linux-stable.git/drivers/of/fdt.c, branch v4.8

drivers/of: Validate device node in __unflatten_device_tree()

2016-08-09T17:36:27+00:00

@mynodes is set to NULL when __unflatten_device_tree() is called
to unflatten device sub-tree in PCI hot add scenario on PowerPC
PowerNV platform. Marking @mynodes detached unconditionally causes
kernel crash as below backtrace shows:

Unable to handle kernel paging request for data at address 0x00000000
Faulting instruction address: 0xc000000000b26f64
cpu 0x0: Vector: 300 (Data Access) at [c000003fcc7cf740]
    pc: c000000000b26f64: __unflatten_device_tree+0xf4/0x190
    lr: c000000000b26f40: __unflatten_device_tree+0xd0/0x190
    sp: c000003fcc7cf9c0
   msr: 900000000280b033
   dar: 0
 dsisr: 40000000
  current = 0xc000003fcc281680
  paca    = 0xc00000000ff00000	 softe: 0	 irq_happened: 0x01
    pid   = 2724, comm = sh
Linux version 4.7.0-gavin-07754-g92a6836 (gwshan@gwshan) (gcc version \
4.9.3 (Buildroot 2016.02-rc2-00093-g5ea3bce) ) #539 SMP Mon Aug 1 \
12:40:29 AEST 2016
enter ? for help
[c000003fcc7cfa50] c000000000b27060 of_fdt_unflatten_tree+0x60/0x90
[c000003fcc7cfaa0] c0000000004c6288 pnv_php_set_slot_power_state+0x118/0x440
[c000003fcc7cfb80] c0000000004c6a10 pnv_php_enable+0xc0/0x170
[c000003fcc7cfbd0] c0000000004c4d80 power_write_file+0xa0/0x190
[c000003fcc7cfc50] c0000000004be93c pci_slot_attr_store+0x3c/0x60
[c000003fcc7cfc70] c0000000002d3fd4 sysfs_kf_write+0x94/0xc0
[c000003fcc7cfcb0] c0000000002d2c30 kernfs_fop_write+0x180/0x260
[c000003fcc7cfd00] c000000000230fe0 __vfs_write+0x40/0x190
[c000003fcc7cfd90] c000000000232278 vfs_write+0xc8/0x240
[c000003fcc7cfde0] c000000000233d90 SyS_write+0x60/0x110
[c000003fcc7cfe30] c000000000009524 system_call+0x38/0x108

This avoids the kernel crash by marking @mynodes detached only when
@mynodes is dereferencing valid device node in __unflatten_device_tree().

Fixes: 1d1bde550ea3 ("of: fdt: mark unflattened tree as detached")
Reported-by: Meng Li 
Signed-off-by: Gavin Shan 
Signed-off-by: Rob Herring

Merge tag 'devicetree-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

2016-07-30T18:32:01+00:00

Pull DeviceTree updates from Rob Herring:

 - remove most of_platform_populate() calls in arch code.  Now the DT
   core code calls it in the default case and platforms only need to
   call it if they have special needs

 - use pr_fmt on all the DT core print statements

 - CoreSight binding doc improvements to block name descriptions

 - add dt_to_config script which can parse dts files and list
   corresponding kernel config options

 - fix memory leak hit with a PowerMac DT

 - correct a bunch of STMicro compatible strings to use the correct
   vendor prefix

 - fix DA9052 PMIC binding doc to match what is actually used in dts
   files

* tag 'devicetree-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (35 commits)
  documentation: da9052: Update regulator bindings names to match DA9052/53 DTS expectations
  xtensa: Partially Revert "xtensa: Remove unnecessary of_platform_populate with default match table"
  xtensa: Fix build error due to missing include file
  MIPS: ath79: Add missing include file
  Fix spelling errors in Documentation/devicetree
  ARM: dts: fix STMicroelectronics compatible strings
  powerpc/dts: fix STMicroelectronics compatible strings
  Documentation: dt: i2c: use correct STMicroelectronics vendor prefix
  scripts/dtc: dt_to_config - kernel config options for a devicetree
  of: fdt: mark unflattened tree as detached
  of: overlay: add resolver error prints
  coresight: document binding acronyms
  Documentation/devicetree: document cavium-pip rx-delay/tx-delay properties
  of: use pr_fmt prefix for all console printing
  of/irq: Mark initialised interrupt controllers as populated
  of: fix memory leak related to safe_name()
  Revert "of/platform: export of_default_bus_match_table"
  of: unittest: use of_platform_default_populate() to populate default bus
  memory: omap-gpmc: use of_platform_default_populate() to populate default bus
  bus: uniphier-system-bus: use of_platform_default_populate() to populate default bus
  ...

of: fdt: mark unflattened tree as detached

2016-07-18T22:27:04+00:00

The tree returned from of_fdt_unflatten_tree cannot be attached to the
live tree because it is not marked as detached so mark it as such. The
dt resolver checks the flag and refuses to process the tree otherwise.

Signed-off-by: Michal Suchanek 
Signed-off-by: Rob Herring

of: use pr_fmt prefix for all console printing

2016-07-18T21:57:42+00:00

Clean-up all the DT printk functions to use common pr_fmt prefix.

Some print statements such as kmalloc errors were redundant, so just
drop those.

Cc: Frank Rowand 
Cc: Pantelis Antoniou 
Reviewed-by: Frank Rowand 
Signed-off-by: Rob Herring

FDT: Add a helper to get the subnode by given name

2016-07-06T09:34:46+00:00

Sometimes it needs to check if there is a subnode of given node in FDT
by given name. Introduce this helper to get the subnode if it exists.

CC: Rob Herring 
Signed-off-by: Shannon Zhao 
Acked-by: Stefano Stabellini 
Acked-by: Rob Herring 
Tested-by: Julien Grall

drivers/of: Fix depth for sub-tree blob in unflatten_dt_nodes()

2016-06-09T19:36:34+00:00

The function is unflattening device sub-tree blob if @dad passed to
the function is valid. Currently, this functionality is used by PPC
PowerNV PCI hotplug driver only. There are possibly multiple nodes
in the first level of depth, fdt_next_node() bails immediately when
@depth becomes negative before the second device node can be probed
successfully. It leads to the device nodes except the first one won't
be unflattened successfully.

This fixes the issue by setting the initial depth (@inital_depth) to
1 when this function is called to unflatten device sub-tree blob. No
logic changes when this function is used to unflatten non-sub-tree
blob.

Cc: Rhyland Klein 
Fixes: 78c44d910 ("drivers/of: Fix depth when unflattening devicetree")
Signed-off-by: Gavin Shan 
Tested-by: Rhyland Klein 
Tested-by: Andrew Donnellan 
Signed-off-by: Rob Herring

drivers/of: Fix build warning in populate_node()

2016-05-19T14:16:35+00:00

Function populate_node() is used to unflatten FDT blob to device
tree. It supports maximal 64 level of device nodes. There is one
array @fpsizes[64] tracking the full name length of last unflattened
device node in the corresponding level (index of element in the
array - 1). Build warning is seen with CONFIG_FRAME_WARN=1024 like
below on ARM64 as Geert reported. The issue can be reproduced on
PPC64 as well.

  $ make drivers/of/fdt.o
  drivers/of/fdt.c:443:1: warning: the frame size of 1136 bytes is \
  larger than 1024 bytes [-Wframe-larger-than=]

This changes the data type of @fpsizes[i] from "unsigned long" to
"unsigned int" to avoid the build warning. The return value type
of populate_node() and its @fpsize argument is adjusted accordingly.
With this applied, 256 bytes saved from the stack frame on ARM64 and
PPC64 platforms and the above warning isn't seen.

Fixes: 50800082f176 ("drivers/of: Avoid recursively calling unflatten_dt_node()")
Reported-by: Geert Uytterhoeven 
Signed-off-by: Gavin Shan 
Signed-off-by: Rob Herring

drivers/of: Fix depth when unflattening devicetree

2016-05-19T14:15:14+00:00

When the implementation for unflatten_dt_node() changed from being
recursive to being non-recursive, it had a side effect of increasing the
depth passed to fdt_next_node() by 1. This is fine most of the time, but
it seems that when the end of the dtb is being parsed, it will cause the
FDT_END condition in fdt_next_node() to return a different value
(returning nextoffset instead of -FDT_ERR_NOTFOUND). This ends up passing
an FDT_ERR_TRUNCATED error back to the unflatten_dt_node() which then
sees that and complains "Error -8 processing FDT" causing boot to fail.

This patch simply avoids incrementing depth and uses modified accesses
for local array indices so that the depth is the same as it was before
the change as far as fdt_next_node() is concerned.

This problem was discovered trying to boot Tegra210-Smaug platforms.

Fixes: 50800082f176 ("drivers/of: Avoid recursively calling unflatten_dt_node()")
Signed-off-by: Rhyland Klein 
[robh: squashed in KASAN fix from Rhyland]
Signed-off-by: Rob Herring

drivers/of: Return allocated memory from of_fdt_unflatten_tree()

2016-05-16T12:22:35+00:00

This returns the allocate memory chunk, storing the unflattened device
tree, from of_fdt_unflatten_tree() so that memory chunk can be released
on demand in PowerNV PCI hotplug driver.

Signed-off-by: Gavin Shan 
Acked-by: Rob Herring 
Signed-off-by: Rob Herring

drivers/of: Specify parent node in of_fdt_unflatten_tree()

2016-05-16T12:22:35+00:00

This adds one more argument to of_fdt_unflatten_tree() to specify
the parent node of the FDT blob that is going to be unflattened.
In the result, the function can be used to unflatten FDT blob that
represents device sub-tree in PowerNV PCI hotplug driver.

Cc: Jyri Sarha 
Signed-off-by: Gavin Shan 
Acked-by: Rob Herring 
Acked-by: Jyri Sarha 
Signed-off-by: Rob Herring