910831cb5c
Now that there are services other than PM and VFS that implement userland system calls directly, these services may need to know about events related to user processes. In particular, signal delivery may have to interrupt blocking system calls, and certain cleanup tasks may have to be performed after a user process exits. This patch aims to implement a generic, lasting solution for this problem, by allowing services to subscribe to "signal delivered" and/or "process exit" events from PM. PM publishes such events by sending messages to its subscribed services, which must then reply an acknowledgment message. For now, only the two aforementioned events are implemented, and only the IPC service makes use of the process event facility. The new process event publish/subscribe system replaces the previous VM notify-sig/watch-exit/query-exit system, which was unsound: 1) it allowed subscription to events from individual processes, and suffered from fundamental race conditions as a result; 2) it relied on "not too many" processes making use of the IPC server functionality in order to avoid loss of notifications. In addition, it had the "ipc" process name hardcoded, did not distinguish between signal delivery and exits, and added a roundtrip to VM for all events from all processes. Change-Id: I75ebad4bc54e646c6433f473294cb4003b2c3430
105 lines
4.8 KiB
C
105 lines
4.8 KiB
C
/* This table has one slot per process. It contains all the process management
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* information for each process. Among other things, it defines the text, data
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* and stack segments, uids and gids, and various flags. The kernel and file
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* systems have tables that are also indexed by process, with the contents
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* of corresponding slots referring to the same process in all three.
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*/
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#include <limits.h>
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#include <minix/timers.h>
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#include <signal.h>
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#include <sys/cdefs.h>
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/* Needs to be included here, for 'ps' etc */
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#include "const.h"
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/*
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* The per-process sigaction structures are stored outside of the mproc table,
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* so that the MIB service can avoid pulling them in, as they account for
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* roughly 80% of the per-process state.
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*/
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typedef struct sigaction ixfer_sigaction;
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EXTERN ixfer_sigaction mpsigact[NR_PROCS][_NSIG];
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EXTERN struct mproc {
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char mp_exitstatus; /* storage for status when process exits */
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char mp_sigstatus; /* storage for signal # for killed procs */
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char mp_eventsub; /* process event subscriber, or NO_EVENTSUB */
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pid_t mp_pid; /* process id */
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endpoint_t mp_endpoint; /* kernel endpoint id */
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pid_t mp_procgrp; /* pid of process group (used for signals) */
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pid_t mp_wpid; /* pid this process is waiting for */
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vir_bytes mp_waddr; /* struct rusage address while waiting */
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int mp_parent; /* index of parent process */
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int mp_tracer; /* index of tracer process, or NO_TRACER */
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/* Child user and system times. Accounting done on child exit. */
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clock_t mp_child_utime; /* cumulative user time of children */
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clock_t mp_child_stime; /* cumulative sys time of children */
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/* Real and effective uids and gids. */
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uid_t mp_realuid; /* process' real uid */
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uid_t mp_effuid; /* process' effective uid */
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gid_t mp_realgid; /* process' real gid */
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gid_t mp_effgid; /* process' effective gid */
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/* Supplemental groups. */
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int mp_ngroups; /* number of supplemental groups */
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gid_t mp_sgroups[NGROUPS_MAX];/* process' supplemental groups */
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/* Signal handling information. */
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sigset_t mp_ignore; /* 1 means ignore the signal, 0 means don't */
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sigset_t mp_catch; /* 1 means catch the signal, 0 means don't */
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sigset_t mp_sigmask; /* signals to be blocked */
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sigset_t mp_sigmask2; /* saved copy of mp_sigmask */
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sigset_t mp_sigpending; /* pending signals to be handled */
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sigset_t mp_ksigpending; /* bitmap for pending signals from the kernel */
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sigset_t mp_sigtrace; /* signals to hand to tracer first */
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ixfer_sigaction *mp_sigact; /* as in sigaction(2), pointer into mpsigact */
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vir_bytes mp_sigreturn; /* address of C library __sigreturn function */
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minix_timer_t mp_timer; /* watchdog timer for alarm(2), setitimer(2) */
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clock_t mp_interval[NR_ITIMERS]; /* setitimer(2) repetition intervals */
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clock_t mp_started; /* when the process was started, for ps(1) */
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unsigned mp_flags; /* flag bits */
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unsigned mp_trace_flags; /* trace options */
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message mp_reply; /* reply message to be sent to one */
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/* Process execution frame. Both fields are used by procfs. */
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vir_bytes mp_frame_addr; /* ptr to proc's initial stack arguments */
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size_t mp_frame_len; /* size of proc's initial stack arguments */
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/* Scheduling priority. */
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signed int mp_nice; /* nice is PRIO_MIN..PRIO_MAX, standard 0. */
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/* User space scheduling */
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endpoint_t mp_scheduler; /* scheduler endpoint id */
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char mp_name[PROC_NAME_LEN]; /* process name */
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int mp_magic; /* sanity check, MP_MAGIC */
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} mproc[NR_PROCS];
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/* Flag values */
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#define IN_USE 0x00001 /* set when 'mproc' slot in use */
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#define WAITING 0x00002 /* set by WAIT4 system call */
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#define ZOMBIE 0x00004 /* waiting for parent to issue WAIT4 call */
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#define PROC_STOPPED 0x00008 /* process is stopped in the kernel */
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#define ALARM_ON 0x00010 /* set when SIGALRM timer started */
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#define EXITING 0x00020 /* set by EXIT, process is now exiting */
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#define TOLD_PARENT 0x00040 /* parent wait() completed, ZOMBIE off */
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#define TRACE_STOPPED 0x00080 /* set if process stopped for tracing */
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#define SIGSUSPENDED 0x00100 /* set by SIGSUSPEND system call */
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#define VFS_CALL 0x00400 /* set if waiting for VFS (normal calls) */
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#define NEW_PARENT 0x00800 /* process's parent changed during VFS call */
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#define UNPAUSED 0x01000 /* VFS has replied to unpause request */
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#define PRIV_PROC 0x02000 /* system process, special privileges */
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#define PARTIAL_EXEC 0x04000 /* process got a new map but no content */
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#define TRACE_EXIT 0x08000 /* tracer is forcing this process to exit */
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#define TRACE_ZOMBIE 0x10000 /* waiting for tracer to issue WAIT4 call */
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#define DELAY_CALL 0x20000 /* waiting for call before sending signal */
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#define TAINTED 0x40000 /* process is 'tainted' */
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#define EVENT_CALL 0x80000 /* waiting for process event subscriber */
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#define MP_MAGIC 0xC0FFEE0
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