linux-stable.git/drivers/base, branch v3.4.106

sysfs: driver core: Fix glue dir race condition by gdp_mutex

2015-02-02T09:05:16+00:00

commit e4a60d139060975eb956717e4f63ae348d4d8cc5 upstream.

There is a race condition when removing glue directory.
It can be reproduced in following test:

path 1: Add first child device
device_add()
    get_device_parent()
            /*find parent from glue_dirs.list*/
            list_for_each_entry(k, &dev->class->p->glue_dirs.list, entry)
                    if (k->parent == parent_kobj) {
                            kobj = kobject_get(k);
                            break;
                    }
            ....
            class_dir_create_and_add()

path2: Remove last child device under glue dir
device_del()
    cleanup_device_parent()
            cleanup_glue_dir()
                    kobject_put(glue_dir);

If path2 has been called cleanup_glue_dir(), but not
call kobject_put(glue_dir), the glue dir is still
in parent's kset list. Meanwhile, path1 find the glue
dir from the glue_dirs.list. Path2 may release glue dir
before path1 call kobject_get(). So kernel will report
the warning and bug_on.

This is a "classic" problem we have of a kref in a list
that can be found while the last instance could be removed
at the same time.

This patch reuse gdp_mutex to fix this race condition.

The following calltrace is captured in kernel 3.4, but
the latest kernel still has this bug.

-----------------------------------------------------
<4>[ 3965.441471] WARNING: at ...include/linux/kref.h:41 kobject_get+0x33/0x40()
<4>[ 3965.441474] Hardware name: Romley
<4>[ 3965.441475] Modules linked in: isd_iop(O) isd_xda(O)...
...
<4>[ 3965.441605] Call Trace:
<4>[ 3965.441611]  [] warn_slowpath_common+0x7a/0xb0
<4>[ 3965.441615]  [] warn_slowpath_null+0x15/0x20
<4>[ 3965.441618]  [] kobject_get+0x33/0x40
<4>[ 3965.441624]  [] get_device_parent.isra.11+0x135/0x1f0
<4>[ 3965.441627]  [] device_add+0xd4/0x6d0
<4>[ 3965.441631]  [] ? dev_set_name+0x3c/0x40
....
<2>[ 3965.441912] kernel BUG at ..../fs/sysfs/group.c:65!
<4>[ 3965.441915] invalid opcode: 0000 [#1] SMP
...
<4>[ 3965.686743]  [] sysfs_create_group+0xe/0x10
<4>[ 3965.686748]  [] blk_trace_init_sysfs+0x14/0x20
<4>[ 3965.686753]  [] blk_register_queue+0x3b/0x120
<4>[ 3965.686756]  [] add_disk+0x1cc/0x490
....
-------------------------------------------------------

Signed-off-by: Yijing Wang 
Signed-off-by: Weng Meiling 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Zefan Li

regmap: fix possible ZERO_SIZE_PTR pointer dereferencing error.

2015-02-02T09:04:44+00:00

commit d6b41cb06044a7d895db82bdd54f6e4219970510 upstream.

Since we cannot make sure the 'val_count' will always be none zero
here, and then if it equals to zero, the kmemdup() will return
ZERO_SIZE_PTR, which equals to ((void *)16).

So this patch fix this with just doing the zero check before calling
kmemdup().

Signed-off-by: Xiubo Li 
Signed-off-by: Mark Brown 
[lizf: Backported to 3.4: release mutex before returning EINVAL]
Signed-off-by: Zefan Li

regmap: debugfs: fix possbile NULL pointer dereference

2015-02-02T09:04:44+00:00

commit 2c98e0c1cc6b8e86f1978286c3d4e0769ee9d733 upstream.

If 'map->dev' is NULL and there will lead dev_name() to be NULL pointer
dereference. So before dev_name(), we need to have check of the map->dev
pionter.

We also should make sure that the 'name' pointer shouldn't be NULL for
debugfs_create_dir(). So here using one default "dummy" debugfs name when
the 'name' pointer and 'map->dev' are both NULL.

Signed-off-by: Xiubo Li 
Signed-off-by: Mark Brown 
[lizf: Backported to 3.4: dev_name() is passed to debugfs_create_dir() in 3.4]
Signed-off-by: Zefan Li

firmware_class: make sure fw requests contain a name

2015-02-02T09:04:39+00:00

commit 471b095dfe0d693a8d624cbc716d1ee4d74eb437 upstream.

An empty firmware request name will trigger warnings when building
device names. Make sure this is caught earlier and rejected.

The warning was visible via the test_firmware.ko module interface:

echo -ne "\x00" > /sys/devices/virtual/misc/test_firmware/trigger_request

Reported-by: Sasha Levin 
Signed-off-by: Kees Cook 
Tested-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman 
[lizf: Backported to 3.4: adjust context]
Signed-off-by: Zefan Li

regmap: Fix handling of volatile registers for format_write() chips

2014-12-01T10:02:20+00:00

commit 5844a8b9d98ec11ce1d77610daacf3f0a0e14715 upstream.

A previous over-zealous factorisation of code means that we only treat
registers as volatile if they are readable. For most devices this is fine
since normally most registers can be read and volatility implies
readability but for format_write() devices where there is no readback from
the hardware and we use volatility to mean simply uncacheability this means
that we end up treating all registers as cacheble.

A bigger refactoring of the code to clarify this is in order but as a fix
make a minimal change and only check readability when checking volatility
if there is no format_write() operation defined for the device.

Signed-off-by: Mark Brown 
Tested-by: Lars-Peter Clausen 
Signed-off-by: Zefan Li

drivercore: deferral race condition fix

2014-06-07T23:02:01+00:00

commit 58b116bce13612e5aa6fcd49ecbd4cf8bb59e835 upstream.

When the kernel is built with CONFIG_PREEMPT it is possible to reach a state
when all modules loaded but some driver still stuck in the deferred list
and there is a need for external event to kick the deferred queue to probe
these drivers.

The issue has been observed on embedded systems with CONFIG_PREEMPT enabled,
audio support built as modules and using nfsroot for root filesystem.

The following log fragment shows such sequence when all audio modules
were loaded but the sound card is not present since the machine driver has
failed to probe due to missing dependency during it's probe.
The board is am335x-evmsk (McASP<->tlv320aic3106 codec) with davinci-evm
machine driver:

...
[   12.615118] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: ENTER
[   12.719969] davinci_evm sound.3: davinci_evm_probe: ENTER
[   12.725753] davinci_evm sound.3: davinci_evm_probe: snd_soc_register_card
[   12.753846] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: snd_soc_register_component
[   12.922051] davinci-mcasp 4803c000.mcasp: davinci_mcasp_probe: snd_soc_register_component DONE
[   12.950839] davinci_evm sound.3: ASoC: platform (null) not registered
[   12.957898] davinci_evm sound.3: davinci_evm_probe: snd_soc_register_card DONE (-517)
[   13.099026] davinci-mcasp 4803c000.mcasp: Kicking the deferred list
[   13.177838] davinci-mcasp 4803c000.mcasp: really_probe: probe_count = 2
[   13.194130] davinci_evm sound.3: snd_soc_register_card failed (-517)
[   13.346755] davinci_mcasp_driver_init: LEAVE
[   13.377446] platform sound.3: Driver davinci_evm requests probe deferral
[   13.592527] platform sound.3: really_probe: probe_count = 0

In the log the machine driver enters it's probe at 12.719969 (this point it
has been removed from the deferred lists). McASP driver already executing
it's probing (since 12.615118).
The machine driver tries to construct the sound card (12.950839) but did
not found one of the components so it fails. After this McASP driver
registers all the ASoC components (the machine driver still in it's probe
function after it failed to construct the card) and the deferred work is
prepared at 13.099026 (note that this time the machine driver is not in the
lists so it is not going to be handled when the work is executing).
Lastly the machine driver exit from it's probe and the core places it to
the deferred list but there will be no other driver going to load and the
deferred queue is not going to be kicked again - till we have external event
like connecting USB stick, etc.

The proposed solution is to try the deferred queue once more when the last
driver is asking for deferring and we had drivers loaded while this last
driver was probing.

This way we can avoid drivers stuck in the deferred queue.

Signed-off-by: Grant Likely 
Reviewed-by: Peter Ujfalusi 
Tested-by: Peter Ujfalusi 
Acked-by: Greg Kroah-Hartman 
Cc: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

drivers/base/memory.c: fix show_mem_removable() to handle missing sections

2013-09-08T04:58:14+00:00

commit 21ea9f5ace3a7317cc3ba1fbc749758021a83136 upstream.

"cat /sys/devices/system/memory/memory*/removable" crashed the system.

The problem is that show_mem_removable() is passing a
bad pfn to is_mem_section_removable(), which causes

    if (!node_online(page_to_nid(page)))

to blow up.  Why is it passing in a bad pfn?

The reason is that show_mem_removable() will loop sections_per_block
times.  sections_per_block is 16, but mem->section_count is 8,
indicating holes in this memory block.  Checking that the memory section
is present before checking to see if the memory section is removable
fixes the problem.

   harp5-sys:~ # cat /sys/devices/system/memory/memory*/removable
   0
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   1
   BUG: unable to handle kernel paging request at ffffea00c3200000
   IP: [] is_pageblock_removable_nolock+0x1/0x90
   PGD 83ffd4067 PUD 37bdfce067 PMD 0
   Oops: 0000 [#1] SMP
   Modules linked in: autofs4 binfmt_misc rdma_ucm rdma_cm iw_cm ib_addr ib_srp scsi_transport_srp scsi_tgt ib_ipoib ib_cm ib_uverbs ib_umad iw_cxgb3 cxgb3 mdio mlx4_en mlx4_ib ib_sa mlx4_core ib_mthca ib_mad ib_core fuse nls_iso8859_1 nls_cp437 vfat fat joydev loop hid_generic usbhid hid hwperf(O) numatools(O) dm_mod iTCO_wdt ipv6 iTCO_vendor_support igb i2c_i801 ioatdma i2c_algo_bit ehci_pci pcspkr lpc_ich i2c_core ehci_hcd ptp sg mfd_core dca rtc_cmos pps_core mperf button xhci_hcd sd_mod crc_t10dif usbcore usb_common scsi_dh_emc scsi_dh_hp_sw scsi_dh_alua scsi_dh_rdac scsi_dh gru(O) xvma(O) xfs crc32c libcrc32c thermal sata_nv processor piix mptsas mptscsih scsi_transport_sas mptbase megaraid_sas fan thermal_sys hwmon ext3 jbd ata_piix ahci libahci libata scsi_mod
   CPU: 4 PID: 5991 Comm: cat Tainted: G           O 3.11.0-rc5-rja-uv+ #10
   Hardware name: SGI UV2000/ROMLEY, BIOS SGI UV 2000/3000 series BIOS 01/15/2013
   task: ffff88081f034580 ti: ffff880820022000 task.ti: ffff880820022000
   RIP: 0010:[]  [] is_pageblock_removable_nolock+0x1/0x90
   RSP: 0018:ffff880820023df8  EFLAGS: 00010287
   RAX: 0000000000040000 RBX: ffffea00c3200000 RCX: 0000000000000004
   RDX: ffffea00c30b0000 RSI: 00000000001c0000 RDI: ffffea00c3200000
   RBP: ffff880820023e38 R08: 0000000000000000 R09: 0000000000000001
   R10: 0000000000000000 R11: 0000000000000001 R12: ffffea00c33c0000
   R13: 0000160000000000 R14: 6db6db6db6db6db7 R15: 0000000000000001
   FS:  00007ffff7fb2700(0000) GS:ffff88083fc80000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: ffffea00c3200000 CR3: 000000081b954000 CR4: 00000000000407e0
   Call Trace:
     show_mem_removable+0x41/0x70
     dev_attr_show+0x2a/0x60
     sysfs_read_file+0xf7/0x1c0
     vfs_read+0xc8/0x130
     SyS_read+0x5d/0xa0
     system_call_fastpath+0x16/0x1b

Signed-off-by: Russ Anderson 
Cc: "Rafael J. Wysocki" 
Cc: Yinghai Lu 
Reviewed-by: Yasuaki Ishimatsu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

regmap: silence GCC warning

2013-09-08T04:58:14+00:00

commit a8f28cfad8cd44d7c34b166d0e5ace1125dbee1f upstream.

Building regmap.o triggers this GCC warning:
    drivers/base/regmap/regmap.c: In function ‘regmap_raw_read’:
    drivers/base/regmap/regmap.c:1172:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]

Long story short: Jakub Jelinek pointed out that there is a type
mismatch between 'num' in regmap_volatile_range() and 'val_count' in
regmap_raw_read(). And indeed, converting 'num' to the type of
'val_count' (ie, size_t) makes this warning go away.

Signed-off-by: Paul Bolle 
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

regmap: cache Fix regcache-rbtree sync

2013-04-12T16:38:43+00:00

commit 8abac3ba51b5525354e9b2ec0eed1c9e95c905d9 upstream.

The last register block, which falls into the specified range, is not handled
correctly. The formula which calculates the number of register which should be
synced is inverse (and off by one). E.g. if all registers in that block should
be synced only one is synced, and if only one should be synced all (but one) are
synced. To calculate the number of registers that need to be synced we need to
subtract the number of the first register in the block from the max register
number and add one. This patch updates the code accordingly.

The issue was introduced in commit ac8d91c ("regmap: Supply ranges to the sync
operations").

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

drivercore: Fix ordering between deferred_probe and exiting initcalls

2013-02-28T14:59:01+00:00

commit d72cca1eee5b26e313da2a380d4862924e271031 upstream.

One of the side effects of deferred probe is that some drivers which
used to be probed before initcalls completed are now happening slightly
later. This causes two problems.
- If a console driver gets deferred, then it may not be ready when
  userspace starts. For example, if a uart depends on pinctrl, then the
  uart will get deferred and /dev/console will not be available
- __init sections will be discarded before built-in drivers are probed.
  Strictly speaking, __init functions should not be called in a drivers
  __probe path, but there are a lot of drivers (console stuff again)
  that do anyway. In the past it was perfectly safe to do so because all
  built-in drivers got probed before the end of initcalls.

This patch fixes the problem by forcing the first pass of the deferred
list to complete at late_initcall time. This is late enough to catch the
drivers that are known to have the above issues.

Signed-off-by: Grant Likely 
Tested-by: Haojian Zhuang 
Cc: Arnd Bergmann 
Cc: Russell King 
Cc: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman