2005-01-06 23:35:40 +00:00
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/*-
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2003-06-22 02:18:31 +00:00
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* Copyright (c) 2003 Ian Dowse. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* Generic message buffer support routines.
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
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#include <sys/lock.h>
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#include <sys/mutex.h>
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2003-06-22 02:18:31 +00:00
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#include <sys/msgbuf.h>
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Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
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/*
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* Maximum number conversion buffer length: uintmax_t in base 2, plus <>
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* around the priority, and a terminating NUL.
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*/
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#define MAXPRIBUF (sizeof(intmax_t) * NBBY + 3)
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2003-06-22 02:18:31 +00:00
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/* Read/write sequence numbers are modulo a multiple of the buffer size. */
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#define SEQMOD(size) ((size) * 16)
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static u_int msgbuf_cksum(struct msgbuf *mbp);
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/*
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* Initialize a message buffer of the specified size at the specified
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* location. This also zeros the buffer area.
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*/
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void
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msgbuf_init(struct msgbuf *mbp, void *ptr, int size)
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{
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mbp->msg_ptr = ptr;
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mbp->msg_size = size;
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mbp->msg_seqmod = SEQMOD(size);
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msgbuf_clear(mbp);
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mbp->msg_magic = MSG_MAGIC;
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Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
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mbp->msg_lastpri = -1;
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mbp->msg_needsnl = 0;
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mtx_init(&mbp->msg_lock, "msgbuf", NULL, MTX_SPIN);
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2003-06-22 02:18:31 +00:00
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}
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/*
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* Reinitialize a message buffer, retaining its previous contents if
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* the size and checksum are correct. If the old contents cannot be
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* recovered, the message buffer is cleared.
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*/
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void
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msgbuf_reinit(struct msgbuf *mbp, void *ptr, int size)
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{
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u_int cksum;
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if (mbp->msg_magic != MSG_MAGIC || mbp->msg_size != size) {
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msgbuf_init(mbp, ptr, size);
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return;
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}
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mbp->msg_seqmod = SEQMOD(size);
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mbp->msg_wseq = MSGBUF_SEQNORM(mbp, mbp->msg_wseq);
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mbp->msg_rseq = MSGBUF_SEQNORM(mbp, mbp->msg_rseq);
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mbp->msg_ptr = ptr;
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cksum = msgbuf_cksum(mbp);
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if (cksum != mbp->msg_cksum) {
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2003-09-05 11:12:00 +00:00
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if (bootverbose) {
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printf("msgbuf cksum mismatch (read %x, calc %x)\n",
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mbp->msg_cksum, cksum);
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printf("Old msgbuf not recovered\n");
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}
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2003-06-22 02:18:31 +00:00
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msgbuf_clear(mbp);
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}
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Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
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mbp->msg_lastpri = -1;
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/* Assume that the old message buffer didn't end in a newline. */
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mbp->msg_needsnl = 1;
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mtx_init(&mbp->msg_lock, "msgbuf", NULL, MTX_SPIN);
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2003-06-22 02:18:31 +00:00
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}
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/*
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* Clear the message buffer.
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*/
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void
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msgbuf_clear(struct msgbuf *mbp)
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{
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bzero(mbp->msg_ptr, mbp->msg_size);
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mbp->msg_wseq = 0;
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mbp->msg_rseq = 0;
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mbp->msg_cksum = 0;
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}
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/*
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* Get a count of the number of unread characters in the message buffer.
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*/
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int
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msgbuf_getcount(struct msgbuf *mbp)
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{
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u_int len;
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len = MSGBUF_SEQSUB(mbp, mbp->msg_wseq, mbp->msg_rseq);
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if (len > mbp->msg_size)
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len = mbp->msg_size;
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return (len);
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}
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/*
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Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
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* Add a character into the message buffer, and update the checksum and
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* sequence number.
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*
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* The caller should hold the message buffer spinlock.
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*/
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static inline void
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msgbuf_do_addchar(struct msgbuf *mbp, u_int *seq, int c)
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{
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u_int pos;
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/* Make sure we properly wrap the sequence number. */
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pos = MSGBUF_SEQ_TO_POS(mbp, *seq);
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mbp->msg_cksum += (u_int)c -
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(u_int)(u_char)mbp->msg_ptr[pos];
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mbp->msg_ptr[pos] = c;
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*seq = MSGBUF_SEQNORM(mbp, *seq + 1);
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}
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/*
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* Append a character to a message buffer.
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2003-06-22 02:18:31 +00:00
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*/
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void
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msgbuf_addchar(struct msgbuf *mbp, int c)
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{
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Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
mtx_lock_spin(&mbp->msg_lock);
|
|
|
|
|
|
|
|
msgbuf_do_addchar(mbp, &mbp->msg_wseq, c);
|
|
|
|
|
|
|
|
mtx_unlock_spin(&mbp->msg_lock);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Append a NUL-terminated string with a priority to a message buffer.
|
|
|
|
* Filter carriage returns if the caller requests it.
|
|
|
|
*
|
|
|
|
* XXX The carriage return filtering behavior is present in the
|
|
|
|
* msglogchar() API, however testing has shown that we don't seem to send
|
|
|
|
* carriage returns down this path. So do we still need it?
|
|
|
|
*/
|
|
|
|
void
|
|
|
|
msgbuf_addstr(struct msgbuf *mbp, int pri, char *str, int filter_cr)
|
|
|
|
{
|
|
|
|
u_int seq;
|
|
|
|
size_t len, prefix_len;
|
|
|
|
char prefix[MAXPRIBUF];
|
|
|
|
int nl, i;
|
|
|
|
|
|
|
|
len = strlen(str);
|
|
|
|
prefix_len = 0;
|
|
|
|
nl = 0;
|
|
|
|
|
|
|
|
/* If we have a zero-length string, no need to do anything. */
|
|
|
|
if (len == 0)
|
|
|
|
return;
|
|
|
|
|
|
|
|
mtx_lock_spin(&mbp->msg_lock);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* If this is true, we may need to insert a new priority sequence,
|
|
|
|
* so prepare the prefix.
|
|
|
|
*/
|
|
|
|
if (pri != -1)
|
|
|
|
prefix_len = sprintf(prefix, "<%d>", pri);
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Starting write sequence number.
|
|
|
|
*/
|
|
|
|
seq = mbp->msg_wseq;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Whenever there is a change in priority, we have to insert a
|
|
|
|
* newline, and a priority prefix if the priority is not -1. Here
|
|
|
|
* we detect whether there was a priority change, and whether we
|
|
|
|
* did not end with a newline. If that is the case, we need to
|
|
|
|
* insert a newline before this string.
|
|
|
|
*/
|
|
|
|
if (mbp->msg_lastpri != pri && mbp->msg_needsnl != 0) {
|
|
|
|
|
|
|
|
msgbuf_do_addchar(mbp, &seq, '\n');
|
|
|
|
mbp->msg_needsnl = 0;
|
|
|
|
}
|
|
|
|
|
|
|
|
for (i = 0; i < len; i++) {
|
|
|
|
/*
|
|
|
|
* If we just had a newline, and the priority is not -1
|
|
|
|
* (and therefore prefix_len != 0), then we need a priority
|
|
|
|
* prefix for this line.
|
|
|
|
*/
|
|
|
|
if (mbp->msg_needsnl == 0 && prefix_len != 0) {
|
|
|
|
int j;
|
|
|
|
|
|
|
|
for (j = 0; j < prefix_len; j++)
|
|
|
|
msgbuf_do_addchar(mbp, &seq, prefix[j]);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Don't copy carriage returns if the caller requested
|
|
|
|
* filtering.
|
|
|
|
*
|
|
|
|
* XXX This matches the behavior of msglogchar(), but is it
|
|
|
|
* necessary? Testing has shown that we don't seem to get
|
|
|
|
* carriage returns here.
|
|
|
|
*/
|
|
|
|
if ((filter_cr != 0) && (str[i] == '\r'))
|
|
|
|
continue;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Clear this flag if we see a newline. This affects whether
|
|
|
|
* we need to insert a new prefix or insert a newline later.
|
|
|
|
*/
|
|
|
|
if (str[i] == '\n')
|
|
|
|
mbp->msg_needsnl = 0;
|
|
|
|
else
|
|
|
|
mbp->msg_needsnl = 1;
|
|
|
|
|
|
|
|
msgbuf_do_addchar(mbp, &seq, str[i]);
|
|
|
|
}
|
|
|
|
/*
|
|
|
|
* Update the write sequence number for the actual number of
|
|
|
|
* characters we put in the message buffer. (Depends on whether
|
|
|
|
* carriage returns are filtered.)
|
|
|
|
*/
|
|
|
|
mbp->msg_wseq = seq;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Set the last priority.
|
|
|
|
*/
|
|
|
|
mbp->msg_lastpri = pri;
|
|
|
|
|
|
|
|
mtx_unlock_spin(&mbp->msg_lock);
|
|
|
|
|
2003-06-22 02:18:31 +00:00
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Read and mark as read a character from a message buffer.
|
|
|
|
* Returns the character, or -1 if no characters are available.
|
|
|
|
*/
|
|
|
|
int
|
|
|
|
msgbuf_getchar(struct msgbuf *mbp)
|
|
|
|
{
|
|
|
|
u_int len, wseq;
|
|
|
|
int c;
|
|
|
|
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
mtx_lock_spin(&mbp->msg_lock);
|
|
|
|
|
2003-06-22 02:18:31 +00:00
|
|
|
wseq = mbp->msg_wseq;
|
|
|
|
len = MSGBUF_SEQSUB(mbp, wseq, mbp->msg_rseq);
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
if (len == 0) {
|
|
|
|
mtx_unlock_spin(&mbp->msg_lock);
|
2003-06-22 02:18:31 +00:00
|
|
|
return (-1);
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
}
|
2003-06-22 02:18:31 +00:00
|
|
|
if (len > mbp->msg_size)
|
|
|
|
mbp->msg_rseq = MSGBUF_SEQNORM(mbp, wseq - mbp->msg_size);
|
|
|
|
c = (u_char)mbp->msg_ptr[MSGBUF_SEQ_TO_POS(mbp, mbp->msg_rseq)];
|
|
|
|
mbp->msg_rseq = MSGBUF_SEQNORM(mbp, mbp->msg_rseq + 1);
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
|
|
|
|
mtx_unlock_spin(&mbp->msg_lock);
|
|
|
|
|
2003-06-22 02:18:31 +00:00
|
|
|
return (c);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Read and mark as read a number of characters from a message buffer.
|
|
|
|
* Returns the number of characters that were placed in `buf'.
|
|
|
|
*/
|
|
|
|
int
|
|
|
|
msgbuf_getbytes(struct msgbuf *mbp, char *buf, int buflen)
|
|
|
|
{
|
|
|
|
u_int len, pos, wseq;
|
|
|
|
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
mtx_lock_spin(&mbp->msg_lock);
|
|
|
|
|
2003-06-22 02:18:31 +00:00
|
|
|
wseq = mbp->msg_wseq;
|
|
|
|
len = MSGBUF_SEQSUB(mbp, wseq, mbp->msg_rseq);
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
if (len == 0) {
|
|
|
|
mtx_unlock_spin(&mbp->msg_lock);
|
2003-06-22 02:18:31 +00:00
|
|
|
return (0);
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
}
|
2003-06-22 02:18:31 +00:00
|
|
|
if (len > mbp->msg_size) {
|
|
|
|
mbp->msg_rseq = MSGBUF_SEQNORM(mbp, wseq - mbp->msg_size);
|
|
|
|
len = mbp->msg_size;
|
|
|
|
}
|
|
|
|
pos = MSGBUF_SEQ_TO_POS(mbp, mbp->msg_rseq);
|
|
|
|
len = min(len, mbp->msg_size - pos);
|
|
|
|
len = min(len, (u_int)buflen);
|
|
|
|
|
|
|
|
bcopy(&mbp->msg_ptr[pos], buf, len);
|
|
|
|
mbp->msg_rseq = MSGBUF_SEQNORM(mbp, mbp->msg_rseq + len);
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
|
|
|
|
mtx_unlock_spin(&mbp->msg_lock);
|
|
|
|
|
2003-06-22 02:18:31 +00:00
|
|
|
return (len);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Peek at the full contents of a message buffer without marking any
|
|
|
|
* data as read. `seqp' should point to an unsigned integer that
|
|
|
|
* msgbuf_peekbytes() can use to retain state between calls so that
|
|
|
|
* the whole message buffer can be read in multiple short reads.
|
|
|
|
* To initialise this variable to the start of the message buffer,
|
|
|
|
* call msgbuf_peekbytes() with a NULL `buf' parameter.
|
|
|
|
*
|
|
|
|
* Returns the number of characters that were placed in `buf'.
|
|
|
|
*/
|
|
|
|
int
|
|
|
|
msgbuf_peekbytes(struct msgbuf *mbp, char *buf, int buflen, u_int *seqp)
|
|
|
|
{
|
|
|
|
u_int len, pos, wseq;
|
|
|
|
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
mtx_lock_spin(&mbp->msg_lock);
|
|
|
|
|
2003-06-22 02:18:31 +00:00
|
|
|
if (buf == NULL) {
|
|
|
|
/* Just initialise *seqp. */
|
|
|
|
*seqp = MSGBUF_SEQNORM(mbp, mbp->msg_wseq - mbp->msg_size);
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
mtx_unlock_spin(&mbp->msg_lock);
|
2003-06-22 02:18:31 +00:00
|
|
|
return (0);
|
|
|
|
}
|
|
|
|
|
|
|
|
wseq = mbp->msg_wseq;
|
|
|
|
len = MSGBUF_SEQSUB(mbp, wseq, *seqp);
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
if (len == 0) {
|
|
|
|
mtx_unlock_spin(&mbp->msg_lock);
|
2003-06-22 02:18:31 +00:00
|
|
|
return (0);
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
}
|
2003-06-22 02:18:31 +00:00
|
|
|
if (len > mbp->msg_size) {
|
|
|
|
*seqp = MSGBUF_SEQNORM(mbp, wseq - mbp->msg_size);
|
|
|
|
len = mbp->msg_size;
|
|
|
|
}
|
|
|
|
pos = MSGBUF_SEQ_TO_POS(mbp, *seqp);
|
|
|
|
len = min(len, mbp->msg_size - pos);
|
|
|
|
len = min(len, (u_int)buflen);
|
|
|
|
bcopy(&mbp->msg_ptr[MSGBUF_SEQ_TO_POS(mbp, *seqp)], buf, len);
|
|
|
|
*seqp = MSGBUF_SEQNORM(mbp, *seqp + len);
|
Fix apparent garbage in the message buffer.
While we have had a fix in place (options PRINTF_BUFR_SIZE=128) to fix
scrambled console output, the message buffer and syslog were still getting
log messages one character at a time. While all of the characters still
made it into the log (courtesy of atomic operations), they were often
interleaved when there were multiple threads writing to the buffer at the
same time.
This fixes message buffer accesses to use buffering logic as well, so that
strings that are less than PRINTF_BUFR_SIZE will be put into the message
buffer atomically. So now dmesg output should look the same as console
output.
subr_msgbuf.c: Convert most message buffer calls to use a new spin
lock instead of atomic variables in some places.
Add a new routine, msgbuf_addstr(), that adds a
NUL-terminated string to a message buffer. This
takes a priority argument, which allows us to
eliminate some races (at least in the the string
at a time case) that are present in the
implementation of msglogchar(). (dangling and
lastpri are static variables, and are subject to
races when multiple callers are present.)
msgbuf_addstr() also allows the caller to request
that carriage returns be stripped out of the
string. This matches the behavior of msglogchar(),
but in testing so far it doesn't appear that any
newlines are being stripped out. So the carriage
return removal functionality may be a candidate
for removal later on if further analysis shows
that it isn't necessary.
subr_prf.c: Add a new msglogstr() routine that calls
msgbuf_logstr().
Rename putcons() to putbuf(). This now handles
buffered output to the message log as well as
the console. Also, remove the logic in putcons()
(now putbuf()) that added a carriage return before
a newline. The console path was the only path that
needed it, and cnputc() (called by cnputs())
already adds a carriage return. So this
duplication resulted in kernel-generated console
output lines ending in '\r''\r''\n'.
Refactor putchar() to handle the new buffering
scheme.
Add buffering to log().
Change log_console() to use msglogstr() instead of
msglogchar(). Don't add extra newlines by default
in log_console(). Hide that behavior behind a
tunable/sysctl (kern.log_console_add_linefeed) for
those who would like the old behavior. The old
behavior led to the insertion of extra newlines
for log output for programs that print out a
string, and then a trailing newline on a separate
write. (This is visible with dmesg -a.)
msgbuf.h: Add a prototype for msgbuf_addstr().
Add three new fields to struct msgbuf, msg_needsnl,
msg_lastpri and msg_lock. The first two are needed
for log message functionality previously handled
by msglogchar(). (Which is still active if
buffering isn't enabled.)
Include sys/lock.h and sys/mutex.h for the new
mutex.
Reviewed by: gibbs
2011-05-31 17:29:58 +00:00
|
|
|
|
|
|
|
mtx_unlock_spin(&mbp->msg_lock);
|
|
|
|
|
2003-06-22 02:18:31 +00:00
|
|
|
return (len);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Compute the checksum for the complete message buffer contents.
|
|
|
|
*/
|
|
|
|
static u_int
|
|
|
|
msgbuf_cksum(struct msgbuf *mbp)
|
|
|
|
{
|
|
|
|
u_int i, sum;
|
|
|
|
|
|
|
|
sum = 0;
|
|
|
|
for (i = 0; i < mbp->msg_size; i++)
|
|
|
|
sum += (u_char)mbp->msg_ptr[i];
|
|
|
|
return (sum);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Copy from one message buffer to another.
|
|
|
|
*/
|
|
|
|
void
|
|
|
|
msgbuf_copy(struct msgbuf *src, struct msgbuf *dst)
|
|
|
|
{
|
|
|
|
int c;
|
|
|
|
|
|
|
|
while ((c = msgbuf_getchar(src)) >= 0)
|
|
|
|
msgbuf_addchar(dst, c);
|
|
|
|
}
|