Messages in this thread | | | Date | Sun, 25 Oct 2015 10:22:32 +0800 | From | Geliang Tang <> | Subject | Re: [PATCH 1/2] pstore: check PSTORE_FLAGS_FRAGILE in pstore_unregister |
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On Fri, Oct 23, 2015 at 09:54:31AM -0700, Kees Cook wrote: > On Fri, Oct 23, 2015 at 7:56 AM, Geliang Tang <geliangtang@163.com> wrote: > > When PSTORE_FLAGS_FRAGILE flag is set, only kmsg is registered in > > pstore_register. So, under these circumstances, only kmsg needs to > > be unregistered in pstore_unregister. > > > > Signed-off-by: Geliang Tang <geliangtang@163.com> > > Would it make more sense to have the pstore_unregister_* calls be > defensive, like kfree() is? In other words, it would be safe to call > them, even if they hadn't been registered? > > Either way, I'm fine with this. Good catch! > > -Kees >
Thanks for your reply.
pstore_unregister_* is defensive as you expected. I have tested it. it is safe to call them if they haven't been registered. This won't cause any trouble.
But logically, we should check this flag in pstore_unregister.
-Geliang Tang
> > --- > > fs/pstore/platform.c | 9 ++++++--- > > 1 file changed, 6 insertions(+), 3 deletions(-) > > > > diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c > > index 0aab920..7ad2038 100644 > > --- a/fs/pstore/platform.c > > +++ b/fs/pstore/platform.c > > @@ -496,9 +496,12 @@ EXPORT_SYMBOL_GPL(pstore_register); > > > > void pstore_unregister(struct pstore_info *psi) > > { > > - pstore_unregister_pmsg(); > > - pstore_unregister_ftrace(); > > - pstore_unregister_console(); > > + if ((psi->flags & PSTORE_FLAGS_FRAGILE) == 0) { > > + pstore_unregister_pmsg(); > > + pstore_unregister_ftrace(); > > + pstore_unregister_console(); > > + } > > + > > pstore_unregister_kmsg(); > > > > free_buf_for_compression(); > > -- > > 2.5.0 > > > > > > > > -- > Kees Cook > Chrome OS Security
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