Fix: header size larger than 256 bytes

When adding large context (e.g. callstack), headers larger than 256
bytes cause discrepancy between calculated size and size written into
the trace buffers. This generates a corrupted trace and triggers a
warning in ring buffer backend, which triggers a safety net disabling
tracing for the current channel.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>

diff --git a/liblttng-ust/lttng-ring-buffer-client.h b/liblttng-ust/lttng-ring-buffer-client.h
index 70235b8a812508bebdee4c456a312a8f0ce6a4dc..3f1e2656437a13b20d4fcbfd8f2b429622b83c78 100644 (file)
--- a/liblttng-ust/lttng-ring-buffer-client.h
+++ b/liblttng-ust/lttng-ring-buffer-client.h
@@ -110,7 +110,7 @@ void ctx_record(struct lttng_ust_lib_ring_buffer_ctx *bufctx,
  * contains.
  */
 static __inline__
-unsigned char record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
+size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
                                 struct channel *chan, size_t offset,
                                 size_t *pre_header_padding,
                                 struct lttng_ust_lib_ring_buffer_ctx *ctx)

diff --git a/liblttng-ust/lttng-ring-buffer-metadata-client.h b/liblttng-ust/lttng-ring-buffer-metadata-client.h
index ed8db359fa1a089563ec09652b8b2e167d959bf5..f3c4a67c8843ea0e9514ff994e04ed16ef979c08 100644 (file)
--- a/liblttng-ust/lttng-ring-buffer-metadata-client.h
+++ b/liblttng-ust/lttng-ring-buffer-metadata-client.h
@@ -52,7 +52,7 @@ static inline uint64_t lib_ring_buffer_clock_read(struct channel *chan)
 }
 
 static inline
-unsigned char record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
+size_t record_header_size(const struct lttng_ust_lib_ring_buffer_config *config,
                                 struct channel *chan, size_t offset,
                                 size_t *pre_header_padding,
                                 struct lttng_ust_lib_ring_buffer_ctx *ctx)