- 10 Oct, 2018 2 commits
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Marc Zyngier authored
Document that we actually work around ARM erratum 1188873 Fixes: 95b861a4 ("arm64: arch_timer: Add workaround for ARM erratum 1188873") Signed-off-by:
Marc Zyngier <marc.zyngier@arm.com> Signed-off-by:
Catalin Marinas <catalin.marinas@arm.com>
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James Morse authored
This reverts commit a1f33941. The unsafe accessors allow the PAN enable/disable calls to be made once for a group of accesses. Adding these means we can now have sequences that look like this: | user_access_begin(); | unsafe_put_user(static-value, x, err); | unsafe_put_user(helper-that-sleeps(), x, err); | user_access_end(); Calling schedule() without taking an exception doesn't switch the PSTATE or TTBRs. We can switch out of a uaccess-enabled region, and run other code with uaccess enabled for a different thread. We can also switch from uaccess-disabled code back into this region, meaning the unsafe_put_user()s will fault. For software-PAN, threads that do this will get stuck as handle_mm_fault() will determine the page has already been mapped in, but we fault again as the page tables aren't loaded. To solve this we need code in __switch_to() that save/restores the PAN state. Acked-by:
Julien Thierry <julien.thierry@arm.com> Acked-by:
Mark Rutland <mark.rutland@arm.com> Signed-off-by:
James Morse <james.morse@arm.com> Signed-off-by:
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- 09 Oct, 2018 1 commit
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Shaokun Zhang authored
Cpu parameter is never used in flush_context, remove it. Acked-by:
Will Deacon <will.deacon@arm.com> Signed-off-by:
Shaokun Zhang <zhangshaokun@hisilicon.com> Signed-off-by:
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- 05 Oct, 2018 3 commits
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James Morse authored
The SDEI header files had an 'arm_' namespace added, but the patterns in the MAINTAINERS files were missed. Oops. Reported-by:
Joe Perches <joe@perches.com> Signed-off-by:
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James Morse authored
__is_defined(__PAGETABLE_P?D_FOLDED) doesn't quite work as intended as these symbols are internal to asm-generic and aren't defined in the way kconfig expects. This makes them always evaluate to false. Switch to #ifdef. Acked-by:
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Kyrylo Tkachov authored
"bellow" -> "below" The recommendation from kegel.com/kerspell is to only fix the howlers. "Bellow" is a synonym of "howl" so this should be appropriate. Signed-off-by:
Kyrylo Tkachov <kyrylo.tkachov@arm.com> Signed-off-by:
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- 03 Oct, 2018 4 commits
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Julien Thierry authored
The status of interrupts might depend on more than just pstate. Use interrupts_disabled() instead of raw_irqs_disabled_flags() to take the full context into account. Acked-by:
Stefano Stabellini <sstabellini@kernel.org> Signed-off-by:
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Julien Thierry authored
For EL0 entries requiring bp_hardening, daif status is kept at DAIF_PROCCTX_NOIRQ until after hardening has been done. Then interrupts are enabled through local_irq_enable(). Before using local_irq_* functions, daifflags should be properly restored to a state where IRQs are enabled. Enable IRQs by restoring DAIF_PROCCTX state after bp hardening. Acked-by:
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Julien Thierry authored
Some of the work done in daifflags save/restore is already provided by irqflags functions. Daifflags should always be a superset of irqflags (it handles irq status + status of other flags). Modifying behaviour of irqflags should alter the behaviour of daifflags. Use irqflags_save/restore functions for the corresponding daifflags operation. Reviewed-by:
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Arnd Bergmann authored
arm64_1188873_read_cntvct_el0() is protected by the correct CONFIG_ARM64_ERRATUM_1188873 #ifdef, but the only reference to it is also inside of an CONFIG_ARM_ARCH_TIMER_OOL_WORKAROUND section, and causes a warning if that is disabled: drivers/clocksource/arm_arch_timer.c:323:20: error: 'arm64_1188873_read_cntvct_el0' defined but not used [-Werror=unused-function] Since the erratum requires that we always apply the workaround in the timer driver, select that symbol as we do for SoC specific errata. Fixes: 95b861a4 ("arm64: arch_timer: Add workaround for ARM erratum 1188873") Acked-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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- 01 Oct, 2018 20 commits
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Marc Zyngier authored
It recently came to light that userspace can execute WFI, and that the arm64 kernel doesn't trap this event. This sounds rather benign, but the kernel should decide when it wants to wait for an interrupt, and not userspace. Let's trap WFI and immediately return after having skipped the instruction. This effectively makes WFI a rather expensive NOP. Signed-off-by:
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Will Deacon authored
We advertise the MRS/MSR instructions for toggling SSBS at EL0 using an HWCAP, so document it along with the others. Signed-off-by:
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Giacomo Travaglini authored
Fix some typos in our hwcap documentation, where we refer to the wrong ID register for some of the capabilities. Acked-by:
Giacomo Travaglini <giacomo.travaglini@arm.com> [will: fix amusing binary constants] Signed-off-by:
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zhong jiang authored
There is an extra semicolon in arch_prepare_kprobe, remove it. Signed-off-by:
zhong jiang <zhongjiang@huawei.com> Signed-off-by:
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Anshuman Khandual authored
At present numa_free_distance() is being called before numa_distance is even initialized with numa_alloc_distance() which is really pointless. Instead lets call numa_free_distance() on the common error path inside numa_init() after numa_alloc_distance() has been successful. Fixes: 1a2db300 ("arm64, numa: Add NUMA support for arm64 platforms") Acked-by:
Punit Agrawal <punit.agrawal@arm.com> Signed-off-by:
Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by:
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Anshuman Khandual authored
The dummy node ID is marked into all memory ranges on the system. So the dummy node really extends the entire memblock.memory. Hence report correct extent information for the dummy node using memblock range helper functions instead of the range [0LLU, PFN_PHYS(max_pfn) - 1)]. Fixes: 1a2db300 ("arm64, numa: Add NUMA support for arm64 platforms") Acked-by:
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Anshuman Khandual authored
fault_info[] and debug_fault_info[] are static arrays defining memory abort exception handling functions looking into ESR fault status code encodings. As esr_to_fault_info() is already available providing fault_info[] array lookup, it really makes sense to have a corresponding debug_fault_info[] array lookup function as well. This just adds an equivalent helper function esr_to_debug_fault_info(). Acked-by:
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Anshuman Khandual authored
Most memory abort exception handling related functions have the arguments in the order (addr, esr, regs) except is_el1_permission_fault(). This changes the argument order in this function as (addr, esr, regs) like others. Acked-by:
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Anshuman Khandual authored
Just replace hard code value of 63 (0x111111) with an existing macro ESR_ELx_FSC when parsing for the status code during fault exception. Acked-by:
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Marc Zyngier authored
When running on Cortex-A76, a timer access from an AArch32 EL0 task may end up with a corrupted value or register. The workaround for this is to trap these accesses at EL1/EL2 and execute them there. This only affects versions r0p0, r1p0 and r2p0 of the CPU. Acked-by:
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Marc Zyngier authored
Just like CNTVCT, we need to handle userspace trapping into the kernel if we're decided that the timer wasn't fit for purpose... 64bit userspace is already dealt with, but we're missing the equivalent compat handling. Reviewed-by:
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Marc Zyngier authored
Since people seem to make a point in breaking the userspace visible counter, we have no choice but to trap the access. We already do this for 64bit userspace, but this is lacking for compat. Let's provide the required handler. Reviewed-by:
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Marc Zyngier authored
We're now ready to start handling CP15 access. Let's add (empty) arrays for both 32 and 64bit accessors, and the code that deals with them. Reviewed-by:
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Marc Zyngier authored
Here's a /really nice/ part of the architecture: a CP15 access is allowed to trap even if it fails its condition check, and SW must handle it. This includes decoding the IT state if this happens in am IT block. As a consequence, SW must also deal with advancing the IT state machine. Reviewed-by:
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Marc Zyngier authored
Instead of directly generating an UNDEF when trapping a CP15 access, let's add a new entry point to that effect (which only generates an UNDEF for now). Acked-by:
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Marc Zyngier authored
So far, we don't have anything to help decoding ESR_ELx when dealing with ESR_ELx_EC_CP15_{32,64}. As we're about to handle some of those, let's add some useful macros. Signed-off-by: -
Ard Biesheuvel authored
arm64 does not define CONFIG_HAVE_ARCH_COMPILER_H, nor does it keep anything useful in its copy of asm/compiler.h, so let's remove it before anybody starts using it. Acked-by:
Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by:
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Will Deacon authored
arch/arm/ defines a SIGMINSTKSZ of 2k, so we should use the same value for compat tasks. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Reviewed-by:
Dave Martin <Dave.Martin@arm.com> Reported-by:
Steve McIntyre <steve.mcintyre@arm.com> Tested-by:
Steve McIntyre <93sam@debian.org> Signed-off-by:
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Will Deacon authored
The sigaltstack(2) system call fails with -ENOMEM if the new alternative signal stack is found to be smaller than SIGMINSTKSZ. On architectures such as arm64, where the native value for SIGMINSTKSZ is larger than the compat value, this can result in an unexpected error being reported to a compat task. See, for example: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=904385 This patch fixes the problem by extending do_sigaltstack to take the minimum signal stack size as an additional parameter, allowing the native and compat system call entry code to pass in their respective values. COMPAT_SIGMINSTKSZ is just defined as SIGMINSTKSZ if it has not been defined by the architecture. Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Oleg Nesterov <oleg@redhat.com> Reported-by:
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Rob Herring authored
In preparation to remove the node name pointer from struct device_node, convert printf users to use the %pOFn format specifier. Cc: Mark Rutland <mark.rutland@arm.com> Cc: linux-arm-kernel@lists.infradead.org Acked-by:
Rob Herring <robh@kernel.org> Signed-off-by:
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- 25 Sep, 2018 4 commits
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Jun Yao authored
Now that deliberate writes to swapper_pg_dir are made via the fixmap, we can defend against errant writes by moving it into the rodata section. Since tramp_pg_dir and reserved_ttbr0 must be at a fixed offset from swapper_pg_dir, and are not modified at runtime, these are also moved into the rodata section. Likewise, idmap_pg_dir is not modified at runtime, and is moved into rodata. Signed-off-by:
Jun Yao <yaojun8558363@gmail.com> Reviewed-by:
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Jun Yao authored
Once swapper_pg_dir is in the rodata section, it will not be possible to modify it directly, but we will need to modify it in some cases. To enable this, we can use the fixmap when deliberately modifying swapper_pg_dir. As the pgd is only transiently mapped, this provides some resilience against illicit modification of the pgd, e.g. for Kernel Space Mirror Attack (KSMA). Signed-off-by:
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Jun Yao authored
Since the address of swapper_pg_dir is fixed for a given kernel image, it is an attractive target for manipulation via an arbitrary write. To mitigate this we'd like to make it read-only by moving it into the rodata section. We require that swapper_pg_dir is at a fixed offset from tramp_pg_dir and reserved_ttbr0, so these will also need to move into rodata. However, swapper_pg_dir is allocated along with some transient page tables used for boot which we do not want to move into rodata. As a step towards this, this patch separates the boot-time page tables into a new init_pg_dir, and reduces swapper_pg_dir to the single page it needs to be. This allows us to retain the relationship between swapper_pg_dir, tramp_pg_dir, and swapper_pg_dir, while cleanly separating these from the boot-time page tables. The init_pg_dir holds all of the pgd/pud/pmd/pte levels needed during boot, and all of these levels will be freed when we switch to the swapper_pg_dir, which is initialized by the existing code in paging_init(). Since we start off on the init_pg_dir, we no longer need to allocate a transient page table in paging_init() in order to ensure that swapper_pg_dir isn't live while we initialize it. There should be no functional change as a result of this patch. Signed-off-by:
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Jun Yao authored
In subsequent patches we'll use a transient pgd during the primary cpu's boot process. To make this work while allowing secondary cpus to use the swapper_pg_dir, we need to pass the relevant TTBR1 pgd as a parameter to __enable_mmu(). This patch updates __enable__mmu() to take this as a parameter, updating callsites to pass swapper_pg_dir for now. There should be no functional change as a result of this patch. Signed-off-by:
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- 24 Sep, 2018 1 commit
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Tri Vo authored
x0 is not callee-saved in the PCS. So there is no need to specify -fcall-used-x0. Clang doesn't currently support -fcall-used flags. This patch will help building the kernel with clang. Tested-by:
Nick Desaulniers <ndesaulniers@google.com> Acked-by:
Tri Vo <trong@android.com> Signed-off-by:
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- 21 Sep, 2018 5 commits
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Andrew Murray authored
Support for VGA_CONSOLE is not allowable due to commit ee23794b ("video: vgacon: Don't build on arm64"), thus remove the associated unused code. Whilst PCI on arm64 would support VGA a valid screen_info structure is missing. Acked-by:
Andrew Murray <andrew.murray@arm.com> Signed-off-by:
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James Morse authored
include/linux/mmzone.h describes ARCH_HAS_HOLES_MEMORYMODEL as relevant when parts the memmap have been free()d. This would happen on systems where memory is smaller than a sparsemem-section, and the extra struct pages are expensive. pfn_valid() on these systems returns true for the whole sparsemem-section, so an extra memmap_valid_within() check is needed. On arm64 we have nomap memory, so always provide pfn_valid() to test for nomap pages. This means ARCH_HAS_HOLES_MEMORYMODEL's extra checks are already rolled up into pfn_valid(). Remove it. Acked-by:
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Anshuman Khandual authored
Armv8.4-A extension enables MRS instruction encodings inside ESR_ELx.ISS during exception class ESR_ELx_EC_SYS64 (0x18). This encoding can be used to emulate MRS instructions which can avoid fetch/decode from user space thus improving performance. This adds a new sys64_hook structure element with applicable ESR mask/value pair for MRS instructions on various system registers but constrained by sysreg encodings which is currently allowed to be emulated. Reviewed-by:
Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by:
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Anshuman Khandual authored
MRS emulation gets triggered with exception class (0x00 or 0x18) eventually calling the function emulate_mrs() which fetches the user space instruction and analyses it's encodings (OP0, OP1, OP2, CRN, CRM, RT). The kernel tries to emulate the given instruction looking into the encoding details. Going forward these encodings can also be parsed from ESR_ELx.ISS fields without requiring to fetch/decode faulting userspace instruction which can improve performance. This factorizes emulate_mrs() function in a way that it can be called directly with MRS encodings (OP0, OP1, OP2, CRN, CRM) for any given target register which can then be used directly from 0x18 exception class. Reviewed-by:
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Anshuman Khandual authored
Extracting target register from ESR.ISS encoding has already been required at multiple instances. Just make it a macro definition and replace all the existing use cases. Reviewed-by:
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