linux-stable.git/drivers/of/fdt.c, branch v4.7

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

drivers/of: Rename unflatten_dt_node()

2016-05-16T12:22:34+00:00

This renames unflatten_dt_node() to unflatten_dt_nodes() as it
populates multiple device nodes from FDT blob. No logical changes
introduced.

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

drivers/of: Avoid recursively calling unflatten_dt_node()

2016-05-16T12:22:34+00:00

In current implementation, unflatten_dt_node() is called recursively
to unflatten device nodes in FDT blob. It's stress to limited stack
capacity, especially to adopt the function to unflatten device sub-tree
that possibly has multiple root nodes. In that case, we runs out of
stack and the system can't boot up successfully.

In order to reuse the function to unflatten device sub-tree, this avoids
calling the function recursively, meaning the device nodes are unflattened
in one call on unflatten_dt_node(): two arrays are introduced to track the
parent path size and the device node of current level of depth, which will
be used by the device node on next level of depth to be unflattened. All
device nodes in more than 64 level of depth are dropped and hopefully,
the system can boot up successfully with the partial device-tree.

Also, the parameter "poffset" and "fpsize" are unused and dropped and the
parameter "dryrun" is figured out from "mem == NULL". Besides, the return
value of the function is changed to indicate the size of memory consumed by
the unflatten device tree or error code.

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

drivers/of: Split unflatten_dt_node()

2016-05-16T12:22:33+00:00

The function unflatten_dt_node() is called recursively to unflatten
device nodes and properties in the FDT blob. It looks complicated
and hard to be understood.

This splits the function into 3 functions: populate_properties(),
populate_node() and unflatten_dt_node(). populate_properties(),
which is called by populate_node(), creates properties for the
indicated device node. The later one creates the device nodes
from FDT blob. populate_node() gets the offset in FDT blob for
next device nodes and then calls populate_node(). No logical
changes introduced.

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

fdt: fix extend of cmd line

2016-04-19T22:25:12+00:00

On arm CONFIG_CMDLINE_EXTEND does not append build-in
cmdline in kernel to U-boot parameters. Fix it here.
Theoretically this patch should repair kdump work where
it adds elfcorehdr= and memmap additional parameters
to second kernel.

Signed-off-by: Max Uvarov 
Signed-off-by: Rob Herring

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2016-03-18T03:03:47+00:00

Pull arm64 updates from Catalin Marinas:
 "Here are the main arm64 updates for 4.6.  There are some relatively
  intrusive changes to support KASLR, the reworking of the kernel
  virtual memory layout and initial page table creation.

  Summary:

   - Initial page table creation reworked to avoid breaking large block
     mappings (huge pages) into smaller ones.  The ARM architecture
     requires break-before-make in such cases to avoid TLB conflicts but
     that's not always possible on live page tables

   - Kernel virtual memory layout: the kernel image is no longer linked
     to the bottom of the linear mapping (PAGE_OFFSET) but at the bottom
     of the vmalloc space, allowing the kernel to be loaded (nearly)
     anywhere in physical RAM

   - Kernel ASLR: position independent kernel Image and modules being
     randomly mapped in the vmalloc space with the randomness is
     provided by UEFI (efi_get_random_bytes() patches merged via the
     arm64 tree, acked by Matt Fleming)

   - Implement relative exception tables for arm64, required by KASLR
     (initial code for ARCH_HAS_RELATIVE_EXTABLE added to lib/extable.c
     but actual x86 conversion to deferred to 4.7 because of the merge
     dependencies)

   - Support for the User Access Override feature of ARMv8.2: this
     allows uaccess functions (get_user etc.) to be implemented using
     LDTR/STTR instructions.  Such instructions, when run by the kernel,
     perform unprivileged accesses adding an extra level of protection.
     The set_fs() macro is used to "upgrade" such instruction to
     privileged accesses via the UAO bit

   - Half-precision floating point support (part of ARMv8.2)

   - Optimisations for CPUs with or without a hardware prefetcher (using
     run-time code patching)

   - copy_page performance improvement to deal with 128 bytes at a time

   - Sanity checks on the CPU capabilities (via CPUID) to prevent
     incompatible secondary CPUs from being brought up (e.g.  weird
     big.LITTLE configurations)

   - valid_user_regs() reworked for better sanity check of the
     sigcontext information (restored pstate information)

   - ACPI parking protocol implementation

   - CONFIG_DEBUG_RODATA enabled by default

   - VDSO code marked as read-only

   - DEBUG_PAGEALLOC support

   - ARCH_HAS_UBSAN_SANITIZE_ALL enabled

   - Erratum workaround Cavium ThunderX SoC

   - set_pte_at() fix for PROT_NONE mappings

   - Code clean-ups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (99 commits)
  arm64: kasan: Fix zero shadow mapping overriding kernel image shadow
  arm64: kasan: Use actual memory node when populating the kernel image shadow
  arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permission
  arm64: Fix misspellings in comments.
  arm64: efi: add missing frame pointer assignment
  arm64: make mrs_s prefixing implicit in read_cpuid
  arm64: enable CONFIG_DEBUG_RODATA by default
  arm64: Rework valid_user_regs
  arm64: mm: check at build time that PAGE_OFFSET divides the VA space evenly
  arm64: KVM: Move kvm_call_hyp back to its original localtion
  arm64: mm: treat memstart_addr as a signed quantity
  arm64: mm: list kernel sections in order
  arm64: lse: deal with clobbered IP registers after branch via PLT
  arm64: mm: dump: Use VA_START directly instead of private LOWEST_ADDR
  arm64: kconfig: add submenu for 8.2 architectural features
  arm64: kernel: acpi: fix ioremap in ACPI parking protocol cpu_postboot
  arm64: Add support for Half precision floating point
  arm64: Remove fixmap include fragility
  arm64: Add workaround for Cavium erratum 27456
  arm64: mm: Mark .rodata as RO
  ...