xnu-3247.1.106.tar.gz

[apple/xnu.git] / bsd / kern / subr_log.c

diff --git a/bsd/kern/subr_log.c b/bsd/kern/subr_log.c
index af0e42341f6ead095a998148ae2c27a547b40063..0f8c00b3696b7baed5ea4b4703f509de61ded2aa 100644 (file)
--- a/bsd/kern/subr_log.c
+++ b/bsd/kern/subr_log.c
@@ -1,5 +1,5 @@
 /*
 /*

- * Copyright (c) 2000-2006 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2000-2010 Apple, Inc. All rights reserved.

  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 


@@ -81,9 +81,9 @@
 #include <sys/conf.h>
 #include <sys/sysctl.h>
 #include <kern/kalloc.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 */
 
 /* XXX should be in a common header somewhere */

-extern void klogwakeup(void);

 extern void logwakeup(void);
 
 #define LOG_RDPRI      (PZERO + 1)
 extern void logwakeup(void);
 
 #define LOG_RDPRI      (PZERO + 1)


@@ -92,6 +92,10 @@ extern void logwakeup(void);
 #define LOG_ASYNC      0x04
 #define LOG_RDWAIT     0x08
 
 #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 */
 struct logsoftc {
        int     sc_state;               /* see above for possibilities */
        struct  selinfo sc_selp;        /* thread waiting for select */


@@ -99,11 +103,10 @@ struct logsoftc {
 } logsoftc;
 
 int    log_open;                       /* also used in log() */
 } logsoftc;
 
 int    log_open;                       /* also used in log() */

-char smsg_bufc[MSG_BSIZE]; /* static buffer */
-struct msgbuf temp_msgbuf = {0,MSG_BSIZE,0,0,smsg_bufc};
-struct msgbuf *msgbufp;
-static int _logentrypend = 0;
-static int log_inited = 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);
 /* the following are implemented in osfmk/kern/printf.c  */
 extern void bsd_log_lock(void);
 extern void bsd_log_unlock(void);


@@ -125,6 +128,16 @@ extern d_select_t       logselect;
 #define        LOG_LOCK() bsd_log_lock()
 #define        LOG_UNLOCK() bsd_log_unlock()
 
 #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*/
 int
 
 /*ARGSUSED*/
 int


@@ -135,21 +148,9 @@ logopen(__unused dev_t dev, __unused int flags, __unused int mode, struct proc *
                LOG_UNLOCK();
                return (EBUSY);
        }
                LOG_UNLOCK();
                return (EBUSY);
        }

-       log_open = 1;

        logsoftc.sc_pgid = p->p_pid;            /* signal process only */
        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);
        LOG_UNLOCK();
 
        return (0);


@@ -160,9 +161,9 @@ int
 logclose(__unused dev_t dev, __unused int flag, __unused int devtype, __unused struct proc *p)
 {
        LOG_LOCK();
 logclose(__unused dev_t dev, __unused int flag, __unused int devtype, __unused struct proc *p)
 {
        LOG_LOCK();

-       log_open = 0;

        selwakeup(&logsoftc.sc_selp);
        selthreadclear(&logsoftc.sc_selp);
        selwakeup(&logsoftc.sc_selp);
        selthreadclear(&logsoftc.sc_selp);

+       log_open = 0;

        LOG_UNLOCK();
        return (0);
 }
        LOG_UNLOCK();
        return (0);
 }


@@ -171,7 +172,7 @@ logclose(__unused dev_t dev, __unused int flag, __unused int devtype, __unused s
 int
 logread(__unused dev_t dev, struct uio *uio, int flag)
 {
 int
 logread(__unused dev_t dev, struct uio *uio, int flag)
 {

-       register long l;
+       int l;

        int error = 0;
 
        LOG_LOCK();
        int error = 0;
 
        LOG_LOCK();


@@ -187,8 +188,7 @@ logread(__unused dev_t dev, struct uio *uio, int flag)
                logsoftc.sc_state |= LOG_RDWAIT;
                LOG_UNLOCK();
                /*
                logsoftc.sc_state |= LOG_RDWAIT;
                LOG_UNLOCK();
                /*

-                * If the wakeup is missed the ligtening bolt will wake this up 
-                * if there are any new characters. If that doesn't do it
+                * If the wakeup is missed 

                 * then wait for 5 sec and reevaluate 
                 */
                if ((error = tsleep((caddr_t)msgbufp, LOG_RDPRI | PCATCH,
                 * then wait for 5 sec and reevaluate 
                 */
                if ((error = tsleep((caddr_t)msgbufp, LOG_RDPRI | PCATCH,


@@ -202,20 +202,24 @@ logread(__unused dev_t dev, struct uio *uio, int flag)
        logsoftc.sc_state &= ~LOG_RDWAIT;
 
        while (uio_resid(uio) > 0) {
        logsoftc.sc_state &= ~LOG_RDWAIT;
 
        while (uio_resid(uio) > 0) {

+               int readpos;
+

                l = msgbufp->msg_bufx - msgbufp->msg_bufr;
                if (l < 0)
                        l = msgbufp->msg_size - msgbufp->msg_bufr;
                l = min(l, uio_resid(uio));
                if (l == 0)
                        break;
                l = msgbufp->msg_bufx - msgbufp->msg_bufr;
                if (l < 0)
                        l = msgbufp->msg_size - msgbufp->msg_bufr;
                l = min(l, uio_resid(uio));
                if (l == 0)
                        break;

+
+               readpos = msgbufp->msg_bufr;

                LOG_UNLOCK();
                LOG_UNLOCK();

-               error = uiomove((caddr_t)&msgbufp->msg_bufc[msgbufp->msg_bufr],
-                       (int)l, uio);
+               error = uiomove((caddr_t)&msgbufp->msg_bufc[readpos],
+                       l, uio);

                LOG_LOCK();
                if (error)
                        break;
                LOG_LOCK();
                if (error)
                        break;

-               msgbufp->msg_bufr += l;
-               if (msgbufp->msg_bufr < 0 || msgbufp->msg_bufr >= msgbufp->msg_size)
+               msgbufp->msg_bufr = readpos + l;
+               if (msgbufp->msg_bufr >= msgbufp->msg_size)

                        msgbufp->msg_bufr = 0;
        }
 out:
                        msgbufp->msg_bufr = 0;
        }
 out:


@@ -269,20 +273,12 @@ logwakeup(void)
        LOG_UNLOCK();
 }
 
        LOG_UNLOCK();
 }
 

-void
-klogwakeup(void)
-{
-       if (_logentrypend) {
-               _logentrypend = 0;
-               logwakeup();
-       }
-}

 
 /*ARGSUSED*/
 int
 logioctl(__unused dev_t dev, u_long com, caddr_t data, __unused int flag, __unused struct proc *p)
 {
 
 /*ARGSUSED*/
 int
 logioctl(__unused dev_t dev, u_long com, caddr_t data, __unused int flag, __unused struct proc *p)
 {

-       long l;
+       int l;

 
        LOG_LOCK();
        switch (com) {
 
        LOG_LOCK();
        switch (com) {


@@ -328,10 +324,7 @@ logioctl(__unused dev_t dev, u_long com, caddr_t data, __unused int flag, __unus
 void
 bsd_log_init(void)
 {
 void
 bsd_log_init(void)
 {

-       if (!log_inited) { 
-               msgbufp = &temp_msgbuf;
-               log_inited = 1;
-       }
+       /* After this point, we must be ready to accept characters */

 }
 
 
 }
 
 


@@ -353,24 +346,11 @@ bsd_log_init(void)
 void
 log_putc_locked(char c)
 {
 void
 log_putc_locked(char c)
 {

-       register struct msgbuf *mbp;
-
-       if (!log_inited) {
-               panic("bsd log is not inited");
-       }
+       struct msgbuf *mbp;

 
        mbp = msgbufp; 
 
        mbp = msgbufp; 

-       if (mbp-> msg_magic != MSG_MAGIC) {
-               register int i;
-
-               mbp->msg_magic = MSG_MAGIC;
-               mbp->msg_bufx = mbp->msg_bufr = 0;
-               for (i=0; i < MSG_BSIZE; i++)
-                       mbp->msg_bufc[i] = 0;
-       }

        mbp->msg_bufc[mbp->msg_bufx++] = c;
        mbp->msg_bufc[mbp->msg_bufx++] = c;

-       _logentrypend = 1;
-       if (mbp->msg_bufx < 0 || mbp->msg_bufx >= msgbufp->msg_size)
+       if (mbp->msg_bufx >= msgbufp->msg_size)

                mbp->msg_bufx = 0;
 }
 
                mbp->msg_bufx = 0;
 }
 


@@ -391,12 +371,16 @@ log_putc_locked(char c)
 void
 log_putc(char c)
 {
 void
 log_putc(char c)
 {

-       if (!log_inited) {
-               panic("bsd log is not inited");
-       }
+       int unread_count = 0;

        LOG_LOCK();
        log_putc_locked(c);
        LOG_LOCK();
        log_putc_locked(c);

+       unread_count = msgbufp->msg_bufx - msgbufp->msg_bufr;

        LOG_UNLOCK();
        LOG_UNLOCK();

+
+       if (unread_count < 0)
+               unread_count = 0 - unread_count;
+       if (c == '\n' || unread_count >= MAX_UNREAD_CHARS)
+               logwakeup();

 }
 
 
 }
 
 


@@ -406,58 +390,143 @@ log_putc(char c)
  * 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
  * 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 MSG_BSIZE characters in size, otherwise
- * memory is dynamically allocated.
- * This function may only be called once, during kernel initialization.
- * Memory management must already be up. The buffer must not have
- * overflown yet.
+ * allocated statically and is CONFIG_MSG_BSIZE characters in size, otherwise
+ * memory is dynamically allocated. Memory management must already be up.

  */
  */

-void
-log_setsize(long size) {
+int
+log_setsize(int size) {

        char *new_logdata;
        char *new_logdata;

-       if (msgbufp->msg_size!=MSG_BSIZE) {
-               printf("log_setsize: attempt to change size more than once\n");
-               return;
-       }
-       if (size==MSG_BSIZE)
-               return;
-       if (size<MSG_BSIZE) { /* we don't support reducing the log size */
-               printf("log_setsize: can't decrease log size\n");
-               return;
-       }
+       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");
        if (!(new_logdata = (char*)kalloc(size))) {
                printf("log_setsize: unable to allocate memory\n");

-               return;
+               return (ENOMEM);

        }
        }

+       bzero(new_logdata, new_logsize);
+

        LOG_LOCK();
        LOG_LOCK();

-       bcopy(smsg_bufc, new_logdata, MSG_BSIZE);
-       bzero(new_logdata+MSG_BSIZE, size - MSG_BSIZE);
+
+       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);
+       }
+       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. */
        /* this memory is now dead - clear it so that it compresses better
           in case of suspend to disk etc. */

-       bzero(smsg_bufc, MSG_BSIZE);
-       msgbufp->msg_size = size;
-       msgbufp->msg_bufc = new_logdata;
+       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();
        LOG_UNLOCK();

-       printf("set system log size to %ld bytes\n", msgbufp->msg_size);
+
+       error = sysctl_io_number(req, bufsize, sizeof(bufsize), &bufsize, NULL);
+       if (error)
+               return (error);
+
+       if (bufsize != old_bufsize) {
+               error = log_setsize(bufsize);
+       }
+
+       return (error);

 }
 
 }
 

-SYSCTL_LONG(_kern, OID_AUTO, msgbuf, CTLFLAG_RD, &temp_msgbuf.msg_size, "");

 
 /*
 
 /*

- * This should be called by single user mode /sbin/dmesg only.
+ * This should be called by /sbin/dmesg only via libproc.

  * It returns as much data still in the buffer as possible.
  */
 int
  * It returns as much data still in the buffer as possible.
  */
 int

-log_dmesg(user_addr_t buffer, uint32_t buffersize, register_t * retval) {
-       unsigned long i;
+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;
        int error = 0, newl, skip;
        char *localbuff, *p, *copystart, ch;

-       long localbuff_size = msgbufp->msg_size+2, copysize;
+       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);
        }
        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();
 
        /* in between here, the log could become bigger, but that's fine */
        LOG_LOCK();
 


@@ -482,8 +551,15 @@ log_dmesg(user_addr_t buffer, uint32_t buffersize, register_t * retval) {
                }
                if (ch == '\0')
                        continue;
                }
                if (ch == '\0')
                        continue;

-               newl = ch == '\n';
+               newl = (ch == '\n');

                localbuff[i++] = ch;
                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';
        }
        if (!newl)
                localbuff[i++] = '\n';