X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/8f6c56a50524aa785f7e596d52dddfb331e18961..bb59bff194111743b33cc36712410b5656329d3c:/bsd/kern/subr_log.c diff --git a/bsd/kern/subr_log.c b/bsd/kern/subr_log.c index 4f9e8c260..0f8c00b36 100644 --- a/bsd/kern/subr_log.c +++ b/bsd/kern/subr_log.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2010 Apple, Inc. All rights reserved. * * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * @@ -77,6 +77,14 @@ #include #include #include +#include +#include +#include +#include +#include + +/* XXX should be in a common header somewhere */ +extern void logwakeup(void); #define LOG_RDPRI (PZERO + 1) @@ -84,6 +92,10 @@ #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 */ @@ -91,15 +103,22 @@ struct logsoftc { } logsoftc; int log_open; /* also used in log() */ -struct msgbuf temp_msgbuf; -struct msgbuf *msgbufp; -static int _logentrypend = 0; -static int log_inited = 0; -void bsd_log_lock(void); -/* the following two are implemented in osfmk/kern/printf.c */ +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 @@ -109,33 +128,29 @@ extern void bsd_log_init(void); #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); @@ -143,30 +158,22 @@ 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); selthreadclear(&logsoftc.sc_selp); + 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; - char localbuff[MSG_BSIZE]; - int copybytes; LOG_LOCK(); while (msgbufp->msg_bufr == msgbufp->msg_bufx) { @@ -181,12 +188,11 @@ logread(dev, uio, flag) 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, - "klog", 5 * hz)) { + if ((error = tsleep((caddr_t)msgbufp, LOG_RDPRI | PCATCH, + "klog", 5 * hz)) != 0) { /* if it times out; ignore */ if (error != EWOULDBLOCK) return (error); @@ -195,23 +201,25 @@ logread(dev, uio, flag) } logsoftc.sc_state &= ~LOG_RDWAIT; - while (uio_resid(uio) > 0) { + int readpos; + l = msgbufp->msg_bufx - msgbufp->msg_bufr; if (l < 0) - l = MSG_BSIZE - msgbufp->msg_bufr; + l = msgbufp->msg_size - msgbufp->msg_bufr; l = min(l, uio_resid(uio)); if (l == 0) break; - bcopy(&msgbufp->msg_bufc[msgbufp->msg_bufr], &localbuff[0], l); + + readpos = msgbufp->msg_bufr; LOG_UNLOCK(); - error = uiomove((caddr_t)&localbuff[0], - (int)l, uio); + 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: @@ -221,13 +229,8 @@ out: /*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) { - switch (rw) { case FREAD: @@ -244,11 +247,9 @@ logselect(dev, rw, wql, p) } void -logwakeup() +logwakeup(void) { - struct proc *p; int pgid; - boolean_t funnel_state; LOG_LOCK(); if (!log_open) { @@ -261,8 +262,8 @@ logwakeup() 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) { @@ -272,32 +273,21 @@ logwakeup() LOG_UNLOCK(); } -void -klogwakeup() -{ - - if (_logentrypend) { - _logentrypend = 0; - logwakeup(); - } -} /*ARGSUSED*/ int -logioctl(dev, 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(); + LOG_LOCK(); switch (com) { /* return number of characters immediately available */ case FIONREAD: l = msgbufp->msg_bufx - msgbufp->msg_bufr; if (l < 0) - l += MSG_BSIZE; + l += msgbufp->msg_size; *(off_t *)data = l; break; @@ -332,37 +322,263 @@ logioctl(dev, com, data, flag) } void -bsd_log_init() +bsd_log_init(void) { - if (!log_inited) { - msgbufp = &temp_msgbuf; - log_inited = 1; - } + /* 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) +{ + 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 (!log_inited) { - panic("bsd log is not inited"); + if (unread_count < 0) + unread_count = 0 - unread_count; + if (c == '\n' || unread_count >= MAX_UNREAD_CHARS) + logwakeup(); +} + + +/* + * 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 = msgbufp; - if (mbp-> msg_magic != MSG_MAGIC) { - register int i; + old_logsize = msgbufp->msg_size; + old_logdata = msgbufp->msg_bufc; + old_bufr = msgbufp->msg_bufr; + old_bufx = msgbufp->msg_bufx; - mbp->msg_magic = MSG_MAGIC; - mbp->msg_bufx = mbp->msg_bufr = 0; - for (i=0; i < MSG_BSIZE; i++) - mbp->msg_bufc[i] = 0; + 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); +}