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 | 42 ++++++++++++++++++++++++++++++++++----
2 files changed, 45 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..1747aa50ecb0 100644
--- a/tools/lib/traceevent/trace-seq.c
+++ b/tools/lib/traceevent/trace-seq.c
@@ -32,8 +32,9 @@
#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 (WARN_ONCE((s)->buffer == TRACE_SEQ_POISON, \
+ "Usage of trace_seq after it was destroyed")) \
+ (s)->state = TRACE_SEQ__BUFFER_POISONED; \
} while (0)
/**
@@ -46,6 +47,7 @@ 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 +83,7 @@ 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 +110,9 @@ 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 +149,9 @@ 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 +182,17 @@ 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 +203,15 @@ 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 +221,9 @@ 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 +231,16 @@ 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;
}
--
1.7.11.7
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