Messages in this thread | | | Date | Tue, 21 Nov 2023 10:20:43 +0000 | From | "Russell King (Oracle)" <> | Subject | Re: [RFC PATCH net-next v2 04/10] net: sfp: Add helper to return the SFP bus name |
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On Tue, Nov 21, 2023 at 02:00:58AM +0100, Andrew Lunn wrote: > > +const char *sfp_get_name(struct sfp_bus *bus) > > +{ > > + if (bus->sfp_dev) > > + return dev_name(bus->sfp_dev); > > + > > + return NULL; > > +} > > Locking? Do you assume rtnl? Does this function need to take rtnl?
Yes, rtnl needs to be held to safely access bus->sfp_dev, and that either needs to happen in this function, or be documented as being requried (and ASSERT_RTNL() added here.)
The reason is that sfp_dev is the SFP socket device which can be unbound via sfp_unregister_socket(), which will set bus->sfp_dev to NULL. This could race with the above.
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