tpm: remove redundant variable len

Variable len is being accumulated but the value is never read. It is
redundant and can be removed. Cleans up clang scan build warning:

drivers/char/tpm/eventlog/tpm1.c:276:2: warning: Value stored to 'len' is never read [deadcode.DeadStores]

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

tpm: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
by explicitly adding a break statement instead of letting the code fall
through to the next case.

Link: https://github.com/KSPP/linux/issues/115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>

tpm: tpm1_bios_measurements_next should increase position index

If .next function does not change position index,
following .show function will repeat output related
to current position index.

In case of /sys/kernel/security/tpm0/ascii_bios_measurements
and binary_bios_measurements:
1) read after lseek beyound end of file generates whole last line.
2) read after lseek to middle of last line generates
expected end of last line and unexpected whole last line once again.

Cc: stable@vger.kernel.org # 4.19.x
Fixes: 1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code ...")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152

Based on 1 normalized pattern(s):

this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation either version 2 of the license or at
your option any later version

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tpm: Fix off-by-one when reading binary_bios_measurements

It is unable to read the entry when it is the only one in
binary_bios_measurements:

00000000 00 00 00 00 08 00 00 00 c4 2f ed ad 26 82 00 cb
00000010 1d 15 f9 78 41 c3 44 e7 9d ae 33 20 00 00 00 00
00000020

This is obviously a firmware problem on my linux machine:

Manufacturer: Inspur
Product Name: SA5212M4
Version: 01

However, binary_bios_measurements should return it any way,
rather than nothing, after all its content is completely
valid.

Fixes: 55a82ab3181b ("tpm: add bios measurement log")
Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Reviewd-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

tpm: Simplify the measurements loop

The responsibility of tpm1_bios_measurements_start() is to walk over the
first *pos measurements, ensuring the skipped and to-be-read
measurements are not out-of-boundary.

This commit simplifies the loop by employing a do-while loop with
the necessary sanity check.

Signed-off-by: Jia Zhang <zhang.jia@linux.alibaba.com>
Reviewd-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

tpm: Move eventlog declarations to its own header

Reduce the size of tpm.h by moving eventlog declarations to a separate
header.

Signed-off-by: Thiebaud Weksteen <tweek@google.com>
Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

tpm: Move shared eventlog functions to common.c

Functions and structures specific to TPM1 are renamed from tpm* to tpm1*.

Signed-off-by: Thiebaud Weksteen <tweek@google.com>
Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

tpm: Move eventlog files to a subdirectory

Signed-off-by: Thiebaud Weksteen <tweek@google.com>
Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>