minix/kernel/proc.h
David van Moolenbroek b423d7b477 Merge of David's ptrace branch. Summary:
o Support for ptrace T_ATTACH/T_DETACH and T_SYSCALL
o PM signal handling logic should now work properly, even with debuggers
  being present
o Asynchronous PM/VFS protocol, full IPC support for senda(), and
  AMF_NOREPLY senda() flag

DETAILS

Process stop and delay call handling of PM:
o Added sys_runctl() kernel call with sys_stop() and sys_resume()
  aliases, for PM to stop and resume a process
o Added exception for sending/syscall-traced processes to sys_runctl(),
  and matching SIGKREADY pseudo-signal to PM
o Fixed PM signal logic to deal with requests from a process after
  stopping it (so-called "delay calls"), using the SIGKREADY facility
o Fixed various PM panics due to race conditions with delay calls versus
  VFS calls
o Removed special PRIO_STOP priority value
o Added SYS_LOCK RTS kernel flag, to stop an individual process from
  running while modifying its process structure

Signal and debugger handling in PM:
o Fixed debugger signals being dropped if a second signal arrives when
  the debugger has not retrieved the first one
o Fixed debugger signals being sent to the debugger more than once
o Fixed debugger signals unpausing process in VFS; removed PM_UNPAUSE_TR
  protocol message
o Detached debugger signals from general signal logic and from being
  blocked on VFS calls, meaning that even VFS can now be traced
o Fixed debugger being unable to receive more than one pending signal in
  one process stop
o Fixed signal delivery being delayed needlessly when multiple signals
  are pending
o Fixed wait test for tracer, which was returning for children that were
  not waited for
o Removed second parallel pending call from PM to VFS for any process
o Fixed process becoming runnable between exec() and debugger trap
o Added support for notifying the debugger before the parent when a
  debugged child exits
o Fixed debugger death causing child to remain stopped forever
o Fixed consistently incorrect use of _NSIG

Extensions to ptrace():
o Added T_ATTACH and T_DETACH ptrace request, to attach and detach a
  debugger to and from a process
o Added T_SYSCALL ptrace request, to trace system calls
o Added T_SETOPT ptrace request, to set trace options
o Added TO_TRACEFORK trace option, to attach automatically to children
  of a traced process
o Added TO_ALTEXEC trace option, to send SIGSTOP instead of SIGTRAP upon
  a successful exec() of the tracee
o Extended T_GETUSER ptrace support to allow retrieving a process's priv
  structure
o Removed T_STOP ptrace request again, as it does not help implementing
  debuggers properly
o Added MINIX3-specific ptrace test (test42)
o Added proper manual page for ptrace(2)

Asynchronous PM/VFS interface:
o Fixed asynchronous messages not being checked when receive() is called
  with an endpoint other than ANY
o Added AMF_NOREPLY senda() flag, preventing such messages from
  satisfying the receive part of a sendrec()
o Added asynsend3() that takes optional flags; asynsend() is now a
  #define passing in 0 as third parameter
o Made PM/VFS protocol asynchronous; reintroduced tell_fs()
o Made PM_BASE request/reply number range unique
o Hacked in a horrible temporary workaround into RS to deal with newly
  revealed RS-PM-VFS race condition triangle until VFS is asynchronous

System signal handling:
o Fixed shutdown logic of device drivers; removed old SIGKSTOP signal
o Removed is-superuser check from PM's do_procstat() (aka getsigset())
o Added sigset macros to allow system processes to deal with the full
  signal set, rather than just the POSIX subset

Miscellaneous PM fixes:
o Split do_getset into do_get and do_set, merging common code and making
  structure clearer
o Fixed setpriority() being able to put to sleep processes using an
  invalid parameter, or revive zombie processes
o Made find_proc() global; removed obsolete proc_from_pid()
o Cleanup here and there

Also included:
o Fixed false-positive boot order kernel warning
o Removed last traces of old NOTIFY_FROM code

THINGS OF POSSIBLE INTEREST

o It should now be possible to run PM at any priority, even lower than
  user processes
o No assumptions are made about communication speed between PM and VFS,
  although communication must be FIFO
o A debugger will now receive incoming debuggee signals at kill time
  only; the process may not yet be fully stopped
o A first step has been made towards making the SYSTEM task preemptible
2009-09-30 09:57:22 +00:00

232 lines
8.8 KiB
C
Executable file

#ifndef PROC_H
#define PROC_H
/* Here is the declaration of the process table. It contains all process
* data, including registers, flags, scheduling priority, memory map,
* accounting, message passing (IPC) information, and so on.
*
* Many assembly code routines reference fields in it. The offsets to these
* fields are defined in the assembler include file sconst.h. When changing
* struct proc, be sure to change sconst.h to match.
*/
#include <minix/com.h>
#include <minix/portio.h>
#include "const.h"
#include "priv.h"
struct proc {
struct stackframe_s p_reg; /* process' registers saved in stack frame */
struct segframe p_seg; /* segment descriptors */
proc_nr_t p_nr; /* number of this process (for fast access) */
struct priv *p_priv; /* system privileges structure */
short p_rts_flags; /* process is runnable only if zero */
short p_misc_flags; /* flags that do not suspend the process */
char p_priority; /* current scheduling priority */
char p_max_priority; /* maximum scheduling priority */
char p_ticks_left; /* number of scheduling ticks left */
char p_quantum_size; /* quantum size in ticks */
struct mem_map p_memmap[NR_LOCAL_SEGS]; /* memory map (T, D, S) */
struct pagefault p_pagefault; /* valid if PAGEFAULT in p_rts_flags set */
struct proc *p_nextpagefault; /* next on PAGEFAULT chain */
clock_t p_user_time; /* user time in ticks */
clock_t p_sys_time; /* sys time in ticks */
clock_t p_virt_left; /* number of ticks left on virtual timer */
clock_t p_prof_left; /* number of ticks left on profile timer */
struct proc *p_nextready; /* pointer to next ready process */
struct proc *p_caller_q; /* head of list of procs wishing to send */
struct proc *p_q_link; /* link to next proc wishing to send */
int p_getfrom_e; /* from whom does process want to receive? */
int p_sendto_e; /* to whom does process want to send? */
sigset_t p_pending; /* bit map for pending kernel signals */
char p_name[P_NAME_LEN]; /* name of the process, including \0 */
endpoint_t p_endpoint; /* endpoint number, generation-aware */
message p_sendmsg; /* Message from this process if SENDING */
message p_delivermsg; /* Message for this process if MF_DELIVERMSG */
vir_bytes p_delivermsg_vir; /* Virtual addr this proc wants message at */
vir_bytes p_delivermsg_lin; /* Linear addr this proc wants message at */
/* If handler functions detect a process wants to do something with
* memory that isn't present, VM has to fix it. Until it has asked
* what needs to be done and fixed it, save necessary state here.
*
* The requester gets a copy of its request message in reqmsg and gets
* VMREQUEST set.
*/
struct {
struct proc *nextrestart; /* next in vmrestart chain */
struct proc *nextrequestor; /* next in vmrequest chain */
#define VMSTYPE_SYS_NONE 0
#define VMSTYPE_KERNELCALL 1
#define VMSTYPE_DELIVERMSG 2
int type; /* suspended operation */
union {
/* VMSTYPE_SYS_MESSAGE */
message reqmsg; /* suspended request message */
} saved;
/* Parameters of request to VM */
vir_bytes start, length; /* memory range */
u8_t writeflag; /* nonzero for write access */
endpoint_t who;
/* VM result when available */
int vmresult;
#if DEBUG_VMASSERT
char stacktrace[200];
#endif
/* If the suspended operation is a sys_call, its details are
* stored here.
*/
} p_vmrequest;
struct proc *next_soft_notify;
int p_softnotified;
#if DEBUG_SCHED_CHECK
int p_ready, p_found;
#define PMAGIC 0xC0FFEE1
int p_magic; /* check validity of proc pointers */
#endif
#if DEBUG_TRACE
int p_schedules;
#endif
};
/* Bits for the runtime flags. A process is runnable iff p_rts_flags == 0. */
#define SLOT_FREE 0x01 /* process slot is free */
#define PROC_STOP 0x02 /* process has been stopped */
#define SENDING 0x04 /* process blocked trying to send */
#define RECEIVING 0x08 /* process blocked trying to receive */
#define SIGNALED 0x10 /* set when new kernel signal arrives */
#define SIG_PENDING 0x20 /* unready while signal being processed */
#define P_STOP 0x40 /* set when process is being traced */
#define NO_PRIV 0x80 /* keep forked system process from running */
#define NO_ENDPOINT 0x100 /* process cannot send or receive messages */
#define VMINHIBIT 0x200 /* not scheduled until pagetable set by VM */
#define PAGEFAULT 0x400 /* process has unhandled pagefault */
#define VMREQUEST 0x800 /* originator of vm memory request */
#define VMREQTARGET 0x1000 /* target of vm memory request */
#define SYS_LOCK 0x2000 /* temporary process lock flag for systask */
/* These runtime flags can be tested and manipulated by these macros. */
#define RTS_ISSET(rp, f) (((rp)->p_rts_flags & (f)) == (f))
/* Set flag and dequeue if the process was runnable. */
#define RTS_SET(rp, f) \
do { \
vmassert(intr_disabled()); \
if(!(rp)->p_rts_flags) { dequeue(rp); } \
(rp)->p_rts_flags |= (f); \
vmassert(intr_disabled()); \
} while(0)
/* Clear flag and enqueue if the process was not runnable but is now. */
#define RTS_UNSET(rp, f) \
do { \
int rts; \
vmassert(intr_disabled()); \
rts = (rp)->p_rts_flags; \
(rp)->p_rts_flags &= ~(f); \
if(rts && !(rp)->p_rts_flags) { enqueue(rp); } \
vmassert(intr_disabled()); \
} while(0)
/* Set flag and dequeue if the process was runnable. */
#define RTS_LOCK_SET(rp, f) \
do { \
int u = 0; \
if(!intr_disabled()) { u = 1; lock; } \
if(!(rp)->p_rts_flags) { dequeue(rp); } \
(rp)->p_rts_flags |= (f); \
if(u) { unlock; } \
} while(0)
/* Clear flag and enqueue if the process was not runnable but is now. */
#define RTS_LOCK_UNSET(rp, f) \
do { \
int rts; \
int u = 0; \
if(!intr_disabled()) { u = 1; lock; } \
rts = (rp)->p_rts_flags; \
(rp)->p_rts_flags &= ~(f); \
if(rts && !(rp)->p_rts_flags) { enqueue(rp); } \
if(u) { unlock; } \
} while(0)
/* Set flags to this value. */
#define RTS_LOCK_SETFLAGS(rp, f) \
do { \
int u = 0; \
if(!intr_disabled()) { u = 1; lock; } \
if(!(rp)->p_rts_flags && (f)) { dequeue(rp); } \
(rp)->p_rts_flags = (f); \
if(u) { unlock; } \
} while(0)
/* Misc flags */
#define MF_REPLY_PEND 0x001 /* reply to IPC_REQUEST is pending */
#define MF_VIRT_TIMER 0x002 /* process-virtual timer is running */
#define MF_PROF_TIMER 0x004 /* process-virtual profile timer is running */
#define MF_ASYNMSG 0x010 /* Asynchrous message pending */
#define MF_FULLVM 0x020
#define MF_DELIVERMSG 0x040 /* Copy message for him before running */
#define MF_SIG_DELAY 0x080 /* Send signal when no longer sending */
#define MF_SC_ACTIVE 0x100 /* Syscall tracing: in a system call now */
#define MF_SC_DEFER 0x200 /* Syscall tracing: deferred system call */
#define MF_SC_TRACE 0x400 /* Syscall tracing: trigger syscall events */
/* Scheduling priorities for p_priority. Values must start at zero (highest
* priority) and increment. Priorities of the processes in the boot image
* can be set in table.c. IDLE must have a queue for itself, to prevent low
* priority user processes to run round-robin with IDLE.
*/
#define NR_SCHED_QUEUES 16 /* MUST equal minimum priority + 1 */
#define TASK_Q 0 /* highest, used for kernel tasks */
#define MAX_USER_Q 0 /* highest priority for user processes */
#define USER_Q 7 /* default (should correspond to nice 0) */
#define MIN_USER_Q 14 /* minimum priority for user processes */
#define IDLE_Q 15 /* lowest, only IDLE process goes here */
/* Magic process table addresses. */
#define BEG_PROC_ADDR (&proc[0])
#define BEG_USER_ADDR (&proc[NR_TASKS])
#define END_PROC_ADDR (&proc[NR_TASKS + NR_PROCS])
#define NIL_PROC ((struct proc *) 0)
#define NIL_SYS_PROC ((struct proc *) 1)
#define cproc_addr(n) (&(proc + NR_TASKS)[(n)])
#define proc_addr(n) (&(proc[NR_TASKS + (n)]))
#define proc_nr(p) ((p)->p_nr)
#define isokprocn(n) ((unsigned) ((n) + NR_TASKS) < NR_PROCS + NR_TASKS)
#define isemptyn(n) isemptyp(proc_addr(n))
#define isemptyp(p) ((p)->p_rts_flags == SLOT_FREE)
#define iskernelp(p) ((p) < BEG_USER_ADDR)
#define iskerneln(n) ((n) < 0)
#define isuserp(p) isusern((p) >= BEG_USER_ADDR)
#define isusern(n) ((n) >= 0)
/* The process table and pointers to process table slots. The pointers allow
* faster access because now a process entry can be found by indexing the
* pproc_addr array, while accessing an element i requires a multiplication
* with sizeof(struct proc) to determine the address.
*/
EXTERN struct proc proc[NR_TASKS + NR_PROCS]; /* process table */
EXTERN struct proc *rdy_head[NR_SCHED_QUEUES]; /* ptrs to ready list headers */
EXTERN struct proc *rdy_tail[NR_SCHED_QUEUES]; /* ptrs to ready list tails */
#endif /* PROC_H */