* [PATCH 2/4] tools lib traceevent: Check return value of realloc()
2013-12-19 9:34 [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq Namhyung Kim
@ 2013-12-19 9:34 ` Namhyung Kim
2013-12-19 9:34 ` [PATCH 3/4] tools lib traceevent: Get rid of malloc_or_die() in trace_seq_init() Namhyung Kim
` (3 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: Namhyung Kim @ 2013-12-19 9:34 UTC (permalink / raw)
To: Steven Rostedt, Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker, Peter Zijlstra, Ingo Molnar, Namhyung Kim,
LKML, Jiri Olsa
From: Namhyung Kim <namhyung.kim@lge.com>
If realloc() fails, it'll leak the buffer. Also increate buffer size
only if the allocation succeeded.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/lib/traceevent/trace-seq.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/tools/lib/traceevent/trace-seq.c b/tools/lib/traceevent/trace-seq.c
index 976ad2a146b3..57405652f26d 100644
--- a/tools/lib/traceevent/trace-seq.c
+++ b/tools/lib/traceevent/trace-seq.c
@@ -79,10 +79,16 @@ void trace_seq_destroy(struct trace_seq *s)
static void expand_buffer(struct trace_seq *s)
{
- s->buffer_size += TRACE_SEQ_BUF_SIZE;
- s->buffer = realloc(s->buffer, s->buffer_size);
- if (!s->buffer)
+ char *buf;
+
+ buf = realloc(s->buffer, s->buffer_size + TRACE_SEQ_BUF_SIZE);
+ if (!buf) {
s->state = TRACE_SEQ__MEM_ALLOC_FAILED;
+ return;
+ }
+
+ s->buffer = buf;
+ s->buffer_size += TRACE_SEQ_BUF_SIZE;
}
/**
--
1.7.11.7
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH 3/4] tools lib traceevent: Get rid of malloc_or_die() in trace_seq_init()
2013-12-19 9:34 [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq Namhyung Kim
2013-12-19 9:34 ` [PATCH 2/4] tools lib traceevent: Check return value of realloc() Namhyung Kim
@ 2013-12-19 9:34 ` Namhyung Kim
2013-12-19 9:34 ` [PATCH 4/4] tools lib traceevent: Get rid of die() finally!! Namhyung Kim
` (2 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: Namhyung Kim @ 2013-12-19 9:34 UTC (permalink / raw)
To: Steven Rostedt, Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker, Peter Zijlstra, Ingo Molnar, Namhyung Kim,
LKML, Jiri Olsa
From: Namhyung Kim <namhyung.kim@lge.com>
Use plain malloc() and check its return value.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/lib/traceevent/trace-seq.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/tools/lib/traceevent/trace-seq.c b/tools/lib/traceevent/trace-seq.c
index 57405652f26d..d24a33190bb8 100644
--- a/tools/lib/traceevent/trace-seq.c
+++ b/tools/lib/traceevent/trace-seq.c
@@ -45,8 +45,11 @@ void trace_seq_init(struct trace_seq *s)
s->len = 0;
s->readpos = 0;
s->buffer_size = TRACE_SEQ_BUF_SIZE;
- s->buffer = malloc_or_die(s->buffer_size);
- s->state = TRACE_SEQ__GOOD;
+ s->buffer = malloc(s->buffer_size);
+ if (s->buffer != NULL)
+ s->state = TRACE_SEQ__GOOD;
+ else
+ s->state = TRACE_SEQ__MEM_ALLOC_FAILED;
}
/**
--
1.7.11.7
^ permalink raw reply related [flat|nested] 10+ messages in thread* [PATCH 4/4] tools lib traceevent: Get rid of die() finally!!
2013-12-19 9:34 [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq Namhyung Kim
2013-12-19 9:34 ` [PATCH 2/4] tools lib traceevent: Check return value of realloc() Namhyung Kim
2013-12-19 9:34 ` [PATCH 3/4] tools lib traceevent: Get rid of malloc_or_die() in trace_seq_init() Namhyung Kim
@ 2013-12-19 9:34 ` Namhyung Kim
2014-01-03 7:05 ` [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq Namhyung Kim
2014-01-03 13:24 ` Jiri Olsa
4 siblings, 0 replies; 10+ messages in thread
From: Namhyung Kim @ 2013-12-19 9:34 UTC (permalink / raw)
To: Steven Rostedt, Arnaldo Carvalho de Melo
Cc: Frederic Weisbecker, Peter Zijlstra, Ingo Molnar, Namhyung Kim,
LKML, Jiri Olsa
From: Namhyung Kim <namhyung.kim@lge.com>
Now all of its users were gone. :)
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
---
tools/lib/traceevent/event-utils.h | 4 ----
tools/lib/traceevent/parse-utils.c | 44 --------------------------------------
2 files changed, 48 deletions(-)
diff --git a/tools/lib/traceevent/event-utils.h b/tools/lib/traceevent/event-utils.h
index e76c9acb92cd..d1dc2170e402 100644
--- a/tools/lib/traceevent/event-utils.h
+++ b/tools/lib/traceevent/event-utils.h
@@ -23,18 +23,14 @@
#include <ctype.h>
/* Can be overridden */
-void die(const char *fmt, ...);
-void *malloc_or_die(unsigned int size);
void warning(const char *fmt, ...);
void pr_stat(const char *fmt, ...);
void vpr_stat(const char *fmt, va_list ap);
/* Always available */
-void __die(const char *fmt, ...);
void __warning(const char *fmt, ...);
void __pr_stat(const char *fmt, ...);
-void __vdie(const char *fmt, ...);
void __vwarning(const char *fmt, ...);
void __vpr_stat(const char *fmt, ...);
diff --git a/tools/lib/traceevent/parse-utils.c b/tools/lib/traceevent/parse-utils.c
index bba701cf10e6..eda07fa31dca 100644
--- a/tools/lib/traceevent/parse-utils.c
+++ b/tools/lib/traceevent/parse-utils.c
@@ -25,40 +25,6 @@
#define __weak __attribute__((weak))
-void __vdie(const char *fmt, va_list ap)
-{
- int ret = errno;
-
- if (errno)
- perror("trace-cmd");
- else
- ret = -1;
-
- fprintf(stderr, " ");
- vfprintf(stderr, fmt, ap);
-
- fprintf(stderr, "\n");
- exit(ret);
-}
-
-void __die(const char *fmt, ...)
-{
- va_list ap;
-
- va_start(ap, fmt);
- __vdie(fmt, ap);
- va_end(ap);
-}
-
-void __weak die(const char *fmt, ...)
-{
- va_list ap;
-
- va_start(ap, fmt);
- __vdie(fmt, ap);
- va_end(ap);
-}
-
void __vwarning(const char *fmt, va_list ap)
{
if (errno)
@@ -117,13 +83,3 @@ void __weak pr_stat(const char *fmt, ...)
__vpr_stat(fmt, ap);
va_end(ap);
}
-
-void __weak *malloc_or_die(unsigned int size)
-{
- void *data;
-
- data = malloc(size);
- if (!data)
- die("malloc");
- return data;
-}
--
1.7.11.7
^ permalink raw reply related [flat|nested] 10+ messages in thread* Re: [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq
2013-12-19 9:34 [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq Namhyung Kim
` (2 preceding siblings ...)
2013-12-19 9:34 ` [PATCH 4/4] tools lib traceevent: Get rid of die() finally!! Namhyung Kim
@ 2014-01-03 7:05 ` Namhyung Kim
2014-01-03 13:24 ` Jiri Olsa
4 siblings, 0 replies; 10+ messages in thread
From: Namhyung Kim @ 2014-01-03 7:05 UTC (permalink / raw)
To: Steven Rostedt
Cc: Arnaldo Carvalho de Melo, Frederic Weisbecker, Peter Zijlstra,
Ingo Molnar, Namhyung Kim, LKML, Jiri Olsa
Ping!
On Thu, 19 Dec 2013 18:34:23 +0900, Namhyung Kim wrote:
> From: Namhyung Kim <namhyung.kim@lge.com>
>
> The trace_seq->state is for tracking errors during the use of
> trace_seq APIs and getting rid of die() in it.
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> tools/lib/traceevent/event-parse.h | 7 +++++++
> tools/lib/traceevent/trace-seq.c | 41 ++++++++++++++++++++++++++++++++++----
> 2 files changed, 44 insertions(+), 4 deletions(-)
>
> diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
> index cf5db9013f2c..3c890cb28db7 100644
> --- a/tools/lib/traceevent/event-parse.h
> +++ b/tools/lib/traceevent/event-parse.h
> @@ -58,6 +58,12 @@ struct pevent_record {
> #endif
> };
>
> +enum trace_seq_fail {
> + TRACE_SEQ__GOOD,
> + TRACE_SEQ__BUFFER_POISONED,
> + TRACE_SEQ__MEM_ALLOC_FAILED,
> +};
> +
> /*
> * Trace sequences are used to allow a function to call several other functions
> * to create a string of data to use (up to a max of PAGE_SIZE).
> @@ -68,6 +74,7 @@ struct trace_seq {
> unsigned int buffer_size;
> unsigned int len;
> unsigned int readpos;
> + enum trace_seq_fail state;
> };
>
> void trace_seq_init(struct trace_seq *s);
> diff --git a/tools/lib/traceevent/trace-seq.c b/tools/lib/traceevent/trace-seq.c
> index d7f2e68bc5b9..976ad2a146b3 100644
> --- a/tools/lib/traceevent/trace-seq.c
> +++ b/tools/lib/traceevent/trace-seq.c
> @@ -32,8 +32,8 @@
> #define TRACE_SEQ_POISON ((void *)0xdeadbeef)
> #define TRACE_SEQ_CHECK(s) \
> do { \
> - if ((s)->buffer == TRACE_SEQ_POISON) \
> - die("Usage of trace_seq after it was destroyed"); \
> + if ((s)->buffer == TRACE_SEQ_POISON) \
> + (s)->state = TRACE_SEQ__BUFFER_POISONED; \
> } while (0)
>
> /**
> @@ -46,6 +46,7 @@ void trace_seq_init(struct trace_seq *s)
> s->readpos = 0;
> s->buffer_size = TRACE_SEQ_BUF_SIZE;
> s->buffer = malloc_or_die(s->buffer_size);
> + s->state = TRACE_SEQ__GOOD;
> }
>
> /**
> @@ -81,7 +82,7 @@ static void expand_buffer(struct trace_seq *s)
> s->buffer_size += TRACE_SEQ_BUF_SIZE;
> s->buffer = realloc(s->buffer, s->buffer_size);
> if (!s->buffer)
> - die("Can't allocate trace_seq buffer memory");
> + s->state = TRACE_SEQ__MEM_ALLOC_FAILED;
> }
>
> /**
> @@ -108,6 +109,9 @@ trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
> TRACE_SEQ_CHECK(s);
>
> try_again:
> + if (s->state != TRACE_SEQ__GOOD)
> + return 0;
> +
> len = (s->buffer_size - 1) - s->len;
>
> va_start(ap, fmt);
> @@ -144,6 +148,9 @@ trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
> TRACE_SEQ_CHECK(s);
>
> try_again:
> + if (s->state != TRACE_SEQ__GOOD)
> + return 0;
> +
> len = (s->buffer_size - 1) - s->len;
>
> ret = vsnprintf(s->buffer + s->len, len, fmt, args);
> @@ -174,11 +181,17 @@ int trace_seq_puts(struct trace_seq *s, const char *str)
>
> TRACE_SEQ_CHECK(s);
>
> + if (s->state != TRACE_SEQ__GOOD)
> + return 0;
> +
> len = strlen(str);
>
> while (len > ((s->buffer_size - 1) - s->len))
> expand_buffer(s);
>
> + if (s->state != TRACE_SEQ__GOOD)
> + return 0;
> +
> memcpy(s->buffer + s->len, str, len);
> s->len += len;
>
> @@ -189,9 +202,15 @@ int trace_seq_putc(struct trace_seq *s, unsigned char c)
> {
> TRACE_SEQ_CHECK(s);
>
> + if (s->state != TRACE_SEQ__GOOD)
> + return 0;
> +
> while (s->len >= (s->buffer_size - 1))
> expand_buffer(s);
>
> + if (s->state != TRACE_SEQ__GOOD)
> + return 0;
> +
> s->buffer[s->len++] = c;
>
> return 1;
> @@ -201,6 +220,9 @@ void trace_seq_terminate(struct trace_seq *s)
> {
> TRACE_SEQ_CHECK(s);
>
> + if (s->state != TRACE_SEQ__GOOD)
> + return;
> +
> /* There's always one character left on the buffer */
> s->buffer[s->len] = 0;
> }
> @@ -208,5 +230,16 @@ void trace_seq_terminate(struct trace_seq *s)
> int trace_seq_do_printf(struct trace_seq *s)
> {
> TRACE_SEQ_CHECK(s);
> - return printf("%.*s", s->len, s->buffer);
> +
> + switch (s->state) {
> + case TRACE_SEQ__GOOD:
> + return printf("%.*s", s->len, s->buffer);
> + case TRACE_SEQ__BUFFER_POISONED:
> + puts("Usage of trace_seq after it was destroyed");
> + break;
> + case TRACE_SEQ__MEM_ALLOC_FAILED:
> + puts("Can't allocate trace_seq buffer memory");
> + break;
> + }
> + return -1;
> }
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq
2013-12-19 9:34 [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq Namhyung Kim
` (3 preceding siblings ...)
2014-01-03 7:05 ` [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq Namhyung Kim
@ 2014-01-03 13:24 ` Jiri Olsa
2014-01-06 7:44 ` Namhyung Kim
4 siblings, 1 reply; 10+ messages in thread
From: Jiri Olsa @ 2014-01-03 13:24 UTC (permalink / raw)
To: Namhyung Kim
Cc: Steven Rostedt, Arnaldo Carvalho de Melo, Frederic Weisbecker,
Peter Zijlstra, Ingo Molnar, Namhyung Kim, LKML
On Thu, Dec 19, 2013 at 06:34:23PM +0900, Namhyung Kim wrote:
> From: Namhyung Kim <namhyung.kim@lge.com>
>
> The trace_seq->state is for tracking errors during the use of
> trace_seq APIs and getting rid of die() in it.
>
> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
> ---
> tools/lib/traceevent/event-parse.h | 7 +++++++
> tools/lib/traceevent/trace-seq.c | 41 ++++++++++++++++++++++++++++++++++----
> 2 files changed, 44 insertions(+), 4 deletions(-)
>
> diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
> index cf5db9013f2c..3c890cb28db7 100644
> --- a/tools/lib/traceevent/event-parse.h
> +++ b/tools/lib/traceevent/event-parse.h
> @@ -58,6 +58,12 @@ struct pevent_record {
> #endif
> };
>
> +enum trace_seq_fail {
> + TRACE_SEQ__GOOD,
> + TRACE_SEQ__BUFFER_POISONED,
> + TRACE_SEQ__MEM_ALLOC_FAILED,
> +};
> +
> /*
> * Trace sequences are used to allow a function to call several other functions
> * to create a string of data to use (up to a max of PAGE_SIZE).
> @@ -68,6 +74,7 @@ struct trace_seq {
> unsigned int buffer_size;
> unsigned int len;
> unsigned int readpos;
> + enum trace_seq_fail state;
> };
>
> void trace_seq_init(struct trace_seq *s);
> diff --git a/tools/lib/traceevent/trace-seq.c b/tools/lib/traceevent/trace-seq.c
> index d7f2e68bc5b9..976ad2a146b3 100644
> --- a/tools/lib/traceevent/trace-seq.c
> +++ b/tools/lib/traceevent/trace-seq.c
> @@ -32,8 +32,8 @@
> #define TRACE_SEQ_POISON ((void *)0xdeadbeef)
> #define TRACE_SEQ_CHECK(s) \
> do { \
> - if ((s)->buffer == TRACE_SEQ_POISON) \
> - die("Usage of trace_seq after it was destroyed"); \
> + if ((s)->buffer == TRACE_SEQ_POISON) \
> + (s)->state = TRACE_SEQ__BUFFER_POISONED; \
So unless we use trace_seq_do_printf we dont have any
notification that this went wrong..?
How about use some sort of WARN_ONCE any time the state
is set != GOOD ?
thanks,
jirka
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq
2014-01-03 13:24 ` Jiri Olsa
@ 2014-01-06 7:44 ` Namhyung Kim
2014-01-06 14:38 ` Jiri Olsa
0 siblings, 1 reply; 10+ messages in thread
From: Namhyung Kim @ 2014-01-06 7:44 UTC (permalink / raw)
To: Jiri Olsa
Cc: Steven Rostedt, Arnaldo Carvalho de Melo, Frederic Weisbecker,
Peter Zijlstra, Ingo Molnar, Namhyung Kim, LKML
Hi Jiri,
On Fri, 3 Jan 2014 14:24:25 +0100, Jiri Olsa wrote:
> On Thu, Dec 19, 2013 at 06:34:23PM +0900, Namhyung Kim wrote:
>> From: Namhyung Kim <namhyung.kim@lge.com>
>>
>> The trace_seq->state is for tracking errors during the use of
>> trace_seq APIs and getting rid of die() in it.
>>
>> Signed-off-by: Namhyung Kim <namhyung@kernel.org>
>> ---
>> tools/lib/traceevent/event-parse.h | 7 +++++++
>> tools/lib/traceevent/trace-seq.c | 41 ++++++++++++++++++++++++++++++++++----
>> 2 files changed, 44 insertions(+), 4 deletions(-)
>>
>> diff --git a/tools/lib/traceevent/event-parse.h b/tools/lib/traceevent/event-parse.h
>> index cf5db9013f2c..3c890cb28db7 100644
>> --- a/tools/lib/traceevent/event-parse.h
>> +++ b/tools/lib/traceevent/event-parse.h
>> @@ -58,6 +58,12 @@ struct pevent_record {
>> #endif
>> };
>>
>> +enum trace_seq_fail {
>> + TRACE_SEQ__GOOD,
>> + TRACE_SEQ__BUFFER_POISONED,
>> + TRACE_SEQ__MEM_ALLOC_FAILED,
>> +};
>> +
>> /*
>> * Trace sequences are used to allow a function to call several other functions
>> * to create a string of data to use (up to a max of PAGE_SIZE).
>> @@ -68,6 +74,7 @@ struct trace_seq {
>> unsigned int buffer_size;
>> unsigned int len;
>> unsigned int readpos;
>> + enum trace_seq_fail state;
>> };
>>
>> void trace_seq_init(struct trace_seq *s);
>> diff --git a/tools/lib/traceevent/trace-seq.c b/tools/lib/traceevent/trace-seq.c
>> index d7f2e68bc5b9..976ad2a146b3 100644
>> --- a/tools/lib/traceevent/trace-seq.c
>> +++ b/tools/lib/traceevent/trace-seq.c
>> @@ -32,8 +32,8 @@
>> #define TRACE_SEQ_POISON ((void *)0xdeadbeef)
>> #define TRACE_SEQ_CHECK(s) \
>> do { \
>> - if ((s)->buffer == TRACE_SEQ_POISON) \
>> - die("Usage of trace_seq after it was destroyed"); \
>> + if ((s)->buffer == TRACE_SEQ_POISON) \
>> + (s)->state = TRACE_SEQ__BUFFER_POISONED; \
>
> So unless we use trace_seq_do_printf we dont have any
> notification that this went wrong..?
Right.
>
> How about use some sort of WARN_ONCE any time the state
> is set != GOOD ?
I'm not sure what's the right thing to do for that case. Printing a
warning message might disturb user's output since it can be in a middle
of some (other) processing and she doesn't want to print anything during
the processing for some reason.
I just thought that it's not so important to print message so keeps the
error internally until it gets printed. But I can be wrong as usual...
Thanks,
Namhyung
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq
2014-01-06 7:44 ` Namhyung Kim
@ 2014-01-06 14:38 ` Jiri Olsa
2014-01-06 14:45 ` Steven Rostedt
0 siblings, 1 reply; 10+ messages in thread
From: Jiri Olsa @ 2014-01-06 14:38 UTC (permalink / raw)
To: Namhyung Kim
Cc: Steven Rostedt, Arnaldo Carvalho de Melo, Frederic Weisbecker,
Peter Zijlstra, Ingo Molnar, Namhyung Kim, LKML
On Mon, Jan 06, 2014 at 04:44:18PM +0900, Namhyung Kim wrote:
SNIP
> >> + (s)->state = TRACE_SEQ__BUFFER_POISONED; \
> >
> > So unless we use trace_seq_do_printf we dont have any
> > notification that this went wrong..?
>
> Right.
>
> >
> > How about use some sort of WARN_ONCE any time the state
> > is set != GOOD ?
>
> I'm not sure what's the right thing to do for that case. Printing a
> warning message might disturb user's output since it can be in a middle
> of some (other) processing and she doesn't want to print anything during
> the processing for some reason.
>
> I just thought that it's not so important to print message so keeps the
> error internally until it gets printed. But I can be wrong as usual...
I think that if she manages to get one of those errors
the perf would fail soon anyway.. so it feels better
to print it out immediately.
jirka
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq
2014-01-06 14:38 ` Jiri Olsa
@ 2014-01-06 14:45 ` Steven Rostedt
2014-01-07 2:48 ` Namhyung Kim
0 siblings, 1 reply; 10+ messages in thread
From: Steven Rostedt @ 2014-01-06 14:45 UTC (permalink / raw)
To: Jiri Olsa
Cc: Namhyung Kim, Arnaldo Carvalho de Melo, Frederic Weisbecker,
Peter Zijlstra, Ingo Molnar, Namhyung Kim, LKML
On Mon, 6 Jan 2014 15:38:28 +0100
Jiri Olsa <jolsa@redhat.com> wrote:
> > I just thought that it's not so important to print message so keeps the
> > error internally until it gets printed. But I can be wrong as usual...
>
> I think that if she manages to get one of those errors
> the perf would fail soon anyway.. so it feels better
> to print it out immediately.
Yeah, using a trace_seq after it has been destroyed is a critical
failure, and a major bug. A print to the user console should not be a
problem here. And actually, crashing is not that bad either, as glibc
does the same with using free() of a freed pointer.
But as this error is major, an unwanted print is minor.
-- Steve
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH 1/4] tools lib traceevent: Add state member to struct trace_seq
2014-01-06 14:45 ` Steven Rostedt
@ 2014-01-07 2:48 ` Namhyung Kim
0 siblings, 0 replies; 10+ messages in thread
From: Namhyung Kim @ 2014-01-07 2:48 UTC (permalink / raw)
To: Steven Rostedt
Cc: Jiri Olsa, Namhyung Kim, Arnaldo Carvalho de Melo,
Frederic Weisbecker, Peter Zijlstra, Ingo Molnar, LKML
Hi Steve and Jiri,
2014-01-06 PM 11:45, Steven Rostedt wrote:
> On Mon, 6 Jan 2014 15:38:28 +0100
> Jiri Olsa <jolsa@redhat.com> wrote:
>
>
>>> I just thought that it's not so important to print message so keeps the
>>> error internally until it gets printed. But I can be wrong as usual...
>>
>> I think that if she manages to get one of those errors
>> the perf would fail soon anyway.. so it feels better
>> to print it out immediately.
>
> Yeah, using a trace_seq after it has been destroyed is a critical
> failure, and a major bug. A print to the user console should not be a
> problem here. And actually, crashing is not that bad either, as glibc
> does the same with using free() of a freed pointer.
>
> But as this error is major, an unwanted print is minor.
OK, I'll add the WARN_ONCE in the TRACE_SEQ_CHECK then.
Thanks,
Namhyung
^ permalink raw reply [flat|nested] 10+ messages in thread