tpm: Begin the process to deprecate user_read_timer
authorJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Tue, 24 Jan 2017 00:06:08 +0000 (17:06 -0700)
committerJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Fri, 3 Feb 2017 20:03:14 +0000 (22:03 +0200)
commitfa2825da6f5d6d45122bd990958970a175fb1aef
treecd28b41d6ee01e2482d54715076a24040b1baa6d
parent1d1915532b3fb0d08aed8b2d8af1c6ea40846782
tpm: Begin the process to deprecate user_read_timer

For a long time the cdev read/write interface had this strange
idea that userspace had to read the result within 60 seconds otherwise
it is discarded. Perhaps this made sense under some older locking regime,
but in the modern kernel it is not required and is just dangerous.

Since something may be relying on this, double the timeout and print a
warning. We can remove the code in a few years, but this should be
enough to prevent new users.

Suggested-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
drivers/char/tpm/tpm-dev.c