On Fri, Jan 15, 2021 at 04:49:57PM -0800, Randy Dunlap wrote: > Hi, > > On 1/15/21 4:12 PM, Wei Liu wrote: > > For built-in drivers, the order of initialization function invocation is > > determined by their link order. > > > > The original code linked TPM drivers before TEE driver when they were > > both built in. That caused fTPM's initialization to be deferred to a > > worker thread instead of running on PID 1. > > > > That is problematic because IMA's initialization routine, which runs on > > PID 1 as a late initcall, needs to have access to the default TPM > > instance. If fTPM's initialization is deferred, IMA will not be able to > > get hold of a TPM instance in time. > > > > Fix this by modifying Makefile to make sure TEE is initialized before > > fTPM when they are both built in. > > > > Signed-off-by: Wei Liu <wei....@kernel.org> > > --- > > drivers/Makefile | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/drivers/Makefile b/drivers/Makefile > > index fd11b9ac4cc3..45ea5ec9d0fd 100644 > > --- a/drivers/Makefile > > +++ b/drivers/Makefile > > @@ -180,6 +180,11 @@ obj-$(CONFIG_NVMEM) += nvmem/ > > obj-$(CONFIG_FPGA) += fpga/ > > obj-$(CONFIG_FSI) += fsi/ > > obj-$(CONFIG_TEE) += tee/ > > + > > +# TPM drivers must come after TEE, otherwise fTPM initialization will be > > +# deferred, which causes IMA to not get a TPM device in time > > +obj-$(CONFIG_TCG_TPM) += char/tpm/ > > + > > obj-$(CONFIG_MULTIPLEXER) += mux/ > > obj-$(CONFIG_UNISYS_VISORBUS) += visorbus/ > > obj-$(CONFIG_SIOX) += siox/ > > > > As I suspected and then tested, since you did not remove the other build > of char/tpm/, this ends up with multiple definition linker errors (below).
Oops, I didn't commit the hunk that removed the line in char/Makefile. But I will hold off sending out v2 until the following discussion is settled. > > I would think that instead of depending on Makefile order you should use > different > initcall levels as needed. Depending on Makefile order is what we did 15 > years ago. > No, not really. The same trick was used in 2014 (1bacc894c227). Both TEE and TPM are just drivers. I think they belong to the same level (at the moment device_initcall). Looking at the list of levels, I'm not sure how I can move TEE to a different level. Out of the seven levels, which one would you suggest I use for which driver? Wei.
