|
|
/* Get destination */
|
|
phys_copy(tab_phys + i*sizeof(tabent) +
|
|
offsetof(struct asynmsg, dst),
|
|
vir2phys(&tabent.dst), sizeof(tabent.dst));
|
|
|
|
if (tabent.dst != dst_e)
|
|
{
|
|
continue;
|
|
}
|
|
|
|
/* Deliver message */
|
|
table_ptr= (asynmsg_t *)privp->s_asyntab;
|
|
m_ptr= &table_ptr[i].msg; /* Note: pointer in the
|
|
* caller's address space.
|
|
*/
|
|
CopyMess(src_ptr->p_nr, src_ptr, m_ptr, dst_ptr,
|
|
dst_ptr->p_messbuf);
|
|
|
|
tabent.result= OK;
|
|
phys_copy(vir2phys(&tabent.result),
|
|
tab_phys + i*sizeof(tabent) +
|
|
offsetof(struct asynmsg, result),
|
|
sizeof(tabent.result));
|
|
tabent.flags= flags | AMF_DONE;
|
|
phys_copy(vir2phys(&tabent.flags),
|
|
tab_phys + i*sizeof(tabent) +
|
|
offsetof(struct asynmsg, flags),
|
|
sizeof(tabent.flags));
|
|
|
|
if (flags & AMF_NOTIFY)
|
|
{
|
|
kprintf("try_one: should notify caller\n");
|
|
}
|
|
return OK;
|
|
}
|
|
if (done)
|
|
privp->s_asynsize= 0;
|
|
return EAGAIN;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* lock_notify *
|
|
*===========================================================================*/
|
|
PUBLIC int lock_notify(src_e, dst_e)
|
|
int src_e; /* (endpoint) sender of the notification */
|
|
int dst_e; /* (endpoint) who is to be notified */
|
|
{
|
|
/* Safe gateway to mini_notify() for tasks and interrupt handlers. The sender
|
|
* is explicitely given to prevent confusion where the call comes from. MINIX
|
|
* kernel is not reentrant, which means to interrupts are disabled after
|
|
* the first kernel entry (hardware interrupt, trap, or exception). Locking
|
|
* is done by temporarily disabling interrupts.
|
|
*/
|
|
int result, src, dst;
|
|
|
|
if(!isokendpt(src_e, &src) || !isokendpt(dst_e, &dst))
|
|
return EDEADSRCDST;
|
|
|
|
/* Exception or interrupt occurred, thus already locked. */
|
|
if (k_reenter >= 0) {
|
|
result = mini_notify(proc_addr(src), dst);
|
|
}
|
|
|
|
/* Call from task level, locking is required. */
|
|
else {
|
|
lock(0, "notify");
|
|
result = mini_notify(proc_addr(src), dst);
|
|
unlock(0);
|
|
}
|
|
return(result);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* enqueue *
|
|
*===========================================================================*/
|
|
PRIVATE void enqueue(rp)
|
|
register struct proc *rp; /* this process is now runnable */
|
|
{
|
|
/* Add 'rp' to one of the queues of runnable processes. This function is
|
|
* responsible for inserting a process into one of the scheduling queues.
|
|
* The mechanism is implemented here. The actual scheduling policy is
|
|
* defined in sched() and pick_proc().
|
|
*/
|
|
int q; /* scheduling queue to use */
|
|
int front; /* add to front or back */
|
|
|
|
#if DEBUG_SCHED_CHECK
|
|
check_runqueues("enqueue1");
|
|
if (rp->p_ready) kprintf("enqueue() already ready process\n");
|
|
#endif
|
|
|
|
/* Determine where to insert to process. */
|
|
sched(rp, &q, &front);
|
|
|
|
/* Now add the process to the queue. */
|
|
if (rdy_head[q] == NIL_PROC) { /* add to empty queue */
|
|
rdy_head[q] = rdy_tail[q] = rp; /* create a new queue */
|
|
rp->p_nextready = NIL_PROC; /* mark new end */
|
|
}
|
|
else if (front) { /* add to head of queue */
|
|
rp->p_nextready = rdy_head[q]; /* chain head of queue */
|
|
rdy_head[q] = rp; /* set new queue head */
|
|
}
|
|
else { /* add to tail of queue */
|
|
rdy_tail[q]->p_nextready = rp; /* chain tail of queue */
|
|
rdy_tail[q] = rp; /* set new queue tail */
|
|
rp->p_nextready = NIL_PROC; /* mark new end */
|
|
}
|
|
|
|
/* Now select the next process to run, if there isn't a current
|
|
* process yet or current process isn't ready any more, or
|
|
* it's PREEMPTIBLE.
|
|
*/
|
|
if(!proc_ptr || proc_ptr->p_rts_flags ||
|
|
(priv(proc_ptr)->s_flags & PREEMPTIBLE)) {
|
|
pick_proc();
|
|
}
|
|
|
|
#if DEBUG_SCHED_CHECK
|
|
rp->p_ready = 1;
|
|
check_runqueues("enqueue2");
|
|
#endif
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* dequeue *
|
|
*===========================================================================*/
|
|
PRIVATE void dequeue(rp)
|
|
register struct proc *rp; /* this process is no longer runnable */
|
|
{
|
|
/* A process must be removed from the scheduling queues, for example, because
|
|
* it has blocked. If the currently active process is removed, a new process
|
|
* is picked to run by calling pick_proc().
|
|
*/
|
|
register int q = rp->p_priority; /* queue to use */
|
|
register struct proc **xpp; /* iterate over queue */
|
|
register struct proc *prev_xp;
|
|
|
|
/* Side-effect for kernel: check if the task's stack still is ok? */
|
|
if (iskernelp(rp)) {
|
|
if (*priv(rp)->s_stack_guard != STACK_GUARD)
|
|
panic("stack overrun by task", proc_nr(rp));
|
|
}
|
|
|
|
#if DEBUG_SCHED_CHECK
|
|
check_runqueues("dequeue1");
|
|
if (! rp->p_ready) kprintf("dequeue() already unready process\n");
|
|
#endif
|
|
|
|
/* Now make sure that the process is not in its ready queue. Remove the
|
|
* process if it is found. A process can be made unready even if it is not
|
|
* running by being sent a signal that kills it.
|
|
*/
|
|
prev_xp = NIL_PROC;
|
|
for (xpp = &rdy_head[q]; *xpp != NIL_PROC; xpp = &(*xpp)->p_nextready) {
|
|
|
|
if (*xpp == rp) { /* found process to remove */
|
|
*xpp = (*xpp)->p_nextready; /* replace with next chain */
|
|
if (rp == rdy_tail[q]) /* queue tail removed */
|
|
rdy_tail[q] = prev_xp; /* set new tail */
|
|
if (rp == proc_ptr || rp == next_ptr) /* active process removed */
|
|
pick_proc(); /* pick new process to run */
|
|
break;
|
|
}
|
|
prev_xp = *xpp; /* save previous in chain */
|
|
}
|
|
|
|
#if DEBUG_SCHED_CHECK
|
|
rp->p_ready = 0;
|
|
check_runqueues("dequeue2");
|
|
#endif
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* sched *
|
|
*===========================================================================*/
|
|
PRIVATE void sched(rp, queue, front)
|
|
register struct proc *rp; /* process to be scheduled */
|
|
int *queue; /* return: queue to use */
|
|
int *front; /* return: front or back */
|
|
{
|
|
/* This function determines the scheduling policy. It is called whenever a
|
|
* process must be added to one of the scheduling queues to decide where to
|
|
* insert it. As a side-effect the process' priority may be updated.
|
|
*/
|
|
int time_left = (rp->p_ticks_left > 0); /* quantum fully consumed */
|
|
|
|
/* Check whether the process has time left. Otherwise give a new quantum
|
|
* and lower the process' priority, unless the process already is in the
|
|
* lowest queue.
|
|
*/
|
|
if (! time_left) { /* quantum consumed ? */
|
|
rp->p_ticks_left = rp->p_quantum_size; /* give new quantum */
|
|
if (rp->p_priority < (IDLE_Q-1)) {
|
|
rp->p_priority += 1; /* lower priority */
|
|
}
|
|
}
|
|
|
|
/* If there is time left, the process is added to the front of its queue,
|
|
* so that it can immediately run. The queue to use simply is always the
|
|
* process' current priority.
|
|
*/
|
|
*queue = rp->p_priority;
|
|
*front = time_left;
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* pick_proc *
|
|
*===========================================================================*/
|
|
PRIVATE void pick_proc()
|
|
{
|
|
/* Decide who to run now. A new process is selected by setting 'next_ptr'.
|
|
* When a billable process is selected, record it in 'bill_ptr', so that the
|
|
* clock task can tell who to bill for system time.
|
|
*/
|
|
register struct proc *rp; /* process to run */
|
|
int q; /* iterate over queues */
|
|
|
|
/* Check each of the scheduling queues for ready processes. The number of
|
|
* queues is defined in proc.h, and priorities are set in the task table.
|
|
* The lowest queue contains IDLE, which is always ready.
|
|
*/
|
|
for (q=0; q < NR_SCHED_QUEUES; q++) {
|
|
if ( (rp = rdy_head[q]) != NIL_PROC) {
|
|
next_ptr = rp; /* run process 'rp' next */
|
|
if (priv(rp)->s_flags & BILLABLE)
|
|
bill_ptr = rp; /* bill for system time */
|
|
return;
|
|
}
|
|
}
|
|
panic("no ready process", NO_NUM);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* balance_queues *
|
|
*===========================================================================*/
|
|
#define Q_BALANCE_TICKS 100
|
|
PUBLIC void balance_queues(tp)
|
|
timer_t *tp; /* watchdog timer pointer */
|
|
{
|
|
/* Check entire process table and give all process a higher priority. This
|
|
* effectively means giving a new quantum. If a process already is at its
|
|
* maximum priority, its quantum will be renewed.
|
|
*/
|
|
static timer_t queue_timer; /* timer structure to use */
|
|
register struct proc* rp; /* process table pointer */
|
|
clock_t next_period; /* time of next period */
|
|
int ticks_added = 0; /* total time added */
|
|
|
|
for (rp=BEG_PROC_ADDR; rp<END_PROC_ADDR; rp++) {
|
|
if (! isemptyp(rp)) { /* check slot use */
|
|
lock(5,"balance_queues");
|
|
if (rp->p_priority > rp->p_max_priority) { /* update priority? */
|
|
if (rp->p_rts_flags == 0) dequeue(rp); /* take off queue */
|
|
ticks_added += rp->p_quantum_size; /* do accounting */
|
|
rp->p_priority -= 1; /* raise priority */
|
|
if (rp->p_rts_flags == 0) enqueue(rp); /* put on queue */
|
|
}
|
|
else {
|
|
ticks_added += rp->p_quantum_size - rp->p_ticks_left;
|
|
rp->p_ticks_left = rp->p_quantum_size; /* give new quantum */
|
|
}
|
|
unlock(5);
|
|
}
|
|
}
|
|
#if DEBUG
|
|
kprintf("ticks_added: %d\n", ticks_added);
|
|
#endif
|
|
|
|
/* Now schedule a new watchdog timer to balance the queues again. The
|
|
* period depends on the total amount of quantum ticks added.
|
|
*/
|
|
next_period = MAX(Q_BALANCE_TICKS, ticks_added); /* calculate next */
|
|
set_timer(&queue_timer, get_uptime() + next_period, balance_queues);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* lock_send *
|
|
*===========================================================================*/
|
|
PUBLIC int lock_send(dst_e, m_ptr)
|
|
int dst_e; /* to whom is message being sent? */
|
|
message *m_ptr; /* pointer to message buffer */
|
|
{
|
|
/* Safe gateway to mini_send() for tasks. */
|
|
int result;
|
|
lock(2, "send");
|
|
result = mini_send(proc_ptr, dst_e, m_ptr, NON_BLOCKING);
|
|
unlock(2);
|
|
return(result);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* lock_enqueue *
|
|
*===========================================================================*/
|
|
PUBLIC void lock_enqueue(rp)
|
|
struct proc *rp; /* this process is now runnable */
|
|
{
|
|
/* Safe gateway to enqueue() for tasks. */
|
|
lock(3, "enqueue");
|
|
enqueue(rp);
|
|
unlock(3);
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* lock_dequeue *
|
|
*===========================================================================*/
|
|
PUBLIC void lock_dequeue(rp)
|
|
struct proc *rp; /* this process is no longer runnable */
|
|
{
|
|
/* Safe gateway to dequeue() for tasks. */
|
|
if (k_reenter >= 0) {
|
|
/* We're in an exception or interrupt, so don't lock (and ...
|
|
* don't unlock).
|
|
*/
|
|
dequeue(rp);
|
|
} else {
|
|
lock(4, "dequeue");
|
|
dequeue(rp);
|
|
unlock(4);
|
|
}
|
|
}
|
|
|
|
/*===========================================================================*
|
|
* isokendpt_f *
|
|
*===========================================================================*/
|
|
#if DEBUG_ENABLE_IPC_WARNINGS
|
|
PUBLIC int isokendpt_f(file, line, e, p, fatalflag)
|
|
char *file;
|
|
int line;
|
|
#else
|
|
PUBLIC int isokendpt_f(e, p, fatalflag)
|
|
#endif
|
|
endpoint_t e;
|
|
int *p, fatalflag;
|
|
{
|
|
int ok = 0;
|
|
/* Convert an endpoint number into a process number.
|
|
* Return nonzero if the process is alive with the corresponding
|
|
* generation number, zero otherwise.
|
|
*
|
|
* This function is called with file and line number by the
|
|
* isokendpt_d macro if DEBUG_ENABLE_IPC_WARNINGS is defined,
|
|
* otherwise without. This allows us to print the where the
|
|
* conversion was attempted, making the errors verbose without
|
|
* adding code for that at every call.
|
|
*
|
|
* If fatalflag is nonzero, we must panic if the conversion doesn't
|
|
* succeed.
|
|
*/
|
|
*p = _ENDPOINT_P(e);
|
|
if(!isokprocn(*p)) {
|
|
#if DEBUG_ENABLE_IPC_WARNINGS
|
|
kprintf("kernel:%s:%d: bad endpoint %d: proc %d out of range\n",
|
|
file, line, e, *p);
|
|
#endif
|
|
} else if(isemptyn(*p)) {
|
|
#if DEBUG_ENABLE_IPC_WARNINGS
|
|
kprintf("kernel:%s:%d: bad endpoint %d: proc %d empty\n", file, line, e, *p);
|
|
#endif
|
|
} else if(proc_addr(*p)->p_endpoint != e) {
|
|
#if DEBUG_ENABLE_IPC_WARNINGS
|
|
kprintf("kernel:%s:%d: bad endpoint %d: proc %d has ept %d (generation %d vs. %d)\n", file, line,
|
|
e, *p, proc_addr(*p)->p_endpoint,
|
|
_ENDPOINT_G(e), _ENDPOINT_G(proc_addr(*p)->p_endpoint));
|
|
#endif
|
|
} else ok = 1;
|
|
if(!ok && fatalflag) {
|
|
panic("invalid endpoint ", e);
|
|
}
|
|
return ok;
|
|
}
|