linux.git/arch/arm64/kernel, branch v4.20 Linux kernel source tree arm64: hibernate: Avoid sending cross-calling with interrupts disabled 2018-12-07T15:52:39+00:00 Will Deacon will.deacon@arm.com 2018-12-07T12:47:10+00:00 b4aecf78083d8c6424657c1746c7c3de6e61669f Since commit 3b8c9f1cdfc50 ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings"), a call to flush_icache_range() will use an IPI to cross-call other online CPUs so that any stale instructions are flushed from their pipelines. This triggers a WARN during the hibernation resume path, where flush_icache_range() is called with interrupts disabled and is therefore prone to deadlock: | Disabling non-boot CPUs ... | CPU1: shutdown | psci: CPU1 killed. | CPU2: shutdown | psci: CPU2 killed. | CPU3: shutdown | psci: CPU3 killed. | WARNING: CPU: 0 PID: 1 at ../kernel/smp.c:416 smp_call_function_many+0xd4/0x350 | Modules linked in: | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc4 #1 Since all secondary CPUs have been taken offline prior to invalidating the I-cache, there's actually no need for an IPI and we can simply call __flush_icache_range() instead. Cc: <stable@vger.kernel.org> Fixes: 3b8c9f1cdfc50 ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings") Reported-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> Tested-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> Tested-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
Since commit 3b8c9f1cdfc50 ("arm64: IPI each CPU after invalidating the
I-cache for kernel mappings"), a call to flush_icache_range() will use
an IPI to cross-call other online CPUs so that any stale instructions
are flushed from their pipelines. This triggers a WARN during the
hibernation resume path, where flush_icache_range() is called with
interrupts disabled and is therefore prone to deadlock:

  | Disabling non-boot CPUs ...
  | CPU1: shutdown
  | psci: CPU1 killed.
  | CPU2: shutdown
  | psci: CPU2 killed.
  | CPU3: shutdown
  | psci: CPU3 killed.
  | WARNING: CPU: 0 PID: 1 at ../kernel/smp.c:416 smp_call_function_many+0xd4/0x350
  | Modules linked in:
  | CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.20.0-rc4 #1

Since all secondary CPUs have been taken offline prior to invalidating
the I-cache, there's actually no need for an IPI and we can simply call
__flush_icache_range() instead.

Cc: <stable@vger.kernel.org>
Fixes: 3b8c9f1cdfc50 ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings")
Reported-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Tested-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com>
Tested-by: James Morse <james.morse@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux 2018-12-01T02:39:07+00:00 Linus Torvalds torvalds@linux-foundation.org 2018-12-01T02:39:07+00:00 868dda00b98ccc701a70b8c1b0168fc3bbfd595d Pull arm64 fixes from Catalin Marinas: - Cortex-A76 erratum workaround - ftrace fix to enable syscall events on arm64 - Fix uninitialised pointer in iort_get_platform_device_domain() * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: ACPI/IORT: Fix iort_get_platform_device_domain() uninitialized pointer value arm64: ftrace: Fix to enable syscall events on arm64 arm64: Add workaround for Cortex-A76 erratum 1286807 
Pull arm64 fixes from Catalin Marinas:

 - Cortex-A76 erratum workaround

 - ftrace fix to enable syscall events on arm64

 - Fix uninitialised pointer in iort_get_platform_device_domain()

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  ACPI/IORT: Fix iort_get_platform_device_domain() uninitialized pointer value
  arm64: ftrace: Fix to enable syscall events on arm64
  arm64: Add workaround for Cortex-A76 erratum 1286807
Merge tag 'trace-v4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace 2018-11-30T17:32:34+00:00 Linus Torvalds torvalds@linux-foundation.org 2018-11-30T17:32:34+00:00 0f1f692375450338a36af308cbb538ffabd130f9 Pull tracing fixes from Steven Rostedt: "While rewriting the function graph tracer, I discovered a design flaw that was introduced by a patch that tried to fix one bug, but by doing so created another bug. As both bugs corrupt the output (but they do not crash the kernel), I decided to fix the design such that it could have both bugs fixed. The original fix, fixed time reporting of the function graph tracer when doing a max_depth of one. This was code that can test how much the kernel interferes with userspace. But in doing so, it could corrupt the time keeping of the function profiler. The issue is that the curr_ret_stack variable was being used for two different meanings. One was to keep track of the stack pointer on the ret_stack (shadow stack used by the function graph tracer), and the other use case was the graph call depth. Although, the two may be closely related, where they got updated was the issue that lead to the two different bugs that required the two use cases to be updated differently. The big issue with this fix is that it requires changing each architecture. The good news is, I was able to remove a lot of code that was duplicated within the architectures and place it into a single location. Then I could make the fix in one place. I pushed this code into linux-next to let it settle over a week, and before doing so, I cross compiled all the affected architectures to make sure that they built fine. In the mean time, I also pulled in a patch that fixes the sched_switch previous tasks state output, that was not actually correct" * tag 'trace-v4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: sched, trace: Fix prev_state output in sched_switch tracepoint function_graph: Have profiler use curr_ret_stack and not depth function_graph: Reverse the order of pushing the ret_stack and the callback function_graph: Move return callback before update of curr_ret_stack function_graph: Use new curr_ret_depth to manage depth instead of curr_ret_stack function_graph: Make ftrace_push_return_trace() static sparc/function_graph: Simplify with function_graph_enter() sh/function_graph: Simplify with function_graph_enter() s390/function_graph: Simplify with function_graph_enter() riscv/function_graph: Simplify with function_graph_enter() powerpc/function_graph: Simplify with function_graph_enter() parisc: function_graph: Simplify with function_graph_enter() nds32: function_graph: Simplify with function_graph_enter() MIPS: function_graph: Simplify with function_graph_enter() microblaze: function_graph: Simplify with function_graph_enter() arm64: function_graph: Simplify with function_graph_enter() ARM: function_graph: Simplify with function_graph_enter() x86/function_graph: Simplify with function_graph_enter() function_graph: Create function_graph_enter() to consolidate architecture code 
Pull tracing fixes from Steven Rostedt:
 "While rewriting the function graph tracer, I discovered a design flaw
  that was introduced by a patch that tried to fix one bug, but by doing
  so created another bug.

  As both bugs corrupt the output (but they do not crash the kernel), I
  decided to fix the design such that it could have both bugs fixed. The
  original fix, fixed time reporting of the function graph tracer when
  doing a max_depth of one. This was code that can test how much the
  kernel interferes with userspace. But in doing so, it could corrupt
  the time keeping of the function profiler.

  The issue is that the curr_ret_stack variable was being used for two
  different meanings. One was to keep track of the stack pointer on the
  ret_stack (shadow stack used by the function graph tracer), and the
  other use case was the graph call depth. Although, the two may be
  closely related, where they got updated was the issue that lead to the
  two different bugs that required the two use cases to be updated
  differently.

  The big issue with this fix is that it requires changing each
  architecture. The good news is, I was able to remove a lot of code
  that was duplicated within the architectures and place it into a
  single location. Then I could make the fix in one place.

  I pushed this code into linux-next to let it settle over a week, and
  before doing so, I cross compiled all the affected architectures to
  make sure that they built fine.

  In the mean time, I also pulled in a patch that fixes the sched_switch
  previous tasks state output, that was not actually correct"

* tag 'trace-v4.20-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  sched, trace: Fix prev_state output in sched_switch tracepoint
  function_graph: Have profiler use curr_ret_stack and not depth
  function_graph: Reverse the order of pushing the ret_stack and the callback
  function_graph: Move return callback before update of curr_ret_stack
  function_graph: Use new curr_ret_depth to manage depth instead of curr_ret_stack
  function_graph: Make ftrace_push_return_trace() static
  sparc/function_graph: Simplify with function_graph_enter()
  sh/function_graph: Simplify with function_graph_enter()
  s390/function_graph: Simplify with function_graph_enter()
  riscv/function_graph: Simplify with function_graph_enter()
  powerpc/function_graph: Simplify with function_graph_enter()
  parisc: function_graph: Simplify with function_graph_enter()
  nds32: function_graph: Simplify with function_graph_enter()
  MIPS: function_graph: Simplify with function_graph_enter()
  microblaze: function_graph: Simplify with function_graph_enter()
  arm64: function_graph: Simplify with function_graph_enter()
  ARM: function_graph: Simplify with function_graph_enter()
  x86/function_graph: Simplify with function_graph_enter()
  function_graph: Create function_graph_enter() to consolidate architecture code
arm64: Add workaround for Cortex-A76 erratum 1286807 2018-11-29T16:45:45+00:00 Catalin Marinas catalin.marinas@arm.com 2018-11-19T11:27:28+00:00 ce8c80c536dac9f325a051b30bf7730ee505eddc On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual address for a cacheable mapping of a location is being accessed by a core while another core is remapping the virtual address to a new physical page using the recommended break-before-make sequence, then under very rare circumstances TLBI+DSB completes before a read using the translation being invalidated has been observed by other observers. The workaround repeats the TLBI+DSB operation and is shared with the Qualcomm Falkor erratum 1009 Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
On the affected Cortex-A76 cores (r0p0 to r3p0), if a virtual address
for a cacheable mapping of a location is being accessed by a core while
another core is remapping the virtual address to a new physical page
using the recommended break-before-make sequence, then under very rare
circumstances TLBI+DSB completes before a read using the translation
being invalidated has been observed by other observers. The workaround
repeats the TLBI+DSB operation and is shared with the Qualcomm Falkor
erratum 1009

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: function_graph: Simplify with function_graph_enter() 2018-11-28T01:30:01+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2018-11-18T22:21:51+00:00 01e0ab2c4ff12358f15a856fd1a7bbea0670972b The function_graph_enter() function does the work of calling the function graph hook function and the management of the shadow stack, simplifying the work done in the architecture dependent prepare_ftrace_return(). Have arm64 use the new code, and remove the shadow stack management as well as having to set up the trace structure. This is needed to prepare for a fix of a design bug on how the curr_ret_stack is used. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: linux-arm-kernel@lists.infradead.org Cc: stable@kernel.org Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback") Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> 
The function_graph_enter() function does the work of calling the function
graph hook function and the management of the shadow stack, simplifying the
work done in the architecture dependent prepare_ftrace_return().

Have arm64 use the new code, and remove the shadow stack management as well as
having to set up the trace structure.

This is needed to prepare for a fix of a design bug on how the curr_ret_stack
is used.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: stable@kernel.org
Fixes: 03274a3ffb449 ("tracing/fgraph: Adjust fgraph depth before calling trace return callback")
Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
arm64: cpufeature: Fix mismerge of CONFIG_ARM64_SSBD block 2018-11-23T18:44:16+00:00 Will Deacon will.deacon@arm.com 2018-11-21T15:07:00+00:00 4f9f49646a5733c0c2bd49940673dde89a9c5add When merging support for SSBD and the CRC32 instructions, the conflict resolution for the new capability entries in arm64_features[] inadvertedly predicated the availability of the CRC32 instructions on CONFIG_ARM64_SSBD, despite the functionality being entirely unrelated. Move the #ifdef CONFIG_ARM64_SSBD down so that it only covers the SSBD capability. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
When merging support for SSBD and the CRC32 instructions, the conflict
resolution for the new capability entries in arm64_features[]
inadvertedly predicated the availability of the CRC32 instructions on
CONFIG_ARM64_SSBD, despite the functionality being entirely unrelated.

Move the #ifdef CONFIG_ARM64_SSBD down so that it only covers the SSBD
capability.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
efi/arm: Defer persistent reservations until after paging_init() 2018-11-15T09:04:46+00:00 Ard Biesheuvel ard.biesheuvel@linaro.org 2018-11-14T17:55:43+00:00 eff896288872d687d9662000ec9ae11b6d61766f The new memory EFI reservation feature we introduced to allow memory reservations to persist across kexec may trigger an unbounded number of calls to memblock_reserve(). The memblock subsystem can deal with this fine, but not before memblock resizing is enabled, which we can only do after paging_init(), when the memory we reallocate the array into is actually mapped. So break out the memreserve table processing into a separate routine and call it after paging_init() on arm64. On ARM, because of limited reviewing bandwidth of the maintainer, we cannot currently fix this, so instead, disable the EFI persistent memreserve entirely on ARM so we can fix it later. Tested-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20181114175544.12860-5-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org> 
The new memory EFI reservation feature we introduced to allow memory
reservations to persist across kexec may trigger an unbounded number
of calls to memblock_reserve(). The memblock subsystem can deal with
this fine, but not before memblock resizing is enabled, which we can
only do after paging_init(), when the memory we reallocate the array
into is actually mapped.

So break out the memreserve table processing into a separate routine
and call it after paging_init() on arm64. On ARM, because of limited
reviewing bandwidth of the maintainer, we cannot currently fix this,
so instead, disable the EFI persistent memreserve entirely on ARM so
we can fix it later.

Tested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20181114175544.12860-5-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux 2018-11-03T17:55:23+00:00 Linus Torvalds torvalds@linux-foundation.org 2018-11-03T17:55:23+00:00 83650fd58a934fad5b7735fea96905ef986c0821 Pull more arm64 updates from Catalin Marinas: - fix W+X page (mark RO) allocated by the arm64 kprobes code - Makefile fix for .i files in out of tree modules * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: kprobe: make page to RO mode when allocate it arm64: kdump: fix small typo arm64: makefile fix build of .i file in external module case 
Pull more arm64 updates from Catalin Marinas:

 - fix W+X page (mark RO) allocated by the arm64 kprobes code

 - Makefile fix for .i files in out of tree modules

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: kprobe: make page to RO mode when allocate it
  arm64: kdump: fix small typo
  arm64: makefile fix build of .i file in external module case
arm64: kprobe: make page to RO mode when allocate it 2018-11-02T18:15:07+00:00 Anders Roxell anders.roxell@linaro.org 2018-10-30T11:38:50+00:00 966866892cf89d606544bca22d584ba2ef9ec208 Commit 1404d6f13e47 ("arm64: dump: Add checking for writable and exectuable pages") has successfully identified code that leaves a page with W+X permissions. [ 3.245140] arm64/mm: Found insecure W+X mapping at address (____ptrval____)/0xffff000000d90000 [ 3.245771] WARNING: CPU: 0 PID: 1 at ../arch/arm64/mm/dump.c:232 note_page+0x410/0x420 [ 3.246141] Modules linked in: [ 3.246653] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc5-next-20180928-00001-ge70ae259b853-dirty #62 [ 3.247008] Hardware name: linux,dummy-virt (DT) [ 3.247347] pstate: 80000005 (Nzcv daif -PAN -UAO) [ 3.247623] pc : note_page+0x410/0x420 [ 3.247898] lr : note_page+0x410/0x420 [ 3.248071] sp : ffff00000804bcd0 [ 3.248254] x29: ffff00000804bcd0 x28: ffff000009274000 [ 3.248578] x27: ffff00000921a000 x26: ffff80007dfff000 [ 3.248845] x25: ffff0000093f5000 x24: ffff000009526f6a [ 3.249109] x23: 0000000000000004 x22: ffff000000d91000 [ 3.249396] x21: ffff000000d90000 x20: 0000000000000000 [ 3.249661] x19: ffff00000804bde8 x18: 0000000000000400 [ 3.249924] x17: 0000000000000000 x16: 0000000000000000 [ 3.250271] x15: ffffffffffffffff x14: 295f5f5f5f6c6176 [ 3.250594] x13: 7274705f5f5f5f28 x12: 2073736572646461 [ 3.250941] x11: 20746120676e6970 x10: 70616d20582b5720 [ 3.251252] x9 : 6572756365736e69 x8 : 3039643030303030 [ 3.251519] x7 : 306666666678302f x6 : ffff0000095467b2 [ 3.251802] x5 : 0000000000000000 x4 : 0000000000000000 [ 3.252060] x3 : 0000000000000000 x2 : ffffffffffffffff [ 3.252323] x1 : 4d151327adc50b00 x0 : 0000000000000000 [ 3.252664] Call trace: [ 3.252953] note_page+0x410/0x420 [ 3.253186] walk_pgd+0x12c/0x238 [ 3.253417] ptdump_check_wx+0x68/0xf8 [ 3.253637] mark_rodata_ro+0x68/0x98 [ 3.253847] kernel_init+0x38/0x160 [ 3.254103] ret_from_fork+0x10/0x18 kprobes allocates a writable executable page with module_alloc() in order to store executable code. Reworked to that when allocate a page it sets mode RO. Inspired by commit 63fef14fc98a ("kprobes/x86: Make insn buffer always ROX and use text_poke()"). Suggested-by: Arnd Bergmann <arnd@arndb.de> Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Reviewed-by: Laura Abbott <labbott@redhat.com> Signed-off-by: Anders Roxell <anders.roxell@linaro.org> [catalin.marinas@arm.com: removed unnecessary casts] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
Commit 1404d6f13e47 ("arm64: dump: Add checking for writable and exectuable pages")
has successfully identified code that leaves a page with W+X
permissions.

[    3.245140] arm64/mm: Found insecure W+X mapping at address (____ptrval____)/0xffff000000d90000
[    3.245771] WARNING: CPU: 0 PID: 1 at ../arch/arm64/mm/dump.c:232 note_page+0x410/0x420
[    3.246141] Modules linked in:
[    3.246653] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.19.0-rc5-next-20180928-00001-ge70ae259b853-dirty #62
[    3.247008] Hardware name: linux,dummy-virt (DT)
[    3.247347] pstate: 80000005 (Nzcv daif -PAN -UAO)
[    3.247623] pc : note_page+0x410/0x420
[    3.247898] lr : note_page+0x410/0x420
[    3.248071] sp : ffff00000804bcd0
[    3.248254] x29: ffff00000804bcd0 x28: ffff000009274000
[    3.248578] x27: ffff00000921a000 x26: ffff80007dfff000
[    3.248845] x25: ffff0000093f5000 x24: ffff000009526f6a
[    3.249109] x23: 0000000000000004 x22: ffff000000d91000
[    3.249396] x21: ffff000000d90000 x20: 0000000000000000
[    3.249661] x19: ffff00000804bde8 x18: 0000000000000400
[    3.249924] x17: 0000000000000000 x16: 0000000000000000
[    3.250271] x15: ffffffffffffffff x14: 295f5f5f5f6c6176
[    3.250594] x13: 7274705f5f5f5f28 x12: 2073736572646461
[    3.250941] x11: 20746120676e6970 x10: 70616d20582b5720
[    3.251252] x9 : 6572756365736e69 x8 : 3039643030303030
[    3.251519] x7 : 306666666678302f x6 : ffff0000095467b2
[    3.251802] x5 : 0000000000000000 x4 : 0000000000000000
[    3.252060] x3 : 0000000000000000 x2 : ffffffffffffffff
[    3.252323] x1 : 4d151327adc50b00 x0 : 0000000000000000
[    3.252664] Call trace:
[    3.252953]  note_page+0x410/0x420
[    3.253186]  walk_pgd+0x12c/0x238
[    3.253417]  ptdump_check_wx+0x68/0xf8
[    3.253637]  mark_rodata_ro+0x68/0x98
[    3.253847]  kernel_init+0x38/0x160
[    3.254103]  ret_from_fork+0x10/0x18

kprobes allocates a writable executable page with module_alloc() in
order to store executable code.
Reworked to that when allocate a page it sets mode RO. Inspired by
commit 63fef14fc98a ("kprobes/x86: Make insn buffer always ROX and use text_poke()").

Suggested-by: Arnd Bergmann <arnd@arndb.de>
Suggested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Laura Abbott <labbott@redhat.com>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
[catalin.marinas@arm.com: removed unnecessary casts]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
arm64: kdump: fix small typo 2018-11-02T17:24:17+00:00 Yangtao Li tiny.windzz@gmail.com 2018-11-02T12:36:19+00:00 5900e02b5b8cac1792c790ac2c6adb695d530fda This brings the kernel doc in line with the function signature. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> 
This brings the kernel doc in line with the function signature.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>