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2016-09-09arm64: lse: convert lse alternatives NOP padding to use __nopsWill Deacon
The LSE atomics are implemented using alternative code sequences of different lengths, and explicit NOP padding is used to ensure the patching works correctly. This patch converts the bulk of the LSE code over to using the __nops macro, which makes it slightly clearer as to what is going on and also consolidates all of the padding at the end of the various sequences. Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: barriers: introduce nops and __nops macros for NOP sequencesWill Deacon
NOP sequences tend to get used for padding out alternative sections and uarch-specific pipeline flushes in errata workarounds. This patch adds macros for generating these sequences as both inline asm blocks, but also as strings suitable for embedding in other asm blocks directly. Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: sysreg: replace open-coded mrs_s/msr_s with {read,write}_sysreg_sWill Deacon
Similar to our {read,write}_sysreg accessors for architected, named system registers, this patch introduces {read,write}_sysreg_s variants that can take arbitrary sys_reg output and therefore access IMPDEF registers or registers that unsupported by binutils. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Remove shadowed asm-generic headersRobin Murphy
We've grown our own versions of bug.h, ftrace.h, pci.h and topology.h, so generating the generic ones as well is unnecessary and a potential source of build hiccups. At the very least, having them present has confused my source-indexing tool, and that simply will not do. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Work around systems with mismatched cache line sizesSuzuki K Poulose
Systems with differing CPU i-cache/d-cache line sizes can cause problems with the cache management by software when the execution is migrated from one to another. Usually, the application reads the cache size on a CPU and then uses that length to perform cache operations. However, if it gets migrated to another CPU with a smaller cache line size, things could go completely wrong. To prevent such cases, always use the smallest cache line size among the CPUs. The kernel CPU feature infrastructure already keeps track of the safe value for all CPUID registers including CTR. This patch works around the problem by : For kernel, dynamically patch the kernel to read the cache size from the system wide copy of CTR_EL0. For applications, trap read accesses to CTR_EL0 (by clearing the SCTLR.UCT) and emulate the mrs instruction to return the system wide safe value of CTR_EL0. For faster access (i.e, avoiding to lookup the system wide value of CTR_EL0 via read_system_reg), we keep track of the pointer to table entry for CTR_EL0 in the CPU feature infrastructure. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Refactor sysinstr exception handlingSuzuki K Poulose
Right now we trap some of the user space data cache operations based on a few Errata (ARM 819472, 826319, 827319 and 824069). We need to trap userspace access to CTR_EL0, if we detect mismatched cache line size. Since both these traps share the EC, refactor the handler a little bit to make it a bit more reader friendly. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Introduce raw_{d,i}cache_line_sizeSuzuki K Poulose
On systems with mismatched i/d cache min line sizes, we need to use the smallest size possible across all CPUs. This will be done by fetching the system wide safe value from CPU feature infrastructure. However the some special users(e.g kexec, hibernate) would need the line size on the CPU (rather than the system wide), when either the system wide feature may not be accessible or it is guranteed that the caller executes with a gurantee of no migration. Provide another helper which will fetch cache line size on the current CPU. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: James Morse <james.morse@arm.com> Reviewed-by: Geoff Levand <geoff@infradead.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: alternative: Add support for patching adrp instructionsSuzuki K Poulose
adrp uses PC-relative address offset to a page (of 4K size) of a symbol. If it appears in an alternative code patched in, we should adjust the offset to reflect the address where it will be run from. This patch adds support for fixing the offset for adrp instructions. Cc: Will Deacon <will.deacon@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: insn: Add helpers for adrp offsetsSuzuki K Poulose
Adds helpers for decoding/encoding the PC relative addresses for adrp. This will be used for handling dynamic patching of 'adrp' instructions in alternative code patching. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: alternative: Disallow patching instructions using literalsSuzuki K Poulose
The alternative code patching doesn't check if the replaced instruction uses a pc relative literal. This could cause silent corruption in the instruction stream as the instruction will be executed from a different address than what it was compiled for. Catch all such cases. Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Suggested-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Rearrange CPU errata workaround checksSuzuki K Poulose
Right now we run through the work around checks on a CPU from __cpuinfo_store_cpu. There are some problems with that: 1) We initialise the system wide CPU feature registers only after the Boot CPU updates its cpuinfo. Now, if a work around depends on the variance of a CPU ID feature (e.g, check for Cache Line size mismatch), we have no way of performing it cleanly for the boot CPU. 2) It is out of place, invoked from __cpuinfo_store_cpu() in cpuinfo.c. It is not an obvious place for that. This patch rearranges the CPU specific capability(aka work around) checks. 1) At the moment we use verify_local_cpu_capabilities() to check if a new CPU has all the system advertised features. Use this for the secondary CPUs to perform the work around check. For that we rename verify_local_cpu_capabilities() => check_local_cpu_capabilities() which: If the system wide capabilities haven't been initialised (i.e, the CPU is activated at the boot), update the system wide detected work arounds. Otherwise (i.e a CPU hotplugged in later) verify that this CPU conforms to the system wide capabilities. 2) Boot CPU updates the work arounds from smp_prepare_boot_cpu() after we have initialised the system wide CPU feature values. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Andre Przywara <andre.przywara@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Use consistent naming for errata handlingSuzuki K Poulose
This is a cosmetic change to rename the functions dealing with the errata work arounds to be more consistent with their naming. 1) check_local_cpu_errata() => update_cpu_errata_workarounds() check_local_cpu_errata() actually updates the system's errata work arounds. So rename it to reflect the same. 2) verify_local_cpu_errata() => verify_local_cpu_errata_workarounds() Use errata_workarounds instead of _errata. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: Set the safe value for L1 icache policySuzuki K Poulose
Right now we use 0 as the safe value for CTR_EL0:L1Ip, which is not defined at the moment. The safer value for the L1Ip should be the weakest of the policies, which happens to be AIVIVT. While at it, fix the comment about safe_val. Cc: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64/numa: remove the limitation that cpu0 must bind to node0Zhen Lei
1. Remove the old binding code. 2. Read the nid of cpu0 from dts. 3. Fallback the nid of cpu0 to 0 when numa=off is set in bootargs. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64/numa: remove some useless codeZhen Lei
When the deleted code is executed, only the bit of cpu0 was set on cpu_possible_mask. So that, only set_cpu_numa_node(0, NUMA_NO_NODE); will be executed. And map_cpu_to_node(0, 0) will soon be called. So these code can be safely removed. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64/numa: support HAVE_SETUP_PER_CPU_AREAZhen Lei
To make each percpu area allocated from its local numa node. Without this patch, all percpu areas will be allocated from the node which cpu0 belongs to. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: numa: Use pr_fmt()Kefeng Wang
Use pr_fmt to prefix kernel output, and remove duplicated msg of NUMA turned off. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09of_numa: Use pr_fmt()Kefeng Wang
Use pr_fmt to prefix kernel output. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09of_numa: Use of_get_next_parent to simplify codeKefeng Wang
Use of_get_next_parent() instead of open-code. Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64/numa: avoid inconsistent information to be printedZhen Lei
numa_init may return error because of numa configuration error. So "No NUMA configuration found" is inaccurate. In fact, specific configuration error information should be immediately printed by the testing branch. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09of/numa: remove a duplicated warningZhen Lei
This warning has been printed in of_numa_parse_cpu_nodes before. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09of/numa: add nid check for memory blockZhen Lei
If the numa-id which was configured in memory@ devicetree node is greater than MAX_NUMNODES, we should report a warning. We have done this for cpus and distance-map dt nodes, this patch help them to be consistent. Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09of/numa: fix a memory@ node can only contains one memory blockZhen Lei
For a normal memory@ devicetree node, its reg property can contains more memory blocks. Because we don't known how many memory blocks maybe contained, so we try from index=0, increase 1 until error returned(the end). Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09of/numa: remove a duplicated pr_debug informationZhen Lei
This information will be printed in the subfunction numa_add_memblk. They are not the same, but very similar. Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09drivers/perf: arm_pmu: expose a cpumask in sysfsMark Rutland
In systems with heterogeneous CPUs, there are multiple logical CPU PMUs, each of which covers a subset of CPUs in the system. In some cases userspace needs to know which CPUs a given logical PMU covers, so we'd like to expose a cpumask under sysfs, similar to what is done for uncore PMUs. Unfortunately, prior to commit 00e727bb389359c8 ("perf stat: Balance opening and reading events"), perf stat only correctly handled a cpumask holding a single CPU, and only when profiling in system-wide mode. In other cases, the presence of a cpumask file could cause perf stat to behave erratically. Thus, exposing a cpumask file would break older perf binaries in cases where they would otherwise work. To avoid this issue while still providing userspace with the information it needs, this patch exposes a differently-named file (cpus) under sysfs. New tools can look for this and operate correctly, while older tools will not be adversely affected by its presence. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09drivers/perf: arm_pmu: only use common attr_groupsMark Rutland
Now that the 32-bit and 64-bit perf backends use the common groups directly, remove the fallback and no longer allow the groups array to be overridden. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm: perf: move to common attr_group fieldsMark Rutland
By using a common attr_groups array, the common arm_pmu code can set up common files (e.g. cpumask) for us in subsequent patches. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: perf: move to common attr_group fieldsMark Rutland
By using a common attr_groups array, the common arm_pmu code can set up common files (e.g. cpumask) for us in subsequent patches. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09drivers/perf: arm_pmu: add common attr group fieldsMark Rutland
In preparation for adding common attribute groups, add an array of attribute group pointers to arm_pmu, which will be used if the backend hasn't already set pmu::attr_groups. Subsequent patches will move backends over to using these, before adding common fields. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: simplify contextidr_thread_switchMark Rutland
When CONFIG_PID_IN_CONTEXTIDR is not selected, we use an empty stub definition of contextidr_thread_switch(). As everything we rely upon exists regardless of CONFIG_PID_IN_CONTEXTIDR, we don't strictly require an empty stub. By using IS_ENABLED() rather than ifdeffery, we avoid duplication, and get compiler coverage on all the code even when CONFIG_PID_IN_CONTEXTIDR is not selected and the code is optimised away. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: simplify sysreg manipulationMark Rutland
A while back we added {read,write}_sysreg accessors to handle accesses to system registers, without the usual boilerplate asm volatile, temporary variable, etc. This patch makes use of these across arm64 to make code shorter and clearer. For sequences with a trailing ISB, the existing isb() macro is also used so that asm blocks can be removed entirely. A few uses of inline assembly for msr/mrs are left as-is. Those manipulating sp_el0 for the current thread_info value have special clobber requiremends. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64/kvm: use {read,write}_sysreg()Mark Rutland
A while back we added {read,write}_sysreg accessors to handle accesses to system registers, without the usual boilerplate asm volatile, temporary variable, etc. This patch makes use of these in the arm64 KVM code to make the code shorter and clearer. At the same time, a comment style violation next to a system register access is fixed up in reset_pmcr, and comments describing whether operations are reads or writes are removed as this is now painfully obvious. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: dcc: simplify accessorsMark Rutland
A while back we added {read,write}_sysreg accessors to handle accesses to system registers, without the usual boilerplate asm volatile, temporary variable, etc. This patch makes use of these in the arm64 DCC accessors to make the code shorter and clearer. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: arch_timer: simplify accessorsMark Rutland
A while back we added {read,write}_sysreg accessors to handle accesses to system registers, without the usual boilerplate asm volatile, temporary variable, etc. This patch makes use of these in the arm64 arch timer accessors to make the code shorter and clearer. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-09arm64: sysreg: allow write_sysreg to use XZRMark Rutland
Currently write_sysreg has to allocate a temporary register to write zero to a system register, which is unfortunate given that the MSR instruction accepts XZR as an operand. Allow XZR to be used when appropriate by fiddling with the assembly constraints. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-08arm64/io: Allow I/O writes to use {W,X}ZRRobin Murphy
When zeroing an I/O location, the current accessors are forced to allocate a temporary register to store the zero for the write. By tweaking the assembly constraints, we can allow the compiler to use the zero register directly in such cases, and save some juggling. Compiling a representative kernel configuration with GCC 6 shows that 2.3KB worth of code can be wasted just on that! text data bss dec hex filename 13316776 3248256 18176769 34741801 2121e29 vmlinux.o.new 13319140 3248256 18176769 34744165 2122765 vmlinux.o.old Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-07arm64: Use static keys for CPU featuresCatalin Marinas
This patch adds static keys transparently for all the cpu_hwcaps features by implementing an array of default-false static keys and enabling them when detected. The cpus_have_cap() check uses the static keys if the feature being checked is a constant, otherwise the compiler generates the bitmap test. Because of the early call to static_branch_enable() via check_local_cpu_errata() -> update_cpu_capabilities(), the jump labels are initialised in cpuinfo_store_boot_cpu(). Cc: Will Deacon <will.deacon@arm.com> Cc: Suzuki K. Poulose <Suzuki.Poulose@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-07jump_labels: Allow array initialisersCatalin Marinas
The static key API is currently designed around single variable definitions. There are cases where an array of static keys is desirable, so extend the API to allow this rather than using the internal static key implementation directly. Cc: Jason Baron <jbaron@akamai.com> Cc: Jonathan Corbet <corbet@lwn.net> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Suggested-by: Dave P Martin <Dave.Martin@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-06arm64: mm: drop fixup_init() and mm.hKefeng Wang
There is only fixup_init() in mm.h , and it is only called in free_initmem(), so move the codes from fixup_init() into free_initmem(), then drop fixup_init() and mm.h. Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-06drivers/perf: arm_pmu: Always consider IRQ0 as an errorMarc Zyngier
As declared by the chief penguin, and enforced by the NO_IRQ brigade, IRQ0 doesn't exist, and is considered as an error (no irq). Unfortunately, the arm_pmu driver still considers it as valid in a large number of cases. Let's fix this. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-05arm64: ftrace: add save_stack_trace_regs()Pratyush Anand
Currently, enabling stacktrace of a kprobe events generates warning: echo stacktrace > /sys/kernel/debug/tracing/trace_options echo "p xhci_irq" > /sys/kernel/debug/tracing/kprobe_events echo 1 > /sys/kernel/debug/tracing/events/kprobes/enable save_stack_trace_regs() not implemented yet. ------------[ cut here ]------------ WARNING: CPU: 1 PID: 0 at ../kernel/stacktrace.c:74 save_stack_trace_regs+0x3c/0x48 Modules linked in: CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.8.0-rc4-dirty #5128 Hardware name: ARM Juno development board (r1) (DT) task: ffff800975dd1900 task.stack: ffff800975ddc000 PC is at save_stack_trace_regs+0x3c/0x48 LR is at save_stack_trace_regs+0x3c/0x48 pc : [<ffff000008126c64>] lr : [<ffff000008126c64>] pstate: 600003c5 sp : ffff80097ef52c00 Call trace: save_stack_trace_regs+0x3c/0x48 __ftrace_trace_stack+0x168/0x208 trace_buffer_unlock_commit_regs+0x5c/0x7c kprobe_trace_func+0x308/0x3d8 kprobe_dispatcher+0x58/0x60 kprobe_breakpoint_handler+0xbc/0x18c brk_handler+0x50/0x90 do_debug_exception+0x50/0xbc This patch implements save_stack_trace_regs(), so that stacktrace of a kprobe events can be obtained. After this patch, there is no warning and we can see the stacktrace for kprobe events in trace buffer. more /sys/kernel/debug/tracing/trace <idle>-0 [004] d.h. 1356.000496: p_xhci_irq_0:(xhci_irq+0x0/0x9ac) <idle>-0 [004] d.h. 1356.000497: <stack trace> => xhci_irq => __handle_irq_event_percpu => handle_irq_event_percpu => handle_irq_event => handle_fasteoi_irq => generic_handle_irq => __handle_domain_irq => gic_handle_irq => el1_irq => arch_cpu_idle => default_idle_call => cpu_startup_entry => secondary_start_kernel => Tested-by: David A. Long <dave.long@linaro.org> Reviewed-by: James Morse <james.morse@arm.com> Signed-off-by: Pratyush Anand <panand@redhat.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-05arm64: kernel: re-export _cpu_resume() from sleep.SArd Biesheuvel
Commit b5fe242972ef ("arm64: kernel: fix style issues in sleep.S") changed the linkage of _cpu_resume() to local, even though the symbol is also referenced from hibernate.c. So revert this change. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-05arm64: Drop generic xlate_dev_mem_{k,}ptr()James Morse
The code that provides /dev/mem uses xlate_dev_mem_{k,}ptr() to avoid making a cachable mapping of a non-cachable area on ia64. On arm64 we do this via phys_mem_access_prot() instead, but provide dummy versions of xlate_dev_mem_{k,}ptr(). These are the same as those in asm-generic/io.h, which we include from asm/io.h Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-02arm64: debug: report TRAP_TRACE instead of TRAP_HWBRPT for singlestepWill Deacon
Single-step traps to userspace (e.g. via ptrace) are expected to use the TRAP_TRACE for the si_code field of the siginfo, as opposed to TRAP_HWBRPT that we report currently. Fix the reported value, which has no effect on existing and legacy builds of GDB. Reported-by: Yao Qi <yao.qi@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-02arm64: head.S: document the use of callee saved registersArd Biesheuvel
Now that the only remaining occurrences of the use of callee saved registers are on the primary boot path, add a comment to the code which register is used for what. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-02arm64: head.S: use ordinary stack frame for __primary_switched()Ard Biesheuvel
Instead of stashing the value of the link register in x28 before setting up the stack and calling into C code, create an ordinary PCS compatible stack frame so that we can push the return address onto the stack. Since exception handlers require a stack as well, assign the stack pointer register before installing the vector table. Note that this accounts for the difference between THREAD_START_SP and THREAD_SIZE, given that the stack pointer is always decremented before calling into any C code. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-02arm64: kernel: drop use of x24 from primary boot pathArd Biesheuvel
Keeping __PHYS_OFFSET in x24 is actually less clear than simply taking the value of __PHYS_OFFSET using an adrp instruction in the three places that we need it. So change that. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-02arm64: kernel: use x30 for __enable_mmu return addressArd Biesheuvel
Using x27 for passing to __enable_mmu what is essentially the return address makes the code look more complicated than it needs to be. So switch to x30/lr, and update the secondary and cpu_resume call sites to simply call __enable_mmu as an ordinary function, with a bl instruction. This requires the callers to be covered by .idmap.text. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-02arm64: head.S: move KASLR processing out of __enable_mmu()Ard Biesheuvel
The KASLR processing is only used by the primary boot path, and complements the processing that takes place in __primary_switch(). Move the two parts together, to make the code easier to understand. Also, fix up a minor whitespace issue. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> [will: fixed conflict with -rc3 due to lack of fd363bd417dd] Signed-off-by: Will Deacon <will.deacon@arm.com>
2016-09-02arm64: kernel: use ordinary return/argument register for el2_setup()Ard Biesheuvel
The function el2_setup() passes its return value in register w20, and in the two cases where the caller actually cares about this return value, it is passed into set_cpu_boot_mode_flag() [almost] directly, which expects its input in w20 as well. So there is no reason to use a 'special' callee saved register here, but we can simply follow the PCS for return value and first argument, respectively. Reviewed-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Will Deacon <will.deacon@arm.com>