kernel.git/arch/arm64/kernel/irq.c, branch linux-5.13.y

arm64: irq: allow FIQs to be handled

2021-03-24T20:19:30Z

On contemporary platforms we don't use FIQ, and treat any stray FIQ as a fatal event. However, some platforms have an interrupt controller wired to FIQ, and need to handle FIQ as part of regular operation. So that we can support both cases dynamically, this patch updates the FIQ exception handling code to operate the same way as the IRQ handling code, with its own handle_arch_fiq handler. Where a root FIQ handler is not registered, an unexpected FIQ exception will trigger the default FIQ handler, which will panic() as today. Where a root FIQ handler is registered, handling of the FIQ is deferred to that handler. As el0_fiq_invalid_compat is supplanted by el0_fiq, the former is removed. For !CONFIG_COMPAT builds we never expect to take an exception from AArch32 EL0, so we keep the common el0_fiq_invalid handler. Signed-off-by: Mark Rutland Tested-by: Hector Martin Cc: James Morse Cc: Marc Zyngier Cc: Thomas Gleixner Cc: Will Deacon Acked-by: Will Deacon Link: https://lore.kernel.org/r/20210315115629.57191-7-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: irq: rework root IRQ handler registration

2021-03-24T20:19:30Z

If we accidentally unmask IRQs before we've registered a root IRQ handler, handle_arch_irq will be NULL, and the IRQ exception handler will branch to a bogus address. To make this easier to debug, this patch initialises handle_arch_irq to a default handler which will panic(), making such problems easier to debug. When we add support for FIQ handlers, we can follow the same approach. When we add support for a root FIQ handler, it's possible to have root IRQ handler without an root FIQ handler, and in theory the inverse is also possible. To permit this, and to keep the IRQ/FIQ registration logic similar, this patch removes the panic in the absence of a root IRQ controller. Instead, set_handle_irq() logs when a handler is registered, which is sufficient for debug purposes. Signed-off-by: Mark Rutland Tested-by: Hector Martin Cc: James Morse Cc: Marc Zyngier Cc: Thomas Gleixner Cc: Will Deacon Acked-by: Will Deacon Link: https://lore.kernel.org/r/20210315115629.57191-4-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: don't use GENERIC_IRQ_MULTI_HANDLER

2021-03-24T20:19:30Z

In subsequent patches we want to allow irqchip drivers to register as FIQ handlers, with a set_handle_fiq() function. To keep the IRQ/FIQ paths similar, we want arm64 to provide both set_handle_irq() and set_handle_fiq(), rather than using GENERIC_IRQ_MULTI_HANDLER for the former. This patch adds an arm64-specific implementation of set_handle_irq(). There should be no functional change as a result of this patch. Signed-off-by: Marc Zyngier [Mark: use a single handler pointer] Signed-off-by: Mark Rutland Tested-by: Hector Martin Cc: James Morse Cc: Thomas Gleixner Cc: Will Deacon Link: https://lore.kernel.org/r/20210315115629.57191-3-mark.rutland@arm.com Signed-off-by: Catalin Marinas

Merge remote-tracking branch 'arm64/for-next/fixes' into for-next/core

2020-12-09T18:04:55Z

* arm64/for-next/fixes: (26 commits) arm64: mte: fix prctl(PR_GET_TAGGED_ADDR_CTRL) if TCF0=NONE arm64: mte: Fix typo in macro definition arm64: entry: fix EL1 debug transitions arm64: entry: fix NMI {user, kernel}->kernel transitions arm64: entry: fix non-NMI kernel<->kernel transitions arm64: ptrace: prepare for EL1 irq/rcu tracking arm64: entry: fix non-NMI user<->kernel transitions arm64: entry: move el1 irq/nmi logic to C arm64: entry: prepare ret_to_user for function call arm64: entry: move enter_from_user_mode to entry-common.c arm64: entry: mark entry code as noinstr arm64: mark idle code as noinstr arm64: syscall: exit userspace before unmasking exceptions arm64: pgtable: Ensure dirty bit is preserved across pte_wrprotect() arm64: pgtable: Fix pte_accessible() ACPI/IORT: Fix doc warnings in iort.c arm64/fpsimd: add to to fix fpsimd build arm64: cpu_errata: Apply Erratum 845719 to KRYO2XX Silver arm64: proton-pack: Add KRYO2XX silver CPUs to spectre-v2 safe-list arm64: kpti: Add KRYO2XX gold/silver CPU cores to kpti safelist ... # Conflicts: # arch/arm64/include/asm/exception.h # arch/arm64/kernel/sdei.c

arm64: scs: use vmapped IRQ and SDEI shadow stacks

2020-12-01T11:23:34Z

Use scs_alloc() to allocate also IRQ and SDEI shadow stacks instead of using statically allocated stacks. Signed-off-by: Sami Tolvanen Acked-by: Will Deacon Link: https://lore.kernel.org/r/20201130233442.2562064-3-samitolvanen@google.com [will: Move CONFIG_SHADOW_CALL_STACK check into init_irq_scs()] Signed-off-by: Will Deacon

arm64: entry: move el1 irq/nmi logic to C

2020-11-30T12:11:38Z

In preparation for reworking the EL1 irq/nmi entry code, move the existing logic to C. We no longer need the asm_nmi_enter() and asm_nmi_exit() wrappers, so these are removed. The new C functions are marked noinstr, which prevents compiler instrumentation and runtime probing. In subsequent patches we'll want the new C helpers to be called in all cases, so we don't bother wrapping the calls with ifdeferry. Even when the new C functions are stubs the trivial calls are unlikely to have a measurable impact on the IRQ or NMI paths anyway. Prototypes are added to as otherwise (in some configurations) GCC will complain about the lack of a forward declaration. We already do this for existing function, e.g. enter_from_user_mode(). The new helpers are marked as noinstr (which prevents all instrumentation, tracing, and kprobes). Otherwise, there should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: James Morse Cc: Will Deacon Link: https://lore.kernel.org/r/20201130115950.22492-7-mark.rutland@arm.com Signed-off-by: Will Deacon

arm64: Remove custom IRQ stat accounting

2020-09-17T15:37:28Z

Let's switch the arm64 code to the core accounting, which already does everything we need. Reviewed-by: Valentin Schneider Acked-by: Catalin Marinas Signed-off-by: Marc Zyngier

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2019-07-08T16:54:55Z

Pull arm64 updates from Catalin Marinas: - arm64 support for syscall emulation via PTRACE_SYSEMU{,_SINGLESTEP} - Wire up VM_FLUSH_RESET_PERMS for arm64, allowing the core code to manage the permissions of executable vmalloc regions more strictly - Slight performance improvement by keeping softirqs enabled while touching the FPSIMD/SVE state (kernel_neon_begin/end) - Expose a couple of ARMv8.5 features to user (HWCAP): CondM (new XAFLAG and AXFLAG instructions for floating point comparison flags manipulation) and FRINT (rounding floating point numbers to integers) - Re-instate ARM64_PSEUDO_NMI support which was previously marked as BROKEN due to some bugs (now fixed) - Improve parking of stopped CPUs and implement an arm64-specific panic_smp_self_stop() to avoid warning on not being able to stop secondary CPUs during panic - perf: enable the ARM Statistical Profiling Extensions (SPE) on ACPI platforms - perf: DDR performance monitor support for iMX8QXP - cache_line_size() can now be set from DT or ACPI/PPTT if provided to cope with a system cache info not exposed via the CPUID registers - Avoid warning on hardware cache line size greater than ARCH_DMA_MINALIGN if the system is fully coherent - arm64 do_page_fault() and hugetlb cleanups - Refactor set_pte_at() to avoid redundant READ_ONCE(*ptep) - Ignore ACPI 5.1 FADTs reported as 5.0 (infer from the 'arm_boot_flags' introduced in 5.1) - CONFIG_RANDOMIZE_BASE now enabled in defconfig - Allow the selection of ARM64_MODULE_PLTS, currently only done via RANDOMIZE_BASE (and an erratum workaround), allowing modules to spill over into the vmalloc area - Make ZONE_DMA32 configurable * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (54 commits) perf: arm_spe: Enable ACPI/Platform automatic module loading arm_pmu: acpi: spe: Add initial MADT/SPE probing ACPI/PPTT: Add function to return ACPI 6.3 Identical tokens ACPI/PPTT: Modify node flag detection to find last IDENTICAL x86/entry: Simplify _TIF_SYSCALL_EMU handling arm64: rename dump_instr as dump_kernel_instr arm64/mm: Drop [PTE|PMD]_TYPE_FAULT arm64: Implement panic_smp_self_stop() arm64: Improve parking of stopped CPUs arm64: Expose FRINT capabilities to userspace arm64: Expose ARMv8.5 CondM capability to userspace arm64: defconfig: enable CONFIG_RANDOMIZE_BASE arm64: ARM64_MODULES_PLTS must depend on MODULES arm64: bpf: do not allocate executable memory arm64/kprobes: set VM_FLUSH_RESET_PERMS on kprobe instruction pages arm64/mm: wire up CONFIG_ARCH_HAS_SET_DIRECT_MAP arm64: module: create module allocations without exec permissions arm64: Allow user selection of ARM64_MODULE_PLTS acpi/arm64: ignore 5.1 FADTs that are reported as 5.0 arm64: Allow selecting Pseudo-NMI again ...

arm64: fix kernel stack overflow in kdump capture kernel

2019-06-21T14:50:23Z

When enabling ARM64_PSEUDO_NMI feature in kdump capture kernel, it will report a kernel stack overflow exception: [ 0.000000] CPU features: detected: IRQ priority masking [ 0.000000] alternatives: patching kernel code [ 0.000000] Insufficient stack space to handle exception! [ 0.000000] ESR: 0x96000044 -- DABT (current EL) [ 0.000000] FAR: 0x0000000000000040 [ 0.000000] Task stack: [0xffff0000097f0000..0xffff0000097f4000] [ 0.000000] IRQ stack: [0x0000000000000000..0x0000000000004000] [ 0.000000] Overflow stack: [0xffff80002b7cf290..0xffff80002b7d0290] [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.34-lw+ #3 [ 0.000000] pstate: 400003c5 (nZcv DAIF -PAN -UAO) [ 0.000000] pc : el1_sync+0x0/0xb8 [ 0.000000] lr : el1_irq+0xb8/0x140 [ 0.000000] sp : 0000000000000040 [ 0.000000] pmr_save: 00000070 [ 0.000000] x29: ffff0000097f3f60 x28: ffff000009806240 [ 0.000000] x27: 0000000080000000 x26: 0000000000004000 [ 0.000000] x25: 0000000000000000 x24: ffff000009329028 [ 0.000000] x23: 0000000040000005 x22: ffff000008095c6c [ 0.000000] x21: ffff0000097f3f70 x20: 0000000000000070 [ 0.000000] x19: ffff0000097f3e30 x18: ffffffffffffffff [ 0.000000] x17: 0000000000000000 x16: 0000000000000000 [ 0.000000] x15: ffff0000097f9708 x14: ffff000089a382ef [ 0.000000] x13: ffff000009a382fd x12: ffff000009824000 [ 0.000000] x11: ffff0000097fb7b0 x10: ffff000008730028 [ 0.000000] x9 : ffff000009440018 x8 : 000000000000000d [ 0.000000] x7 : 6b20676e69686374 x6 : 000000000000003b [ 0.000000] x5 : 0000000000000000 x4 : ffff000008093600 [ 0.000000] x3 : 0000000400000008 x2 : 7db2e689fc2b8e00 [ 0.000000] x1 : 0000000000000000 x0 : ffff0000097f3e30 [ 0.000000] Kernel panic - not syncing: kernel stack overflow [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.34-lw+ #3 [ 0.000000] Call trace: [ 0.000000] dump_backtrace+0x0/0x1b8 [ 0.000000] show_stack+0x24/0x30 [ 0.000000] dump_stack+0xa8/0xcc [ 0.000000] panic+0x134/0x30c [ 0.000000] __stack_chk_fail+0x0/0x28 [ 0.000000] handle_bad_stack+0xfc/0x108 [ 0.000000] __bad_stack+0x90/0x94 [ 0.000000] el1_sync+0x0/0xb8 [ 0.000000] init_gic_priority_masking+0x4c/0x70 [ 0.000000] smp_prepare_boot_cpu+0x60/0x68 [ 0.000000] start_kernel+0x1e8/0x53c [ 0.000000] ---[ end Kernel panic - not syncing: kernel stack overflow ]--- The reason is init_gic_priority_masking() may unmask PSR.I while the irq stacks are not inited yet. Some "NMI" could be raised unfortunately and it will just go into this exception. In this patch, we just write the PMR in smp_prepare_boot_cpu(), and delay unmasking PSR.I after irq stacks inited in init_IRQ(). Fixes: e79321883842 ("arm64: Switch to PMR masking when starting CPUs") Cc: Will Deacon Reviewed-by: Marc Zyngier Signed-off-by: Wei Li [JT: make init_gic_priority_masking() not modify daif, rebase on other priority masking fixes] Signed-off-by: Julien Thierry Signed-off-by: Catalin Marinas

arm64: Fix interrupt tracing in the presence of NMIs

2019-06-21T14:49:58Z

In the presence of any form of instrumentation, nmi_enter() should be done before calling any traceable code and any instrumentation code. Currently, nmi_enter() is done in handle_domain_nmi(), which is much too late as instrumentation code might get called before. Move the nmi_enter/exit() calls to the arch IRQ vector handler. On arm64, it is not possible to know if the IRQ vector handler was called because of an NMI before acknowledging the interrupt. However, It is possible to know whether normal interrupts could be taken in the interrupted context (i.e. if taking an NMI in that context could introduce a potential race condition). When interrupting a context with IRQs disabled, call nmi_enter() as soon as possible. In contexts with IRQs enabled, defer this to the interrupt controller, which is in a better position to know if an interrupt taken is an NMI. Fixes: bc3c03ccb464 ("arm64: Enable the support of pseudo-NMIs") Cc: # 5.1.x- Cc: Will Deacon Cc: Thomas Gleixner Cc: Jason Cooper Cc: Mark Rutland Reviewed-by: Marc Zyngier Signed-off-by: Julien Thierry Signed-off-by: Catalin Marinas