linux-stable.git/drivers/char/hw_random, branch linux-3.16.y

x86/cpu: Rename cpu_data.x86_mask to cpu_data.x86_stepping

2020-06-11T18:05:55+00:00

commit b399151cb48db30ad1e0e93dd40d68c6d007b637 upstream.

x86_mask is a confusing name which is hard to associate with the
processor's stepping.

Additionally, correct an indent issue in lib/cpu.c.

Signed-off-by: Jia Zhang 
[ Updated it to more recent kernels. ]
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: bp@alien8.de
Cc: tony.luck@intel.com
Link: http://lkml.kernel.org/r/1514771530-70829-1-git-send-email-qianyue.zj@alibaba-inc.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman 
[bwh: Backported to 3.16:
 - Drop changes in arch/x86/lib/cpu.c
 - Adjust filenames, context]
Signed-off-by: Ben Hutchings

hwrng: omap3-rom - Call clk_disable_unprepare() on exit only if not idled

2020-02-11T20:03:14+00:00

commit eaecce12f5f0d2c35d278e41e1bc4522393861ab upstream.

When unloading omap3-rom-rng, we'll get the following:

WARNING: CPU: 0 PID: 100 at drivers/clk/clk.c:948 clk_core_disable

This is because the clock may be already disabled by omap3_rom_rng_idle().
Let's fix the issue by checking for rng_idle on exit.

Cc: Aaro Koskinen 
Cc: Adam Ford 
Cc: Pali Rohár 
Cc: Sebastian Reichel 
Cc: Tero Kristo 
Fixes: 1c6b7c2108bd ("hwrng: OMAP3 ROM Random Number Generator support")
Signed-off-by: Tony Lindgren 
Signed-off-by: Herbert Xu 
Signed-off-by: Ben Hutchings

hwrng: core - don't wait on add_early_randomness()

2019-12-10T18:01:22+00:00

commit 78887832e76541f77169a24ac238fccb51059b63 upstream.

add_early_randomness() is called by hwrng_register() when the
hardware is added. If this hardware and its module are present
at boot, and if there is no data available the boot hangs until
data are available and can't be interrupted.

For instance, in the case of virtio-rng, in some cases the host can be
not able to provide enough entropy for all the guests.

We can have two easy ways to reproduce the problem but they rely on
misconfiguration of the hypervisor or the egd daemon:

- if virtio-rng device is configured to connect to the egd daemon of the
host but when the virtio-rng driver asks for data the daemon is not
connected,

- if virtio-rng device is configured to connect to the egd daemon of the
host but the egd daemon doesn't provide data.

The guest kernel will hang at boot until the virtio-rng driver provides
enough data.

To avoid that, call rng_get_data() in non-blocking mode (wait=0)
from add_early_randomness().

Signed-off-by: Laurent Vivier 
Fixes: d9e797261933 ("hwrng: add randomness to system from rng...")
Reviewed-by: Theodore Ts'o 
Signed-off-by: Herbert Xu 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

hwrng: core - Don't use a stack buffer in add_early_randomness()

2017-02-23T03:54:17+00:00

commit 6d4952d9d9d4dc2bb9c0255d95a09405a1e958f7 upstream.

hw_random carefully avoids using a stack buffer except in
add_early_randomness().  This causes a crash in virtio_rng if
CONFIG_VMAP_STACK=y.

Reported-by: Matt Mullins 
Tested-by: Matt Mullins 
Fixes: d3cc7996473a ("hwrng: fetch randomness only after device init")
Signed-off-by: Andy Lutomirski 
Signed-off-by: Herbert Xu 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

hwrng: omap - Fix assumption that runtime_get_sync will always succeed

2016-11-20T01:16:42+00:00

commit 61dc0a446e5d08f2de8a24b45f69a1e302bb1b1b upstream.

pm_runtime_get_sync does return a error value that must be checked for
error conditions, else, due to various reasons, the device maynot be
enabled and the system will crash due to lack of clock to the hardware
module.

Before:
12.562784] [00000000] *pgd=fe193835
12.562792] Internal error: : 1406 [#1] SMP ARM
[...]
12.562864] CPU: 1 PID: 241 Comm: modprobe Not tainted 4.7.0-rc4-next-20160624 #2
12.562867] Hardware name: Generic DRA74X (Flattened Device Tree)
12.562872] task: ed51f140 ti: ed44c000 task.ti: ed44c000
12.562886] PC is at omap4_rng_init+0x20/0x84 [omap_rng]
12.562899] LR is at set_current_rng+0xc0/0x154 [rng_core]
[...]

After the proper checks:
[   94.366705] omap_rng 48090000.rng: _od_fail_runtime_resume: FIXME:
missing hwmod/omap_dev info
[   94.375767] omap_rng 48090000.rng: Failed to runtime_get device -19
[   94.382351] omap_rng 48090000.rng: initialization failed.

Fixes: 665d92fa85b5 ("hwrng: OMAP: convert to use runtime PM")
Cc: Paul Walmsley 
Signed-off-by: Nishanth Menon 
Signed-off-by: Herbert Xu 
Signed-off-by: Ben Hutchings

hwrng: pseries - port to new read API and fix stack corruption

2014-11-27T11:21:35+00:00

commit 24c65bc7037e7d0f362c0df70d17dd72ee64b8b9 upstream.

The add_early_randomness() function in drivers/char/hw_random/core.c passes
a 16-byte buffer to pseries_rng_data_read(). Unfortunately, plpar_hcall()
returns four 64-bit values and trashes 16 bytes on the stack.

This bug has been lying around for a long time. It got unveiled by:

commit d3cc7996473a7bdd33256029988ea690754e4e2a
Author: Amit Shah 
Date:   Thu Jul 10 15:42:34 2014 +0530

    hwrng: fetch randomness only after device init

It may trig a oops while loading or unloading the pseries-rng module for both
PowerVM and PowerKVM guests.

This patch does two things:
- pass an intermediate well sized buffer to plpar_hcall(). This is acceptalbe
  since we're not on a hot path.
- move to the new read API so that we know the return buffer size for sure.

Signed-off-by: Greg Kurz 
Signed-off-by: Herbert Xu 
Signed-off-by: Luis Henriques

virtio-rng: skip reading when we start to remove the device

2014-11-05T15:54:38+00:00

commit f49819560f53b7f3a596a8ea2e6764dc86695b62 upstream.

Before we really unregister the hwrng device, reading will get stuck if
the virtio device is reset. We should return error for reading when we
start to remove the device.

Signed-off-by: Amos Kong 
Reviewed-by: Amit Shah 
Signed-off-by: Rusty Russell 
Signed-off-by: Luis Henriques

virtio-rng: fix stuck of hot-unplugging busy device

2014-11-05T15:54:09+00:00

commit 3856e548372513665670ca5db60d9a74b970fe0d upstream.

When we try to hot-remove a busy virtio-rng device from QEMU monitor,
the device can't be hot-removed. Because virtio-rng driver hangs at
wait_for_completion_killable().

This patch exits the waiting by completing have_data completion before
unregistering, resets data_avail to avoid the hwrng core use wrong
buffer bytes.

Signed-off-by: Amos Kong 
Reviewed-by: Amit Shah 
Signed-off-by: Rusty Russell 
Signed-off-by: Luis Henriques

Revert "hwrng: virtio - ensure reads happen after successful probe"

2014-10-05T20:41:08+00:00

commit eeec626366ffe558fc3d5685bd2b49a962acf57d upstream.

This reverts commit e052dbf554610e2104c5a7518c4d8374bed701bb.

Now that we use the virtio ->scan() function to register with the hwrng
core, we will not get read requests till probe is successfully finished.

So revert the workaround we had in place to refuse read requests while
we were not yet setup completely.

Signed-off-by: Amit Shah 
Signed-off-by: Rusty Russell 
Signed-off-by: Greg Kroah-Hartman

virtio: rng: delay hwrng_register() till driver is ready

2014-10-05T20:41:08+00:00

commit 5c06273401f2eb7b290cadbae18ee00f8f65e893 upstream.

Instead of calling hwrng_register() in the probe routing, call it in the
scan routine.  This ensures that when hwrng_register() is successful,
and it requests a few random bytes to seed the kernel's pool at init,
we're ready to service that request.

This will also enable us to remove the workaround added previously to
check whether probe was completed, and only then ask for data from the
host.  The revert follows in the next commit.

There's a slight behaviour change here on unsuccessful hwrng_register().
Previously, when hwrng_register() failed, the probe() routine would
fail, and the vqs would be torn down, and driver would be marked not
initialized.  Now, the vqs will remain initialized, driver would be
marked initialized as well, but won't be available in the list of RNGs
available to hwrng core.  To fix the failures, the procedure remains the
same, i.e. unload and re-load the module, and hope things succeed the
next time around.

Signed-off-by: Amit Shah 
Signed-off-by: Rusty Russell 
Signed-off-by: Greg Kroah-Hartman