linux-stable.git/drivers/rtc, branch v4.14.44

rtc: goldfish: Add missing MODULE_LICENSE

2018-05-25T14:18:02+00:00

[ Upstream commit 82d632b85eb89f97051530f556cb49ee1c04bde7 ]

Fix the following warning in MIPS allmodconfig by adding a
MODULE_LICENSE() at the end of rtc-goldfish.c, based on the file header
comment which says GNU General Public License version 2:

WARNING: modpost: missing MODULE_LICENSE() in drivers/rtc/rtc-goldfish.o

Fixes: f22d9cdcb5eb ("rtc: goldfish: Add RTC driver for Android emulator")
Signed-off-by: James Hogan 
Cc: Miodrag Dinic 
Cc: Alessandro Zummo 
Cc: Alexandre Belloni 
Cc: linux-rtc@vger.kernel.org
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rtc: rp5c01: fix possible race condition

2018-05-25T14:18:01+00:00

[ Upstream commit bcdd559268039d8340d38fa58668393596e29fdc ]

The probe function is not allowed to fail after registering the RTC because
the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev->owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod->module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Switch to devm_rtc_allocate_device/rtc_register_device to register the rtc
as late as possible.

Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rtc: tx4939: avoid unintended sign extension on a 24 bit shift

2018-05-25T14:18:01+00:00

[ Upstream commit 347876ad47b9923ce26e686173bbf46581802ffa ]

The shifting of buf[5] by 24 bits to the left will be promoted to
a 32 bit signed int and then sign-extended to an unsigned long. If
the top bit of buf[5] is set then all then all the upper bits sec
end up as also being set because of the sign-extension. Fix this by
casting buf[5] to an unsigned long before the shift.

Detected by CoverityScan, CID#1465292 ("Unintended sign extension")

Fixes: 0e1492330cd2 ("rtc: add rtc-tx4939 driver")
Signed-off-by: Colin Ian King 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rtc: m41t80: fix race conditions

2018-05-25T14:18:01+00:00

[ Upstream commit 10d0c768cc6d581523d673b9d1b54213f8a5eb24 ]

The IRQ is requested before the struct rtc is allocated and registered, but
this struct is used in the IRQ handler, leading to:

Unable to handle kernel NULL pointer dereference at virtual address 0000017c
pgd = a38a2f9b
[0000017c] *pgd=00000000
Internal error: Oops: 5 [#1] ARM
Modules linked in:
CPU: 0 PID: 613 Comm: irq/48-m41t80 Not tainted 4.16.0-rc1+ #42
Hardware name: Atmel SAMA5
PC is at mutex_lock+0x14/0x38
LR is at m41t80_handle_irq+0x1c/0x9c
pc : []    lr : []    psr: 20000013
sp : dec73f30  ip : 00000000  fp : dec56d98
r10: df437cf0  r9 : c0a03008  r8 : c0145ffc
r7 : df5c4300  r6 : dec568d0  r5 : df593000  r4 : 0000017c
r3 : df592800  r2 : 60000013  r1 : df593000  r0 : 0000017c
Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 10c53c7d  Table: 20004059  DAC: 00000051
Process irq/48-m41t80 (pid: 613, stack limit = 0xb52d091e)
Stack: (0xdec73f30 to 0xdec74000)
3f20:                                     dec56840 df5c4300 00000001 df5c4300
3f40: c0145ffc c0146018 dec56840 ffffe000 00000001 c0146290 dec567c0 00000000
3f60: c0146084 ed7c9a62 c014615c dec56d80 dec567c0 00000000 dec72000 dec56840
3f80: c014615c c012ffc0 dec72000 dec567c0 c012fe80 00000000 00000000 00000000
3fa0: 00000000 00000000 00000000 c01010e8 00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000 29282726 2d2c2b2a
[] (mutex_lock) from [] (m41t80_handle_irq+0x1c/0x9c)
[] (m41t80_handle_irq) from [] (irq_thread_fn+0x1c/0x54)
[] (irq_thread_fn) from [] (irq_thread+0x134/0x1c0)
[] (irq_thread) from [] (kthread+0x140/0x148)
[] (kthread) from [] (ret_from_fork+0x14/0x2c)
Exception stack(0xdec73fb0 to 0xdec73ff8)
3fa0:                                     00000000 00000000 00000000 00000000
3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Code: e3c33d7f e3c3303f f5d0f000 e593300c (e1901f9f)
---[ end trace 22b027302eb7c604 ]---
genirq: exiting task "irq/48-m41t80" (613) is an active IRQ thread (irq 48)

Also, there is another possible race condition. The probe function is not
allowed to fail after the RTC is registered because the following may
happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev->owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod->module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Switch to devm_rtc_allocate_device/rtc_register_device to allocate the rtc
before requesting the IRQ and register it as late as possible.

Signed-off-by: Alexandre Belloni 

Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rtc: rk808: fix possible race condition

2018-05-25T14:18:01+00:00

[ Upstream commit 201fac95e799c3d0304ec724d555e1251b9f6e84 ]

The probe function is not allowed to fail after registering the RTC because
the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev->owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod->module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Switch to devm_rtc_allocate_device/rtc_register_device to register the rtc
as late as possible.

Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rtc: hctosys: Ensure system time doesn't overflow time_t

2018-05-25T14:18:00+00:00

[ Upstream commit b3a5ac42ab18b7d1a8f2f072ca0ee76a3b754a43 ]

On 32bit platforms, time_t is still a signed 32bit long. If it is
overflowed, userspace and the kernel cant agree on the current system time.
This causes multiple issues, in particular with systemd:
https://github.com/systemd/systemd/issues/1143

A good workaround is to simply avoid using hctosys which is something I
greatly encourage as the time is better set by userspace.

However, many distribution enable it and use systemd which is rendering the
system unusable in case the RTC holds a date after 2038 (and more so after
2106). Many drivers have workaround for this case and they should be
eliminated so there is only one place left to fix when userspace is able to
cope with dates after the 31bit overflow.

Acked-by: Arnd Bergmann 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rtc: snvs: Fix usage of snvs_rtc_enable

2018-05-25T14:18:00+00:00

[ Upstream commit 1485991c024603b2fb4ae77beb7a0d741128a48e ]

commit 179a502f8c46 ("rtc: snvs: add Freescale rtc-snvs driver") introduces
the SNVS RTC driver with a function snvs_rtc_enable().

snvs_rtc_enable() can return an error on the enable path however this
driver does not currently trap that failure on the probe() path and
consequently if enabling the RTC fails we encounter a later error spinning
forever in rtc_write_sync_lp().

[   36.093481] [] (__irq_svc) from [] (_raw_spin_unlock_irqrestore+0x34/0x44)
[   36.102122] [] (_raw_spin_unlock_irqrestore) from [] (regmap_read+0x4c/0x5c)
[   36.110938] [] (regmap_read) from [] (rtc_write_sync_lp+0x6c/0x98)
[   36.118881] [] (rtc_write_sync_lp) from [] (snvs_rtc_alarm_irq_enable+0x40/0x4c)
[   36.128041] [] (snvs_rtc_alarm_irq_enable) from [] (rtc_timer_do_work+0xd8/0x1a8)
[   36.137291] [] (rtc_timer_do_work) from [] (process_one_work+0x28c/0x76c)
[   36.145840] [] (process_one_work) from [] (worker_thread+0x34/0x58c)
[   36.153961] [] (worker_thread) from [] (kthread+0x138/0x150)
[   36.161388] [] (kthread) from [] (ret_from_fork+0x14/0x20)
[   36.168635] rcu_sched kthread starved for 2602 jiffies! g496 c495 f0x2 RCU_GP_WAIT_FQS(3) ->state=0x0 ->cpu=0
[   36.178564] rcu_sched       R  running task        0     8      2 0x00000000
[   36.185664] [] (__schedule) from [] (schedule+0x3c/0xa0)
[   36.192739] [] (schedule) from [] (schedule_timeout+0x78/0x4e0)
[   36.200422] [] (schedule_timeout) from [] (rcu_gp_kthread+0x648/0x1864)
[   36.208800] [] (rcu_gp_kthread) from [] (kthread+0x138/0x150)
[   36.216309] [] (kthread) from [] (ret_from_fork+0x14/0x20)

This patch fixes by parsing the result of rtc_write_sync_lp() and
propagating both in the probe and elsewhere. If the RTC doesn't start we
don't proceed loading the driver and don't get into this loop mess later
on.

Fixes: 179a502f8c46 ("rtc: snvs: add Freescale rtc-snvs driver")
Signed-off-by: Bryan O'Donoghue 
Acked-by: Shawn Guo 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rtc: opal: Fix OPAL RTC driver OPAL_BUSY loops

2018-05-01T19:58:24+00:00

commit 682e6b4da5cbe8e9a53f979a58c2a9d7dc997175 upstream.

The OPAL RTC driver does not sleep in case it gets OPAL_BUSY or
OPAL_BUSY_EVENT from firmware, which causes large scheduling
latencies, up to 50 seconds have been observed here when RTC stops
responding (BMC reboot can do it).

Fix this by converting it to the standard form OPAL_BUSY loop that
sleeps.

Fixes: 628daa8d5abf ("powerpc/powernv: Add RTC and NVRAM support plus RTAS fallbacks")
Cc: stable@vger.kernel.org # v3.2+
Signed-off-by: Nicholas Piggin 
Acked-by: Alexandre Belloni 
Signed-off-by: Michael Ellerman 
Signed-off-by: Greg Kroah-Hartman

clk: divider: fix incorrect usage of container_of

2018-04-12T10:32:13+00:00

[ Upstream commit 12a26c298d2a8b1cab498533fa65198e49e3afd3 ]

divider_recalc_rate() is an helper function used by clock divider of
different types, so the structure containing the 'hw' pointer is not
always a 'struct clk_divider'

At the following line:
> div = _get_div(table, val, flags, divider->width);

in several cases, the value of 'divider->width' is garbage as the actual
structure behind this memory is not a 'struct clk_divider'

Fortunately, this width value is used by _get_val() only when
CLK_DIVIDER_MAX_AT_ZERO flag is set. This has never been the case so
far when the structure is not a 'struct clk_divider'. This is probably
why we did not notice this bug before

Fixes: afe76c8fd030 ("clk: allow a clk divider with max divisor when zero")
Signed-off-by: Jerome Brunet 
Acked-by: Alexandre Belloni 
Acked-by: Sylvain Lemieux 
Signed-off-by: Stephen Boyd 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rtc: ac100: Fix multiple race conditions

2018-03-24T10:01:24+00:00

[ Upstream commit 994ec64c0a193940be7a6fd074668b9446d3b6c3 ]

The probe function is not allowed to fail after registering the RTC because
the following may happen:

CPU0:                                CPU1:
sys_load_module()
 do_init_module()
  do_one_initcall()
   cmos_do_probe()
    rtc_device_register()
     __register_chrdev()
     cdev->owner = struct module*
                                     open("/dev/rtc0")
    rtc_device_unregister()
  module_put()
  free_module()
   module_free(mod->module_core)
   /* struct module *module is now
      freed */
                                      chrdev_open()
                                       spin_lock(cdev_lock)
                                       cdev_get()
                                        try_module_get()
                                         module_is_live()
                                         /* dereferences already
                                            freed struct module* */

Also, the interrupt handler: ac100_rtc_irq() is dereferencing chip->rtc but
this may still be NULL when it is called, resulting in:
Unable to handle kernel NULL pointer dereference at virtual address 00000194
pgd = (ptrval)
[00000194] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in:
CPU: 0 PID: 72 Comm: irq/71-ac100-rt Not tainted 4.15.0-rc1-next-20171201-dirty #120
Hardware name: Allwinner sun8i Family
task: (ptrval) task.stack: (ptrval)
PC is at mutex_lock+0x14/0x3c
LR is at ac100_rtc_irq+0x38/0xc8
pc : []    lr : []    psr: 60000053
sp : ee9c9f28  ip : 00000000  fp : ee9adfdc
r10: 00000000  r9 : c0a04c48  r8 : c015ed18
r7 : ee9bd600  r6 : ee9c9f28  r5 : ee9af590  r4 : c0a04c48
r3 : ef3cb3c0  r2 : 00000000  r1 : ee9af590  r0 : 00000194
Flags: nZCv  IRQs on  FIQs off  Mode SVC_32  ISA ARM  Segment none
Control: 10c5387d  Table: 4000406a  DAC: 00000051
Process irq/71-ac100-rt (pid: 72, stack limit = 0x(ptrval))
Stack: (0xee9c9f28 to 0xee9ca000)
9f20:                   00000000 7c2fd1be c015ed18 ee9adf40 ee9c0400 ee9c0400
9f40: ee9adf40 c015ed34 ee9c8000 ee9adf64 ee9c0400 c015f040 ee9adf80 00000000
9f60: c015ee24 7c2fd1be ee9adfc0 ee9adf80 00000000 ee9c8000 ee9adf40 c015eef4
9f80: ef1eba34 c0138f14 ee9c8000 ee9adf80 c0138df4 00000000 00000000 00000000
9fa0: 00000000 00000000 00000000 c01010e8 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000 ffffffff ffffffff
[] (mutex_lock) from [] (ac100_rtc_irq+0x38/0xc8)
[] (ac100_rtc_irq) from [] (irq_thread_fn+0x1c/0x54)
[] (irq_thread_fn) from [] (irq_thread+0x14c/0x214)
[] (irq_thread) from [] (kthread+0x120/0x150)
[] (kthread) from [] (ret_from_fork+0x14/0x2c)

Solve both issues by moving to
devm_rtc_allocate_device()/rtc_register_device()

Reported-by: Quentin Schulz 
Tested-by: Quentin Schulz 
Signed-off-by: Alexandre Belloni 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman