Messages in this thread |  | | Date | Mon, 3 Oct 2016 15:42:25 +0300 | From | Jarkko Sakkinen <> | Subject | Re: [PATCH] tpm: don't destroy chip device prematurely |
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On Mon, Oct 03, 2016 at 07:38:44AM +0000, Winkler, Tomas wrote: > > > > > On Sun, Oct 02, 2016 at 01:24:55PM +0300, Jarkko Sakkinen wrote: > > > > On Sun, Oct 02, 2016 at 01:17:55PM +0300, Jarkko Sakkinen wrote: > > > > > On Sun, Oct 02, 2016 at 10:39:31AM +0300, Tomas Winkler wrote: > > > > > > In tpm_del_char_device device_del is called prior to > > > > > > tpm2_shutdown where it is still used. > > > > > > > > > > > > Fortunately, so far chip->dev was used only for printouts int > > > > > > tpm2_shutdown flow, hence system didn't crash. But with the > > > > > > introduction of runtime power management it will result in > > > > > > shutting down the parent device while it still in use. > > > > > > > > > > > > Fixes: 20e0152393b41 ("tpm: fix crash in tpm_tis > > > > > > deinitialization") > > > > > > Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> > > > > > > > > > > Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > > > > > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> > > > > > > > > Applied. > > > > > > This patch is wrong, I though the comments were clear. All entry > > > points to find the device must be deleted before we commit to shutting > > down the device. > > > > > > You need to figure out some other way to solve your problem. > > > > Please be more specific regarding flows you think will be wrong with this > > patch, you must agree that the current code is broken even w/o runtime pm. > > I've looked to the registration code and it indeed has few more issues > Maybe TPM_CHIP_FLAG_REGISTERED can be used for sealing the access to the device during deregistration, current usage is void.
Good catch BTW. This flag has gone quite obsolote.
/Jarkko
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