Sorry for the late review, I was busy getting ready for kernel summit and then traveling too much.
On Fri, 18 Oct 2013 17:59:42 -0300 "Geyslan G. Bem" <[email protected]> wrote: > In 'system_tr_open()': > Fix possible 'dir' assignment after freeing it. > > In both functions: > Restructures logic conditions testing 'tracing_is_disabled()' > return before the others tests. > Centralizes the exiting in accordance to Coding Style, Chapter 7. > > Signed-off-by: Geyslan G. Bem <[email protected]> > --- > kernel/trace/trace_events.c | 46 > +++++++++++++++++++++++---------------------- > 1 file changed, 24 insertions(+), 22 deletions(-) > > diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c > index 368a4d5..0f56ebf 100644 > --- a/kernel/trace/trace_events.c > +++ b/kernel/trace/trace_events.c > @@ -1060,7 +1060,10 @@ static int subsystem_open(struct inode *inode, struct > file *filp) > struct event_subsystem *system = NULL; > struct ftrace_subsystem_dir *dir = NULL; /* Initialize for gcc */ > struct trace_array *tr; > - int ret; > + int ret = -ENODEV; > + > + if (tracing_is_disabled()) > + return ret; > > /* Make sure the system still exists */ > mutex_lock(&trace_types_lock); > @@ -1082,23 +1085,21 @@ static int subsystem_open(struct inode *inode, struct > file *filp) > mutex_unlock(&trace_types_lock); > > if (!system) > - return -ENODEV; > + return ret; > > /* Some versions of gcc think dir can be uninitialized here */ > WARN_ON(!dir); > > /* Still need to increment the ref count of the system */ > - if (trace_array_get(tr) < 0) { > - put_system(dir); > - return -ENODEV; > - } > + ret = trace_array_get(tr); > + if (ret) > + goto err_get; > > - ret = tracing_open_generic(inode, filp); > - if (ret < 0) { > - trace_array_put(tr); > - put_system(dir); > - } > + filp->private_data = dir; > + return 0; > > +err_get: > + put_system(dir); > return ret; I don't see any improvement in the above code, except for the initial check of tracing_is_disabled(). Just add: if (tracing_is_disabled()) return -ENODEV; no need for all the fancy work with using ret and goto. > } > > @@ -1106,28 +1107,29 @@ static int system_tr_open(struct inode *inode, struct > file *filp) > { > struct ftrace_subsystem_dir *dir; > struct trace_array *tr = inode->i_private; > - int ret; > + int ret = -ENODEV; > > - if (trace_array_get(tr) < 0) > - return -ENODEV; > + if (tracing_is_disabled()) > + return ret; > + > + ret = trace_array_get(tr); > + if (ret) > + return ret; > > /* Make a temporary dir that has no system but points to tr */ > dir = kzalloc(sizeof(*dir), GFP_KERNEL); > if (!dir) { > - trace_array_put(tr); > - return -ENOMEM; > + ret = -ENOMEM; > + goto err_dir; > } > > dir->tr = tr; > > - ret = tracing_open_generic(inode, filp); > - if (ret < 0) { > - trace_array_put(tr); > - kfree(dir); > - } > - > filp->private_data = dir; > + return 0; > Again, we don't need the goto and err_dir. The simple fix is to finish the function with: ret = tracing_open_generic(inode, filp); if (ret < 0) { trace_array_put(tr); kfree(dir); return ret; } filp->private_data = dir; return 0; -- Steve > +err_dir: > + trace_array_put(tr); > return ret; > } > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
