[ltt-dev] Assertion failure

[Mathieu Desnoyers]

* Klein, Russell (russell_klein at mentor.com) wrote:
> Mathieu,
> 
> Unfortunately not, this is the highest revision which is supported by
> the linux I am running.  I am willing to backport a fix if you can point
> me in the general direction.

See the following commit in the git tree:


commit 578e232ab4e234294d03fb7022863b45c801eaa1
Author: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>
Date:   Tue Aug 17 18:23:21 2010 -0400

    UST strncpy assert fix
    
    fix off by one in strncpy and write asserts(). Shows only when the event
    reserved fits the exact end of buffer.
    
    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>

diff --git a/libust/buffers.h b/libust/buffers.h
index 63449d6..9fedc48 100644
--- a/libust/buffers.h
+++ b/libust/buffers.h
@@ -522,7 +522,8 @@ static __inline__ int ust_buffers_write(struct ust_buffer *buf, size_t offset,
 	size_t buf_offset = BUFFER_OFFSET(offset, buf->chan);
 
 	assert(buf_offset < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
-	assert(buf_offset + len < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
+	assert(buf_offset + len
+	       <= buf->chan->subbuf_size*buf->chan->subbuf_cnt);
 
 	ust_buffers_do_copy(buf->buf_data + buf_offset, src, len);
 
@@ -590,7 +591,8 @@ int ust_buffers_strncpy(struct ust_buffer *buf, size_t offset, const void *src,
 	int terminated;
 
 	assert(buf_offset < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
-	assert(buf_offset + len < buf->chan->subbuf_size*buf->chan->subbuf_cnt);
+	assert(buf_offset + len
+	       <= buf->chan->subbuf_size*buf->chan->subbuf_cnt);
 
 	copied = ust_buffers_do_strncpy(buf->buf_data + buf_offset,
 				        src, len, &terminated);

-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com