[RFC][PATCH 02/23 v4] tracing: Add trace_seq_has_overflowed() and trace_handle_return()

From: Steven Rostedt
Date: Thu Nov 13 2014 - 20:22:34 EST


From: "Steven Rostedt (Red Hat)" <rostedt@xxxxxxxxxxx>

Adding a trace_seq_has_overflowed() which returns true if the trace_seq
had too much written into it allows us to simplify the code.

Instead of checking the return value of every call to trace_seq_printf()
and friends, they can all be called normally, and at the end we can
return !trace_seq_has_overflowed() instead.

Several functions also return TRACE_TYPE_PARTIAL_LINE when the trace_seq
overflowed and TRACE_TYPE_HANDLED otherwise. Another helper function
was created called trace_handle_return() which takes a trace_seq and
returns these enums. Using this helper function also simplifies the
code.

This change also makes it possible to remove the return values of
trace_seq_printf() and friends. They should instead just be
void functions.

Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
include/linux/ftrace_event.h | 11 ++
include/linux/trace_seq.h | 12 ++
include/trace/ftrace.h | 6 +-
kernel/trace/trace.c | 69 +++----
kernel/trace/trace.h | 1 +
kernel/trace/trace_output.c | 416 +++++++++++++++++--------------------------
kernel/trace/trace_output.h | 16 +-
7 files changed, 231 insertions(+), 300 deletions(-)

diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h
index 28672e87e910..0bebb5c348b8 100644
--- a/include/linux/ftrace_event.h
+++ b/include/linux/ftrace_event.h
@@ -138,6 +138,17 @@ enum print_line_t {
TRACE_TYPE_NO_CONSUME = 3 /* Handled but ask to not consume */
};

+/*
+ * Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq
+ * overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function
+ * simplifies those functions and keeps them in sync.
+ */
+static inline enum print_line_t trace_handle_return(struct trace_seq *s)
+{
+ return trace_seq_has_overflowed(s) ?
+ TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED;
+}
+
void tracing_generic_entry_update(struct trace_entry *entry,
unsigned long flags,
int pc);
diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h
index ea6c9dea79e3..07eda413dfcf 100644
--- a/include/linux/trace_seq.h
+++ b/include/linux/trace_seq.h
@@ -40,6 +40,18 @@ trace_seq_buffer_ptr(struct trace_seq *s)
return s->buffer + s->len;
}

+/**
+ * trace_seq_has_overflowed - return true if the trace_seq took too much
+ * @s: trace sequence descriptor
+ *
+ * Returns true if too much data was added to the trace_seq and it is
+ * now full and will not take anymore.
+ */
+static inline bool trace_seq_has_overflowed(struct trace_seq *s)
+{
+ return s->full || s->len > PAGE_SIZE - 1;
+}
+
/*
* Currently only defined when tracing is enabled.
*/
diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h
index 26b4f2e13275..f13471b5d27a 100644
--- a/include/trace/ftrace.h
+++ b/include/trace/ftrace.h
@@ -280,11 +280,9 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int flags, \
if (ret) \
return ret; \
\
- ret = trace_seq_printf(s, print); \
- if (!ret) \
- return TRACE_TYPE_PARTIAL_LINE; \
+ trace_seq_printf(s, print); \
\
- return TRACE_TYPE_HANDLED; \
+ return trace_handle_return(s); \
} \
static struct trace_event_functions ftrace_event_type_funcs_##call = { \
.trace = ftrace_raw_output_##call, \
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 8a528392b1f4..f5a435a6e8fb 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -2648,24 +2648,21 @@ static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
event = ftrace_find_event(entry->type);

if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
- if (iter->iter_flags & TRACE_FILE_LAT_FMT) {
- if (!trace_print_lat_context(iter))
- goto partial;
- } else {
- if (!trace_print_context(iter))
- goto partial;
- }
+ if (iter->iter_flags & TRACE_FILE_LAT_FMT)
+ trace_print_lat_context(iter);
+ else
+ trace_print_context(iter);
}

+ if (trace_seq_has_overflowed(s))
+ return TRACE_TYPE_PARTIAL_LINE;
+
if (event)
return event->funcs->trace(iter, sym_flags, event);

- if (!trace_seq_printf(s, "Unknown type %d\n", entry->type))
- goto partial;
+ trace_seq_printf(s, "Unknown type %d\n", entry->type);

- return TRACE_TYPE_HANDLED;
-partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(s);
}

static enum print_line_t print_raw_fmt(struct trace_iterator *iter)
@@ -2676,22 +2673,20 @@ static enum print_line_t print_raw_fmt(struct trace_iterator *iter)

entry = iter->ent;

- if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
- if (!trace_seq_printf(s, "%d %d %llu ",
- entry->pid, iter->cpu, iter->ts))
- goto partial;
- }
+ if (trace_flags & TRACE_ITER_CONTEXT_INFO)
+ trace_seq_printf(s, "%d %d %llu ",
+ entry->pid, iter->cpu, iter->ts);
+
+ if (trace_seq_has_overflowed(s))
+ return TRACE_TYPE_PARTIAL_LINE;

event = ftrace_find_event(entry->type);
if (event)
return event->funcs->raw(iter, 0, event);

- if (!trace_seq_printf(s, "%d ?\n", entry->type))
- goto partial;
+ trace_seq_printf(s, "%d ?\n", entry->type);

- return TRACE_TYPE_HANDLED;
-partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(s);
}

static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
@@ -2704,9 +2699,11 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
entry = iter->ent;

if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
- SEQ_PUT_HEX_FIELD_RET(s, entry->pid);
- SEQ_PUT_HEX_FIELD_RET(s, iter->cpu);
- SEQ_PUT_HEX_FIELD_RET(s, iter->ts);
+ SEQ_PUT_HEX_FIELD(s, entry->pid);
+ SEQ_PUT_HEX_FIELD(s, iter->cpu);
+ SEQ_PUT_HEX_FIELD(s, iter->ts);
+ if (trace_seq_has_overflowed(s))
+ return TRACE_TYPE_PARTIAL_LINE;
}

event = ftrace_find_event(entry->type);
@@ -2716,9 +2713,9 @@ static enum print_line_t print_hex_fmt(struct trace_iterator *iter)
return ret;
}

- SEQ_PUT_FIELD_RET(s, newline);
+ SEQ_PUT_FIELD(s, newline);

- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(s);
}

static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
@@ -2730,9 +2727,11 @@ static enum print_line_t print_bin_fmt(struct trace_iterator *iter)
entry = iter->ent;

if (trace_flags & TRACE_ITER_CONTEXT_INFO) {
- SEQ_PUT_FIELD_RET(s, entry->pid);
- SEQ_PUT_FIELD_RET(s, iter->cpu);
- SEQ_PUT_FIELD_RET(s, iter->ts);
+ SEQ_PUT_FIELD(s, entry->pid);
+ SEQ_PUT_FIELD(s, iter->cpu);
+ SEQ_PUT_FIELD(s, iter->ts);
+ if (trace_seq_has_overflowed(s))
+ return TRACE_TYPE_PARTIAL_LINE;
}

event = ftrace_find_event(entry->type);
@@ -2778,10 +2777,12 @@ enum print_line_t print_trace_line(struct trace_iterator *iter)
{
enum print_line_t ret;

- if (iter->lost_events &&
- !trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
- iter->cpu, iter->lost_events))
- return TRACE_TYPE_PARTIAL_LINE;
+ if (iter->lost_events) {
+ trace_seq_printf(&iter->seq, "CPU:%d [LOST %lu EVENTS]\n",
+ iter->cpu, iter->lost_events);
+ if (trace_seq_has_overflowed(&iter->seq))
+ return TRACE_TYPE_PARTIAL_LINE;
+ }

if (iter->trace && iter->trace->print_line) {
ret = iter->trace->print_line(iter);
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 3376de623ea0..19418221b302 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -14,6 +14,7 @@
#include <linux/trace_seq.h>
#include <linux/ftrace_event.h>
#include <linux/compiler.h>
+#include <linux/trace_seq.h>

#ifdef CONFIG_FTRACE_SYSCALLS
#include <asm/unistd.h> /* For NR_SYSCALLS */
diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c
index cfa91de22e27..163c11b6b8ff 100644
--- a/kernel/trace/trace_output.c
+++ b/kernel/trace/trace_output.c
@@ -25,15 +25,12 @@ enum print_line_t trace_print_bputs_msg_only(struct trace_iterator *iter)
struct trace_seq *s = &iter->seq;
struct trace_entry *entry = iter->ent;
struct bputs_entry *field;
- int ret;

trace_assign_type(field, entry);

- ret = trace_seq_puts(s, field->str);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
+ trace_seq_puts(s, field->str);

- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(s);
}

enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
@@ -41,15 +38,12 @@ enum print_line_t trace_print_bprintk_msg_only(struct trace_iterator *iter)
struct trace_seq *s = &iter->seq;
struct trace_entry *entry = iter->ent;
struct bprint_entry *field;
- int ret;

trace_assign_type(field, entry);

- ret = trace_seq_bprintf(s, field->fmt, field->buf);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
+ trace_seq_bprintf(s, field->fmt, field->buf);

- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(s);
}

enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
@@ -57,15 +51,12 @@ enum print_line_t trace_print_printk_msg_only(struct trace_iterator *iter)
struct trace_seq *s = &iter->seq;
struct trace_entry *entry = iter->ent;
struct print_entry *field;
- int ret;

trace_assign_type(field, entry);

- ret = trace_seq_puts(s, field->buf);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
+ trace_seq_puts(s, field->buf);

- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(s);
}

const char *
@@ -193,7 +184,6 @@ int ftrace_raw_output_prep(struct trace_iterator *iter,
struct trace_seq *s = &iter->seq;
struct trace_seq *p = &iter->tmp_seq;
struct trace_entry *entry;
- int ret;

event = container_of(trace_event, struct ftrace_event_call, event);
entry = iter->ent;
@@ -204,8 +194,9 @@ int ftrace_raw_output_prep(struct trace_iterator *iter,
}

trace_seq_init(p);
- ret = trace_seq_printf(s, "%s: ", ftrace_event_name(event));
- if (!ret)
+ trace_seq_printf(s, "%s: ", ftrace_event_name(event));
+
+ if (trace_seq_has_overflowed(s))
return TRACE_TYPE_PARTIAL_LINE;

return 0;
@@ -216,18 +207,11 @@ static int ftrace_output_raw(struct trace_iterator *iter, char *name,
char *fmt, va_list ap)
{
struct trace_seq *s = &iter->seq;
- int ret;

- ret = trace_seq_printf(s, "%s: ", name);
- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- ret = trace_seq_vprintf(s, fmt, ap);
+ trace_seq_printf(s, "%s: ", name);
+ trace_seq_vprintf(s, fmt, ap);

- if (!ret)
- return TRACE_TYPE_PARTIAL_LINE;
-
- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(s);
}

int ftrace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...)
@@ -260,7 +244,7 @@ static inline const char *kretprobed(const char *name)
}
#endif /* CONFIG_KRETPROBES */

-static int
+static void
seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)
{
#ifdef CONFIG_KALLSYMS
@@ -271,12 +255,11 @@ seq_print_sym_short(struct trace_seq *s, const char *fmt, unsigned long address)

name = kretprobed(str);

- return trace_seq_printf(s, fmt, name);
+ trace_seq_printf(s, fmt, name);
#endif
- return 1;
}

-static int
+static void
seq_print_sym_offset(struct trace_seq *s, const char *fmt,
unsigned long address)
{
@@ -287,9 +270,8 @@ seq_print_sym_offset(struct trace_seq *s, const char *fmt,
sprint_symbol(str, address);
name = kretprobed(str);

- return trace_seq_printf(s, fmt, name);
+ trace_seq_printf(s, fmt, name);
#endif
- return 1;
}

#ifndef CONFIG_64BIT
@@ -320,14 +302,14 @@ int seq_print_user_ip(struct trace_seq *s, struct mm_struct *mm,
if (file) {
ret = trace_seq_path(s, &file->f_path);
if (ret)
- ret = trace_seq_printf(s, "[+0x%lx]",
- ip - vmstart);
+ trace_seq_printf(s, "[+0x%lx]",
+ ip - vmstart);
}
up_read(&mm->mmap_sem);
}
if (ret && ((sym_flags & TRACE_ITER_SYM_ADDR) || !file))
- ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
- return ret;
+ trace_seq_printf(s, " <" IP_FMT ">", ip);
+ return !trace_seq_has_overflowed(s);
}

int
@@ -335,7 +317,6 @@ seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
unsigned long sym_flags)
{
struct mm_struct *mm = NULL;
- int ret = 1;
unsigned int i;

if (trace_flags & TRACE_ITER_SYM_USEROBJ) {
@@ -354,48 +335,45 @@ seq_print_userip_objs(const struct userstack_entry *entry, struct trace_seq *s,
for (i = 0; i < FTRACE_STACK_ENTRIES; i++) {
unsigned long ip = entry->caller[i];

- if (ip == ULONG_MAX || !ret)
+ if (ip == ULONG_MAX || trace_seq_has_overflowed(s))
break;
- if (ret)
- ret = trace_seq_puts(s, " => ");
+
+ trace_seq_puts(s, " => ");
+
if (!ip) {
- if (ret)
- ret = trace_seq_puts(s, "??");
- if (ret)
- ret = trace_seq_putc(s, '\n');
+ trace_seq_puts(s, "??");
+ trace_seq_putc(s, '\n');
continue;
}
- if (!ret)
- break;
- if (ret)
- ret = seq_print_user_ip(s, mm, ip, sym_flags);
- ret = trace_seq_putc(s, '\n');
+
+ seq_print_user_ip(s, mm, ip, sym_flags);
+ trace_seq_putc(s, '\n');
}

if (mm)
mmput(mm);
- return ret;
+
+ return !trace_seq_has_overflowed(s);
}

int
seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags)
{
- int ret;
-
- if (!ip)
- return trace_seq_putc(s, '0');
+ if (!ip) {
+ trace_seq_putc(s, '0');
+ goto out;
+ }

if (sym_flags & TRACE_ITER_SYM_OFFSET)
- ret = seq_print_sym_offset(s, "%s", ip);
+ seq_print_sym_offset(s, "%s", ip);
else
- ret = seq_print_sym_short(s, "%s", ip);
-
- if (!ret)
- return 0;
+ seq_print_sym_short(s, "%s", ip);

if (sym_flags & TRACE_ITER_SYM_ADDR)
- ret = trace_seq_printf(s, " <" IP_FMT ">", ip);
- return ret;
+ trace_seq_printf(s, " <" IP_FMT ">", ip);
+
+ out:
+ return !trace_seq_has_overflowed(s);
}

/**
@@ -413,7 +391,6 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
char irqs_off;
int hardirq;
int softirq;
- int ret;

hardirq = entry->flags & TRACE_FLAG_HARDIRQ;
softirq = entry->flags & TRACE_FLAG_SOFTIRQ;
@@ -445,16 +422,15 @@ int trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry)
softirq ? 's' :
'.';

- if (!trace_seq_printf(s, "%c%c%c",
- irqs_off, need_resched, hardsoft_irq))
- return 0;
+ trace_seq_printf(s, "%c%c%c",
+ irqs_off, need_resched, hardsoft_irq);

if (entry->preempt_count)
- ret = trace_seq_printf(s, "%x", entry->preempt_count);
+ trace_seq_printf(s, "%x", entry->preempt_count);
else
- ret = trace_seq_putc(s, '.');
+ trace_seq_putc(s, '.');

- return ret;
+ return !trace_seq_has_overflowed(s);
}

static int
@@ -464,9 +440,8 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu)

trace_find_cmdline(entry->pid, comm);

- if (!trace_seq_printf(s, "%8.8s-%-5d %3d",
- comm, entry->pid, cpu))
- return 0;
+ trace_seq_printf(s, "%8.8s-%-5d %3d",
+ comm, entry->pid, cpu);

return trace_print_lat_fmt(s, entry);
}
@@ -493,24 +468,29 @@ lat_print_timestamp(struct trace_iterator *iter, u64 next_ts)
unsigned long rel_usec = do_div(rel_ts, USEC_PER_MSEC);
unsigned long rel_msec = (unsigned long)rel_ts;

- return trace_seq_printf(
- s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
- ns2usecs(iter->ts),
- abs_msec, abs_usec,
- rel_msec, rel_usec);
+ trace_seq_printf(
+ s, "[%08llx] %ld.%03ldms (+%ld.%03ldms): ",
+ ns2usecs(iter->ts),
+ abs_msec, abs_usec,
+ rel_msec, rel_usec);
+
} else if (verbose && !in_ns) {
- return trace_seq_printf(
- s, "[%016llx] %lld (+%lld): ",
- iter->ts, abs_ts, rel_ts);
+ trace_seq_printf(
+ s, "[%016llx] %lld (+%lld): ",
+ iter->ts, abs_ts, rel_ts);
+
} else if (!verbose && in_ns) {
- return trace_seq_printf(
- s, " %4lldus%c: ",
- abs_ts,
- rel_ts > preempt_mark_thresh_us ? '!' :
- rel_ts > 1 ? '+' : ' ');
+ trace_seq_printf(
+ s, " %4lldus%c: ",
+ abs_ts,
+ rel_ts > preempt_mark_thresh_us ? '!' :
+ rel_ts > 1 ? '+' : ' ');
+
} else { /* !verbose && !in_ns */
- return trace_seq_printf(s, " %4lld: ", abs_ts);
+ trace_seq_printf(s, " %4lld: ", abs_ts);
}
+
+ return !trace_seq_has_overflowed(s);
}

int trace_print_context(struct trace_iterator *iter)
@@ -520,34 +500,29 @@ int trace_print_context(struct trace_iterator *iter)
unsigned long long t;
unsigned long secs, usec_rem;
char comm[TASK_COMM_LEN];
- int ret;

trace_find_cmdline(entry->pid, comm);

- ret = trace_seq_printf(s, "%16s-%-5d [%03d] ",
+ trace_seq_printf(s, "%16s-%-5d [%03d] ",
comm, entry->pid, iter->cpu);
- if (!ret)
- return 0;

- if (trace_flags & TRACE_ITER_IRQ_INFO) {
- ret = trace_print_lat_fmt(s, entry);
- if (!ret)
- return 0;
- }
+ if (trace_flags & TRACE_ITER_IRQ_INFO)
+ trace_print_lat_fmt(s, entry);

if (iter->iter_flags & TRACE_FILE_TIME_IN_NS) {
t = ns2usecs(iter->ts);
usec_rem = do_div(t, USEC_PER_SEC);
secs = (unsigned long)t;
- return trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
+ trace_seq_printf(s, " %5lu.%06lu: ", secs, usec_rem);
} else
- return trace_seq_printf(s, " %12llu: ", iter->ts);
+ trace_seq_printf(s, " %12llu: ", iter->ts);
+
+ return !trace_seq_has_overflowed(s);
}

int trace_print_lat_context(struct trace_iterator *iter)
{
u64 next_ts;
- int ret;
/* trace_find_next_entry will reset ent_size */
int ent_size = iter->ent_size;
struct trace_seq *s = &iter->seq;
@@ -567,18 +542,17 @@ int trace_print_lat_context(struct trace_iterator *iter)

trace_find_cmdline(entry->pid, comm);

- ret = trace_seq_printf(
- s, "%16s %5d %3d %d %08x %08lx ",
- comm, entry->pid, iter->cpu, entry->flags,
- entry->preempt_count, iter->idx);
+ trace_seq_printf(
+ s, "%16s %5d %3d %d %08x %08lx ",
+ comm, entry->pid, iter->cpu, entry->flags,
+ entry->preempt_count, iter->idx);
} else {
- ret = lat_print_generic(s, entry, iter->cpu);
+ lat_print_generic(s, entry, iter->cpu);
}

- if (ret)
- ret = lat_print_timestamp(iter, next_ts);
+ lat_print_timestamp(iter, next_ts);

- return ret;
+ return !trace_seq_has_overflowed(s);
}

static const char state_to_char[] = TASK_STATE_TO_CHAR_STR;
@@ -764,10 +738,9 @@ EXPORT_SYMBOL_GPL(unregister_ftrace_event);
enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags,
struct trace_event *event)
{
- if (!trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type))
- return TRACE_TYPE_PARTIAL_LINE;
+ trace_seq_printf(&iter->seq, "type: %d\n", iter->ent->type);

- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(&iter->seq);
}

/* TRACE_FN */
@@ -779,24 +752,16 @@ static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags,

trace_assign_type(field, iter->ent);

- if (!seq_print_ip_sym(s, field->ip, flags))
- goto partial;
+ seq_print_ip_sym(s, field->ip, flags);

if ((flags & TRACE_ITER_PRINT_PARENT) && field->parent_ip) {
- if (!trace_seq_puts(s, " <-"))
- goto partial;
- if (!seq_print_ip_sym(s,
- field->parent_ip,
- flags))
- goto partial;
+ trace_seq_puts(s, " <-");
+ seq_print_ip_sym(s, field->parent_ip, flags);
}
- if (!trace_seq_putc(s, '\n'))
- goto partial;

- return TRACE_TYPE_HANDLED;
+ trace_seq_putc(s, '\n');

- partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(s);
}

static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,
@@ -806,12 +771,11 @@ static enum print_line_t trace_fn_raw(struct trace_iterator *iter, int flags,

trace_assign_type(field, iter->ent);

- if (!trace_seq_printf(&iter->seq, "%lx %lx\n",
- field->ip,
- field->parent_ip))
- return TRACE_TYPE_PARTIAL_LINE;
+ trace_seq_printf(&iter->seq, "%lx %lx\n",
+ field->ip,
+ field->parent_ip);

- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(&iter->seq);
}

static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,
@@ -822,10 +786,10 @@ static enum print_line_t trace_fn_hex(struct trace_iterator *iter, int flags,

trace_assign_type(field, iter->ent);

- SEQ_PUT_HEX_FIELD_RET(s, field->ip);
- SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip);
+ SEQ_PUT_HEX_FIELD(s, field->ip);
+ SEQ_PUT_HEX_FIELD(s, field->parent_ip);

- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(s);
}

static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,
@@ -836,10 +800,10 @@ static enum print_line_t trace_fn_bin(struct trace_iterator *iter, int flags,

trace_assign_type(field, iter->ent);

- SEQ_PUT_FIELD_RET(s, field->ip);
- SEQ_PUT_FIELD_RET(s, field->parent_ip);
+ SEQ_PUT_FIELD(s, field->ip);
+ SEQ_PUT_FIELD(s, field->parent_ip);

- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(s);
}

static struct trace_event_functions trace_fn_funcs = {
@@ -868,18 +832,17 @@ static enum print_line_t trace_ctxwake_print(struct trace_iterator *iter,
T = task_state_char(field->next_state);
S = task_state_char(field->prev_state);
trace_find_cmdline(field->next_pid, comm);
- if (!trace_seq_printf(&iter->seq,
- " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
- field->prev_pid,
- field->prev_prio,
- S, delim,
- field->next_cpu,
- field->next_pid,
- field->next_prio,
- T, comm))
- return TRACE_TYPE_PARTIAL_LINE;
-
- return TRACE_TYPE_HANDLED;
+ trace_seq_printf(&iter->seq,
+ " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n",
+ field->prev_pid,
+ field->prev_prio,
+ S, delim,
+ field->next_cpu,
+ field->next_pid,
+ field->next_prio,
+ T, comm);
+
+ return trace_handle_return(&iter->seq);
}

static enum print_line_t trace_ctx_print(struct trace_iterator *iter, int flags,
@@ -904,17 +867,16 @@ static int trace_ctxwake_raw(struct trace_iterator *iter, char S)
if (!S)
S = task_state_char(field->prev_state);
T = task_state_char(field->next_state);
- if (!trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
- field->prev_pid,
- field->prev_prio,
- S,
- field->next_cpu,
- field->next_pid,
- field->next_prio,
- T))
- return TRACE_TYPE_PARTIAL_LINE;
-
- return TRACE_TYPE_HANDLED;
+ trace_seq_printf(&iter->seq, "%d %d %c %d %d %d %c\n",
+ field->prev_pid,
+ field->prev_prio,
+ S,
+ field->next_cpu,
+ field->next_pid,
+ field->next_prio,
+ T);
+
+ return trace_handle_return(&iter->seq);
}

static enum print_line_t trace_ctx_raw(struct trace_iterator *iter, int flags,
@@ -942,15 +904,15 @@ static int trace_ctxwake_hex(struct trace_iterator *iter, char S)
S = task_state_char(field->prev_state);
T = task_state_char(field->next_state);

- SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid);
- SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio);
- SEQ_PUT_HEX_FIELD_RET(s, S);
- SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu);
- SEQ_PUT_HEX_FIELD_RET(s, field->next_pid);
- SEQ_PUT_HEX_FIELD_RET(s, field->next_prio);
- SEQ_PUT_HEX_FIELD_RET(s, T);
+ SEQ_PUT_HEX_FIELD(s, field->prev_pid);
+ SEQ_PUT_HEX_FIELD(s, field->prev_prio);
+ SEQ_PUT_HEX_FIELD(s, S);
+ SEQ_PUT_HEX_FIELD(s, field->next_cpu);
+ SEQ_PUT_HEX_FIELD(s, field->next_pid);
+ SEQ_PUT_HEX_FIELD(s, field->next_prio);
+ SEQ_PUT_HEX_FIELD(s, T);

- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(s);
}

static enum print_line_t trace_ctx_hex(struct trace_iterator *iter, int flags,
@@ -973,15 +935,15 @@ static enum print_line_t trace_ctxwake_bin(struct trace_iterator *iter,

trace_assign_type(field, iter->ent);

- SEQ_PUT_FIELD_RET(s, field->prev_pid);
- SEQ_PUT_FIELD_RET(s, field->prev_prio);
- SEQ_PUT_FIELD_RET(s, field->prev_state);
- SEQ_PUT_FIELD_RET(s, field->next_cpu);
- SEQ_PUT_FIELD_RET(s, field->next_pid);
- SEQ_PUT_FIELD_RET(s, field->next_prio);
- SEQ_PUT_FIELD_RET(s, field->next_state);
+ SEQ_PUT_FIELD(s, field->prev_pid);
+ SEQ_PUT_FIELD(s, field->prev_prio);
+ SEQ_PUT_FIELD(s, field->prev_state);
+ SEQ_PUT_FIELD(s, field->next_cpu);
+ SEQ_PUT_FIELD(s, field->next_pid);
+ SEQ_PUT_FIELD(s, field->next_prio);
+ SEQ_PUT_FIELD(s, field->next_state);

- return TRACE_TYPE_HANDLED;
+ return trace_handle_return(s);
}

static struct trace_event_functions trace_ctx_funcs = {
@@ -1021,23 +983,19 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter,
trace_assign_type(field, iter->ent);
end = (unsigned long *)((long)iter->ent + iter->ent_size);

- if (!trace_seq_puts(s, "<stack trace>\n"))
- goto partial;
+ trace_seq_puts(s, "<stack trace>\n");

for (p = field->caller; p && *p != ULONG_MAX && p < end; p++) {
- if (!trace_seq_puts(s, " => "))
- goto partial;

- if (!seq_print_ip_sym(s, *p, flags))
- goto partial;
- if (!trace_seq_putc(s, '\n'))
- goto partial;
- }
+ if (trace_seq_has_overflowed(s))
+ break;

- return TRACE_TYPE_HANDLED;
+ trace_seq_puts(s, " => ");
+ seq_print_ip_sym(s, *p, flags);
+ trace_seq_putc(s, '\n');
+ }

- partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(s);
}

static struct trace_event_functions trace_stack_funcs = {
@@ -1058,16 +1016,10 @@ static enum print_line_t trace_user_stack_print(struct trace_iterator *iter,

trace_assign_type(field, iter->ent);

- if (!trace_seq_puts(s, "<user stack trace>\n"))
- goto partial;
-
- if (!seq_print_userip_objs(field, s, flags))
- goto partial;
-
- return TRACE_TYPE_HANDLED;
+ trace_seq_puts(s, "<user stack trace>\n");
+ seq_print_userip_objs(field, s, flags);

- partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(s);
}

static struct trace_event_functions trace_user_stack_funcs = {
@@ -1090,19 +1042,11 @@ trace_bputs_print(struct trace_iterator *iter, int flags,

trace_assign_type(field, entry);

- if (!seq_print_ip_sym(s, field->ip, flags))
- goto partial;
+ seq_print_ip_sym(s, field->ip, flags);
+ trace_seq_puts(s, ": ");
+ trace_seq_puts(s, field->str);

- if (!trace_seq_puts(s, ": "))
- goto partial;
-
- if (!trace_seq_puts(s, field->str))
- goto partial;
-
- return TRACE_TYPE_HANDLED;
-
- partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(s);
}


@@ -1115,16 +1059,10 @@ trace_bputs_raw(struct trace_iterator *iter, int flags,

trace_assign_type(field, iter->ent);

- if (!trace_seq_printf(s, ": %lx : ", field->ip))
- goto partial;
-
- if (!trace_seq_puts(s, field->str))
- goto partial;
+ trace_seq_printf(s, ": %lx : ", field->ip);
+ trace_seq_puts(s, field->str);

- return TRACE_TYPE_HANDLED;
-
- partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(s);
}

static struct trace_event_functions trace_bputs_funcs = {
@@ -1148,19 +1086,11 @@ trace_bprint_print(struct trace_iterator *iter, int flags,

trace_assign_type(field, entry);

- if (!seq_print_ip_sym(s, field->ip, flags))
- goto partial;
-
- if (!trace_seq_puts(s, ": "))
- goto partial;
-
- if (!trace_seq_bprintf(s, field->fmt, field->buf))
- goto partial;
+ seq_print_ip_sym(s, field->ip, flags);
+ trace_seq_puts(s, ": ");
+ trace_seq_bprintf(s, field->fmt, field->buf);

- return TRACE_TYPE_HANDLED;
-
- partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(s);
}


@@ -1173,16 +1103,10 @@ trace_bprint_raw(struct trace_iterator *iter, int flags,

trace_assign_type(field, iter->ent);

- if (!trace_seq_printf(s, ": %lx : ", field->ip))
- goto partial;
-
- if (!trace_seq_bprintf(s, field->fmt, field->buf))
- goto partial;
+ trace_seq_printf(s, ": %lx : ", field->ip);
+ trace_seq_bprintf(s, field->fmt, field->buf);

- return TRACE_TYPE_HANDLED;
-
- partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(s);
}

static struct trace_event_functions trace_bprint_funcs = {
@@ -1204,16 +1128,10 @@ static enum print_line_t trace_print_print(struct trace_iterator *iter,

trace_assign_type(field, iter->ent);

- if (!seq_print_ip_sym(s, field->ip, flags))
- goto partial;
-
- if (!trace_seq_printf(s, ": %s", field->buf))
- goto partial;
+ seq_print_ip_sym(s, field->ip, flags);
+ trace_seq_printf(s, ": %s", field->buf);

- return TRACE_TYPE_HANDLED;
-
- partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(s);
}

static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,
@@ -1223,13 +1141,9 @@ static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags,

trace_assign_type(field, iter->ent);

- if (!trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf))
- goto partial;
-
- return TRACE_TYPE_HANDLED;
+ trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf);

- partial:
- return TRACE_TYPE_PARTIAL_LINE;
+ return trace_handle_return(&iter->seq);
}

static struct trace_event_functions trace_print_funcs = {
diff --git a/kernel/trace/trace_output.h b/kernel/trace/trace_output.h
index 80b25b585a70..8ef2c40efb3c 100644
--- a/kernel/trace/trace_output.h
+++ b/kernel/trace/trace_output.h
@@ -35,17 +35,11 @@ trace_print_lat_fmt(struct trace_seq *s, struct trace_entry *entry);
extern int __unregister_ftrace_event(struct trace_event *event);
extern struct rw_semaphore trace_event_sem;

-#define SEQ_PUT_FIELD_RET(s, x) \
-do { \
- if (!trace_seq_putmem(s, &(x), sizeof(x))) \
- return TRACE_TYPE_PARTIAL_LINE; \
-} while (0)
-
-#define SEQ_PUT_HEX_FIELD_RET(s, x) \
-do { \
- if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
- return TRACE_TYPE_PARTIAL_LINE; \
-} while (0)
+#define SEQ_PUT_FIELD(s, x) \
+ trace_seq_putmem(s, &(x), sizeof(x))
+
+#define SEQ_PUT_HEX_FIELD(s, x) \
+ trace_seq_putmem_hex(s, &(x), sizeof(x))

#endif

--
2.1.1


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/