linux-toradex.git/arch/arm64, branch v4.4.7 Linux kernel for Apalis and Colibri modules arm64: account for sparsemem section alignment when choosing vmemmap offset 2016-03-16T15:42:57+00:00 Ard Biesheuvel ard.biesheuvel@linaro.org 2016-03-08T14:09:29+00:00 97142f3009557c27091c694f927041f28ef81573 commit 36e5cd6b897e17d03008f81e075625d8e43e52d0 upstream. Commit dfd55ad85e4a ("arm64: vmemmap: use virtual projection of linear region") fixed an issue where the struct page array would overflow into the adjacent virtual memory region if system RAM was placed so high up in physical memory that its addresses were not representable in the build time configured virtual address size. However, the fix failed to take into account that the vmemmap region needs to be relatively aligned with respect to the sparsemem section size, so that a sequence of page structs corresponding with a sparsemem section in the linear region appears naturally aligned in the vmemmap region. So round up vmemmap to sparsemem section size. Since this essentially moves the projection of the linear region up in memory, also revert the reduction of the size of the vmemmap region. Fixes: dfd55ad85e4a ("arm64: vmemmap: use virtual projection of linear region") Tested-by: Mark Langsdorf <mlangsdo@redhat.com> Tested-by: David Daney <david.daney@cavium.com> Tested-by: Robert Richter <rrichter@cavium.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 36e5cd6b897e17d03008f81e075625d8e43e52d0 upstream.

Commit dfd55ad85e4a ("arm64: vmemmap: use virtual projection of linear
region") fixed an issue where the struct page array would overflow into the
adjacent virtual memory region if system RAM was placed so high up in
physical memory that its addresses were not representable in the build time
configured virtual address size.

However, the fix failed to take into account that the vmemmap region needs
to be relatively aligned with respect to the sparsemem section size, so that
a sequence of page structs corresponding with a sparsemem section in the
linear region appears naturally aligned in the vmemmap region.

So round up vmemmap to sparsemem section size. Since this essentially moves
the projection of the linear region up in memory, also revert the reduction
of the size of the vmemmap region.

Fixes: dfd55ad85e4a ("arm64: vmemmap: use virtual projection of linear region")
Tested-by: Mark Langsdorf <mlangsdo@redhat.com>
Tested-by: David Daney <david.daney@cavium.com>
Tested-by: Robert Richter <rrichter@cavium.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: vmemmap: use virtual projection of linear region 2016-03-09T23:34:52+00:00 Ard Biesheuvel ard.biesheuvel@linaro.org 2016-02-26T16:57:13+00:00 e75c4b65150f099789821cb5e3f0efc964c1db05 commit dfd55ad85e4a7fbaa82df12467515ac3c81e8a3e upstream. Commit dd006da21646 ("arm64: mm: increase VA range of identity map") made some changes to the memory mapping code to allow physical memory to reside at an offset that exceeds the size of the virtual mapping. However, since the size of the vmemmap area is proportional to the size of the VA area, but it is populated relative to the physical space, we may end up with the struct page array being mapped outside of the vmemmap region. For instance, on my Seattle A0 box, I can see the following output in the dmesg log. vmemmap : 0xffffffbdc0000000 - 0xffffffbfc0000000 ( 8 GB maximum) 0xffffffbfc0000000 - 0xffffffbfd0000000 ( 256 MB actual) We can fix this by deciding that the vmemmap region is not a projection of the physical space, but of the virtual space above PAGE_OFFSET, i.e., the linear region. This way, we are guaranteed that the vmemmap region is of sufficient size, and we can even reduce the size by half. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit dfd55ad85e4a7fbaa82df12467515ac3c81e8a3e upstream.

Commit dd006da21646 ("arm64: mm: increase VA range of identity map") made
some changes to the memory mapping code to allow physical memory to reside
at an offset that exceeds the size of the virtual mapping.

However, since the size of the vmemmap area is proportional to the size of
the VA area, but it is populated relative to the physical space, we may
end up with the struct page array being mapped outside of the vmemmap
region. For instance, on my Seattle A0 box, I can see the following output
in the dmesg log.

   vmemmap : 0xffffffbdc0000000 - 0xffffffbfc0000000   (     8 GB maximum)
             0xffffffbfc0000000 - 0xffffffbfd0000000   (   256 MB actual)

We can fix this by deciding that the vmemmap region is not a projection of
the physical space, but of the virtual space above PAGE_OFFSET, i.e., the
linear region. This way, we are guaranteed that the vmemmap region is of
sufficient size, and we can even reduce the size by half.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm/arm64: KVM: Fix ioctl error handling 2016-03-09T23:34:51+00:00 Michael S. Tsirkin mst@redhat.com 2016-02-28T15:32:07+00:00 d1c623c9c264c6cb045015900f8ce1e60b4d2c7d commit 4cad67fca3fc952d6f2ed9e799621f07666a560f upstream. Calling return copy_to_user(...) in an ioctl will not do the right thing if there's a pagefault: copy_to_user returns the number of bytes not copied in this case. Fix up kvm to do return copy_to_user(...)) ? -EFAULT : 0; everywhere. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4cad67fca3fc952d6f2ed9e799621f07666a560f upstream.

Calling return copy_to_user(...) in an ioctl will not
do the right thing if there's a pagefault:
copy_to_user returns the number of bytes not copied
in this case.

Fix up kvm to do
	return copy_to_user(...)) ?  -EFAULT : 0;

everywhere.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: errata: Add -mpc-relative-literal-loads to build flags 2016-03-03T23:07:08+00:00 dann frazier dann.frazier@canonical.com 2016-01-25T23:52:16+00:00 db8bb76c6f9564e18d5dda4d89e4fc70dc83c3fd commit 67dfa1751ce71e629aad7c438e1678ad41054677 upstream. GCC6 (and Linaro's 2015.12 snapshot of GCC5) has a new default that uses adrp/ldr or adrp/add to address literal pools. When CONFIG_ARM64_ERRATUM_843419 is enabled, modules built with this toolchain fail to load: module libahci: unsupported RELA relocation: 275 This patch fixes the problem by passing '-mpc-relative-literal-loads' to the compiler. Cc: stable@vger.kernel.org Fixes: df057cc7b4fa ("arm64: errata: add module build workaround for erratum #843419") BugLink: http://bugs.launchpad.net/bugs/1533009 Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Suggested-by: Christophe Lyon <christophe.lyon@linaro.org> Signed-off-by: Dann Frazier <dann.frazier@canonical.com> [will: backport to 4.4-stable] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 67dfa1751ce71e629aad7c438e1678ad41054677 upstream.

GCC6 (and Linaro's 2015.12 snapshot of GCC5) has a new default that uses
adrp/ldr or adrp/add to address literal pools. When CONFIG_ARM64_ERRATUM_843419
is enabled, modules built with this toolchain fail to load:

  module libahci: unsupported RELA relocation: 275

This patch fixes the problem by passing '-mpc-relative-literal-loads'
to the compiler.

Cc: stable@vger.kernel.org
Fixes: df057cc7b4fa ("arm64: errata: add module build workaround for erratum #843419")
BugLink: http://bugs.launchpad.net/bugs/1533009
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Suggested-by: Christophe Lyon <christophe.lyon@linaro.org>
Signed-off-by: Dann Frazier <dann.frazier@canonical.com>
[will: backport to 4.4-stable]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: dma-mapping: fix handling of devices registered before arch_initcall 2016-02-25T20:01:20+00:00 Marek Szyprowski m.szyprowski@samsung.com 2016-02-16T14:14:44+00:00 593337c55ac30807f38ca924e716edfdc4e6a916 commit 722ec35f7faefcc34d12616eca7976a848870f9d upstream. This patch ensures that devices, which got registered before arch_initcall will be handled correctly by IOMMU-based DMA-mapping code. Fixes: 13b8629f6511 ("arm64: Add IOMMU dma_ops") Acked-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 722ec35f7faefcc34d12616eca7976a848870f9d upstream.

This patch ensures that devices, which got registered before arch_initcall
will be handled correctly by IOMMU-based DMA-mapping code.

Fixes: 13b8629f6511 ("arm64: Add IOMMU dma_ops")
Acked-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: mm: avoid calling apply_to_page_range on empty range 2016-02-25T20:01:19+00:00 Mika Penttilä mika.penttila@nextfour.com 2016-01-26T15:47:25+00:00 a68f555363f5e43d0da4a6d025e23db74e2b4f1f commit 57adec866c0440976c96a4b8f5b59fb411b1cacb upstream. Calling apply_to_page_range with an empty range results in a BUG_ON from the core code. This can be triggered by trying to load the st_drv module with CONFIG_DEBUG_SET_MODULE_RONX enabled: kernel BUG at mm/memory.c:1874! Internal error: Oops - BUG: 0 [#1] PREEMPT SMP Modules linked in: CPU: 3 PID: 1764 Comm: insmod Not tainted 4.5.0-rc1+ #2 Hardware name: ARM Juno development board (r0) (DT) task: ffffffc9763b8000 ti: ffffffc975af8000 task.ti: ffffffc975af8000 PC is at apply_to_page_range+0x2cc/0x2d0 LR is at change_memory_common+0x80/0x108 This patch fixes the issue by making change_memory_common (called by the set_memory_* functions) a NOP when numpages == 0, therefore avoiding the erroneous call to apply_to_page_range and bringing us into line with x86 and s390. Reviewed-by: Laura Abbott <labbott@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 57adec866c0440976c96a4b8f5b59fb411b1cacb upstream.

Calling apply_to_page_range with an empty range results in a BUG_ON
from the core code. This can be triggered by trying to load the st_drv
module with CONFIG_DEBUG_SET_MODULE_RONX enabled:

  kernel BUG at mm/memory.c:1874!
  Internal error: Oops - BUG: 0 [#1] PREEMPT SMP
  Modules linked in:
  CPU: 3 PID: 1764 Comm: insmod Not tainted 4.5.0-rc1+ #2
  Hardware name: ARM Juno development board (r0) (DT)
  task: ffffffc9763b8000 ti: ffffffc975af8000 task.ti: ffffffc975af8000
  PC is at apply_to_page_range+0x2cc/0x2d0
  LR is at change_memory_common+0x80/0x108

This patch fixes the issue by making change_memory_common (called by the
set_memory_* functions) a NOP when numpages == 0, therefore avoiding the
erroneous call to apply_to_page_range and bringing us into line with x86
and s390.

Reviewed-by: Laura Abbott <labbott@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Mika Penttilä <mika.penttila@nextfour.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: kernel: fix architected PMU registers unconditional access 2016-01-31T19:29:04+00:00 Lorenzo Pieralisi lorenzo.pieralisi@arm.com 2016-01-13T14:50:03+00:00 9497f702ab82314dffa457823be91783ca5a4531 commit f436b2ac90a095746beb6729b8ee8ed87c9eaede upstream. The Performance Monitors extension is an optional feature of the AArch64 architecture, therefore, in order to access Performance Monitors registers safely, the kernel should detect the architected PMU unit presence through the ID_AA64DFR0_EL1 register PMUVer field before accessing them. This patch implements a guard by reading the ID_AA64DFR0_EL1 register PMUVer field to detect the architected PMU presence and prevent accessing PMU system registers if the Performance Monitors extension is not implemented in the core. Cc: Peter Maydell <peter.maydell@linaro.org> Cc: Mark Rutland <mark.rutland@arm.com> Fixes: 60792ad349f3 ("arm64: kernel: enforce pmuserenr_el0 initialization and restore") Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Reported-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f436b2ac90a095746beb6729b8ee8ed87c9eaede upstream.

The Performance Monitors extension is an optional feature of the
AArch64 architecture, therefore, in order to access Performance
Monitors registers safely, the kernel should detect the architected
PMU unit presence through the ID_AA64DFR0_EL1 register PMUVer field
before accessing them.

This patch implements a guard by reading the ID_AA64DFR0_EL1 register
PMUVer field to detect the architected PMU presence and prevent accessing
PMU system registers if the Performance Monitors extension is not
implemented in the core.

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Fixes: 60792ad349f3 ("arm64: kernel: enforce pmuserenr_el0 initialization and restore")
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: kernel: enforce pmuserenr_el0 initialization and restore 2016-01-31T19:29:04+00:00 Lorenzo Pieralisi lorenzo.pieralisi@arm.com 2015-12-18T10:35:54+00:00 f50c2907a9b3dfc1ba840e6cc9884cf77d9e44cc commit 60792ad349f3c6dc5735aafefe5dc9121c79e320 upstream. The pmuserenr_el0 register value is architecturally UNKNOWN on reset. Current kernel code resets that register value iff the core pmu device is correctly probed in the kernel. On platforms with missing DT pmu nodes (or disabled perf events in the kernel), the pmu is not probed, therefore the pmuserenr_el0 register is not reset in the kernel, which means that its value retains the reset value that is architecturally UNKNOWN (system may run with eg pmuserenr_el0 == 0x1, which means that PMU counters access is available at EL0, which must be disallowed). This patch adds code that resets pmuserenr_el0 on cold boot and restores it on core resume from shutdown, so that the pmuserenr_el0 setup is always enforced in the kernel. Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 60792ad349f3c6dc5735aafefe5dc9121c79e320 upstream.

The pmuserenr_el0 register value is architecturally UNKNOWN on reset.
Current kernel code resets that register value iff the core pmu device is
correctly probed in the kernel. On platforms with missing DT pmu nodes (or
disabled perf events in the kernel), the pmu is not probed, therefore the
pmuserenr_el0 register is not reset in the kernel, which means that its
value retains the reset value that is architecturally UNKNOWN (system
may run with eg pmuserenr_el0 == 0x1, which means that PMU counters access
is available at EL0, which must be disallowed).

This patch adds code that resets pmuserenr_el0 on cold boot and restores
it on core resume from shutdown, so that the pmuserenr_el0 setup is
always enforced in the kernel.

Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: mm: ensure that the zero page is visible to the page table walker 2016-01-31T19:29:04+00:00 Will Deacon will.deacon@arm.com 2015-12-10T16:05:36+00:00 8182d4cf11a77f2c2b6afe85366e9328107b6256 commit 32d6397805d00573ce1fa55f408ce2bca15b0ad3 upstream. In paging_init, we allocate the zero page, memset it to zero and then point TTBR0 to it in order to avoid speculative fetches through the identity mapping. In order to guarantee that the freshly zeroed page is indeed visible to the page table walker, we need to execute a dsb instruction prior to writing the TTBR. Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 32d6397805d00573ce1fa55f408ce2bca15b0ad3 upstream.

In paging_init, we allocate the zero page, memset it to zero and then
point TTBR0 to it in order to avoid speculative fetches through the
identity mapping.

In order to guarantee that the freshly zeroed page is indeed visible to
the page table walker, we need to execute a dsb instruction prior to
writing the TTBR.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
arm64: Clear out any singlestep state on a ptrace detach operation 2016-01-31T19:29:03+00:00 John Blackwood john.blackwood@ccur.com 2015-12-07T11:50:34+00:00 c01afb9239eaee84a93e7b0319e3935f55604361 commit 5db4fd8c52810bd9740c1240ebf89223b171aa70 upstream. Make sure to clear out any ptrace singlestep state when a ptrace(2) PTRACE_DETACH call is made on arm64 systems. Otherwise, the previously ptraced task will die off with a SIGTRAP signal if the debugger just previously singlestepped the ptraced task. Signed-off-by: John Blackwood <john.blackwood@ccur.com> [will: added comment to justify why this is in the arch code] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5db4fd8c52810bd9740c1240ebf89223b171aa70 upstream.

Make sure to clear out any ptrace singlestep state when a ptrace(2)
PTRACE_DETACH call is made on arm64 systems.

Otherwise, the previously ptraced task will die off with a SIGTRAP
signal if the debugger just previously singlestepped the ptraced task.

Signed-off-by: John Blackwood <john.blackwood@ccur.com>
[will: added comment to justify why this is in the arch code]
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>