On Fri, Apr 28, 2017 at 03:39:05PM -0600, Jason Gunthorpe wrote: > On Fri, Apr 28, 2017 at 02:32:31PM -0700, Josh Zimmerman wrote: > > On Fri, Apr 28, 2017 at 11:43 AM, Jason Gunthorpe > > <[email protected]> wrote: > > > On Fri, Apr 28, 2017 at 11:27:16AM -0700, Josh Zimmerman wrote: > > >> It sounds like there are several intertwined issues here. I'd like to > > >> keep this patch relatively minimal, so here are my current thoughts on > > >> a path forward: > > >> > > >> * Refactor references to chip->ops to go through tpm_try_get_ops, as > > >> mentioned in the previous patch > > > > > > As I said, if you rely on the fact that sysfs does not exist for TPM2 > > > then this should already be done for the TPM2 case and an incremental > > > later patch could solve this problem in sysfs to turn shutdown on for > > > tpm1. As long as this logic is clearly documented it is probably an OK > > > step for now. > > > > This I'm not actually sure about: it seems that there are other places > > than sysfs where chip->ops is referenced without being guarded by > > tpm_try_get_ops. If we rely on just NULLing out chip->ops this could > > be dangerous. I'll look at sending a patch for this first. > > If that is the case then we have an existing bug.. > > The only other user entry point is via the cdev, and those call > try_get_ops around all calls down into the tpm code. > > Everything coming in via the kapi must call tpm_chip_find_get, which > does try_get_ops.
See the comment in tpm_sysfs_add_device. /Jarkko ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ tpmdd-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/tpmdd-devel
