[PATCH][GIT PULL v2][v3.3] tracepoints/module: Fix disablingtracepoints with taint CRAP or OOT

[Steven Rostedt]

On Mon, 2012-01-16 at 08:24 +0100, Ingo Molnar wrote:
> * Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> 
> >  	/*
> >  	 * We skip modules that tain the kernel, especially those with different
> 
> While touching this commit we might as well fix the typo here?
> 
> >  	 * module header (for forced load), to make sure we don't cause a crash.
> 
> ... and the second typo as well?
> 
> > +	 * Staging and out-of-tree modules are fine.
> >  	 */
> 
> I'd phrase it as 'out-of-tree GPL modules'.

Thanks!

Updated:

Please pull the latest tip/perf/urgent-2 tree, which can be found at:

  git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
tip/perf/urgent-2

Head SHA1: c10076c4304083af15a41f6bc5e657e781c1f9a6


Steven Rostedt (1):
      tracepoints/module: Fix disabling tracepoints with taint CRAP or OOT

----
 kernel/tracepoint.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)
---------------------------
commit c10076c4304083af15a41f6bc5e657e781c1f9a6
Author: Steven Rostedt <srostedt@xxxxxxxxxx>
Date:   Fri Jan 13 21:40:59 2012 -0500

    tracepoints/module: Fix disabling tracepoints with taint CRAP or OOT
    
    Tracepoints are disabled for tainted modules, which is usually because the
    module is either proprietary or was forced, and we don't want either of them
    using kernel tracepoints.
    
    But, a module can also be tainted by being in the staging directory or
    compiled out of tree. Either is fine for use with tracepoints, no need
    to punish them.  I found this out when I noticed that my sample trace event
    module, when done out of tree, stopped working.
    
    Cc: stable@xxxxxxxxxxxxxxx # 3.2
    Cc: Mathieu Desnoyers <mathieu.desnoyers@xxxxxxxxxxxx>
    Cc: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
    Cc: Dave Jones <davej@xxxxxxxxxx>
    Cc: Greg Kroah-Hartman <gregkh@xxxxxxx>
    Cc: Rusty Russell <rusty@xxxxxxxxxxxxxxx>
    Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>

diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index db110b8..f1539de 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -634,10 +634,11 @@ static int tracepoint_module_coming(struct module *mod)
 	int ret = 0;
 
 	/*
-	 * We skip modules that tain the kernel, especially those with different
-	 * module header (for forced load), to make sure we don't cause a crash.
+	 * We skip modules that taint the kernel, especially those with different
+	 * module headers (for forced load), to make sure we don't cause a crash.
+	 * Staging and out-of-tree GPL modules are fine.
 	 */
-	if (mod->taints)
+	if (mod->taints & ~((1 << TAINT_OOT_MODULE) | (1 << TAINT_CRAP)))
 		return 0;
 	mutex_lock(&tracepoints_mutex);
 	tp_mod = kmalloc(sizeof(struct tp_module), GFP_KERNEL);

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