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2017-12-16arm64: KVM: fix VTTBR_BADDR_MASK BUG_ON off-by-oneKristina Martsenko1-2/+1
commit 26aa7b3b1c0fb3f1a6176a0c1847204ef4355693 upstream. VTTBR_BADDR_MASK is used to sanity check the size and alignment of the VTTBR address. It seems to currently be off by one, thereby only allowing up to 47-bit addresses (instead of 48-bit) and also insufficiently checking the alignment. This patch fixes it. As an example, with 4k pages, before this patch we have: PHYS_MASK_SHIFT = 48 VTTBR_X = 37 - 24 = 13 VTTBR_BADDR_SHIFT = 13 - 1 = 12 VTTBR_BADDR_MASK = ((1 << 35) - 1) << 12 = 0x00007ffffffff000 Which is wrong, because the mask doesn't allow bit 47 of the VTTBR address to be set, and only requires the address to be 12-bit (4k) aligned, while it actually needs to be 13-bit (8k) aligned because we concatenate two 4k tables. With this patch, the mask becomes 0x0000ffffffffe000, which is what we want. Fixes: 0369f6a34b9f ("arm64: KVM: EL2 register definitions") Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-08-24mm: revert x86_64 and arm64 ELF_ET_DYN_BASE base changesKees Cook1-2/+2
commit c715b72c1ba406f133217b509044c38d8e714a37 upstream. Moving the x86_64 and arm64 PIE base from 0x555555554000 to 0x000100000000 broke AddressSanitizer. This is a partial revert of: eab09532d400 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE") 02445990a96e ("arm64: move ELF_ET_DYN_BASE to 4GB / 4MB") The AddressSanitizer tool has hard-coded expectations about where executable mappings are loaded. The motivation for changing the PIE base in the above commits was to avoid the Stack-Clash CVEs that allowed executable mappings to get too close to heap and stack. This was mainly a problem on 32-bit, but the 64-bit bases were moved too, in an effort to proactively protect those systems (proofs of concept do exist that show 64-bit collisions, but other recent changes to fix stack accounting and setuid behaviors will minimize the impact). The new 32-bit PIE base is fine for ASan (since it matches the ET_EXEC base), so only the 64-bit PIE base needs to be reverted to let x86 and arm64 ASan binaries run again. Future changes to the 64-bit PIE base on these architectures can be made optional once a more dynamic method for dealing with AddressSanitizer is found. (e.g. always loading PIE into the mmap region for marked binaries.) Link: http://lkml.kernel.org/r/20170807201542.GA21271@beast Fixes: eab09532d400 ("binfmt_elf: use ELF_ET_DYN_BASE only for PIE") Fixes: 02445990a96e ("arm64: move ELF_ET_DYN_BASE to 4GB / 4MB") Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Kostya Serebryany <kcc@google.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21arm64: move ELF_ET_DYN_BASE to 4GB / 4MBKees Cook1-6/+6
commit 02445990a96e60a67526510d8b00f7e3d14101c3 upstream. Now that explicitly executed loaders are loaded in the mmap region, we have more freedom to decide where we position PIE binaries in the address space to avoid possible collisions with mmap or stack regions. For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit address space for 32-bit pointers. On 32-bit use 4MB, to match ARM. This could be 0x8000, the standard ET_EXEC load address, but that is needlessly close to the NULL address, and anyone running arm compat PIE will have an MMU, so the tight mapping is not needed. Link: http://lkml.kernel.org/r/1498251600-132458-4-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-05ARM64/ACPI: Fix BAD_MADT_GICC_ENTRY() macro implementationLorenzo Pieralisi1-3/+3
commit cb7cf772d83d2d4e6995c5bb9e0fb59aea8f7080 upstream. The BAD_MADT_GICC_ENTRY() macro checks if a GICC MADT entry passes muster from an ACPI specification standpoint. Current macro detects the MADT GICC entry length through ACPI firmware version (it changed from 76 to 80 bytes in the transition from ACPI 5.1 to ACPI 6.0 specification) but always uses (erroneously) the ACPICA (latest) struct (ie struct acpi_madt_generic_interrupt - that is 80-bytes long) length to check if the current GICC entry memory record exceeds the MADT table end in memory as defined by the MADT table header itself, which may result in false negatives depending on the ACPI firmware version and how the MADT entries are laid out in memory (ie on ACPI 5.1 firmware MADT GICC entries are 76 bytes long, so by adding 80 to a GICC entry start address in memory the resulting address may well be past the actual MADT end, triggering a false negative). Fix the BAD_MADT_GICC_ENTRY() macro by reshuffling the condition checks and update them to always use the firmware version specific MADT GICC entry length in order to carry out boundary checks. Fixes: b6cfb277378e ("ACPI / ARM64: add BAD_MADT_GICC_ENTRY() macro") Reported-by: Julien Grall <julien.grall@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Julien Grall <julien.grall@arm.com> Cc: Hanjun Guo <hanjun.guo@linaro.org> Cc: Al Stone <ahs3@redhat.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14arm64: ensure extension of smp_store_release valueMark Rutland1-4/+14
commit 994870bead4ab19087a79492400a5478e2906196 upstream. When an inline assembly operand's type is narrower than the register it is allocated to, the least significant bits of the register (up to the operand type's width) are valid, and any other bits are permitted to contain any arbitrary value. This aligns with the AAPCS64 parameter passing rules. Our __smp_store_release() implementation does not account for this, and implicitly assumes that operands have been zero-extended to the width of the type being stored to. Thus, we may store unknown values to memory when the value type is narrower than the pointer type (e.g. when storing a char to a long). This patch fixes the issue by casting the value operand to the same width as the pointer operand in all cases, which ensures that the value is zero-extended as we expect. We use the same union trickery as __smp_load_acquire and {READ,WRITE}_ONCE() to avoid GCC complaining that pointers are potentially cast to narrower width integers in unreachable paths. A whitespace issue at the top of __smp_store_release() is also corrected. No changes are necessary for __smp_load_acquire(). Load instructions implicitly clear any upper bits of the register, and the compiler will only consider the least significant bits of the register as valid regardless. Fixes: 47933ad41a86 ("arch: Introduce smp_load_acquire(), smp_store_release()") Fixes: 878a84d5a8a1 ("arm64: add missing data types in smp_load_acquire/smp_store_release") Cc: <stable@vger.kernel.org> # 3.14.x- Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14arm64: entry: improve data abort handling of tagged pointersKristina Martsenko1-0/+13
commit 276e93279a630657fff4b086ba14c95955912dfa upstream. This backport has a minor difference from the upstream commit: it adds the asm-uaccess.h file, which is not present in 4.4, because 4.4 does not have commit b4b8664d291a ("arm64: don't pull uaccess.h into *.S"). Original patch description: When handling a data abort from EL0, we currently zero the top byte of the faulting address, as we assume the address is a TTBR0 address, which may contain a non-zero address tag. However, the address may be a TTBR1 address, in which case we should not zero the top byte. This patch fixes that. The effect is that the full TTBR1 address is passed to the task's signal handler (or printed out in the kernel log). When handling a data abort from EL1, we leave the faulting address intact, as we assume it's either a TTBR1 address or a TTBR0 address with tag 0x00. This is true as far as I'm aware, we don't seem to access a tagged TTBR0 address anywhere in the kernel. Regardless, it's easy to forget about address tags, and code added in the future may not always remember to remove tags from addresses before accessing them. So add tag handling to the EL1 data abort handler as well. This also makes it consistent with the EL0 data abort handler. Fixes: d50240a5f6ce ("arm64: mm: permit use of tagged pointers at EL0") Reviewed-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-14arm64: hw_breakpoint: fix watchpoint matching for tagged pointersKristina Martsenko1-0/+8
commit 7dcd9dd8cebe9fa626af7e2358d03a37041a70fb upstream. This backport has a few small differences from the upstream commit: - The address tag is removed in watchpoint_handler() instead of get_distance_from_watchpoint(), because 4.4 does not have commit fdfeff0f9e3d ("arm64: hw_breakpoint: Handle inexact watchpoint addresses"). - A macro is backported (untagged_addr), as it is not present in 4.4. Original patch description: When we take a watchpoint exception, the address that triggered the watchpoint is found in FAR_EL1. We compare it to the address of each configured watchpoint to see which one was hit. The configured watchpoint addresses are untagged, while the address in FAR_EL1 will have an address tag if the data access was done using a tagged address. The tag needs to be removed to compare the address to the watchpoints. Currently we don't remove it, and as a result can report the wrong watchpoint as being hit (specifically, always either the highest TTBR0 watchpoint or lowest TTBR1 watchpoint). This patch removes the tag. Fixes: d50240a5f6ce ("arm64: mm: permit use of tagged pointers at EL0") Acked-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25arm64: uaccess: ensure extension of access_ok() addrMark Rutland1-1/+2
commit a06040d7a791a9177581dcf7293941bd92400856 upstream. Our access_ok() simply hands its arguments over to __range_ok(), which implicitly assummes that the addr parameter is 64 bits wide. This isn't necessarily true for compat code, which might pass down a 32-bit address parameter. In these cases, we don't have a guarantee that the address has been zero extended to 64 bits, and the upper bits of the register may contain unknown values, potentially resulting in a suprious failure. Avoid this by explicitly casting the addr parameter to an unsigned long (as is done on other architectures), ensuring that the parameter is widened appropriately. Fixes: 0aea86a2176c ("arm64: User access library functions") Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25arm64: xchg: hazard against entire exchange variableMark Rutland1-1/+1
commit fee960bed5e857eb126c4e56dd9ff85938356579 upstream. The inline assembly in __XCHG_CASE() uses a +Q constraint to hazard against other accesses to the memory location being exchanged. However, the pointer passed to the constraint is a u8 pointer, and thus the hazard only applies to the first byte of the location. GCC can take advantage of this, assuming that other portions of the location are unchanged, as demonstrated with the following test case: union u { unsigned long l; unsigned int i[2]; }; unsigned long update_char_hazard(union u *u) { unsigned int a, b; a = u->i[1]; asm ("str %1, %0" : "+Q" (*(char *)&u->l) : "r" (0UL)); b = u->i[1]; return a ^ b; } unsigned long update_long_hazard(union u *u) { unsigned int a, b; a = u->i[1]; asm ("str %1, %0" : "+Q" (*(long *)&u->l) : "r" (0UL)); b = u->i[1]; return a ^ b; } The linaro 15.08 GCC 5.1.1 toolchain compiles the above as follows when using -O2 or above: 0000000000000000 <update_char_hazard>: 0: d2800001 mov x1, #0x0 // #0 4: f9000001 str x1, [x0] 8: d2800000 mov x0, #0x0 // #0 c: d65f03c0 ret 0000000000000010 <update_long_hazard>: 10: b9400401 ldr w1, [x0,#4] 14: d2800002 mov x2, #0x0 // #0 18: f9000002 str x2, [x0] 1c: b9400400 ldr w0, [x0,#4] 20: 4a000020 eor w0, w1, w0 24: d65f03c0 ret This patch fixes the issue by passing an unsigned long pointer into the +Q constraint, as we do for our cmpxchg code. This may hazard against more than is necessary, but this is better than missing a necessary hazard. Fixes: 305d454aaa29 ("arm64: atomics: implement native {relaxed, acquire, release} atomics") Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-03-12arm/arm64: KVM: Enforce unconditional flush to PoC when mapping to stage-2Marc Zyngier1-2/+1
commit 8f36ebaf21fdae99c091c67e8b6fab33969f2667 upstream. When we fault in a page, we flush it to the PoC (Point of Coherency) if the faulting vcpu has its own caches off, so that it can observe the page we just brought it. But if the vcpu has its caches on, we skip that step. Bad things happen when *another* vcpu tries to access that page with its own caches disabled. At that point, there is no garantee that the data has made it to the PoC, and we access stale data. The obvious fix is to always flush to PoC when a page is faulted in, no matter what the state of the vcpu is. Fixes: 2d58b733c876 ("arm64: KVM: force cache clean on page fault when caches are off") Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-26arm64/ptrace: Avoid uninitialised struct padding in fpr_set()Dave Martin1-0/+1
commit aeb1f39d814b2e21e5e5706a48834bfd553d0059 upstream. This patch adds an explicit __reserved[] field to user_fpsimd_state to replace what was previously unnamed padding. This ensures that data in this region are propagated across assignment rather than being left possibly uninitialised at the destination. Fixes: 60ffc30d5652 ("arm64: Exception handling") Signed-off-by: Dave Martin <Dave.Martin@arm.com> Acked-by: Will Deacon <Will.Deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-15arm64: futex.h: Add missing PAN togglingJames Morse1-0/+2
commit 811d61e384e24759372bb3f01772f3744b0a8327 upstream. futex.h's futex_atomic_cmpxchg_inatomic() does not use the __futex_atomic_op() macro and needs its own PAN toggling. This was missed when the feature was implemented. Fixes: 338d4f49d6f ("arm64: kernel: Add support for Privileged Access Never") Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Mian Yousaf Kaukab <yousaf.kaukab@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-12-08arm64: cpufeature: Schedule enable() calls instead of calling them via IPIJames Morse2-2/+2
commit 2a6dcb2b5f3e21592ca8dfa198dcce7bec09b020 upstream. The enable() call for a cpufeature/errata is called using on_each_cpu(). This issues a cross-call IPI to get the work done. Implicitly, this stashes the running PSTATE in SPSR when the CPU receives the IPI, and restores it when we return. This means an enable() call can never modify PSTATE. To allow PAN to do this, change the on_each_cpu() call to use stop_machine(). This schedules the work on each CPU which allows us to modify PSTATE. This involves changing the protype of all the enable() functions. enable_cpu_capabilities() is called during boot and enables the feature on all online CPUs. This path now uses stop_machine(). CPU features for hotplug'd CPUs are enabled by verify_local_cpu_features() which only acts on the local CPU, and can already modify the running PSTATE as it is called from secondary_start_kernel(). Reported-by: Tony Thompson <anthony.thompson@arm.com> Reported-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> [Removed enable() hunks for features/errata v4.4. doesn't have. Changed caps->enable arg in enable_cpu_capabilities()] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-10-28arm64: percpu: rewrite ll/sc loops in assemblyWill Deacon1-64/+56
commit 1e6e57d9b34a9075d5f9e2048ea7b09756590d11 upstream. Writing the outer loop of an LL/SC sequence using do {...} while constructs potentially allows the compiler to hoist memory accesses between the STXR and the branch back to the LDXR. On CPUs that do not guarantee forward progress of LL/SC loops when faced with memory accesses to the same ERG (up to 2k) between the failed STXR and the branch back, we may end up livelocking. This patch avoids this issue in our percpu atomics by rewriting the outer loop as part of the LL/SC inline assembly block. Fixes: f97fc810798c ("arm64: percpu: Implement this_cpu operations") Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-24arm64: spinlocks: implement smp_mb__before_spinlock() as smp_mb()Will Deacon1-0/+10
commit 872c63fbf9e153146b07f0cece4da0d70b283eeb upstream. smp_mb__before_spinlock() is intended to upgrade a spin_lock() operation to a full barrier, such that prior stores are ordered with respect to loads and stores occuring inside the critical section. Unfortunately, the core code defines the barrier as smp_wmb(), which is insufficient to provide the required ordering guarantees when used in conjunction with our load-acquire-based spinlock implementation. This patch overrides the arm64 definition of smp_mb__before_spinlock() to map to a full smp_mb(). Cc: Peter Zijlstra <peterz@infradead.org> Reported-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-15arm64: Add workaround for Cavium erratum 27456Andrew Pinski1-1/+2
[ Upstream commit 104a0c02e8b1936c049e18a6d4e4ab040fb61213 ] On ThunderX T88 pass 1.x through 2.1 parts, broadcast TLBI instructions may cause the icache to become corrupted if it contains data for a non-current ASID. This patch implements the workaround (which invalidates the local icache when switching the mm) by using code patching. Signed-off-by: Andrew Pinski <apinski@cavium.com> Signed-off-by: David Daney <david.daney@cavium.com> Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-15arm64: KVM: Configure TCR_EL2.PS at runtimeTirumalesh Chalamarla1-2/+0
[ Upstream commit 3c5b1d92b3b02be07873d611a27950addff544d3 ] Setting TCR_EL2.PS to 40 bits is wrong on systems with less that less than 40 bits of physical addresses. and breaks KVM on systems where the RAM is above 40 bits. This patch uses ID_AA64MMFR0_EL1.PARange to set TCR_EL2.PS dynamically, just like we already do for VTCR_EL2.PS. [Marc: rewrote commit message, patch tidy up] Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-15irqchip/gic-v3: Make sure read from ICC_IAR1_EL1 is visible on redestributorTirumalesh Chalamarla1-0/+1
[ Upstream commit 1a1ebd5fb1e203ee8cc73508cc7a38ac4b804596 ] The ARM GICv3 specification mentions the need for dsb after a read from the ICC_IAR1_EL1 register: 4.1.1 Physical CPU Interface: The effects of reading ICC_IAR0_EL1 and ICC_IAR1_EL1 on the state of a returned INTID are not guaranteed to be visible until after the execution of a DSB. Not having this could result in missed interrupts, so let's add the required barrier. [Marc: fixed commit message] Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Tirumalesh Chalamarla <tchalamarla@caviumnetworks.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-07arm64: Define AT_VECTOR_SIZE_ARCH for ARCH_DLINFOJames Hogan2-0/+3
commit 3146bc64d12377a74dbda12b96ea32da3774ae07 upstream. AT_VECTOR_SIZE_ARCH should be defined with the maximum number of NEW_AUX_ENT entries that ARCH_DLINFO can contain, but it wasn't defined for arm64 at all even though ARCH_DLINFO will contain one NEW_AUX_ENT for the VDSO address. This shouldn't be a problem as AT_VECTOR_SIZE_BASE includes space for AT_BASE_PLATFORM which arm64 doesn't use, but lets define it now and add the comment above ARCH_DLINFO as found in several other architectures to remind future modifiers of ARCH_DLINFO to keep AT_VECTOR_SIZE_ARCH up to date. Fixes: f668cd1673aa ("arm64: ELF definitions") Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-20arm64: kernel: Save and restore UAO and addr_limit on exception entryJames Morse1-0/+2
commit e19a6ee2460bdd0d0055a6029383422773f9999a upstream. If we take an exception while at EL1, the exception handler inherits the original context's addr_limit and PSTATE.UAO values. To be consistent always reset addr_limit and PSTATE.UAO on (re-)entry to EL1. This prevents accidental re-use of the original context's addr_limit. Based on a similar patch for arm from Russell King. Cc: <stable@vger.kernel.org> # 4.6- Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> [ backport to stop perf misusing inherited addr_limit. Removed code interacting with UAO and the irqstack ] Link: https://bugs.chromium.org/p/project-zero/issues/detail?id=822 Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-07-27arm64: Rework valid_user_regsMark Rutland1-29/+4
commit dbd4d7ca563fd0a8949718d35ce197e5642d5d9d upstream. We validate pstate using PSR_MODE32_BIT, which is part of the user-provided pstate (and cannot be trusted). Also, we conflate validation of AArch32 and AArch64 pstate values, making the code difficult to reason about. Instead, validate the pstate value based on the associated task. The task may or may not be current (e.g. when using ptrace), so this must be passed explicitly by callers. To avoid circular header dependencies via sched.h, is_compat_task is pulled out of asm/ptrace.h. To make the code possible to reason about, the AArch64 and AArch32 validation is split into separate functions. Software must respect the RES0 policy for SPSR bits, and thus the kernel mirrors the hardware policy (RAZ/WI) for bits as-yet unallocated. When these acquire an architected meaning writes may be permitted (potentially with additional validation). Signed-off-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Will Deacon <will.deacon@arm.com> Cc: Dave Martin <dave.martin@arm.com> Cc: James Morse <james.morse@arm.com> Cc: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> [ rebased for v4.1+ This avoids a user-triggerable Oops() if a task is switched to a mode not supported by the kernel (e.g. switching a 64-bit task to AArch32). ] Signed-off-by: James Morse <james.morse@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> [backport] Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-24arm64: Provide "model name" in /proc/cpuinfo for PER_LINUX32 tasksCatalin Marinas1-2/+2
commit e47b020a323d1b2a7b1e9aac86e99eae19463630 upstream. This patch brings the PER_LINUX32 /proc/cpuinfo format more in line with the 32-bit ARM one by providing an additional line: model name : ARMv8 Processor rev X (v8l) Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01arm64: Implement pmdp_set_access_flags() for hardware AF/DBMCatalin Marinas1-0/+10
commit 282aa7051b0169991b34716f0f22d9c2f59c46c4 upstream. The update to the accessed or dirty states for block mappings must be done atomically on hardware with support for automatic AF/DBM. The ptep_set_access_flags() function has been fixed as part of commit 66dbd6e61a52 ("arm64: Implement ptep_set_access_flags() for hardware AF/DBM"). This patch brings pmdp_set_access_flags() in line with the pte counterpart. Fixes: 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits") Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01arm64: Implement ptep_set_access_flags() for hardware AF/DBMCatalin Marinas1-0/+5
commit 66dbd6e61a526ae7d11a208238ae2c17e5cacb6b upstream. When hardware updates of the access and dirty states are enabled, the default ptep_set_access_flags() implementation based on calling set_pte_at() directly is potentially racy. This triggers the "racy dirty state clearing" warning in set_pte_at() because an existing writable PTE is overridden with a clean entry. There are two main scenarios for this situation: 1. The CPU getting an access fault does not support hardware updates of the access/dirty flags. However, a different agent in the system (e.g. SMMU) can do this, therefore overriding a writable entry with a clean one could potentially lose the automatically updated dirty status 2. A more complex situation is possible when all CPUs support hardware AF/DBM: a) Initial state: shareable + writable vma and pte_none(pte) b) Read fault taken by two threads of the same process on different CPUs c) CPU0 takes the mmap_sem and proceeds to handling the fault. It eventually reaches do_set_pte() which sets a writable + clean pte. CPU0 releases the mmap_sem d) CPU1 acquires the mmap_sem and proceeds to handle_pte_fault(). The pte entry it reads is present, writable and clean and it continues to pte_mkyoung() e) CPU1 calls ptep_set_access_flags() If between (d) and (e) the hardware (another CPU) updates the dirty state (clears PTE_RDONLY), CPU1 will override the PTR_RDONLY bit marking the entry clean again. This patch implements an arm64-specific ptep_set_access_flags() function to perform an atomic update of the PTE flags. Fixes: 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits") Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Ming Lei <tom.leiming@gmail.com> Tested-by: Julien Grall <julien.grall@arm.com> Cc: Will Deacon <will.deacon@arm.com> [will: reworded comment] Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01arm64: Ensure pmd_present() returns false after pmd_mknotpresent()Catalin Marinas2-3/+2
commit 5bb1cc0ff9a6b68871970737e6c4c16919928d8b upstream. Currently, pmd_present() only checks for a non-zero value, returning true even after pmd_mknotpresent() (which only clears the type bits). This patch converts pmd_present() to using pte_present(), similar to the other pmd_*() checks. As a side effect, it will return true for PROT_NONE mappings, though they are not yet used by the kernel with transparent huge pages. For consistency, also change pmd_mknotpresent() to only clear the PMD_SECT_VALID bit, even though the PMD_TABLE_BIT is already 0 for block mappings (no functional change). The unused PMD_SECT_PROT_NONE definition is removed as transparent huge pages use the pte page prot values. Fixes: 9c7e535fcc17 ("arm64: mm: Route pmd thp functions through pte equivalents") Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-06-01arm64: Fix typo in the pmdp_huge_get_and_clear() definitionCatalin Marinas1-3/+3
commit 911f56eeb87ee378f5e215469268a7a2f68a5a8a upstream. With hardware AF/DBM support, pmd modifications (transparent huge pages) should be performed atomically using load/store exclusive. The initial patches defined the get-and-clear function and __HAVE_ARCH_* macro without the "huge" word, leaving the pmdp_huge_get_and_clear() to the default, non-atomic implementation. Fixes: 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits") Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04arm64: Update PTE_RDONLY in set_pte_at() for PROT_NONE permissionCatalin Marinas1-1/+2
commit fdc69e7df3cb24f18a93192641786e5b7ecd1dfe upstream. The set_pte_at() function must update the hardware PTE_RDONLY bit depending on the state of the PTE_WRITE and PTE_DIRTY bits of the given entry value. However, it currently only performs this for pte_valid() entries, ignoring PTE_PROT_NONE. The side-effect is that PROT_NONE mappings would not have the PTE_RDONLY bit set. Without CONFIG_ARM64_HW_AFDBM, this is not an issue since such PROT_NONE pages are not accessible anyway. With commit 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits"), the ptep_set_wrprotect() function was re-written to cope with automatic hardware updates of the dirty state. As an optimisation, only PTE_RDONLY is checked to assess the "dirty" status. Since set_pte_at() does not set this bit for PROT_NONE mappings, such pages may be considered "dirty" as a result of ptep_set_wrprotect(). This patch updates the pte_valid() check to pte_present() in set_pte_at(). It also adds PTE_PROT_NONE to the swap entry bits comment. Fixes: 2f4b829c625e ("arm64: Add support for hardware updates of the access and dirty pte bits") Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Ganapatrao Kulkarni <gkulkarni@caviumnetworks.com> Tested-by: Ganapatrao Kulkarni <gkulkarni@cavium.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-05-04arm64: Honour !PTE_WRITE in set_pte_at() for kernel mappingsCatalin Marinas1-11/+10
commit ac15bd63bbb24238f763ec5b24ee175ec301e8cd upstream. Currently, set_pte_at() only checks the software PTE_WRITE bit for user mappings when it sets or clears the hardware PTE_RDONLY accordingly. The kernel ptes are written directly without any modification, relying solely on the protection bits in macros like PAGE_KERNEL. However, modifying kernel pte attributes via pte_wrprotect() would be ignored by set_pte_at(). Since pte_wrprotect() does not set PTE_RDONLY (it only clears PTE_WRITE), the new permission is not taken into account. This patch changes set_pte_at() to adjust the read-only permission for kernel ptes as well. As a side effect, existing PROT_* definitions used for kernel ioremap*() need to include PTE_DIRTY | PTE_WRITE. (additionally, white space fix for PTE_KERNEL_ROX) Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-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>
2016-04-20arm64: opcodes.h: Add arm big-endian config options before including arm headerJames Morse1-0/+4
commit a6002ec5a8c68e69706b2efd6db6d682d0ab672c upstream. arm and arm64 use different config options to specify big endian. This needs taking into account when including code/headers between the two architectures. A case in point is PAN, which uses the __instr_arm() macro to output instructions. The macro comes from opcodes.h, which lives under arch/arm. On a big-endian build the mismatched config options mean the instruction isn't byte swapped correctly, resulting in undefined instruction exceptions during boot: | alternatives: patching kernel code | kdevtmpfs[87]: undefined instruction: pc=ffffffc0004505b4 | kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c | kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c | kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c | kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c | kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c | kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c | kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c | kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c | kdevtmpfs[87]: undefined instruction: pc=ffffffc00076231c | Internal error: Oops - undefined instruction: 0 [#1] SMP | Modules linked in: | CPU: 0 PID: 87 Comm: kdevtmpfs Not tainted 4.1.16+ #5 | Hardware name: Hisilicon PhosphorHi1382 EVB (DT) | task: ffffffc336591700 ti: ffffffc3365a4000 task.ti: ffffffc3365a4000 | PC is at dump_instr+0x68/0x100 | LR is at do_undefinstr+0x1d4/0x2a4 | pc : [<ffffffc00076231c>] lr : [<ffffffc0000811d4>] pstate: 604001c5 | sp : ffffffc3365a6450 Reported-by: Hanjun Guo <guohanjun@huawei.com> Tested-by: Xuefeng Wang <wxf.wang@hisilicon.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-03-16arm64: account for sparsemem section alignment when choosing vmemmap offsetArd Biesheuvel1-2/+3
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>
2016-03-09arm64: vmemmap: use virtual projection of linear regionArd Biesheuvel1-3/+4
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>
2015-12-13Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixlets from Thomas Gleixner: "Two trivial fixes which add missing header fileas and forward declarations so the code will compile even when the magic include chains are different" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/gic-v3: Add missing include for barrier.h irqchip/gic-v3: Add missing struct device_node declaration
2015-12-11arm64: Improve error reporting on set_pte_at() checksCatalin Marinas1-4/+8
Currently the BUG_ON() checks do not give enough information about the PTEs being set. This patch changes BUG_ON to WARN_ONCE and dumps the values of the old and new PTEs. In addition, the checks are only made if the new PTE entry is valid. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Ming Lei <tom.leiming@gmail.com> Cc: Will Deacon <will.deacon@arm.com>
2015-12-10irqchip/gic-v3: Add missing include for barrier.hMarc Zyngier1-0/+1
Both the 32bit and 64bit versions of the GICv3 header file are using barriers, but neglect to include barrier.h, leading to an interesting splat in some circumstances. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Cc: <linux-arm-kernel@lists.infradead.org> Cc: Jason Cooper <jason@lakedaemon.net> Link: http://lkml.kernel.org/r/1449483072-17694-3-git-send-email-marc.zyngier@arm.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-04Merge tag 'kvm-arm-for-v4.4-rc4' of ↵Paolo Bonzini1-5/+13
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into kvm-master KVM/ARM fixes for v4.4-rc4 - A series of fixes to deal with the aliasing between the sp and xzr register - A fix for the cache flush fix that went in -rc3
2015-12-04arm64: KVM: Get rid of old vcpu_reg()Pavel Fedin1-8/+3
Using oldstyle vcpu_reg() accessor is proven to be inappropriate and unsafe on ARM64. This patch converts the rest of use cases to new accessors and completely removes vcpu_reg() on ARM64. Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-04arm64: KVM: Correctly handle zero register during MMIOPavel Fedin1-0/+13
On ARM64 register index of 31 corresponds to both zero register and SP. However, all memory access instructions, use ZR as transfer register. SP is used only as a base register in indirect memory addressing, or by register-register arithmetics, which cannot be trapped here. Correct emulation is achieved by introducing new register accessor functions, which can do special handling for reg_num == 31. These new accessors intentionally do not rely on old vcpu_reg() on ARM64, because it is to be removed. Since the affected code is shared by both ARM flavours, implementations of these accessors are also added to ARM32 code. This patch fixes setting MMIO register to a random value (actually SP) instead of zero by something like: *((volatile int *)reg) = 0; compilers tend to generate "str wzr, [xx]" here [Marc: Fixed 32bit splat] Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-11-27Merge tag 'arm64-fixes' of ↵Linus Torvalds2-4/+24
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Catalin Marinas: - Build fix when !CONFIG_UID16 (the patch is touching generic files but it only affects arm64 builds; submitted by Arnd Bergmann) - EFI fixes to deal with early_memremap() returning NULL and correctly mapping run-time regions - Fix CPUID register extraction of unsigned fields (not to be sign-extended) - ASID allocator fix to deal with long-running tasks over multiple generation roll-overs - Revert support for marking page ranges as contiguous PTEs (it leads to TLB conflicts and requires additional non-trivial kernel changes) - Proper early_alloc() failure check - Disable KASan for 48-bit VA and 16KB page configuration (the pgd is larger than the KASan shadow memory) - Update the fault_info table (original descriptions based on early engineering spec) * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: efi: fix initcall return values arm64: efi: deal with NULL return value of early_memremap() arm64: debug: Treat the BRPs/WRPs as unsigned arm64: cpufeature: Track unsigned fields arm64: cpufeature: Add helpers for extracting unsigned values Revert "arm64: Mark kernel page ranges contiguous" arm64: mm: keep reserved ASIDs in sync with mm after multiple rollovers arm64: KASAN depends on !(ARM64_16K_PAGES && ARM64_VA_BITS_48) arm64: efi: correctly map runtime regions arm64: mm: fix fault_info table xFSC decoding arm64: fix building without CONFIG_UID16 arm64: early_alloc: Fix check for allocation failure
2015-11-26Merge tag 'for-linus-4.4-rc2-tag' of ↵Linus Torvalds1-0/+5
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen bug fixes from David Vrabel: - Fix gntdev and numa balancing. - Fix x86 boot crash due to unallocated legacy irq descs. - Fix overflow in evtchn device when > 1024 event channels. * tag 'for-linus-4.4-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/evtchn: dynamically grow pending event channel ring xen/events: Always allocate legacy interrupts on PV guests xen/gntdev: Grant maps should not be subject to NUMA balancing
2015-11-26arm64: debug: Treat the BRPs/WRPs as unsignedSuzuki K. Poulose1-2/+4
IDAA64DFR0_EL1: BRPs and WRPs are unsigned values. Use the appropriate helpers to extract those fields. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-26arm64: cpufeature: Track unsigned fieldsSuzuki K. Poulose1-2/+8
Some of the feature bits have unsigned values and need to be treated accordingly to avoid errors. Adds the property to the feature bits and use the appropriate field extract helpers. Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-26xen/events: Always allocate legacy interrupts on PV guestsBoris Ostrovsky1-0/+5
After commit 8c058b0b9c34 ("x86/irq: Probe for PIC presence before allocating descs for legacy IRQs") early_irq_init() will no longer preallocate descriptors for legacy interrupts if PIC does not exist, which is the case for Xen PV guests. Therefore we may need to allocate those descriptors ourselves. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-11-26arm64: cpufeature: Add helpers for extracting unsigned valuesSuzuki K. Poulose1-0/+12
The cpuid_feature_extract_field() extracts the feature value as a signed integer. This could be problematic for features whose values are unsigned. e.g, ID_AA64DFR0_EL1:BRPs. Add an unsigned variant for the unsigned fields. Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reported-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-24arm64: KVM: Add workaround for Cortex-A57 erratum 834220Marc Zyngier1-1/+2
Cortex-A57 parts up to r1p2 can misreport Stage 2 translation faults when a Stage 1 permission fault or device alignment fault should have been reported. This patch implements the workaround (which is to validate that the Stage-1 translation actually succeeds) by using code patching. Cc: stable@vger.kernel.org Reviewed-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-24arm64: KVM: Fix AArch32 to AArch64 register mappingMarc Zyngier1-3/+5
When running a 32bit guest under a 64bit hypervisor, the ARMv8 architecture defines a mapping of the 32bit registers in the 64bit space. This includes banked registers that are being demultiplexed over the 64bit ones. On exceptions caused by an operation involving a 32bit register, the HW exposes the register number in the ESR_EL2 register. It was so far understood that SW had to distinguish between AArch32 and AArch64 accesses (based on the current AArch32 mode and register number). It turns out that I misinterpreted the ARM ARM, and the clue is in D1.20.1: "For some exceptions, the exception syndrome given in the ESR_ELx identifies one or more register numbers from the issued instruction that generated the exception. Where the exception is taken from an Exception level using AArch32 these register numbers give the AArch64 view of the register." Which means that the HW is already giving us the translated version, and that we shouldn't try to interpret it at all (for example, doing an MMIO operation from the IRQ mode using the LR register leads to very unexpected behaviours). The fix is thus not to perform a call to vcpu_reg32() at all from vcpu_reg(), and use whatever register number is supplied directly. The only case we need to find out about the mapping is when we actively generate a register access, which only occurs when injecting a fault in a guest. Cc: stable@vger.kernel.org Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-18arm64: barriers: fix smp_load_acquire to work with const argumentsWill Deacon1-6/+10
A newly introduced function in include/net/sock.h passes a const argument to smp_load_acquire: static inline int sk_state_load(const struct sock *sk) { return smp_load_acquire(&sk->sk_state); } This cause an allmodconfig build failure, since our underlying load-acquire implementation does not handle const types correctly: include/net/sock.h: In function 'sk_state_load': ./arch/arm64/include/asm/barrier.h:71:3: error: read-only variable '___p1' used as 'asm' output asm volatile ("ldarb %w0, %1" \ This patch fixes the problem by reusing the trick in READ_ONCE that loads via a non-const member of an anonymous union. This has the advantage of allowing us to use smp_load_acquire on packed structures (e.g. arch_spinlock_t) as well as primitive types. Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Daney <david.daney@cavium.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Reported-by: Arnd Bergmann <arnd@arndb.de> Reported-by: David Daney <david.daney@cavium.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-18arm64: Fix R/O permissions in mark_rodata_roLaura Abbott1-0/+1
The permissions in mark_rodata_ro trigger a build error with STRICT_MM_TYPECHECKS. Fix this by introducing PAGE_KERNEL_ROX for the same reasons as PAGE_KERNEL_RO. From Ard: "PAGE_KERNEL_EXEC has PTE_WRITE set as well, making the range writeable under the ARMv8.1 DBM feature, that manages the dirty bit in hardware (writing to a page with the PTE_RDONLY and PTE_WRITE bits both set will clear the PTE_RDONLY bit in that case)" Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-18arm64: use non-global mappings for UEFI runtime regionsArd Biesheuvel1-1/+1
As pointed out by Russell King in response to the proposed ARM version of this code, the sequence to switch between the UEFI runtime mapping and current's actual userland mapping (and vice versa) is potentially unsafe, since it leaves a time window between the switch to the new page tables and the TLB flush where speculative accesses may hit on stale global TLB entries. So instead, use non-global mappings, and perform the switch via the ordinary ASID-aware context switch routines. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-17arm64: do not include ptrace.h from compat.hArnd Bergmann1-2/+1
including ptrace.h brings a definition of BITS_PER_PAGE into device drivers and cause a build warning in allmodconfig builds: drivers/block/drbd/drbd_bitmap.c:482:0: warning: "BITS_PER_PAGE" redefined #define BITS_PER_PAGE (1UL << (PAGE_SHIFT + 3)) This uses a slightly different way to express current_pt_regs() that avoids the use of the header and gets away with the already included asm/ptrace.h. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-17arm64: simplify dma_get_opsArnd Bergmann1-10/+3
Including linux/acpi.h from asm/dma-mapping.h causes tons of compile-time warnings, e.g. drivers/isdn/mISDN/dsp_ecdis.h:43:0: warning: "FALSE" redefined drivers/isdn/mISDN/dsp_ecdis.h:44:0: warning: "TRUE" redefined drivers/net/fddi/skfp/h/targetos.h:62:0: warning: "TRUE" redefined drivers/net/fddi/skfp/h/targetos.h:63:0: warning: "FALSE" redefined However, it looks like the dependency should not even there as I do not see why __generic_dma_ops() cares about whether we have an ACPI based system or not. The current behavior is to fall back to the global dma_ops when a device has not set its own dma_ops, but only for DT based systems. This seems dangerous, as a random device might have different requirements regarding IOMMU or coherency, so we should really never have that fallback and just forbid DMA when we have not initialized DMA for a device. This removes the global dma_ops variable and the special-casing for ACPI, and just returns the dma ops that got set for the device, or the dummy_dma_ops if none were present. The original code has apparently been copied from arm32 where we rely on it for ISA devices things like the floppy controller, but we should have no such devices on ARM64. Signed-off-by: Arnd Bergmann <arnd@arndb.de> [catalin.marinas@arm.com: removed acpi_disabled check in arch_setup_dma_ops()] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>