IFC @ r255692

Comment out IA32_MISC_ENABLE MSR access - this doesn't exist on AMD.
Need to sort out how arch-specific MSRs will be handled.

Reduce the scope of the proctree_lock. If several processes cause
continuous calls to the uprintf(9), the proctree_lock could be
shared-locked for indefinite amount of time, starving exclusive
reques

Reduce the scope of the proctree_lock. If several processes cause
continuous calls to the uprintf(9), the proctree_lock could be
shared-locked for indefinite amount of time, starving exclusive
requests. Since proctree_lock is needed for fork() and exit(), this
effectively stops the machine.

While there, do the similar reduction for tprintf(9).

Reported and tested by: pho
Reviewed by: ed
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Approved by: re (glebius)

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Merge head

IFC @ r255459

MFC

Add a vtprintf. It is to tprintf what vprintf is to printf.

Reviewed by: kib

IFC @230489 (pending review).

IFC @ r226824

Fix double vision syndrome (read: double output) when in the
debugger without a panic.

IFC @ r222830

MFC

Set pca.p_bufr to NULL when we haven't allocated a buffer.

Otherwise, p_bufr is set to garbage on the stack, and if that garbage
happens to be non-NULL, and the TOLOG or TOCONS flag is set, putbuf()

Set pca.p_bufr to NULL when we haven't allocated a buffer.

Otherwise, p_bufr is set to garbage on the stack, and if that garbage
happens to be non-NULL, and the TOLOG or TOCONS flag is set, putbuf()
will get called and attempt to fill the non-existent buffer.

This is really only relevant for tprintf() (and only when the priority is
not -1), but set it in uprintf() and ttyprintf() for completeness.

The next step, to avoid log buffer scrambling, would be to add the
PRINTF_BUFR_SIZE code to tprintf(), but this should prevent panics.

Submitted by: rmacklem
Found by: pho

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MFC

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 mess

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

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Merge svn+ssh://svn.freebsd.org/base/head@211344

Use type-specific inline function imax() instead of deprecated macro MAX().

Prodded by: bde

Implement optional 'precision' for numbers. Previously, it was parsed but
ignored. Some third-party modules (e.g., APCICA) prefer this format over
zero padding flag '0'.

IFH@204581

MFC @199204

Make /dev/klog and kern.msgbuf* MPSAFE.

Normally msgbufp is locked using Giant. Switch it to use the
msgbuf_lock. Instead of changing the tsleep() calls to msleep(), just
convert it to condvar(9).

Make /dev/klog and kern.msgbuf* MPSAFE.

Normally msgbufp is locked using Giant. Switch it to use the
msgbuf_lock. Instead of changing the tsleep() calls to msleep(), just
convert it to condvar(9).

In my opinion the locking around msgbuf_peekbytes() still remains
questionable. It looks like locks are dropped while performing copies of
multiple blocks to userspace, which may cause the msgbuf to be reset in
the mean time. At least getting it underneath from Giant should make it
a little easier for us to figure out how to solve that.

Reminded by: rdivacky

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Merge from head

Merge from head up to r188941 (last revision before the USB stack switch)

Update the projects tree to a newer FreeBSD current.

Remove redundant code in printf() and vprintf().

printf() and vprintf() are exactly the same, except the way arguments
are passed. Just like we see in other pieces of code (i.e. libc's
printf()), im

Remove redundant code in printf() and vprintf().

printf() and vprintf() are exactly the same, except the way arguments
are passed. Just like we see in other pieces of code (i.e. libc's
printf()), implement printf() using vprintf().

Submitted by: Christoph Mallon <christoph mallon gmx de>

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Revert previous commit to subr_prf.c and make it more tidy.

As mentioned by bz and bde, the change I made wasn't the proper way to
fix. Inspired by bde's patch, perform some small cleanups to uprint

Revert previous commit to subr_prf.c and make it more tidy.

As mentioned by bz and bde, the change I made wasn't the proper way to
fix. Inspired by bde's patch, perform some small cleanups to uprintf().

Reviewed by: bz

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