/*
 * Copyright (C) 2009 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License (not later!)
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this program; if not,  see <http://www.gnu.org/licenses>
 *
 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>

#include <asm/bug.h>
#include "event-parse.h"
#include "event-utils.h"

/*
 * The TRACE_SEQ_POISON is to catch the use of using
 * a trace_seq structure after it was destroyed.
 */
#define TRACE_SEQ_POISON	((void *)0xdeadbeef)
#define TRACE_SEQ_CHECK(s)						\
do {									\
	if (WARN_ONCE((s)->buffer == TRACE_SEQ_POISON,			\
		      "Usage of trace_seq after it was destroyed"))	\
		(s)->state = TRACE_SEQ__BUFFER_POISONED;		\
} while (0)

#define TRACE_SEQ_CHECK_RET_N(s, n)		\
do {						\
	TRACE_SEQ_CHECK(s);			\
	if ((s)->state != TRACE_SEQ__GOOD)	\
		return n; 			\
} while (0)

#define TRACE_SEQ_CHECK_RET(s)   TRACE_SEQ_CHECK_RET_N(s, )
#define TRACE_SEQ_CHECK_RET0(s)  TRACE_SEQ_CHECK_RET_N(s, 0)

/**
 * trace_seq_init - initialize the trace_seq structure
 * @s: a pointer to the trace_seq structure to initialize
 */
void trace_seq_init(struct trace_seq *s)
{
	s->len = 0;
	s->readpos = 0;
	s->buffer_size = TRACE_SEQ_BUF_SIZE;
	s->buffer = malloc(s->buffer_size);
	if (s->buffer != NULL)
		s->state = TRACE_SEQ__GOOD;
	else
		s->state = TRACE_SEQ__MEM_ALLOC_FAILED;
}

/**
 * trace_seq_reset - re-initialize the trace_seq structure
 * @s: a pointer to the trace_seq structure to reset
 */
void trace_seq_reset(struct trace_seq *s)
{
	if (!s)
		return;
	TRACE_SEQ_CHECK(s);
	s->len = 0;
	s->readpos = 0;
}

/**
 * trace_seq_destroy - free up memory of a trace_seq
 * @s: a pointer to the trace_seq to free the buffer
 *
 * Only frees the buffer, not the trace_seq struct itself.
 */
void trace_seq_destroy(struct trace_seq *s)
{
	if (!s)
		return;
	TRACE_SEQ_CHECK_RET(s);
	free(s->buffer);
	s->buffer = TRACE_SEQ_POISON;
}

static void expand_buffer(struct trace_seq *s)
{
	char *buf;

	buf = realloc(s->buffer, s->buffer_size + TRACE_SEQ_BUF_SIZE);
	if (WARN_ONCE(!buf, "Can't allocate trace_seq buffer memory")) {
		s->state = TRACE_SEQ__MEM_ALLOC_FAILED;
		return;
	}

	s->buffer = buf;
	s->buffer_size += TRACE_SEQ_BUF_SIZE;
}

/**
 * trace_seq_printf - sequence printing of trace information
 * @s: trace sequence descriptor
 * @fmt: printf format string
 *
 * It returns 0 if the trace oversizes the buffer's free
 * space, 1 otherwise.
 *
 * The tracer may use either sequence operations or its own
 * copy to user routines. To simplify formating of a trace
 * trace_seq_printf is used to store strings into a special
 * buffer (@s). Then the output may be either used by
 * the sequencer or pulled into another buffer.
 */
int
trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
{
	va_list ap;
	int len;
	int ret;

 try_again:
	TRACE_SEQ_CHECK_RET0(s);

	len = (s->buffer_size - 1) - s->len;

	va_start(ap, fmt);
	ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
	va_end(ap);

	if (ret >= len) {
		expand_buffer(s);
		goto try_again;
	}

	s->len += ret;

	return 1;
}

/**
 * trace_seq_vprintf - sequence printing of trace information
 * @s: trace sequence descriptor
 * @fmt: printf format string
 *
 * The tracer may use either sequence operations or its own
 * copy to user routines. To simplify formating of a trace
 * trace_seq_printf is used to store strings into a special
 * buffer (@s). Then the output may be either used by
 * the sequencer or pulled into another buffer.
 */
int
trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
{
	int len;
	int ret;

 try_again:
	TRACE_SEQ_CHECK_RET0(s);

	len = (s->buffer_size - 1) - s->len;

	ret = vsnprintf(s->buffer + s->len, len, fmt, args);

	if (ret >= len) {
		expand_buffer(s);
		goto try_again;
	}

	s->len += ret;

	return len;
}

/**
 * trace_seq_puts - trace sequence printing of simple string
 * @s: trace sequence descriptor
 * @str: simple string to record
 *
 * The tracer may use either the sequence operations or its own
 * copy to user routines. This function records a simple string
 * into a special buffer (@s) for later retrieval by a sequencer
 * or other mechanism.
 */
int trace_seq_puts(struct trace_seq *s, const char *str)
{
	int len;

	TRACE_SEQ_CHECK_RET0(s);

	len = strlen(str);

	while (len > ((s->buffer_size - 1) - s->len))
		expand_buffer(s);

	TRACE_SEQ_CHECK_RET0(s);

	memcpy(s->buffer + s->len, str, len);
	s->len += len;

	return len;
}

int trace_seq_putc(struct trace_seq *s, unsigned char c)
{
	TRACE_SEQ_CHECK_RET0(s);

	while (s->len >= (s->buffer_size - 1))
		expand_buffer(s);

	TRACE_SEQ_CHECK_RET0(s);

	s->buffer[s->len++] = c;

	return 1;
}

void trace_seq_terminate(struct trace_seq *s)
{
	TRACE_SEQ_CHECK_RET(s);

	/* There's always one character left on the buffer */
	s->buffer[s->len] = 0;
}

int trace_seq_do_fprintf(struct trace_seq *s, FILE *fp)
{
	TRACE_SEQ_CHECK(s);

	switch (s->state) {
	case TRACE_SEQ__GOOD:
		return fprintf(fp, "%.*s", s->len, s->buffer);
	case TRACE_SEQ__BUFFER_POISONED:
		fprintf(fp, "%s\n", "Usage of trace_seq after it was destroyed");
		break;
	case TRACE_SEQ__MEM_ALLOC_FAILED:
		fprintf(fp, "%s\n", "Can't allocate trace_seq buffer memory");
		break;
	}
	return -1;
}

int trace_seq_do_printf(struct trace_seq *s)
{
	return trace_seq_do_fprintf(s, stdout);
}
v class='commit-subject'>x86/mce: Make timer handling more robust</div><div class='commit-msg'>Erik reported that on a preproduction hardware a CMCI storm triggers the
BUG_ON in add_timer_on(). The reason is that the per CPU MCE timer is
started by the CMCI logic before the MCE CPU hotplug callback starts the
timer with add_timer_on(). So the timer is already queued which triggers
the BUG.

Using add_timer_on() is pretty pointless in this code because the timer is
strictlty per CPU, initialized as pinned and all operations which arm the
timer happen on the CPU to which the timer belongs.

Simplify the whole machinery by using mod_timer() instead of add_timer_on()
which avoids the problem because mod_timer() can handle already queued
timers. Use __start_timer() everywhere so the earliest armed expiry time is
preserved.

Reported-by: Erik Veijola &lt;erik.veijola@intel.com&gt;
Tested-by: Borislav Petkov &lt;bp@alien8.de&gt;
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Reviewed-by: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Tony Luck &lt;tony.luck@intel.com&gt;
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701310936080.3457@nanos
Signed-off-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;

</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=0becc0ae5b42828785b589f686725ff5bc3b9b25'>Diffstat</a> (limited to 'include/trace/events/cma.h')</div><table summary='diffstat' class='diffstat'>