Commit Graph

7228 Commits

Author SHA1 Message Date
Linus Torvalds
bfebeb1672 Merge tag 'rtc-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux
Pull RTC updates from Alexandre Belloni:
 "It is now possible to add custom sysfs attributes while avoiding a
  possible race condition. Unused code has been removed resulting in a
  nice reduction of the code base. And more drivers have been switched
  to SPDX by their maintainers.

 Summary:

  Subsystem:
   - new helpers to add custom sysfs attributes
   - struct rtc_task removal along with rtc_irq_[un]register()
   - rtc_irq_set_state and rtc_irq_set_freq are not exported anymore

  Drivers:
   - armada38x: reset after rtc power loss
   - ds1307: now supports m41t11
   - isl1208: now supports isl1219 and tamper detection
   - pcf2127: internal SRAM support"

* tag 'rtc-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux: (34 commits)
  rtc: ds1307: simplify hwmon config
  rtc: s5m: Add SPDX license identifier
  rtc: maxim: Add SPDX license identifiers
  rtc: isl1219: add device tree documentation
  rtc: isl1208: set ev-evienb bit from device tree
  rtc: isl1208: Add "evdet" interrupt source for isl1219
  rtc: isl1208: add support for isl1219 with tamper detection
  rtc: sysfs: facilitate attribute add to rtc device
  rtc: remove struct rtc_task
  char: rtc: remove task handling
  rtc: pcf85063: preserve control register value between stop and start
  rtc: sh: remove unused variable rtc_dev
  rtc: unexport rtc_irq_set_*
  rtc: simplify rtc_irq_set_state/rtc_irq_set_freq
  rtc: remove irq_task and irq_task_lock
  rtc: remove rtc_irq_register/rtc_irq_unregister
  rtc: sh: remove dead code
  rtc: sa1100: don't set PIE frequency
  rtc: ds1307: support m41t11 variant
  rtc: ds1307: fix data pointer to m41t0
  ...
2018-08-20 16:30:27 -07:00
Linus Torvalds
d5acba26bf Merge tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH:
 "Here is the bit set of char/misc drivers for 4.19-rc1

  There is a lot here, much more than normal, seems like everyone is
  writing new driver subsystems these days... Anyway, major things here
  are:

   - new FSI driver subsystem, yet-another-powerpc low-level hardware
     bus

   - gnss, finally an in-kernel GPS subsystem to try to tame all of the
     crazy out-of-tree drivers that have been floating around for years,
     combined with some really hacky userspace implementations. This is
     only for GNSS receivers, but you have to start somewhere, and this
     is great to see.

  Other than that, there are new slimbus drivers, new coresight drivers,
  new fpga drivers, and loads of DT bindings for all of these and
  existing drivers.

  All of these have been in linux-next for a while with no reported
  issues"

* tag 'char-misc-4.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (255 commits)
  android: binder: Rate-limit debug and userspace triggered err msgs
  fsi: sbefifo: Bump max command length
  fsi: scom: Fix NULL dereference
  misc: mic: SCIF Fix scif_get_new_port() error handling
  misc: cxl: changed asterisk position
  genwqe: card_base: Use true and false for boolean values
  misc: eeprom: assignment outside the if statement
  uio: potential double frees if __uio_register_device() fails
  eeprom: idt_89hpesx: clean up an error pointer vs NULL inconsistency
  misc: ti-st: Fix memory leak in the error path of probe()
  android: binder: Show extra_buffers_size in trace
  firmware: vpd: Fix section enabled flag on vpd_section_destroy
  platform: goldfish: Retire pdev_bus
  goldfish: Use dedicated macros instead of manual bit shifting
  goldfish: Add missing includes to goldfish.h
  mux: adgs1408: new driver for Analog Devices ADGS1408/1409 mux
  dt-bindings: mux: add adi,adgs1408
  Drivers: hv: vmbus: Cleanup synic memory free path
  Drivers: hv: vmbus: Remove use of slow_virt_to_phys()
  Drivers: hv: vmbus: Reset the channel callback in vmbus_onoffer_rescind()
  ...
2018-08-18 11:04:51 -07:00
Linus Torvalds
c715ebeb03 Merge branch 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull TPM updates from James Morris:

 - Migrate away from PM runtime as explicit cmdReady/goIdle transactions
   for every command is a spec requirement. PM runtime adds only a layer
   of complexity on our case.

 - tpm_tis drivers can now specify the hwrng quality.

 - TPM 2.0 code uses now tpm_buf for constructing messages. Jarkko
   thinks Tomas Winkler has done the same for TPM 1.2, and will start
   digging those changes from the patchwork in the near future.

 - Bug fixes and clean ups

* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  ima: Get rid of ima_used_chip and use ima_tpm_chip != NULL instead
  ima: Use tpm_default_chip() and call TPM functions with a tpm_chip
  tpm: replace TPM_TRANSMIT_RAW with TPM_TRANSMIT_NESTED
  tpm: Convert tpm_find_get_ops() to use tpm_default_chip()
  tpm: Implement tpm_default_chip() to find a TPM chip
  tpm: rename tpm_chip_find_get() to tpm_find_get_ops()
  tpm: Allow tpm_tis drivers to set hwrng quality.
  tpm: Return the actual size when receiving an unsupported command
  tpm: separate cmd_ready/go_idle from runtime_pm
  tpm/tpm_i2c_infineon: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)
  tpm_tis_spi: Pass the SPI IRQ down to the driver
  tpm: migrate tpm2_get_random() to use struct tpm_buf
  tpm: migrate tpm2_get_tpm_pt() to use struct tpm_buf
  tpm: migrate tpm2_probe() to use struct tpm_buf
  tpm: migrate tpm2_shutdown() to use struct tpm_buf
2018-08-15 22:51:12 -07:00
Linus Torvalds
99a2c789dd Merge tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull random updates from Ted Ts'o:
 "Some changes to trust cpu-based hwrng (such as RDRAND) for
  initializing hashed pointers and (optionally, controlled by a config
  option) to initialize the CRNG to avoid boot hangs"

* tag 'random_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: Make crng state queryable
  random: remove preempt disabled region
  random: add a config option to trust the CPU's hwrng
  vsprintf: Add command line option debug_boot_weak_hash
  vsprintf: Use hw RNG for ptr_key
  random: Return nbytes filled from hw RNG
  random: Fix whitespace pre random-bytes work
2018-08-15 21:16:02 -07:00
Herbert Xu
c5f5aeef9b Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux
Merge mainline to pick up c7513c2a27 ("crypto/arm64: aes-ce-gcm -
add missing kernel_neon_begin/end pair").
2018-08-03 17:55:12 +08:00
Jason A. Donenfeld
9a47249d44 random: Make crng state queryable
It is very useful to be able to know whether or not get_random_bytes_wait
/ wait_for_random_bytes is going to block or not, or whether plain
get_random_bytes is going to return good randomness or bad randomness.

The particular use case is for mitigating certain attacks in WireGuard.
A handshake packet arrives and is queued up. Elsewhere a worker thread
takes items from the queue and processes them. In replying to these
items, it needs to use some random data, and it has to be good random
data. If we simply block until we can have good randomness, then it's
possible for an attacker to fill the queue up with packets waiting to be
processed. Upon realizing the queue is full, WireGuard will detect that
it's under a denial of service attack, and behave accordingly. A better
approach is just to drop incoming handshake packets if the crng is not
yet initialized.

This patch, therefore, makes that information directly accessible.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-08-02 17:33:06 -04:00
Alexandre Belloni
f7430151d8 char: rtc: remove task handling
Since commit 9e7002a70e ("char: rtc: remove unused rtc_control() API"),
it is not possible to set a callback anymore, remove its handling from the
interrupt handler.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2018-08-02 17:16:03 +02:00
Linus Torvalds
a26fb01c28 Merge tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random
Pull random fixes from Ted Ts'o:
 "In reaction to the fixes to address CVE-2018-1108, some Linux
  distributions that have certain systemd versions in some cases
  combined with patches to libcrypt for FIPS/FEDRAMP compliance, have
  led to boot-time stalls for some hardware.

  The reaction by some distros and Linux sysadmins has been to install
  packages that try to do complicated things with the CPU and hope that
  leads to randomness.

  To mitigate this, if RDRAND is available, mix it into entropy provided
  by userspace. It won't hurt, and it will probably help"

* tag 'random_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/random:
  random: mix rdrand with entropy sent in from userspace
2018-07-28 19:40:06 -07:00
Jarkko Sakkinen
58bac8cc30 tpm: replace TPM_TRANSMIT_RAW with TPM_TRANSMIT_NESTED
As TPM_TRANSMIT_RAW always requires also not to take locks for obvious
reasons (deadlock), this commit renames the flag as TPM_TRANSMIT_NESTED
and prevents taking tpm_mutex when the flag is given to tpm_transmit().

Suggested-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-07-28 17:03:11 +03:00
Stefan Berger
eccc9bb844 tpm: Convert tpm_find_get_ops() to use tpm_default_chip()
Convert tpm_find_get_ops() to use tpm_default_chip() in case no chip
is passed in.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.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>
2018-07-28 17:03:11 +03:00
Stefan Berger
aaae815363 tpm: Implement tpm_default_chip() to find a TPM chip
Implement tpm_default_chip() to find the first TPM chip and return it to
the caller while increasing the reference count on its device. This
function can be used by other subsystems, such as IMA, to find the system's
default TPM chip and use it for all subsequent TPM operations.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-07-28 17:03:11 +03:00
Stefan Berger
fc1d52b745 tpm: rename tpm_chip_find_get() to tpm_find_get_ops()
Rename tpm_chip_find_get() to tpm_find_get_ops() to more closely match
the tpm_put_ops() counter part.

Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-07-28 17:03:11 +03:00
Louis Collard
7a64c5597a tpm: Allow tpm_tis drivers to set hwrng quality.
Adds plumbing required for drivers based on tpm_tis to set hwrng quality.

Signed-off-by: Louis Collard <louiscollard@chromium.org>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-07-28 17:03:11 +03:00
Ricardo Schwarzmeier
36a11029b0 tpm: Return the actual size when receiving an unsupported command
The userpace expects to read the number of bytes stated in the header.
Returning the size of the buffer instead would be unexpected.

Cc: stable@vger.kernel.org
Fixes: 095531f891 ("tpm: return a TPM_RC_COMMAND_CODE response if command is not implemented")
Signed-off-by: Ricardo Schwarzmeier <Ricardo.Schwarzmeier@infineon.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-07-28 17:03:11 +03:00
Tomas Winkler
627448e85c tpm: separate cmd_ready/go_idle from runtime_pm
Fix tpm ptt initialization error:
tpm tpm0: A TPM error (378) occurred get tpm pcr allocation.

We cannot use go_idle cmd_ready commands via runtime_pm handles
as with the introduction of localities this is no longer an optional
feature, while runtime pm can be not enabled.
Though cmd_ready/go_idle provides a power saving, it's also a part of
TPM2 protocol and should be called explicitly.
This patch exposes cmd_read/go_idle via tpm class ops and removes
runtime pm support as it is not used by any driver.

When calling from nested context always use both flags:
TPM_TRANSMIT_UNLOCKED and TPM_TRANSMIT_RAW. Both are needed to resolve
tpm spaces and locality request recursive calls to tpm_transmit().
TPM_TRANSMIT_RAW should never be used standalone as it will fail
on double locking. While TPM_TRANSMIT_UNLOCKED standalone should be
called from non-recursive locked contexts.

New wrappers are added tpm_cmd_ready() and tpm_go_idle() to
streamline tpm_try_transmit code.

tpm_crb no longer needs own power saving functions and can drop using
tpm_pm_suspend/resume.

This patch cannot be really separated from the locality fix.
Fixes: 888d867df4 (tpm: cmd_ready command can be issued only after granting locality)

Cc: stable@vger.kernel.org
Fixes: 888d867df4 (tpm: cmd_ready command can be issued only after granting locality)
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>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-07-28 17:03:11 +03:00
Peter Rosin
79e2472f99 tpm/tpm_i2c_infineon: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)
Locking the root adapter for __i2c_transfer will deadlock if the
device sits behind a mux-locked I2C mux. Switch to the finer-grained
i2c_lock_bus with the I2C_LOCK_SEGMENT flag. If the device does not
sit behind a mux-locked mux, the two locking variants are equivalent.

Signed-off-by: Peter Rosin <peda@axentia.se>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2018-07-28 17:03:11 +03:00
Linus Walleij
1a339b658d tpm_tis_spi: Pass the SPI IRQ down to the driver
An SPI TPM device managed directly on an embedded board using
the SPI bus and some GPIO or similar line as IRQ handler will
pass the IRQn from the TPM device associated with the SPI
device. This is already handled by the SPI core, so make sure
to pass this down to the core as well.

(The TPM core habit of using -1 to signal no IRQ is dubious
(as IRQ 0 is NO_IRQ) but I do not want to mess with that
semantic in this patch.)

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
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>
2018-07-28 17:03:11 +03:00
Jarkko Sakkinen
ce63c05b66 tpm: migrate tpm2_get_random() to use struct tpm_buf
In order to make struct tpm_buf the first class object for constructing
TPM commands, migrate tpm2_get_random() to use it. In addition, removed
remaining references to struct tpm2_cmd. All of them use it to acquire
the length of the response, which can be achieved by using
tpm_buf_length().

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Nayna Jain<nayna@linux.vnet.ibm.com>
2018-07-28 17:03:11 +03:00
Jarkko Sakkinen
2ab3241161 tpm: migrate tpm2_get_tpm_pt() to use struct tpm_buf
In order to make struct tpm_buf the first class object for constructing TPM
commands, migrate tpm2_get_tpm_pt() to use it.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Tested-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
2018-07-28 17:03:11 +03:00
Jarkko Sakkinen
94e266ba1f tpm: migrate tpm2_probe() to use struct tpm_buf
In order to make struct tpm_buf the first class object for constructing TPM
commands, migrate tpm2_probe() to use it.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Acked-by: Jay Freyensee <why2jjj.linux@gmail.com>
Reviewed-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Tested-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
2018-07-28 17:03:11 +03:00
Jarkko Sakkinen
cc26c6ef58 tpm: migrate tpm2_shutdown() to use struct tpm_buf
In order to make struct tpm_buf the first class object for constructing TPM
commands, migrated tpm2_shutdown() to use it.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Tested-by: Nayna Jain <nayna@linux.vnet.ibm.com>
Reviewed-by: Jerry Snitselaar <jsnitsel@redhat.com>
2018-07-28 17:03:11 +03:00
Vinod Koul
5a2c3a395a hwrng: msm - remove msm hw_random driver
This driver is for a psedo-rng so should not be added in hwrng.
Remove it so that it's replacement can be added.

Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2018-07-27 19:04:30 +08:00
Kirill A. Shutemov
bfd40eaff5 mm: fix vma_is_anonymous() false-positives
vma_is_anonymous() relies on ->vm_ops being NULL to detect anonymous
VMA.  This is unreliable as ->mmap may not set ->vm_ops.

False-positive vma_is_anonymous() may lead to crashes:

	next ffff8801ce5e7040 prev ffff8801d20eca50 mm ffff88019c1e13c0
	prot 27 anon_vma ffff88019680cdd8 vm_ops 0000000000000000
	pgoff 0 file ffff8801b2ec2d00 private_data 0000000000000000
	flags: 0xff(read|write|exec|shared|mayread|maywrite|mayexec|mayshare)
	------------[ cut here ]------------
	kernel BUG at mm/memory.c:1422!
	invalid opcode: 0000 [#1] SMP KASAN
	CPU: 0 PID: 18486 Comm: syz-executor3 Not tainted 4.18.0-rc3+ #136
	Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google
	01/01/2011
	RIP: 0010:zap_pmd_range mm/memory.c:1421 [inline]
	RIP: 0010:zap_pud_range mm/memory.c:1466 [inline]
	RIP: 0010:zap_p4d_range mm/memory.c:1487 [inline]
	RIP: 0010:unmap_page_range+0x1c18/0x2220 mm/memory.c:1508
	Call Trace:
	 unmap_single_vma+0x1a0/0x310 mm/memory.c:1553
	 zap_page_range_single+0x3cc/0x580 mm/memory.c:1644
	 unmap_mapping_range_vma mm/memory.c:2792 [inline]
	 unmap_mapping_range_tree mm/memory.c:2813 [inline]
	 unmap_mapping_pages+0x3a7/0x5b0 mm/memory.c:2845
	 unmap_mapping_range+0x48/0x60 mm/memory.c:2880
	 truncate_pagecache+0x54/0x90 mm/truncate.c:800
	 truncate_setsize+0x70/0xb0 mm/truncate.c:826
	 simple_setattr+0xe9/0x110 fs/libfs.c:409
	 notify_change+0xf13/0x10f0 fs/attr.c:335
	 do_truncate+0x1ac/0x2b0 fs/open.c:63
	 do_sys_ftruncate+0x492/0x560 fs/open.c:205
	 __do_sys_ftruncate fs/open.c:215 [inline]
	 __se_sys_ftruncate fs/open.c:213 [inline]
	 __x64_sys_ftruncate+0x59/0x80 fs/open.c:213
	 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
	 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Reproducer:

	#include <stdio.h>
	#include <stddef.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>
	#include <sys/types.h>
	#include <sys/stat.h>
	#include <sys/ioctl.h>
	#include <sys/mman.h>
	#include <unistd.h>
	#include <fcntl.h>

	#define KCOV_INIT_TRACE			_IOR('c', 1, unsigned long)
	#define KCOV_ENABLE			_IO('c', 100)
	#define KCOV_DISABLE			_IO('c', 101)
	#define COVER_SIZE			(1024<<10)

	#define KCOV_TRACE_PC  0
	#define KCOV_TRACE_CMP 1

	int main(int argc, char **argv)
	{
		int fd;
		unsigned long *cover;

		system("mount -t debugfs none /sys/kernel/debug");
		fd = open("/sys/kernel/debug/kcov", O_RDWR);
		ioctl(fd, KCOV_INIT_TRACE, COVER_SIZE);
		cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
				PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
		munmap(cover, COVER_SIZE * sizeof(unsigned long));
		cover = mmap(NULL, COVER_SIZE * sizeof(unsigned long),
				PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0);
		memset(cover, 0, COVER_SIZE * sizeof(unsigned long));
		ftruncate(fd, 3UL << 20);
		return 0;
	}

This can be fixed by assigning anonymous VMAs own vm_ops and not relying
on it being NULL.

If ->mmap() failed to set ->vm_ops, mmap_region() will set it to
dummy_vm_ops.  This way we will have non-NULL ->vm_ops for all VMAs.

Link: http://lkml.kernel.org/r/20180724121139.62570-4-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: syzbot+3f84280d52be9b7083cc@syzkaller.appspotmail.com
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-26 19:38:03 -07:00
Ingo Molnar
b34fbaa928 random: remove preempt disabled region
No need to keep preemption disabled across the whole function.

mix_pool_bytes() uses a spin_lock() to protect the pool and there are
other places like write_pool() whhich invoke mix_pool_bytes() without
disabling preemption.
credit_entropy_bits() is invoked from other places like
add_hwgenerator_randomness() without disabling preemption.

Before commit 95b709b6be ("random: drop trickle mode") the function
used __this_cpu_inc_return() which would require disabled preemption.
The preempt_disable() section was added in commit 43d5d3018c37 ("[PATCH]
random driver preempt robustness", history tree).  It was claimed that
the code relied on "vt_ioctl() being called under BKL".

Cc: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
[bigeasy: enhance the commit message]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-07-24 15:44:32 -04:00
Theodore Ts'o
39a8883a2b random: add a config option to trust the CPU's hwrng
This gives the user building their own kernel (or a Linux
distribution) the option of deciding whether or not to trust the CPU's
hardware random number generator (e.g., RDRAND for x86 CPU's) as being
correctly implemented and not having a back door introduced (perhaps
courtesy of a Nation State's law enforcement or intelligence
agencies).

This will prevent getrandom(2) from blocking, if there is a
willingness to trust the CPU manufacturer.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2018-07-24 15:43:24 -04:00