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2016-01-17arm64: insn: remove BUG_ON from codegenZi Shen Lim1-53/+112
During code generation, we used to BUG_ON unknown/unsupported encoding or invalid parameters. Instead, now we report these as errors and simply return the instruction AARCH64_BREAK_FAULT. Users of these codegen helpers should check for and handle this failure condition as appropriate. Otherwise, unhandled codegen failure will result in trapping at run-time due to AARCH64_BREAK_FAULT, which is arguably better than a BUG_ON. Signed-off-by: Zi Shen Lim <zlim.lnx@gmail.com> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-01-12Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds1-39/+1
Pull KVM updates from Paolo Bonzini: "PPC changes will come next week. - s390: Support for runtime instrumentation within guests, support of 248 VCPUs. - ARM: rewrite of the arm64 world switch in C, support for 16-bit VM identifiers. Performance counter virtualization missed the boat. - x86: Support for more Hyper-V features (synthetic interrupt controller), MMU cleanups" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (115 commits) kvm: x86: Fix vmwrite to SECONDARY_VM_EXEC_CONTROL kvm/x86: Hyper-V SynIC timers tracepoints kvm/x86: Hyper-V SynIC tracepoints kvm/x86: Update SynIC timers on guest entry only kvm/x86: Skip SynIC vector check for QEMU side kvm/x86: Hyper-V fix SynIC timer disabling condition kvm/x86: Reorg stimer_expiration() to better control timer restart kvm/x86: Hyper-V unify stimer_start() and stimer_restart() kvm/x86: Drop stimer_stop() function kvm/x86: Hyper-V timers fix incorrect logical operation KVM: move architecture-dependent requests to arch/ KVM: renumber vcpu->request bits KVM: document which architecture uses each request bit KVM: Remove unused KVM_REQ_KICK to save a bit in vcpu->requests kvm: x86: Check kvm_write_guest return value in kvm_write_wall_clock KVM: s390: implement the RI support of guest kvm/s390: drop unpaired smp_mb kvm: x86: fix comment about {mmu,nested_mmu}.gva_to_gpa KVM: x86: MMU: Use clear_page() instead of init_shadow_page_table() arm/arm64: KVM: Detect vGIC presence at runtime ...
2016-01-12Merge tag 'for-linus-4.5-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds2-0/+26
Pull xen updates from David Vrabel: "Xen features and fixes for 4.5-rc0: - Stolen ticks and PV wallclock support for arm/arm64 - Add grant copy ioctl to gntdev device" * tag 'for-linus-4.5-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen/gntdev: add ioctl for grant copy x86/xen: don't reset vcpu_info on a cancelled suspend xen/gntdev: constify mmu_notifier_ops structures xen/grant-table: constify gnttab_ops structure xen/time: use READ_ONCE xen/x86: convert remaining timespec to timespec64 in xen_pvclock_gtod_notify xen/x86: support XENPF_settime64 xen/arm: set the system time in Xen via the XENPF_settime64 hypercall xen/arm: introduce xen_read_wallclock arm: extend pvclock_wall_clock with sec_hi xen: introduce XENPF_settime64 xen/arm: introduce HYPERVISOR_platform_op on arm and arm64 xen: rename dom0_op to platform_op xen/arm: account for stolen ticks arm64: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops arm: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_ops missing include asm/paravirt.h in cputime.c xen: move xen_setup_runstate_info and get_runstate_snapshot to drivers/xen/time.c
2016-01-12Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-armLinus Torvalds5-30/+53
Pull ARM updates from Russell King: - UEFI boot and runtime services support for ARM from Ard Biesheuvel and Roy Franz. - DT compatibility with old atags booting protocol for Nokia N900 devices from Ivaylo Dimitrov. - PSCI firmware interface using new arm-smc calling convention from Jens Wiklander. - Runtime patching for udiv/sdiv instructions for ARMv7 CPUs that support these instructions from Nicolas Pitre. - L2x0 cache updates from Dirk B and Linus Walleij. - Randconfig fixes from Arnd Bergmann. - ARMv7M (nommu) updates from Ezequiel Garcia * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (34 commits) ARM: 8481/2: drivers: psci: replace psci firmware calls ARM: 8480/2: arm64: add implementation for arm-smccc ARM: 8479/2: add implementation for arm-smccc ARM: 8478/2: arm/arm64: add arm-smccc ARM: 8494/1: mm: Enable PXN when running non-LPAE kernel on LPAE processor ARM: 8496/1: OMAP: RX51: save ATAGS data in the early boot stage ARM: 8495/1: ATAGS: move save_atags() to arch/arm/include/asm/setup.h ARM: 8452/3: PJ4: make coprocessor access sequences buildable in Thumb2 mode ARM: 8482/1: l2x0: make it possible to disable outer sync from DT ARM: 8488/1: Make IPI_CPU_BACKTRACE a "non-secure" SGI ARM: 8487/1: Remove IPI_CALL_FUNC_SINGLE ARM: 8485/1: cpuidle: remove cpu parameter from the cpuidle_ops suspend hook ARM: 8484/1: Documentation: l2c2x0: Mention separate controllers explicitly ARM: 8483/1: Documentation: l2c: Rename l2cc to l2c2x0 ARM: 8477/1: runtime patch udiv/sdiv instructions into __aeabi_{u}idiv() ARM: 8476/1: VDSO: use PTR_ERR_OR_ZERO for vma check ARM: 8453/2: proc-v7.S: don't locate temporary stack space in .text section ARM: add UEFI stub support ARM: wire up UEFI init and runtime support ARM: only consider memblocks with NOMAP cleared for linear mapping ...
2016-01-12Merge tag 'arm64-perf' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds1-54/+209
Pull arm[64] perf updates from Will Deacon: "In the past, I have funnelled perf updates through the respective architecture trees, but now that the arm/arm64 perf driver has been largely consolidated under drivers/perf/, it makes more sense to send a separate pull, particularly as I'm listed as maintainer for all the files involved. I offered the branch to arm-soc, but Arnd suggested that I just send it to you directly. So, here is the arm/arm64 perf queue for 4.5. The main features are described below, but the most useful change is from Drew, which advertises our architected event mapping in sysfs so that the perf tool is a lot more user friendly and no longer requires the use of magic hex constants for profiling common events. - Support for the CPU PMU in Cortex-A72 - Add sysfs entries to describe the architected events and their mappings for PMUv{1-3}" * tag 'arm64-perf' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: perf: add support for Cortex-A72 arm64: perf: add format entry to describe event -> config mapping ARM: perf: add format entry to describe event -> config mapping arm64: kernel: enforce pmuserenr_el0 initialization and restore arm64: perf: Correct Cortex-A53/A57 compatible values arm64: perf: Add event descriptions arm64: perf: Convert event enums to #defines arm: perf: Add event descriptions arm: perf: Convert event enums to #defines drivers/perf: kill armpmu_register
2016-01-12Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds19-439/+271
Pull arm64 updates from Will Deacon: "Here is the core arm64 queue for 4.5. As you might expect, the Christmas break resulted in a number of patches not making the final cut, so 4.6 is likely to be larger than usual. There's still some useful stuff here, however, and it's detailed below. The EFI changes have been Reviewed-by Matt and the memblock change got an "OK" from akpm. Summary: - Support for a separate IRQ stack, although we haven't reduced the size of our thread stack just yet since we don't have enough data to determine a safe value - Refactoring of our EFI initialisation and runtime code into drivers/firmware/efi/ so that it can be reused by arch/arm/. - Ftrace improvements when unwinding in the function graph tracer - Document our silicon errata handling process - Cache flushing optimisation when mapping executable pages - Support for hugetlb mappings using the contiguous hint in the pte" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (45 commits) arm64: head.S: use memset to clear BSS efi: stub: define DISABLE_BRANCH_PROFILING for all architectures arm64: entry: remove pointless SPSR mode check arm64: mm: move pgd_cache initialisation to pgtable_cache_init arm64: module: avoid undefined shift behavior in reloc_data() arm64: module: fix relocation of movz instruction with negative immediate arm64: traps: address fallout from printk -> pr_* conversion arm64: ftrace: fix a stack tracer's output under function graph tracer arm64: pass a task parameter to unwind_frame() arm64: ftrace: modify a stack frame in a safe way arm64: remove irq_count and do_softirq_own_stack() arm64: hugetlb: add support for PTE contiguous bit arm64: Use PoU cache instr for I/D coherency arm64: Defer dcache flush in __cpu_copy_user_page arm64: reduce stack use in irq_handler arm64: mm: ensure that the zero page is visible to the page table walker arm64: Documentation: add list of software workarounds for errata arm64: mm: place __cpu_setup in .text arm64: cmpxchg: Don't incldue linux/mmdebug.h arm64: mm: fold alternatives into .init ...
2016-01-12Merge branch 'devel-stable' into for-linusRussell King1-317/+17
2016-01-06arm64: head.S: use memset to clear BSSMark Rutland1-8/+7
Currently we use an open-coded memzero to clear the BSS. As it is a trivial implementation, it is sub-optimal. Our optimised memset doesn't use the stack, is position-independent, and for the memzero case can use of DC ZVA to clear large blocks efficiently. In __mmap_switched the MMU is on and there are no live caller-saved registers, so we can safely call an uninstrumented memset. This patch changes __mmap_switched to use memset when clearing the BSS. We use the __pi_memset alias so as to avoid any instrumentation in all kernel configurations. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-06arm64: entry: remove pointless SPSR mode checkMark Rutland1-4/+0
In work_pending, we may skip work if the stacked SPSR value represents anything other than an EL0 context. We then immediately invoke the kernel_exit 0 macro as part of ret_to_user, assuming a return to EL0. This is somewhat confusing. We use work_pending as part of the ret_to_user/ret_fast_syscall state machine. We only use ret_fast_syscall in the return from an SVC issued from EL0. We use ret_to_user for return from EL0 exception handlers and also for return from ret_from_fork in the case the task was not a kernel thread (i.e. it is a user task). Thus in all cases the stacked SPSR value must represent an EL0 context, and the check is redundant. This patch removes it, along with the now unused no_work_pending label. Cc: Chris Metcalf <cmetcalf@ezchip.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-05arm64: module: avoid undefined shift behavior in reloc_data()Ard Biesheuvel1-16/+4
Compilers may engage the improbability drive when encountering shifts by a distance that is a multiple of the size of the operand type. Since the required bounds check is very simple here, we can get rid of all the fuzzy masking, shifting and comparing, and use the documented bounds directly. Reported-by: David Binderman <dcb314@hotmail.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-05arm64: module: fix relocation of movz instruction with negative immediateArd Biesheuvel1-33/+18
The test whether a movz instruction with a signed immediate should be turned into a movn instruction (i.e., when the immediate is negative) is flawed, since the value of imm is always positive. Also, the subsequent bounds check is incorrect since the limit update never executes, due to the fact that the imm_type comparison will always be false for negative signed immediates. Let's fix this by performing the sign test on sval directly, and replacing the bounds check with a simple comparison against U16_MAX. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: tidied up use of sval, renamed MOVK enum value to MOVKZ] Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-01-05Merge branches 'misc' and 'misc-rc6' into for-linusRussell King5-30/+53
2016-01-04ARM: 8481/2: drivers: psci: replace psci firmware callsJens Wiklander2-29/+1
Switch to use a generic interface for issuing SMC/HVC based on ARM SMC Calling Convention. Removes now the now unused psci-call.S. Acked-by: Will Deacon <will.deacon@arm.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2016-01-04ARM: 8480/2: arm64: add implementation for arm-smcccJens Wiklander4-1/+52
Adds implementation for arm-smccc and enables CONFIG_HAVE_SMCCC. Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2015-12-22arm64: perf: add support for Cortex-A72Will Deacon1-1/+12
Cortex-A72 has a PMUv3 implementation that is compatible with the PMU implemented by Cortex-A57. This patch hooks up the new compatible string so that the Cortex-A57 event mappings are used. Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-22arm64: perf: add format entry to describe event -> config mappingWill Deacon1-2/+16
It's all very well providing an events directory to userspace that details our events in terms of "event=0xNN", but if we don't define how to encode the "event" field in the perf attr.config, then it's a waste of time. This patch adds a single format entry to describe that the event field occupies the bottom 10 bits of our config field on ARMv8 (PMUv3). Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-21arm64: traps: address fallout from printk -> pr_* conversionWill Deacon1-5/+5
Commit ac7b406c1a9d ("arm64: Use pr_* instead of printk") was a fairly mindless s/printk/pr_*/ change driven by a complaint from checkpatch. As is usual with such changes, this has led to some odd behaviour on arm64: * syslog now picks up the "pr_emerg" line from dump_backtrace, but not the actual trace, which leads to a bunch of "kernel:Call trace:" lines in the log * __{pte,pmd,pgd}_error print at KERN_CRIT, as opposed to KERN_ERR which is used by other architectures. This patch restores the original printk behaviour for dump_backtrace and downgrade the pgtable error macros to KERN_ERR. Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-21arm64: ftrace: fix a stack tracer's output under function graph tracerAKASHI Takahiro6-6/+49
Function graph tracer modifies a return address (LR) in a stack frame to hook a function return. This will result in many useless entries (return_to_handler) showing up in a) a stack tracer's output b) perf call graph (with perf record -g) c) dump_backtrace (at panic et al.) For example, in case of a), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo 1 > /proc/sys/kernel/stack_trace_enabled $ cat /sys/kernel/debug/tracing/stack_trace Depth Size Location (54 entries) ----- ---- -------- 0) 4504 16 gic_raise_softirq+0x28/0x150 1) 4488 80 smp_cross_call+0x38/0xb8 2) 4408 48 return_to_handler+0x0/0x40 3) 4360 32 return_to_handler+0x0/0x40 ... In case of b), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ perf record -e mem:XXX:x -ag -- sleep 10 $ perf report ... | | |--0.22%-- 0x550f8 | | | 0x10888 | | | el0_svc_naked | | | sys_openat | | | return_to_handler | | | return_to_handler ... In case of c), $ echo function_graph > /sys/kernel/debug/tracing/current_tracer $ echo c > /proc/sysrq-trigger ... Call trace: [<ffffffc00044d3ac>] sysrq_handle_crash+0x24/0x30 [<ffffffc000092250>] return_to_handler+0x0/0x40 [<ffffffc000092250>] return_to_handler+0x0/0x40 ... This patch replaces such entries with real addresses preserved in current->ret_stack[] at unwind_frame(). This way, we can cover all the cases. Reviewed-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [will: fixed minor context changes conflicting with irq stack bits] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-21arm64: pass a task parameter to unwind_frame()AKASHI Takahiro6-9/+9
Function graph tracer modifies a return address (LR) in a stack frame to hook a function's return. This will result in many useless entries (return_to_handler) showing up in a call stack list. We will fix this problem in a later patch ("arm64: ftrace: fix a stack tracer's output under function graph tracer"). But since real return addresses are saved in ret_stack[] array in struct task_struct, unwind functions need to be notified of, in addition to a stack pointer address, which task is being traced in order to find out real return addresses. This patch extends unwind functions' interfaces by adding an extra argument of a pointer to task_struct. Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-21arm64: ftrace: modify a stack frame in a safe wayAKASHI Takahiro1-7/+4
Function graph tracer modifies a return address (LR) in a stack frame by calling ftrace_prepare_return() in a traced function's function prologue. The current code does this modification before preserving an original address at ftrace_push_return_trace() and there is always a small window of inconsistency when an interrupt occurs. This doesn't matter, as far as an interrupt stack is introduced, because stack tracer won't be invoked in an interrupt context. But it would be better to proactively minimize such a window by moving the LR modification after ftrace_push_return_trace(). Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-21arm64: remove irq_count and do_softirq_own_stack()James Morse2-46/+11
sysrq_handle_reboot() re-enables interrupts while on the irq stack. The irq_stack implementation wrongly assumed this would only ever happen via the softirq path, allowing it to update irq_count late, in do_softirq_own_stack(). This means if an irq occurs in sysrq_handle_reboot(), during emergency_restart() the stack will be corrupted, as irq_count wasn't updated. Lose the optimisation, and instead of moving the adding/subtracting of irq_count into irq_stack_entry/irq_stack_exit, remove it, and compare sp_el0 (struct thread_info) with sp & ~(THREAD_SIZE - 1). This tells us if we are on a task stack, if so, we can safely switch to the irq stack. Finally, remove do_softirq_own_stack(), we don't need it anymore. Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: James Morse <james.morse@arm.com> [will: use get_thread_info macro] Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-21arm64: kernel: enforce pmuserenr_el0 initialization and restoreLorenzo Pieralisi1-3/+0
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: <stable@vger.kernel.org> 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>
2015-12-21arm64: introduce CONFIG_PARAVIRT, PARAVIRT_TIME_ACCOUNTING and pv_time_opsStefano Stabellini2-0/+26
Introduce CONFIG_PARAVIRT and PARAVIRT_TIME_ACCOUNTING on ARM64. Necessary duplication of paravirt.h and paravirt.c with ARM. The only paravirt interface supported is pv_time_ops.steal_clock, so no runtime pvops patching needed. This allows us to make use of steal_account_process_tick for stolen ticks accounting. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-15arm64: reduce stack use in irq_handlerJames Morse2-8/+23
The code for switching to irq_stack stores three pieces of information on the stack, fp+lr, as a fake stack frame (that lets us walk back onto the interrupted tasks stack frame), and the address of the struct pt_regs that contains the register values from kernel entry. (which dump_backtrace() will print in any stack trace). To reduce this, we store fp, and the pointer to the struct pt_regs. unwind_frame() can recognise this as the irq_stack dummy frame, (as it only appears at the top of the irq_stack), and use the struct pt_regs values to find the missing interrupted link-register. Suggested-by: Will Deacon <will.deacon@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-15Merge branch 'aarch64/efi' into aarch64/for-next/coreWill Deacon1-317/+17
Merge in EFI memblock changes from Ard, which form the preparatory work for UEFI support on 32-bit ARM.
2015-12-14arm64: KVM: Cleanup asm-offset.cMarc Zyngier1-39/+0
As we've now rewritten most of our code-base in C, most of the KVM-specific code in asm-offset.c is useless. Delete-time again! Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-14arm64: KVM: Turn system register numbers to an enumMarc Zyngier1-0/+1
Having the system register numbers as #defines has been a pain since day one, as the ordering is pretty fragile, and moving things around leads to renumbering and epic conflict resolutions. Now that we're mostly acessing the sysreg file in C, an enum is a much better type to use, and we can clean things up a bit. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-12-10arm64: mm: fold alternatives into .initMark Rutland2-9/+2
Currently we treat the alternatives separately from other data that's only used during initialisation, using separate .altinstructions and .altinstr_replacement linker sections. These are freed for general allocation separately from .init*. This is problematic as: * We do not remove execute permissions, as we do for .init, leaving the memory executable. * We pad between them, making the kernel Image bianry up to PAGE_SIZE bytes larger than necessary. This patch moves the two sections into the contiguous region used for .init*. This saves some memory, ensures that we remove execute permissions, and allows us to remove some code made redundant by this reorganisation. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-10arm64: Remove redundant padding from linker scriptMark Rutland1-2/+0
Currently we place an ALIGN_DEBUG_RO between text and data for the .text and .init sections, and depending on configuration each of these may result in up to SECTION_SIZE bytes worth of padding (for DEBUG_RODATA_ALIGN). We make no distinction between the text and data in each of these sections at any point when creating the initial page tables in head.S. We also make no distinction when modifying the tables; __map_memblock, fixup_executable, mark_rodata_ro, and fixup_init only work at section granularity. Thus this padding is unnecessary. For the spit between init text and data we impose a minimum alignment of 16 bytes, but this is also unnecessary. The init data is output immediately after the padding before any symbols are defined, so this is not required to keep a symbol for linker a section array correctly associated with the data. Any objects within the section will be given at least their usual alignment regardless. This patch removes the redundant padding. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Jeremy Linton <jeremy.linton@arm.com> Cc: Laura Abbott <labbott@fedoraproject.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-10arm64: don't call C code with el0's fp registerJames Morse1-0/+2
On entry from el0, we save all the registers on the kernel stack, and restore them before returning. x29 remains unchanged when we call out to C code, which will store x29 as the frame-pointer on the stack. Instead, write 0 into x29 after entry from el0, to avoid any risk of tracing into user space. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-10arm64: when walking onto the task stack, check sp & fp are in current->stackJames Morse1-2/+10
When unwind_frame() reaches the bottom of the irq_stack, the last fp points to the original task stack. unwind_frame() uses IRQ_STACK_TO_TASK_STACK() to find the sp value. If either values is wrong, we may end up walking a corrupt stack. Check these values are sane by testing if they are both on the stack pointed to by current->stack. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-10arm64: Add this_cpu_ptr() assembler macro for use in entry.SJames Morse1-3/+1
irq_stack is a per_cpu variable, that needs to be access from entry.S. Use an assembler macro instead of the unreadable details. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-09arm64/efi: refactor EFI init and runtime code for reuse by 32-bit ARMArd Biesheuvel1-0/+23
This refactors the EFI init and runtime code that will be shared between arm64 and ARM so that it can be built for both archs. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-09arm64/efi: split off EFI init and runtime code for reuse by 32-bit ARMArd Biesheuvel1-325/+1
This splits off the early EFI init and runtime code that - discovers the EFI params and the memory map from the FDT, and installs the memblocks and config tables. - prepares and installs the EFI page tables so that UEFI Runtime Services can be invoked at the virtual address installed by the stub. This will allow it to be reused for 32-bit ARM. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-09arm64/efi: mark UEFI reserved regions as MEMBLOCK_NOMAPArd Biesheuvel1-3/+4
Change the EFI memory reservation logic to use memblock_mark_nomap() rather than memblock_reserve() to mark UEFI reserved regions as occupied. In addition to reserving them against allocations done by memblock, this will also prevent them from being covered by the linear mapping. Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-09arm64: irq: fix walking from irq stack to task stackWill Deacon1-1/+1
Running with CONFIG_DEBUG_SPINLOCK=y can trigger a BUG with the new IRQ stack code: BUG: spinlock lockup suspected on CPU#1 This is due to the IRQ_STACK_TO_TASK_STACK macro incorrectly retrieving the task stack pointer stashed at the top of the IRQ stack. Sayeth James: | Yup, this is what is happening. Its an off-by-one due to broken | thinking about how the stack works. My broken thinking was: | | > top ------------ | > | dummy_lr | <- irq_stack_ptr | > ------------ | > | x29 | | > ------------ | > | x19 | <- irq_stack_ptr - 0x10 | > ------------ | > | xzr | | > ------------ | | But the stack-pointer is decreased before use. So it actually looks | like this: | | > ------------ | > | | <- irq_stack_ptr | > top ------------ | > | dummy_lr | | > ------------ | > | x29 | <- irq_stack_ptr - 0x10 | > ------------ | > | x19 | | > ------------ | > | xzr | <- irq_stack_ptr - 0x20 | > ------------ | | The value being used as the original stack is x29, which in all the | tests is sp but without the current frames data, hence there are no | missing frames in the output. | | Jungseok Lee picked it up with a 32bit user space because aarch32 | can't use x29, so it remains 0 forever. The fix he posted is correct. This patch fixes the macro and adds some of this wisdom to a comment, so that the layout of the IRQ stack is well understood. Cc: James Morse <james.morse@arm.com> Reported-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-08arm64: Add do_softirq_own_stack() and enable irq_stacksJames Morse2-3/+77
entry.S is modified to switch to the per_cpu irq_stack during el{0,1}_irq. irq_count is used to detect recursive interrupts on the irq_stack, it is updated late by do_softirq_own_stack(), when called on the irq_stack, before __do_softirq() re-enables interrupts to process softirqs. do_softirq_own_stack() is added by this patch, but does not yet switch stack. This patch adds the dummy stack frame and data needed by the previous stack tracing patches. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-08arm64: Modify stack trace and dump for use with irq_stackAKASHI Takahiro3-3/+43
This patch allows unwind_frame() to traverse from interrupt stack to task stack correctly. It requires data from a dummy stack frame, created during irq_stack_entry(), added by a later patch. A similar approach is taken to modify dump_backtrace(), which expects to find struct pt_regs underneath any call to functions marked __exception. When on an irq_stack, the struct pt_regs is stored on the old task stack, the location of which is stored in the dummy stack frame. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org> [james.morse: merged two patches, reworked for per_cpu irq_stacks, and no alignment guarantees, added irq_stack definitions] Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-08arm64: Store struct thread_info in sp_el0Jungseok Lee3-3/+20
There is need for figuring out how to manage struct thread_info data when IRQ stack is introduced. struct thread_info information should be copied to IRQ stack under the current thread_info calculation logic whenever context switching is invoked. This is too expensive to keep supporting the approach. Instead, this patch pays attention to sp_el0 which is an unused scratch register in EL1 context. sp_el0 utilization not only simplifies the management, but also prevents text section size from being increased largely due to static allocated IRQ stack as removing masking operation using THREAD_SIZE in many places. Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Jungseok Lee <jungseoklee85@gmail.com> Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-07arm64: Clear out any singlestep state on a ptrace detach operationJohn Blackwood1-0/+6
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. Cc: <stable@vger.kernel.org> 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>
2015-12-07arm64: update linker script to increased L1_CACHE_BYTES valueArd Biesheuvel1-2/+3
Bring the linker script in line with the recent increase of L1_CACHE_BYTES to 128. Replace the hardcoded value of 64 with the symbolic constant. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Rutland <mark.rutland@arm.com> [catalin.marinas@arm.com: fix up RW_DATA_SECTION as well] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-12-04arm64: Add trace_hardirqs_off annotation in ret_to_userCatalin Marinas1-0/+3
When a kernel is built with CONFIG_TRACE_IRQFLAGS the following warning is produced when entering userspace for the first time: WARNING: at /work/Linux/linux-2.6-aarch64/kernel/locking/lockdep.c:3519 Modules linked in: CPU: 1 PID: 1 Comm: systemd Not tainted 4.4.0-rc3+ #639 Hardware name: Juno (DT) task: ffffffc9768a0000 ti: ffffffc9768a8000 task.ti: ffffffc9768a8000 PC is at check_flags.part.22+0x19c/0x1a8 LR is at check_flags.part.22+0x19c/0x1a8 pc : [<ffffffc0000fba6c>] lr : [<ffffffc0000fba6c>] pstate: 600001c5 sp : ffffffc9768abe10 x29: ffffffc9768abe10 x28: ffffffc9768a8000 x27: 0000000000000000 x26: 0000000000000001 x25: 00000000000000a6 x24: ffffffc00064be6c x23: ffffffc0009f249e x22: ffffffc9768a0000 x21: ffffffc97fea5480 x20: 00000000000001c0 x19: ffffffc00169a000 x18: 0000005558cc7b58 x17: 0000007fb78e3180 x16: 0000005558d2e238 x15: ffffffffffffffff x14: 0ffffffffffffffd x13: 0000000000000008 x12: 0101010101010101 x11: 7f7f7f7f7f7f7f7f x10: fefefefefefeff63 x9 : 7f7f7f7f7f7f7f7f x8 : 6e655f7371726964 x7 : 0000000000000001 x6 : ffffffc0001079c4 x5 : 0000000000000000 x4 : 0000000000000001 x3 : ffffffc001698438 x2 : 0000000000000000 x1 : ffffffc9768a0000 x0 : 000000000000002e Call trace: [<ffffffc0000fba6c>] check_flags.part.22+0x19c/0x1a8 [<ffffffc0000fc440>] lock_is_held+0x80/0x98 [<ffffffc00064bafc>] __schedule+0x404/0x730 [<ffffffc00064be6c>] schedule+0x44/0xb8 [<ffffffc000085bb0>] ret_to_user+0x0/0x24 possible reason: unannotated irqs-off. irq event stamp: 502169 hardirqs last enabled at (502169): [<ffffffc000085a98>] el0_irq_naked+0x1c/0x24 hardirqs last disabled at (502167): [<ffffffc0000bb3bc>] __do_softirq+0x17c/0x298 softirqs last enabled at (502168): [<ffffffc0000bb43c>] __do_softirq+0x1fc/0x298 softirqs last disabled at (502143): [<ffffffc0000bb830>] irq_exit+0xa0/0xf0 This happens because we disable interrupts in ret_to_user before calling schedule() in work_resched. This patch adds the necessary trace_hardirqs_off annotation. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-04arm64: ftrace: fix the comments for ftrace_modify_codeLi Bin1-6/+5
There is no need to worry about module and __init text disappearing case, because that ftrace has a module notifier that is called when a module is being unloaded and before the text goes away and this code grabs the ftrace_lock mutex and removes the module functions from the ftrace list, such that it will no longer do any modifications to that module's text, the update to make functions be traced or not is done under the ftrace_lock mutex as well. And by now, __init section codes should not been modified by ftrace, because it is black listed in recordmcount.c and ignored by ftrace. Suggested-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Li Bin <huawei.libin@huawei.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-04arm64: ftrace: stop using kstop_machine to enable/disable tracingLi Bin1-0/+5
For ftrace on arm64, kstop_machine which is hugely disruptive to a running system is not needed to convert nops to ftrace calls or back, because that to be modified instrucions, that NOP, B or BL, are all safe instructions which called "concurrent modification and execution of instructions", that can be executed by one thread of execution as they are being modified by another thread of execution without requiring explicit synchronization. Signed-off-by: Li Bin <huawei.libin@huawei.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-12-02arm64: add __init/__initdata section marker to some functions/variablesJisheng Zhang3-8/+9
These functions/variables are not needed after booting, so mark them as __init or __initdata. Signed-off-by: Jisheng Zhang <jszhang@marvell.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2015-11-27Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linuxLinus Torvalds2-27/+43
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
2015-11-26arm64: efi: fix initcall return valuesArd Biesheuvel1-5/+5
Even though initcall return values are typically ignored, the prototype is to return 0 on success or a negative errno value on error. So fix the arm_enable_runtime_services() implementation to return 0 on conditions that are not in fact errors, and return a meaningful error code otherwise. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-26arm64: efi: deal with NULL return value of early_memremap()Ard Biesheuvel1-1/+13
Add NULL return value checks to two invocations of early_memremap() in the UEFI init code. For the UEFI configuration tables, we just warn since we have a better chance of being able to report the issue in a way that can actually be noticed by a human operator if we don't abort right away. For the UEFI memory map, however, all we can do is panic() since we cannot proceed without a description of memory. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk> Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2015-11-26arm64: cpufeature: Track unsigned fieldsSuzuki K. Poulose1-14/+23
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>
2015-11-25arm64: efi: correctly map runtime regionsMark Rutland1-7/+2
The kernel may use a page granularity of 4K, 16K, or 64K depending on configuration. When mapping EFI runtime regions, we use memrange_efi_to_native to round the physical base address of a region down to a kernel page boundary, and round the size up to a kernel page boundary, adding the residue left over from rounding down the physical base address. We do not round down the virtual base address. In __create_mapping we account for the offset of the virtual base from a granule boundary, adding the residue to the size before rounding the base down to said granule boundary. Thus we account for the residue twice, and when the residue is non-zero will cause __create_mapping to map an additional page at the end of the region. Depending on the memory map, this page may be in a region we are not intended/permitted to map, or may clash with a different region that we wish to map. In typical cases, mapping the next item in the memory map will overwrite the erroneously created entry, as we sort the memory map in the stub. As __create_mapping can cope with base addresses which are not page aligned, we can instead rely on it to map the region appropriately, and simplify efi_virtmap_init by removing the unnecessary code. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Leif Lindholm <leif.lindholm@linaro.org> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>