Messages in this thread | | | Date | Wed, 23 Jan 2013 18:02:35 -0500 | From | Steven Rostedt <> | Subject | Re: [tracepoint] cargo-culting considered harmful... |
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On Wed, Jan 23, 2013 at 10:55:24PM +0000, Al Viro wrote: > In samples/tracepoints/tracepoint-probe-sample.c: > /* > * Here the caller only guarantees locking for struct file and struct inode. > * Locking must therefore be done in the probe to use the dentry. > */ > static void probe_subsys_event(void *ignore, > struct inode *inode, struct file *file) > { > path_get(&file->f_path); > dget(file->f_path.dentry); > printk(KERN_INFO "Event is encountered with filename %s\n", > file->f_path.dentry->d_name.name); > dput(file->f_path.dentry); > path_put(&file->f_path); > } > > note that > * file->f_path is already pinned down by open(), path_get() does not > provide anything extra. > * file->f_path.dentry is already pinned by open() *and* path_get() > just above that dget(). > * ->d_name.name *IS* *NOT* *PROTECTED* by pinning dentry down, > whether it's done once or thrice. > > I do realize that it's just an example, but perhaps we should rename that > file to match the contents? The only question is whether it should be > git mv samples/tracepoints/{tracepoint-probe-sample,cargo-cult}.c > or git mv samples cargo-cult...
I wonder if we should just remove the samples/tracepoints/ all together. The tracepoint code is now only used internally by the trace_event code, and there should not be any users of tracepoints directly.
-- Steve
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