android_kernel_samsung_univ.../drivers/char
Jiri Slaby 6f61bd5c4f hwrng: core - sleep interruptible in read
commit 1ab87298cb59b649d8d648d25dc15b36ab865f5a upstream.

hwrng kthread can be waiting via hwrng_fillfn for some data from a rng
like virtio-rng:
hwrng           D ffff880093e17798     0   382      2 0x00000000
...
Call Trace:
 [<ffffffff817339c6>] wait_for_completion_killable+0x96/0x210
 [<ffffffffa00aa1b7>] virtio_read+0x57/0xf0 [virtio_rng]
 [<ffffffff814f4a35>] hwrng_fillfn+0x75/0x130
 [<ffffffff810aa243>] kthread+0xf3/0x110

And when some user program tries to read the /dev node in this state,
we get:
rngd            D ffff880093e17798     0   762      1 0x00000004
...
Call Trace:
 [<ffffffff817351ac>] mutex_lock_nested+0x15c/0x3e0
 [<ffffffff814f478e>] rng_dev_read+0x6e/0x240
 [<ffffffff81231958>] __vfs_read+0x28/0xe0
 [<ffffffff81232393>] vfs_read+0x83/0x130

And this is indeed unkillable. So use mutex_lock_interruptible
instead of mutex_lock in rng_dev_read and exit immediatelly when
interrupted. And possibly return already read data, if any (as POSIX
allows).

v2: use ERESTARTSYS instead of EINTR

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: <linux-crypto@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17 09:35:28 +01:00
..
agp agp/uninorth: fix a memleak in create_gatt_table 2015-10-02 22:57:59 +10:00
hw_random hwrng: core - sleep interruptible in read 2018-01-17 09:35:28 +01:00
ipmi ipmi: Stop timers before cleaning up the module 2017-12-16 10:33:56 +01:00
mwave
pcmcia pcmcia: remove left-over %Z format 2017-06-07 12:06:01 +02:00
tpm tpm: Replace device number bitmap with IDR 2017-08-06 19:19:43 -07:00
xilinx_hwicap
xillybus char: xillybus: Allow 64-bit DMA on PCIe interface 2015-08-05 12:27:09 -07:00
apm-emulation.c
applicom.c
applicom.h
bfin-otp.c
bsr.c
ds1302.c
ds1620.c
dsp56k.c
dtlk.c
efirtc.c drivers/char: make efirtc.c driver explicitly non-modular 2015-09-20 19:32:35 -07:00
generic_nvram.c
genrtc.c
hangcheck-timer.c
hpet.c drivers/char: make hpet.c explicitly non-modular 2015-09-20 19:32:35 -07:00
Kconfig char: lack of bool string made CONFIG_DEVPORT always on 2017-04-21 09:30:06 +02:00
lp.c char: lp: fix possible integer overflow in lp_setup() 2017-05-25 14:30:07 +02:00
Makefile
mbcs.c
mbcs.h
mem.c x86/mm/pat, /dev/mem: Remove superfluous error message 2018-01-17 09:35:28 +01:00
misc.c char: make misc_deregister a void function 2015-08-05 10:35:49 -07:00
mmtimer.c
mspec.c
nsc_gpio.c
nvram.c char/nvram: Use bitwise OR to obtain Atari video mode data 2015-08-05 13:30:16 -07:00
nwbutton.c
nwbutton.h
nwflash.c
pc8736x_gpio.c
ppdev.c
ps3flash.c
random.c random: properly align get_random_int_hash 2017-06-14 13:16:23 +02:00
raw.c
rtc.c
scx200_gpio.c
snsc_event.c
snsc.c drivers/char: make SGI snsc.c driver explicitly non-modular 2015-09-20 19:32:35 -07:00
snsc.h
sonypi.c
tb0219.c
tile-srom.c
tlclk.c
toshiba.c toshiba laptop: replace ioremap_cache with ioremap 2015-08-05 17:26:00 -07:00
ttyprintk.c
uv_mmtimer.c
virtio_console.c virtio_console: fix a crash in config_work_handler 2017-07-05 14:37:18 +02:00