tracing: protect reader of cmdline output
authorSteven Rostedt <srostedt@redhat.com>
Mon, 16 Mar 2009 23:20:15 +0000 (19:20 -0400)
committerSteven Rostedt <srostedt@redhat.com>
Tue, 17 Mar 2009 03:27:06 +0000 (23:27 -0400)
commit4ca530852346be239b7c19e7bec5d2b78855bebe
tree96e5252faaf362115a96ed6df7c4e4f698a027dc
parent03303549b1695dc024d4a653cc16bd79f78f9750
tracing: protect reader of cmdline output

Impact: fix to one cause of incorrect comm outputs in trace

The spinlock only protected the creation of a comm <=> pid pair.
But it was possible that a reader could look up a pid, and get the
wrong comm because it had no locking.

This also required changing trace_find_cmdline to copy the comm cache
and not just send back a pointer to it.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
kernel/trace/blktrace.c
kernel/trace/trace.c
kernel/trace/trace.h
kernel/trace/trace_functions_graph.c
kernel/trace/trace_output.c