| Age | Commit message (Collapse) | Author |
|---|
|
initialized
The Tausworthe PRNG is initialized at late_initcall time. At that time the
entropy pool serving get_random_bytes is not filled sufficiently. This
patch adds an additional reseeding step as soon as the nonblocking pool
gets marked as initialized.
On some machines it might be possible that late_initcall gets called after
the pool has been initialized. In this situation we won't reseed again.
(A call to prandom_seed_late blocks later invocations of early reseed
attempts.)
Joint work with Daniel Borkmann.
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Acked-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Commit b5b4bb3f6a11f9 (of: only include prom.h on sparc) removed implicit
includes of of_*.h headers by powerpc's prom.h. Some components were
missed in initial clean-up patch, so add the necessary includes to fix
powerpc builds.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Vinod Koul <vinod.koul@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-ide@vger.kernel.org
Cc: linux-crypto@vger.kernel.org
|
|
|
|
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
Since we initialize jiffies to wrap five minutes before boot (see
INITIAL_JIFFIES defined in include/linux/jiffies.h) it's important to
make sure the last_time field is initialized to INITIAL_JIFFIES.
Otherwise, the entropy estimator will overestimate the amount of
entropy resulting from the first call to add_timer_randomness(),
generally by about 8 bits.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
The rand_initialize() function was being run fairly late in the kernel
boot sequence. This was unfortunate, since it zero'ed the entropy
counters, thus throwing away credit that was accumulated earlier in
the boot sequence, and it also meant that initcall functions run
before rand_initialize were using a minimally initialized pool.
To fix this, fix init_std_data() to no longer zap the entropy counter;
it wasn't necessary, and move rand_initialize() to be an early
initcall.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
Print a notification to the console when the nonblocking pool is
initialized. Also printk a warning when a process tries reading from
/dev/urandom before it is fully initialized.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
Change add_timer_randomness() so that it directs incoming entropy to
the nonblocking pool first if it hasn't been fully initialized yet.
This matches the strategy we use in add_interrupt_randomness(), which
allows us to push the randomness where we need it the most during when
the system is first booting up, so that get_random_bytes() and
/dev/urandom become safe to use as soon as possible.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
This adds a driver for hardware random number generator present
on Qualcomm MSM SoC's.
Signed-off-by: Stanimir Varbanov <svarbanov@mm-sol.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
|
|
If virtqueue_get_buf() returns with a NULL pointer it should be verified
if the virtqueue is broken, in order to avoid loop calling cpu_relax().
Signed-off-by: Heinz Graalfs <graalfs@linux.vnet.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
|
|
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|
|
just like the other entries
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
|
|
This patch changes the displayed module name from
tpm_tis_i2c_infineon to its actual name tpm_i2c_infineon.
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
|
|
This is based on the work of Teddy Reed <teddy@prosauce.org> published
on GitHub:
https://github.com/theopolis/tpm-i2c-atmel.git
34894b988b67e0ae55088d6388e77b0dbf10c07d
That driver was never merged, I have taken it as a starting port,
forward ported, tested and revised the driver:
- Make it broadly textually similar to the Infineon and Nuvoton I2C
driver
- Place everything in a format suitable for mainline inclusion
- Use high level I2C functions i2c_master_send and
i2c_master_recv for data xfer
- Use the timeout system from the core code, by faking out a status
register
- Only I2C transfer the number of bytes in the reply, not a fixed
message size.
- checkpatch cleanups
- Testing on ARM Kirkwood, with this device tree, using a
AT97SC3204T-X1A180
tpm@29 {
compatible = "atmel,at97sc3204t";
reg = <0x29>;
};
Signed-off-by: Teddy Reed <teddy@prosauce.org>
[jgg: revised and tested]
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
[phuewe: minor whitespace changes]
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
|
|
This chip is/was also branded as a Winbond WPCT301.
Originally written by Dan Morav <dmorav@nuvoton.com> and posted to LKML:
https://lkml.org/lkml/2011/9/7/206
The original posting was not merged, I have taken it as a
starting point, forward ported, tested and revised the driver:
- Rework interrupt handling to work properly with level triggered
interrupts. The old version just locked up.
- Synchronize various items with Peter Huewe's Infineon driver:
* Add durations/timeouts sysfs calls
* Remove I2C device auto-detection
* Don't fiddle with chip->release
* Call tpm_dev_vendor_release in the probe error path
* Use MODULE_DEVICE_TABLE for the I2C ids
* Provide OF compatible strings for DT support
* Use SIMPLE_DEV_PM_OPS
* Use module_i2c_driver
- checkpatch cleanups
- Testing on ARM Kirkwood with GPIO interrupts, with this device tree:
tpm@57 {
compatible = "nuvoton,npct501";
reg = <0x57>;
interrupt-parent = <&gpio1>;
interrupts = <6 IRQ_TYPE_LEVEL_LOW>;
};
Signed-off-by: Dan Morav <dmorav@nuvoton.com>
[jgg: revised and tested]
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
[phuewe: minor whitespace changes, fixed module name in kconfig]
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
|
|
Now that we can have multiple .c files in the tpm module there is
no reason for tpm-bios.
tpm-bios exported several functions: tpm_bios_log_setup,
tpm_bios_log_teardown, tpm_add_ppi, and tpm_remove_ppi.
They are only used by tpm, and if tpm-bios is built then
tpm will unconditionally require them. Further, tpm-bios does
nothing on its own, it has no module_init function.
Thus we remove the exports and merge the modules to simplify things.
The Makefile conditions are changed slightly to match the code,
tpm_ppi is always required if CONFIG_ACPI is set.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
|
|
This is preparation for making the tpm module multi-file. kbuild does
not like having a .c file with the same name as a module. We wish to
keep the tpm module name so that userspace doesn't see this change.
tpm-interface.c is chosen because the next several commits in the series
migrate items into tpm-sysfs.c, tpm-dev.c and tpm-class.c. All that will
be left is tpm command processing and interfacing code.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
|
|
before we rename the file it might be a good idea to cleanup the long
persisting checkpatch warnings.
Since everything is really trivial, splitting the patch up would only
result in noise.
For the interested reader - here the checkpatch warnings:
(regrouped for easer readability)
ERROR: trailing whitespace
+ * Specifications at www.trustedcomputinggroup.org^I $
+ * $
+^I/* $
+^I parameters (RSA 12->bytes: keybit, #primes, expbit) $
WARNING: unnecessary whitespace before a quoted newline
+ "invalid count value %x %zx \n", count, bufsiz);
ERROR: do not use assignment in if condition
+ if ((rc = chip->vendor.send(chip, (u8 *) buf, count)) < 0) {
ERROR: space required after that ',' (ctx:VxV)
+ len = tpm_transmit(chip,(u8 *) cmd, len);
^
ERROR: "foo * bar" should be "foo *bar"
+ssize_t tpm_show_enabled(struct device * dev, struct device_attribute * attr,
+ssize_t tpm_show_enabled(struct device * dev, struct device_attribute * attr,
+ssize_t tpm_show_active(struct device * dev, struct device_attribute * attr,
+ssize_t tpm_show_active(struct device * dev, struct device_attribute * attr,
+ssize_t tpm_show_owned(struct device * dev, struct device_attribute * attr,
+ssize_t tpm_show_owned(struct device * dev, struct device_attribute * attr,
+ssize_t tpm_show_temp_deactivated(struct device * dev,
+ struct device_attribute * attr, char *buf)
WARNING: please, no space before tabs
+ * @chip_num: ^Itpm idx # or ANY$
+ * @res_buf: ^ITPM_PCR value$
+ * ^I^Isize of res_buf is 20 bytes (or NULL if you don't care)$
+ * @chip_num: ^Itpm idx # or AN&$
+ * @hash: ^Ihash value used to extend pcr value$
ERROR: code indent should use tabs where possible
+^I TPM_ORD_CONTINUE_SELFTEST);$
WARNING: line over 80 characters
+static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask, bool check_cancel,
ERROR: trailing whitespace
+ * Called from tpm_<specific>.c probe function only for devices $
total: 16 errors, 7 warnings, 1554 lines checked
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
|
|
The version of the TPM should not depend on the bus it is connected
through. 1.1, 1.2 and soon 2.0 TPMS will be all be able to use the
same bus interfaces.
Make tpm_show_caps try the 1.2 capability first. If that fails then
fall back to the 1.1 capability. This effectively auto-detects what
interface the TPM supports at run-time.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Reviewed-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
|
|
For some reason this driver thinks that chip->data_buffer needs
to be set before it can call tpm_pm_*. This is not true. data_buffer
is used only by /dev/tpmX, which is why it is managed exclusively
by the fops functions.
Cc: Mathias Leblanc <mathias.leblanc@st.com>
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
|
|
TPM drivers should not call dev_set_drvdata (or aliases), only the core
code is allowed to call dev_set_drvdata, and it does it during
tpm_register_hardware.
These extra sets are harmless, but are an anti-pattern that many drivers
have copied.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Reviewed-by: Peter Huewe <peterhuewe@gmx.de>
Acked-by: Ashley Lai <adlai@linux.vnet.ibm.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
|
|
misc_open sets the file->private_date to the misc_dev when calling
open. We can use container_of to go from the misc_dev back to the
tpm_chip.
Future clean ups will move tpm_open into a new file and this change
means we do not have to export the tpm_chip list.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Reviewed-by: Peter Huewe <peterhuewe@gmx.de>
Acked-by: Ashley Lai <adlai@linux.vnet.ibm.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
|
|
Just put the memory directly in the chip structure, rather than
in a 2nd dedicated kmalloc.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Reviewed-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Acked-by: Ashley Lai <adlai@linux.vnet.ibm.com>
|
|
Commit e0dd03caf20d040a0a86 ("tpm: return chip from
tpm_register_hardware") changed the code path here so that
ateml_get_base_addr no longer directly altered the tpm_vendor_specific
structure, and instead placed the base address on the stack.
The commit missed updating the request_region call, which would have
resulted in request_region being called with 0 as the base address.
I don't know if request_region(0, ..) will fail, if so the
driver has been broken since 2006 and we should remove it
from the tree as it has no users.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Reviewed-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
|
|
This suppresses compile warnings on 32 bit builds.
Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Joel Schopp <jschopp@linux.vnet.ibm.com>
Reviewed-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Acked-by: Ashley Lai <adlai@linux.vnet.ibm.com>
|
|
We want the fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
This lets the transport do endian conversion if necessary, and insulates
the drivers from the difference.
Most drivers can use the simple helpers virtio_cread() and virtio_cwrite().
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
|
|
This patch proposes to remove the use of the IRQF_DISABLED flag
It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
This patch proposes to remove the use of the IRQF_DISABLED flag
It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
This patch proposes to remove the use of the IRQF_DISABLED flag
It's a NOOP since 2.6.35 and it will be removed one day.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
This driver provides kernel-side support for the Random Number
Generator hardware found on OMAP34xx processors.
This driver comes from Maemo 2.6.28 kernel and was tested on Nokia RX-51.
It is platform device because it needs board specific function for smc calls.
Signed-off-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull Xen fixes from Stefano Stabellini:
"A small fix for Xen on x86_32 and a build fix for xen-tpmfront on
arm64"
* tag 'stable/for-linus-3.12-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen: Fix possible user space selector corruption
tpm: xen-tpmfront: fix missing declaration of xen_domain
|
|
Add a driver for the hwrng found in power7+ systems, based on the
existing code for the arch_get_random_long() hook.
We only register a single instance of the driver, not one per device,
because we use the existing per_cpu array of devices in the arch code.
This means we always read from the "closest" device, avoiding inter-chip
memory traffic.
Signed-off-by: Guo Chao <yan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
|
|
We don't expect to get errors from the hypervisor when reading the rng,
but if we do we should pass the error up to the hwrng driver. Otherwise
the hwrng driver will continue calling us forever.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull /dev/random changes from Ted Ts'o:
"These patches are designed to enable improvements to /dev/random for
non-x86 platforms, in particular MIPS and ARM"
* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
random: allow architectures to optionally define random_get_entropy()
random: run random_int_secret_init() run after all late_initcalls
|
|
Instead of using the random driver's ad-hoc DEBUG_ENT() mechanism, use
tracepoints instead. This allows for a much more fine-grained control
of which debugging mechanism which a developer might need, and unifies
the debugging messages with all of the existing tracepoints.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
As the input pool gets filled, start transfering entropy to the output
pools until they get filled. This allows us to use the output pools
to store more system entropy. Waste not, want not....
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
The add_timer_randomness() used to drop into trickle mode when entropy
pool was estimated to be 87.5% full. This was important when
add_timer_randomness() was used to sample interrupts. It's not used
for this any more --- add_interrupt_randomness() now uses fast_mix()
instead. By elimitating trickle mode, it allows us to fully utilize
entropy provided by add_input_randomness() and add_disk_randomness()
even when the input pool is above the old trickle threshold of 87.5%.
This helps to answer the criticism in [1] in their hypothetical
scenario where our entropy estimator was inaccurate, even though the
measurements in [2] seem to indicate that our entropy estimator given
real-life entropy collection is actually pretty good, albeit on the
conservative side (which was as it was designed).
[1] http://eprint.iacr.org/2013/338.pdf
[2] http://eprint.iacr.org/2012/251.pdf
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
Our mixing functions were analyzed by Lacharme, Roeck, Strubel, and
Videau in their paper, "The Linux Pseudorandom Number Generator
Revisited" (see: http://eprint.iacr.org/2012/251.pdf).
They suggested a slight change to improve our mixing functions
slightly. I also adjusted the comments to better explain what is
going on, and to document why the polynomials were changed.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
By mixing the entropy in chunks of 32-bit words instead of byte by
byte, we can speed up the fast_mix function significantly. Since it
is called on every single interrupt, on systems with a very heavy
interrupt load, this can make a noticeable difference.
Also fix a compilation warning in add_interrupt_randomness() and avoid
xor'ing cycles and jiffies together just in case we have an
architecture which tries to define random_get_entropy() by returning
jiffies.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reported-by: Jörn Engel <joern@logfs.org>
|
|
In order to avoid draining the input pool of its entropy at too high
of a rate, enforce a minimum time interval between reseedings of the
urandom pool. This is set to 60 seconds by default.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
Use smaller types to slightly shrink the size of the entropy store
structure.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
The add_device_randomness() function calls mix_pool_bytes() twice for
the input pool and the non-blocking pool, for a total of four times.
By using _mix_pool_byte() and taking the spinlock in
add_device_randomness(), we can halve the number of times we need
take each pool's spinlock.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
Fix a problem where get_random_bytes_arch() was calling the tracepoint
get_random_bytes(). So add a new tracepoint for
get_random_bytes_arch(), and make get_random_bytes() and
get_random_bytes_arch() call their correct tracepoint.
Also, add a new tracepoint for add_device_randomness()
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
When we write entropy into a non-empty pool, we currently don't
account at all for the fact that we will probabilistically overwrite
some of the entropy in that pool. This means that unless the pool is
fully empty, we are currently *guaranteed* to overestimate the amount
of entropy in the pool!
Assuming Shannon entropy with zero correlations we end up with an
exponentally decaying value of new entropy added:
entropy <- entropy + (pool_size - entropy) *
(1 - exp(-add_entropy/pool_size))
However, calculations involving fractional exponentials are not
practical in the kernel, so apply a piecewise linearization:
For add_entropy <= pool_size/2 then
(1 - exp(-add_entropy/pool_size)) >= (add_entropy/pool_size)*0.7869...
... so we can approximate the exponential with
3/4*add_entropy/pool_size and still be on the
safe side by adding at most pool_size/2 at a time.
In order for the loop not to take arbitrary amounts of time if a bad
ioctl is received, terminate if we are within one bit of full. This
way the loop is guaranteed to terminate after no more than
log2(poolsize) iterations, no matter what the input value is. The
vast majority of the time the loop will be executed exactly once.
The piecewise linearization is very conservative, approaching 3/4 of
the usable input value for small inputs, however, our entropy
estimation is pretty weak at best, especially for small values; we
have no handle on correlation; and the Shannon entropy measure (Rényi
entropy of order 1) is not the correct one to use in the first place,
but rather the correct entropy measure is the min-entropy, the Rényi
entropy of infinite order.
As such, this conservatism seems more than justified.
This does introduce fractional bit values. I have left it to have 3
bits of fraction, so that with a pool of 2^12 bits the multiply in
credit_entropy_bits() can still fit into an int, as 2*(3+12) < 31. It
is definitely possible to allow for more fractional accounting, but
that multiply then would have to be turned into a 32*32 -> 64 multiply.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: DJ Johnston <dj.johnston@intel.com>
|
|
Allow fractional bits of entropy to be tracked by scaling the entropy
counter (fixed point). This will be used in a subsequent patch that
accounts for entropy lost due to overwrites.
[ Modified by tytso to fix up a few missing places where the
entropy_count wasn't properly converted from fractional bits to
bits. ]
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Use a macro to statically compute poolbitshift (will be used in a
subsequent patch), poolbytes, and poolbits. On virtually all
architectures the cost of a memory load with an offset is the same as
the one of a memory load.
It is still possible for this to generate worse code since the C
compiler doesn't know the fixed relationship between these fields, but
that is somewhat unlikely.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
|
|
Previously if CPU chip had a built-in random number generator (i.e.,
RDRAND on newer x86 chips), we mixed it in at the very end of
extract_buf() using an XOR operation.
We now mix it in right after the calculate a hash across the entire
pool. This has the advantage that any contribution of entropy from
the CPU's HWRNG will get mixed back into the pool. In addition, it
means that if the HWRNG has any defects (either accidentally or
maliciously introduced), this will be mitigated via the non-linear
transform of the SHA-1 hash function before we hand out generated
output.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
|
|
Allow architectures which have a disabled get_cycles() function to
provide a random_get_entropy() function which provides a fine-grained,
rapidly changing counter that can be used by the /dev/random driver.
For example, an architecture might have a rapidly changing register
used to control random TLB cache eviction, or DRAM refresh that
doesn't meet the requirements of get_cycles(), but which is good
enough for the needs of the random driver.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org
|
|
xen-tpmfront fails to build on arm64 with the following error:
drivers/char/tpm/xen-tpmfront.c: In function ‘xen_tpmfront_init’:
drivers/char/tpm/xen-tpmfront.c:422:2: error: implicit declaration of function ‘xen_domain’ [-Werror=implicit-function-declaration]
Add include of xen/xen.h to fix this.
Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: Ashley Lai <adlai@linux.vnet.ibm.com>
Acked-by: Ashley Lai <adlai@linux.vnet.ibm.com>
Cc: Leonidas Da Silva Barbosa <leosilva@linux.vnet.ibm.com>
Cc: Rajiv Andrade <mail@srajiv.net>
Cc: Marcel Selhorst <tpmdd@selhorst.net>
Cc: Sirrix AG <tpmdd@sirrix.com>
Cc: tpmdd-devel@lists.sourceforge.net
|
