]> git.saurik.com Git - apple/xnu.git/blobdiff - bsd/kern/subr_log.c
xnu-3247.1.106.tar.gz
[apple/xnu.git] / bsd / kern / subr_log.c
index 4a4a9a06ac4a900b7963422bd806346f0d22523b..0f8c00b3696b7baed5ea4b4703f509de61ded2aa 100644 (file)
@@ -1,23 +1,29 @@
 /*
- * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2010 Apple, Inc. All rights reserved.
  *
- * @APPLE_LICENSE_HEADER_START@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
- * The contents of this file constitute Original Code as defined in and
- * are subject to the Apple Public Source License Version 1.1 (the
- * "License").  You may not use this file except in compliance with the
- * License.  Please obtain a copy of the License at
- * http://www.apple.com/publicsource and read it before using this file.
+ * This file contains Original Code and/or Modifications of Original Code
+ * as defined in and that are subject to the Apple Public Source License
+ * Version 2.0 (the 'License'). You may not use this file except in
+ * compliance with the License. The rights granted to you under the License
+ * may not be used to create, or enable the creation or redistribution of,
+ * unlawful or unlicensed copies of an Apple operating system, or to
+ * circumvent, violate, or enable the circumvention or violation of, any
+ * terms of an Apple operating system software license agreement.
  * 
- * This Original Code and all software distributed under the License are
- * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * Please obtain a copy of the License at
+ * http://www.opensource.apple.com/apsl/ and read it before using this file.
+ * 
+ * The Original Code and all software distributed under the License are
+ * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
- * License for the specific language governing rights and limitations
- * under the License.
+ * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
+ * Please see the License for the specific language governing rights and
+ * limitations under the License.
  * 
- * @APPLE_LICENSE_HEADER_END@
+ * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  */
 /* Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved */
 /*
 
 #include <sys/param.h>
 #include <sys/systm.h>
-#include <sys/proc.h>
+#include <sys/proc_internal.h>
 #include <sys/vnode.h>
 #include <sys/ioctl.h>
 #include <sys/msgbuf.h>
-#include <sys/file.h>
+#include <sys/file_internal.h>
 #include <sys/errno.h>
 #include <sys/select.h>
+#include <sys/kernel.h>
 #include <kern/thread.h>
+#include <sys/lock.h>
+#include <sys/signalvar.h>
+#include <sys/conf.h>
+#include <sys/sysctl.h>
+#include <kern/kalloc.h>
+#include <pexpert/pexpert.h>
+
+/* XXX should be in a common header somewhere */
+extern void logwakeup(void);
 
 #define LOG_RDPRI      (PZERO + 1)
 
 #define LOG_ASYNC      0x04
 #define LOG_RDWAIT     0x08
 
+#define MAX_UNREAD_CHARS (CONFIG_MSG_BSIZE/2)
+/* All globals should be accessed under LOG_LOCK() */
+
+/* logsoftc only valid while log_open=1 */
 struct logsoftc {
        int     sc_state;               /* see above for possibilities */
        struct  selinfo sc_selp;        /* thread waiting for select */
@@ -83,46 +103,54 @@ struct logsoftc {
 } logsoftc;
 
 int    log_open;                       /* also used in log() */
-struct msgbuf temp_msgbuf;
-struct msgbuf *msgbufp;
-static int _logentrypend = 0;
+char smsg_bufc[CONFIG_MSG_BSIZE]; /* static buffer */
+struct msgbuf msgbuf = {MSG_MAGIC,sizeof(smsg_bufc),0,0,smsg_bufc};
+struct msgbuf *msgbufp __attribute__((used)) = &msgbuf;
+
+/* the following are implemented in osfmk/kern/printf.c  */
+extern void bsd_log_lock(void);
+extern void bsd_log_unlock(void);
+extern void bsd_log_init(void);
+
+/* XXX wants a linker set so these can be static */
+extern d_open_t         logopen;
+extern d_close_t        logclose;
+extern d_read_t         logread;
+extern d_ioctl_t        logioctl;
+extern d_select_t       logselect;
 
 /*
  * Serialize log access.  Note that the log can be written at interrupt level,
  * so any log manipulations that can be done from, or affect, another processor
  * at interrupt level must be guarded with a spin lock.
  */
-decl_simple_lock_data(,log_lock);      /* stop races dead in their tracks */
-#define        LOG_LOCK()      simple_lock(&log_lock)
-#define        LOG_UNLOCK()    simple_unlock(&log_lock)
-#define        LOG_LOCK_INIT() simple_lock_init(&log_lock)
+
+#define        LOG_LOCK() bsd_log_lock()
+#define        LOG_UNLOCK() bsd_log_unlock()
+
+#if DEBUG
+#define LOG_SETSIZE_DEBUG(x...) kprintf(x)
+#else
+#define LOG_SETSIZE_DEBUG(x...) do { } while(0)
+#endif
+
+static int sysctl_kern_msgbuf(struct sysctl_oid *oidp,
+                               void *arg1,
+                               int arg2,
+                               struct sysctl_req *req);
 
 /*ARGSUSED*/
-logopen(dev, flags, mode, p)
-       dev_t dev;
-       int flags, mode;
-       struct proc *p;
+int
+logopen(__unused dev_t dev, __unused int flags, __unused int mode, struct proc *p)
 {
        LOG_LOCK();
        if (log_open) {
                LOG_UNLOCK();
                return (EBUSY);
        }
-       log_open = 1;
        logsoftc.sc_pgid = p->p_pid;            /* signal process only */
-       /*
-        * Potential race here with putchar() but since putchar should be
-        * called by autoconf, msg_magic should be initialized by the time
-        * we get here.
-        */
-       if (msgbufp->msg_magic != MSG_MAGIC) {
-               register int i;
+       log_open = 1;
 
-               msgbufp->msg_magic = MSG_MAGIC;
-               msgbufp->msg_bufx = msgbufp->msg_bufr = 0;
-               for (i=0; i < MSG_BSIZE; i++)
-                       msgbufp->msg_bufc[i] = 0;
-       }
        LOG_UNLOCK();
 
        return (0);
@@ -130,147 +158,136 @@ logopen(dev, flags, mode, p)
 
 /*ARGSUSED*/
 int
-logclose(dev, flag)
-       dev_t dev;
+logclose(__unused dev_t dev, __unused int flag, __unused int devtype, __unused struct proc *p)
 {
-       int oldpri;
        LOG_LOCK();
-       log_open = 0;
        selwakeup(&logsoftc.sc_selp);
-       oldpri = splhigh();
        selthreadclear(&logsoftc.sc_selp);
-       splx(oldpri);
+       log_open = 0;
        LOG_UNLOCK();
        return (0);
 }
 
 /*ARGSUSED*/
 int
-logread(dev, uio, flag)
-       dev_t dev;
-       struct uio *uio;
-       int flag;
+logread(__unused dev_t dev, struct uio *uio, int flag)
 {
-       register long l;
-       register int s;
+       int l;
        int error = 0;
 
-       s = splhigh();
+       LOG_LOCK();
        while (msgbufp->msg_bufr == msgbufp->msg_bufx) {
                if (flag & IO_NDELAY) {
-                       splx(s);
-                       return (EWOULDBLOCK);
+                       error = EWOULDBLOCK;
+                       goto out;
                }
                if (logsoftc.sc_state & LOG_NBIO) {
-                       splx(s);
-                       return (EWOULDBLOCK);
+                       error = EWOULDBLOCK;
+                       goto out;
                }
                logsoftc.sc_state |= LOG_RDWAIT;
-               if (error = tsleep((caddr_t)msgbufp, LOG_RDPRI | PCATCH,
-                               "klog", 0)) {
-                       splx(s);
-                       return (error);
+               LOG_UNLOCK();
+               /*
+                * If the wakeup is missed 
+                * then wait for 5 sec and reevaluate 
+                */
+               if ((error = tsleep((caddr_t)msgbufp, LOG_RDPRI | PCATCH,
+                               "klog", 5 * hz)) != 0) {
+                       /* if it times out; ignore */
+                       if (error != EWOULDBLOCK)
+                               return (error);
                }
+               LOG_LOCK();
        }
-       splx(s);
        logsoftc.sc_state &= ~LOG_RDWAIT;
 
-       while (uio->uio_resid > 0) {
+       while (uio_resid(uio) > 0) {
+               int readpos;
+
                l = msgbufp->msg_bufx - msgbufp->msg_bufr;
                if (l < 0)
-                       l = MSG_BSIZE - msgbufp->msg_bufr;
-               l = min(l, uio->uio_resid);
+                       l = msgbufp->msg_size - msgbufp->msg_bufr;
+               l = min(l, uio_resid(uio));
                if (l == 0)
                        break;
-               error = uiomove((caddr_t)&msgbufp->msg_bufc[msgbufp->msg_bufr],
-                       (int)l, uio);
+
+               readpos = msgbufp->msg_bufr;
+               LOG_UNLOCK();
+               error = uiomove((caddr_t)&msgbufp->msg_bufc[readpos],
+                       l, uio);
+               LOG_LOCK();
                if (error)
                        break;
-               msgbufp->msg_bufr += l;
-               if (msgbufp->msg_bufr < 0 || msgbufp->msg_bufr >= MSG_BSIZE)
+               msgbufp->msg_bufr = readpos + l;
+               if (msgbufp->msg_bufr >= msgbufp->msg_size)
                        msgbufp->msg_bufr = 0;
        }
+out:
+       LOG_UNLOCK();
        return (error);
 }
 
 /*ARGSUSED*/
 int
-logselect(dev, rw, wql, p)
-       dev_t dev;
-       int rw;
-       void * wql;
-       struct proc *p;
+logselect(__unused dev_t dev, int rw, void * wql, struct proc *p)
 {
-       int s = splhigh();
-
        switch (rw) {
 
        case FREAD:
+               LOG_LOCK();     
                if (msgbufp->msg_bufr != msgbufp->msg_bufx) {
-                       splx(s);
+                       LOG_UNLOCK();
                        return (1);
                }
                selrecord(p, &logsoftc.sc_selp, wql);
+               LOG_UNLOCK();
                break;
        }
-       splx(s);
        return (0);
 }
 
 void
-logwakeup()
+logwakeup(void)
 {
-       struct proc *p;
        int pgid;
-       boolean_t funnel_state;
 
-       if (!log_open)
+       LOG_LOCK();     
+       if (!log_open) {
+               LOG_UNLOCK();
                return;
-       funnel_state = thread_funnel_set(kernel_flock, TRUE);
+       }
        selwakeup(&logsoftc.sc_selp);
        if (logsoftc.sc_state & LOG_ASYNC) {
-               LOG_LOCK();
                pgid = logsoftc.sc_pgid;
                LOG_UNLOCK();
                if (pgid < 0)
                        gsignal(-pgid, SIGIO); 
-               else if (p = pfind(pgid))
-                       psignal(p, SIGIO);
+               else 
+                       proc_signal(pgid, SIGIO);
+               LOG_LOCK();
        }
        if (logsoftc.sc_state & LOG_RDWAIT) {
                wakeup((caddr_t)msgbufp);
                logsoftc.sc_state &= ~LOG_RDWAIT;
        }
-       (void) thread_funnel_set(kernel_flock, funnel_state);
+       LOG_UNLOCK();
 }
 
-void
-klogwakeup()
-{
-
-       if (_logentrypend) {
-               _logentrypend = 0;
-               logwakeup();
-       }
-}
 
 /*ARGSUSED*/
 int
-logioctl(com, data, flag)
-       caddr_t data;
+logioctl(__unused dev_t dev, u_long com, caddr_t data, __unused int flag, __unused struct proc *p)
 {
-       long l;
-       int s;
+       int l;
 
+       LOG_LOCK();
        switch (com) {
 
        /* return number of characters immediately available */
        case FIONREAD:
-               s = splhigh();
                l = msgbufp->msg_bufx - msgbufp->msg_bufr;
-               splx(s);
                if (l < 0)
-                       l += MSG_BSIZE;
+                       l += msgbufp->msg_size;
                *(off_t *)data = l;
                break;
 
@@ -289,49 +306,279 @@ logioctl(com, data, flag)
                break;
 
        case TIOCSPGRP:
-               LOG_LOCK();
                logsoftc.sc_pgid = *(int *)data;
-               LOG_UNLOCK();
                break;
 
        case TIOCGPGRP:
-               LOG_LOCK();
                *(int *)data = logsoftc.sc_pgid;
-               LOG_UNLOCK();
                break;
 
        default:
+               LOG_UNLOCK();
                return (-1);
        }
+       LOG_UNLOCK();
        return (0);
 }
 
 void
-log_init()
+bsd_log_init(void)
+{
+       /* After this point, we must be ready to accept characters */
+}
+
+
+/*
+ * log_putc_locked
+ *
+ * Decription: Output a character to the log; assumes the LOG_LOCK() is held
+ *             by the caller.
+ *
+ * Parameters: c                               Character to output
+ *
+ * Returns:    (void)
+ *
+ * Notes:      This functions is used for multibyte output to the log; it
+ *             should be used preferrentially where possible to ensure that
+ *             log entries do not end up interspersed due to preemption or
+ *             SMP reentrancy.
+ */
+void
+log_putc_locked(char c)
 {
-       msgbufp = &temp_msgbuf;
-       LOG_LOCK_INIT();
+       struct msgbuf *mbp;
+
+       mbp = msgbufp; 
+       mbp->msg_bufc[mbp->msg_bufx++] = c;
+       if (mbp->msg_bufx >= msgbufp->msg_size)
+               mbp->msg_bufx = 0;
 }
 
+
+/*
+ * log_putc
+ *
+ * Decription: Output a character to the log; assumes the LOG_LOCK() is NOT
+ *             held by the caller.
+ *
+ * Parameters: c                               Character to output
+ *
+ * Returns:    (void)
+ *
+ * Notes:      This function is used for syingle byte output to the log.  It
+ *             primarily exists to maintain binary backward compatibility.
+ */
 void
 log_putc(char c)
 {
-       register struct msgbuf *mbp;
+       int unread_count = 0;
+       LOG_LOCK();
+       log_putc_locked(c);
+       unread_count = msgbufp->msg_bufx - msgbufp->msg_bufr;
+       LOG_UNLOCK();
+
+       if (unread_count < 0)
+               unread_count = 0 - unread_count;
+       if (c == '\n' || unread_count >= MAX_UNREAD_CHARS)
+               logwakeup();
+}
 
-       if (msgbufp == NULL)
-               msgbufp =&temp_msgbuf;
 
-       mbp = msgbufp; 
-       if (mbp-> msg_magic != MSG_MAGIC) { 
-               register int i;
+/*
+ * it is possible to increase the kernel log buffer size by adding
+ *   msgbuf=n
+ * to the kernel command line, and to read the current size using
+ *   sysctl kern.msgbuf
+ * If there is no parameter on the kernel command line, the buffer is
+ * allocated statically and is CONFIG_MSG_BSIZE characters in size, otherwise
+ * memory is dynamically allocated. Memory management must already be up.
+ */
+int
+log_setsize(int size) {
+       char *new_logdata;
+       int new_logsize, new_bufr, new_bufx;
+       char *old_logdata;
+       int old_logsize, old_bufr, old_bufx;
+       int i, count;
+       char *p, ch;
+
+       if (size > MAX_MSG_BSIZE)
+               return (EINVAL);
+
+       if (size <= 0)
+               return (EINVAL);
+
+       new_logsize = size;
+       if (!(new_logdata = (char*)kalloc(size))) {
+               printf("log_setsize: unable to allocate memory\n");
+               return (ENOMEM);
+       }
+       bzero(new_logdata, new_logsize);
+
+       LOG_LOCK();
 
-               mbp->msg_magic = MSG_MAGIC;
-               mbp->msg_bufx = mbp->msg_bufr = 0;
-               for (i=0; i < MSG_BSIZE; i++)
-                       mbp->msg_bufc[i] = 0;
+       old_logsize = msgbufp->msg_size;
+       old_logdata = msgbufp->msg_bufc;
+       old_bufr = msgbufp->msg_bufr;
+       old_bufx = msgbufp->msg_bufx;
+
+       LOG_SETSIZE_DEBUG("log_setsize(%d): old_logdata %p old_logsize %d old_bufr %d old_bufx %d\n",
+                                         size, old_logdata, old_logsize, old_bufr, old_bufx);
+
+       /* start "new_logsize" bytes before the write pointer */
+       if (new_logsize <= old_bufx) {
+               count = new_logsize;
+               p = old_logdata + old_bufx - count;
+       } else {
+               /*
+                * if new buffer is bigger, copy what we have and let the
+                * bzero above handle the difference
+                */
+               count = MIN(new_logsize, old_logsize);
+               p = old_logdata + old_logsize - (count - old_bufx);
        }
-       mbp->msg_bufc[mbp->msg_bufx++] = c;
-       _logentrypend = 1;
-       if (mbp->msg_bufx < 0 || mbp->msg_bufx >= MSG_BSIZE)
-               mbp->msg_bufx = 0;
+       for (i = 0; i < count; i++) {
+               if (p >= old_logdata + old_logsize)
+                       p = old_logdata;
+
+               ch = *p++;
+               new_logdata[i] = ch;
+       }
+
+       new_bufx = i;
+       if (new_bufx >= new_logsize)
+               new_bufx = 0;
+       msgbufp->msg_bufx = new_bufx;
+
+       new_bufr = old_bufx - old_bufr; /* how much were we trailing bufx by? */
+       if (new_bufr < 0)
+               new_bufr += old_logsize;
+       new_bufr = new_bufx - new_bufr; /* now relative to oldest data in new buffer */
+       if (new_bufr < 0)
+               new_bufr += new_logsize;
+       msgbufp->msg_bufr = new_bufr;
+
+       msgbufp->msg_size = new_logsize;
+       msgbufp->msg_bufc = new_logdata;
+
+       LOG_SETSIZE_DEBUG("log_setsize(%d): new_logdata %p new_logsize %d new_bufr %d new_bufx %d\n",
+                                         size, new_logdata, new_logsize, new_bufr, new_bufx);
+
+       LOG_UNLOCK();
+
+       /* this memory is now dead - clear it so that it compresses better
+          in case of suspend to disk etc. */
+       bzero(old_logdata, old_logsize);
+       if (old_logdata != smsg_bufc) {
+               /* dynamic memory that must be freed */
+               kfree(old_logdata, old_logsize);
+       }
+
+       printf("set system log size to %d bytes\n", new_logsize);
+
+       return 0;
+}
+
+SYSCTL_PROC(_kern, OID_AUTO, msgbuf, CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_LOCKED, 0, 0, sysctl_kern_msgbuf, "I", "");
+
+static int sysctl_kern_msgbuf(struct sysctl_oid *oidp __unused,
+                                                         void *arg1 __unused,
+                                                         int arg2 __unused,
+                                                         struct sysctl_req *req)
+{
+       int old_bufsize, bufsize;
+       int error;
+
+       LOG_LOCK();
+       old_bufsize = bufsize = msgbufp->msg_size;
+       LOG_UNLOCK();
+
+       error = sysctl_io_number(req, bufsize, sizeof(bufsize), &bufsize, NULL);
+       if (error)
+               return (error);
+
+       if (bufsize != old_bufsize) {
+               error = log_setsize(bufsize);
+       }
+
+       return (error);
+}
+
+
+/*
+ * This should be called by /sbin/dmesg only via libproc.
+ * It returns as much data still in the buffer as possible.
+ */
+int
+log_dmesg(user_addr_t buffer, uint32_t buffersize, int32_t * retval) {
+       uint32_t i;
+       uint32_t localbuff_size;
+       int error = 0, newl, skip;
+       char *localbuff, *p, *copystart, ch;
+       size_t copysize;
+
+       LOG_LOCK();
+       localbuff_size = (msgbufp->msg_size + 2); /* + '\n' + '\0' */
+       LOG_UNLOCK();
+
+       /* Allocate a temporary non-circular buffer for copyout */
+       if (!(localbuff = (char *)kalloc(localbuff_size))) {
+               printf("log_dmesg: unable to allocate memory\n");
+               return (ENOMEM);
+       }
+
+       /* in between here, the log could become bigger, but that's fine */
+       LOG_LOCK();
+
+       /*
+        * The message buffer is circular; start at the write pointer, and
+        * make one loop up to write pointer - 1.
+        */
+       p = msgbufp->msg_bufc + msgbufp->msg_bufx;
+       for (i = newl = skip = 0; p != msgbufp->msg_bufc + msgbufp->msg_bufx - 1; ++p) {
+               if (p >= msgbufp->msg_bufc + msgbufp->msg_size)
+                       p = msgbufp->msg_bufc;
+               ch = *p;
+               /* Skip "\n<.*>" syslog sequences. */
+               if (skip) {
+                       if (ch == '>')
+                               newl = skip = 0;
+                       continue;
+               }
+               if (newl && ch == '<') {
+                       skip = 1;
+                       continue;
+               }
+               if (ch == '\0')
+                       continue;
+               newl = (ch == '\n');
+               localbuff[i++] = ch;
+               /* The original version of this routine contained a buffer
+                * overflow. At the time, a "small" targeted fix was desired
+                * so the change below to check the buffer bounds was made.
+                * TODO: rewrite this needlessly convoluted routine.
+                */
+               if (i == (localbuff_size - 2))
+                       break;
+       }
+       if (!newl)
+               localbuff[i++] = '\n';
+       localbuff[i++] = 0;
+
+       if (buffersize >= i) {
+               copystart = localbuff;
+               copysize = i;
+       } else {
+               copystart = localbuff + i - buffersize;
+               copysize = buffersize;
+       }
+
+       LOG_UNLOCK();
+
+       error = copyout(copystart, buffer, copysize);
+       if (!error)
+               *retval = copysize;
+
+       kfree(localbuff, localbuff_size);
+       return (error);
 }