tracing: Fix fields of struct trace_iterator that are zeroed by mistake
authorAndrew Vagin <avagin@openvz.org>
Fri, 2 Aug 2013 17:16:43 +0000 (21:16 +0400)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 15 Aug 2013 05:59:07 +0000 (22:59 -0700)
commit2d7ddf0a8fa2cffded6b8785f16e0c08c66f5007
tree8542d2e7c90cf09ef0abf9fe4d2d7b9ed0a9a735
parentb97f921b94b1e70d5de999fd820ccf8504dc6528
tracing: Fix fields of struct trace_iterator that are zeroed by mistake

commit ed5467da0e369e65b247b99eb6403cb79172bcda upstream.

tracing_read_pipe zeros all fields bellow "seq". The declaration contains
a comment about that, but it doesn't help.

The first field is "snapshot", it's true when current open file is
snapshot. Looks obvious, that it should not be zeroed.

The second field is "started". It was converted from cpumask_t to
cpumask_var_t (v2.6.28-4983-g4462344), in other words it was
converted from cpumask to pointer on cpumask.

Currently the reference on "started" memory is lost after the first read
from tracing_read_pipe and a proper object will never be freed.

The "started" is never dereferenced for trace_pipe, because trace_pipe
can't have the TRACE_FILE_ANNOTATE options.

Link: http://lkml.kernel.org/r/1375463803-3085183-1-git-send-email-avagin@openvz.org

Signed-off-by: Andrew Vagin <avagin@openvz.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
include/linux/ftrace_event.h
kernel/trace/trace.c