Ping!
On Thu, 19 Dec 2013 18:34:23 +0900, Namhyung Kim wrote:
> From: Namhyung Kim <namhyung....@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 <namhy...@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;
> }
--
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