aboutsummaryrefslogtreecommitdiff
path: root/arch
AgeCommit message (Collapse)AuthorFilesLines
2020-12-02arm64: head.S: always initialize PSTATEMark Rutland2-11/+26
As with SCTLR_ELx and other control registers, some PSTATE bits are UNKNOWN out-of-reset, and we may not be able to rely on hardware or firmware to initialize them to our liking prior to entry to the kernel, e.g. in the primary/secondary boot paths and return from idle/suspend. It would be more robust (and easier to reason about) if we consistently initialized PSTATE to a default value, as we do with control registers. This will ensure that the kernel is not adversely affected by bits it is not aware of, e.g. when support for a feature such as PAN/UAO is disabled. This patch ensures that PSTATE is consistently initialized at boot time via an ERET. This is not intended to relax the existing requirements (e.g. DAIF bits must still be set prior to entering the kernel). For features detected dynamically (which may require system-wide support), it is still necessary to subsequently modify PSTATE. As ERET is not always a Context Synchronization Event, an ISB is placed before each exception return to ensure updates to control registers have taken effect. This handles the kernel being entered with SCTLR_ELx.EOS clear (or any future control bits being in an UNKNOWN state). Signed-off-by: Mark Rutland <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: James Morse <[email protected]> Cc: Will Deacon <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Catalin Marinas <[email protected]>
2020-12-02arm64: head.S: cleanup SCTLR_ELx initializationMark Rutland3-10/+16
Let's make SCTLR_ELx initialization a bit clearer by using meaningful names for the initialization values, following the same scheme for SCTLR_EL1 and SCTLR_EL2. These definitions will be used more widely in subsequent patches. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: James Morse <[email protected]> Cc: Will Deacon <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Catalin Marinas <[email protected]>
2020-12-02arm64: head.S: rename el2_setup -> init_kernel_elMark Rutland2-8/+9
For a while now el2_setup has performed some basic initialization of EL1 even when the kernel is booted at EL1, so the name is a little misleading. Further, some comments are stale as with VHE it doesn't drop the CPU to EL1. To clarify things, rename el2_setup to init_kernel_el, and update comments to be clearer as to the function's purpose. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: James Morse <[email protected]> Cc: Will Deacon <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Catalin Marinas <[email protected]>
2020-12-02arm64: add C wrappers for SET_PSTATE_*()Mark Rutland3-3/+7
To make callsites easier to read, add trivial C wrappers for the SET_PSTATE_*() helpers, and convert trivial uses over to these. The new wrappers will be used further in subsequent patches. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: James Morse <[email protected]> Cc: Will Deacon <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Catalin Marinas <[email protected]>
2020-12-02arm64: ensure ERET from kthread is illegalMark Rutland1-9/+8
For consistency, all tasks have a pt_regs reserved at the highest portion of their task stack. Among other things, this ensures that a task's SP is always pointing within its stack rather than pointing immediately past the end. While it is never legitimate to ERET from a kthread, we take pains to initialize pt_regs for kthreads as if this were legitimate. As this is never legitimate, the effects of an erroneous return are rarely tested. Let's simplify things by initializing a kthread's pt_regs such that an ERET is caught as an illegal exception return, and removing the explicit initialization of other exception context. Note that as spectre_v4_enable_task_mitigation() only manipulates the PSTATE within the unused regs this is safe to remove. As user tasks will have their exception context initialized via start_thread() or start_compat_thread(), this should only impact cases where something has gone very wrong and we'd like that to be clearly indicated. Signed-off-by: Mark Rutland <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: James Morse <[email protected]> Cc: Will Deacon <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Catalin Marinas <[email protected]>
2020-11-09arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=yWill Deacon4-3/+76
When building with LTO, there is an increased risk of the compiler converting an address dependency headed by a READ_ONCE() invocation into a control dependency and consequently allowing for harmful reordering by the CPU. Ensure that such transformations are harmless by overriding the generic READ_ONCE() definition with one that provides acquire semantics when building with LTO. Acked-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Mark Rutland <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2020-11-09arm64: alternatives: Remove READ_ONCE() usage during patch operationWill Deacon1-3/+4
In preparation for patching the internals of READ_ONCE() itself, replace its usage on the alternatives patching patch with a volatile variable instead. Acked-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Mark Rutland <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2020-11-09arm64: cpufeatures: Add capability for LDAPR instructionWill Deacon3-1/+15
Armv8.3 introduced the LDAPR instruction, which provides weaker memory ordering semantics than LDARi (RCpc vs RCsc). Generally, we provide an RCsc implementation when implementing the Linux memory model, but LDAPR can be used as a useful alternative to dependency ordering, particularly when the compiler is capable of breaking the dependencies. Since LDAPR is not available on all CPUs, add a cpufeature to detect it at runtime and allow the instruction to be used with alternative code patching. Acked-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Mark Rutland <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2020-11-09arm64: alternatives: Split up alternative.hWill Deacon5-209/+222
asm/alternative.h contains both the macros needed to use alternatives, as well the type definitions and function prototypes for applying them. Split the header in two, so that alternatives can be used from core header files such as linux/compiler.h without the risk of circular includes Acked-by: Peter Zijlstra (Intel) <[email protected]> Acked-by: Mark Rutland <[email protected]> Signed-off-by: Will Deacon <[email protected]>
2020-11-09arm64: uaccess: move uao_* alternatives to asm-uaccess.hMark Rutland3-60/+60
The uao_* alternative asm macros are only used by the uaccess assembly routines in arch/arm64/lib/, where they are included indirectly via asm-uaccess.h. Since they're specific to the uaccess assembly (and will lose the alternatives in subsequent patches), let's move them into asm-uaccess.h. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland <[email protected]> Cc: Catalin Marinas <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: James Morse <[email protected]> Cc: Will Deacon <[email protected]> [will: update #include in mte.S to pull in uao asm macros] Signed-off-by: Will Deacon <[email protected]>
2020-11-08Merge tag 'x86-urgent-2020-11-08' of ↵Linus Torvalds5-32/+54
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "A set of x86 fixes: - Use SYM_FUNC_START_WEAK in the mem* ASM functions instead of a combination of .weak and SYM_FUNC_START_LOCAL which makes LLVMs integrated assembler upset - Correct the mitigation selection logic which prevented the related prctl to work correctly - Make the UV5 hubless system work correctly by fixing up the malformed table entries and adding the missing ones" * tag 'x86-urgent-2020-11-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/platform/uv: Recognize UV5 hubless system identifier x86/platform/uv: Remove spaces from OEM IDs x86/platform/uv: Fix missing OEM_TABLE_ID x86/speculation: Allow IBPB to be conditionally enabled on CPUs with always-on STIBP x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S
2020-11-08Merge tag 'powerpc-5.10-3' of ↵Linus Torvalds10-104/+44
git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: - fix miscompilation with GCC 4.9 by using asm_goto_volatile for put_user() - fix for an RCU splat at boot caused by a recent lockdep change - fix for a possible deadlock in our EEH debugfs code - several fixes for handling of _PAGE_ACCESSED on 32-bit platforms - build fix when CONFIG_NUMA=n Thanks to Andreas Schwab, Christophe Leroy, Oliver O'Halloran, Qian Cai, and Scott Cheloha. * tag 'powerpc-5.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/numa: Fix build when CONFIG_NUMA=n powerpc/8xx: Manage _PAGE_ACCESSED through APG bits in L1 entry powerpc/8xx: Always fault when _PAGE_ACCESSED is not set powerpc/40x: Always fault when _PAGE_ACCESSED is not set powerpc/603: Always fault when _PAGE_ACCESSED is not set powerpc: Use asm_goto_volatile for put_user() powerpc/smp: Call rcu_cpu_starting() earlier powerpc/eeh_cache: Fix a possible debugfs deadlock
2020-11-07Merge tag 'riscv-for-linus-5.10-rc3' of ↵Linus Torvalds8-23/+47
git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux Pull RISC-V fixes from Palmer Dabbelt: - SPDX comment style fix - ignore memory that is unusable - avoid setting a kernel text offset for the !MMU kernels, where skipping the first page of memory is both unnecessary and costly - avoid passing the flag bits in satp to pfn_to_virt() - fix __put_kernel_nofault, where we had the arguments to __put_user_nocheck reversed - workaround for a bug in the FU540 to avoid triggering PMP issues during early boot - change to how we pull symbols out of the vDSO. The old mechanism was removed from binutils-2.35 (and has been backported to Debian's 2.34) * tag 'riscv-for-linus-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: RISC-V: Fix the VDSO symbol generaton for binutils-2.35+ RISC-V: Use non-PGD mappings for early DTB access riscv: uaccess: fix __put_kernel_nofault() riscv: fix pfn_to_virt err in do_page_fault(). riscv: Set text_offset correctly for M-Mode RISC-V: Remove any memblock representing unusable memory area risc-v: kernel: ftrace: Fixes improper SPDX comment style
2020-11-07x86/platform/uv: Recognize UV5 hubless system identifierMike Travis1-3/+10
Testing shows a problem in that UV5 hubless systems were not being recognized. Add them to the list of OEM IDs checked. Fixes: 6c7794423a998 ("Add UV5 direct references") Signed-off-by: Mike Travis <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-11-07x86/platform/uv: Remove spaces from OEM IDsMike Travis1-0/+3
Testing shows that trailing spaces caused problems with the OEM_ID and the OEM_TABLE_ID. One being that the OEM_ID would not string compare correctly. Another the OEM_ID and OEM_TABLE_ID would be concatenated in the printout. Remove any trailing spaces. Fixes: 1e61f5a95f191 ("Add and decode Arch Type in UVsystab") Signed-off-by: Mike Travis <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-11-07x86/platform/uv: Fix missing OEM_TABLE_IDMike Travis1-2/+5
Testing shows a problem in that the OEM_TABLE_ID was missing for hubless systems. This is used to determine the APIC type (legacy or extended). Add the OEM_TABLE_ID to the early hubless processing. Fixes: 1e61f5a95f191 ("Add and decode Arch Type in UVsystab") Signed-off-by: Mike Travis <[email protected]> Signed-off-by: Thomas Gleixner <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-11-06Merge tag 'arm64-fixes' of ↵Linus Torvalds7-59/+67
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull arm64 fixes from Will Deacon: "Here's the weekly batch of fixes for arm64. Not an awful lot here, but there are still a few unresolved issues relating to CPU hotplug, RCU and IRQ tracing that I hope to queue fixes for next week. Summary: - Fix early use of kprobes - Fix kernel placement in kexec_file_load() - Bump maximum number of NUMA nodes" * tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: arm64: kexec_file: try more regions if loading segments fails arm64: kprobes: Use BRK instead of single-step when executing instructions out-of-line arm64: NUMA: Kconfig: Increase NODES_SHIFT to 4
2020-11-06Merge tag 'arc-5.10-rc3' of ↵Linus Torvalds3-19/+22
git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc Pull ARC fixes from Vineet Gupta: - Unbork HSDKv1 platform (won't boot) due to memory map issue - Prevent stack unwinder from infinite looping * tag 'arc-5.10-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: ARC: [plat-hsdk] Remap CCMs super early in asm boot trampoline ARC: stack unwinding: avoid indefinite looping
2020-11-06Merge tag 's390-5.10-3' of ↵Linus Torvalds8-40/+48
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux Pull s390 fixes from Heiko Carstens: - fix reference counting for ap devices - fix paes selftest - fix pmd_deref()/pud_deref() so they can also handle large pages - remove unused vdso file and defines - update defconfigs - call rcu_cpu_starting() early in smp init code to avoid lockdep warnings - fix hotplug of PCI function missing bus * tag 's390-5.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/pci: fix hot-plug of PCI function missing bus s390/smp: move rcu_cpu_starting() earlier s390/pkey: fix paes selftest failure with paes and pkey static build s390: update defconfigs s390/vdso: remove unused constants s390/vdso: remove empty unused file s390/mm: make pmd/pud_deref() large page aware s390/ap: fix ap devices reference counting
2020-11-06RISC-V: Fix the VDSO symbol generaton for binutils-2.35+Palmer Dabbelt3-9/+16
We were relying on GNU ld's ability to re-link executable files in order to extract our VDSO symbols. This behavior was deemed a bug as of binutils-2.35 (specifically the binutils-gdb commit a87e1817a4 ("Have the linker fail if any attempt to link in an executable is made."), but as that has been backported to at least Debian's binutils-2.34 in may manifest in other places. The previous version of this was a bit of a mess: we were linking a static executable version of the VDSO, containing only a subset of the input symbols, which we then linked into the kernel. This worked, but certainly wasn't a supported path through the toolchain. Instead this new version parses the textual output of nm to produce a symbol table. Both rely on near-zero addresses being linkable, but as we rely on weak undefined symbols being linkable elsewhere I don't view this as a major issue. Fixes: e2c0cdfba7f6 ("RISC-V: User-facing API") Signed-off-by: Palmer Dabbelt <[email protected]>
2020-11-06RISC-V: Use non-PGD mappings for early DTB accessAnup Patel1-0/+14
Currently, we use PGD mappings for early DTB mapping in early_pgd but this breaks Linux kernel on SiFive Unleashed because on SiFive Unleashed PMP checks don't work correctly for PGD mappings. To fix early DTB mappings on SiFive Unleashed, we use non-PGD mappings (i.e. PMD) for early DTB access. Fixes: 8f3a2b4a96dc ("RISC-V: Move DT mapping outof fixmap") Signed-off-by: Anup Patel <[email protected]> Reviewed-by: Atish Patra <[email protected]> Tested-by: Atish Patra <[email protected]> Signed-off-by: Palmer Dabbelt <[email protected]>
2020-11-06riscv: uaccess: fix __put_kernel_nofault()Changbin Du1-1/+1
The copy_from_kernel_nofault() is broken on riscv because the 'dst' and 'src' are mistakenly reversed in __put_kernel_nofault() macro. copy_to_kernel_nofault: ... 0xffffffe0003159b8 <+30>: sd a4,0(a1) # a1 aka 'src' Fixes: d464118cdc ("riscv: implement __get_kernel_nofault and __put_user_nofault") Signed-off-by: Changbin Du <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Reviewed-by: Anup Patel <[email protected]> Tested-by: Anup Patel <[email protected]> Signed-off-by: Palmer Dabbelt <[email protected]>
2020-11-05riscv: fix pfn_to_virt err in do_page_fault().Liu Shaohua1-1/+3
The argument to pfn_to_virt() should be pfn not the value of CSR_SATP. Reviewed-by: Palmer Dabbelt <[email protected]> Reviewed-by: Anup Patel <[email protected]> Signed-off-by: liush <[email protected]> Reviewed-by: Pekka Enberg <[email protected]> Signed-off-by: Palmer Dabbelt <[email protected]>
2020-11-06powerpc/numa: Fix build when CONFIG_NUMA=nScott Cheloha1-3/+9
Add a non-NUMA definition for of_drconf_to_nid_single() to topology.h so we have one even if powerpc/mm/numa.c is not compiled. On a non-NUMA kernel the appropriate node id is always first_online_node. Fixes: 72cdd117c449 ("pseries/hotplug-memory: hot-add: skip redundant LMB lookup") Reported-by: kernel test robot <[email protected]> Signed-off-by: Scott Cheloha <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-11-05riscv: Set text_offset correctly for M-ModeSean Anderson1-0/+5
M-Mode Linux is loaded at the start of RAM, not 2MB later. Perhaps this should be calculated based on PAGE_OFFSET somehow? Even better would be to deprecate text_offset and instead introduce something absolute. Signed-off-by: Sean Anderson <[email protected]> Signed-off-by: Palmer Dabbelt <[email protected]>
2020-11-05arm64: kexec_file: try more regions if loading segments failsBenjamin Gwin2-11/+39
It's possible that the first region picked for the new kernel will make it impossible to fit the other segments in the required 32GB window, especially if we have a very large initrd. Instead of giving up, we can keep testing other regions for the kernel until we find one that works. Suggested-by: Ryan O'Leary <[email protected]> Signed-off-by: Benjamin Gwin <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Will Deacon <[email protected]>
2020-11-05x86/speculation: Allow IBPB to be conditionally enabled on CPUs with ↵Anand K Mistry1-18/+33
always-on STIBP On AMD CPUs which have the feature X86_FEATURE_AMD_STIBP_ALWAYS_ON, STIBP is set to on and spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED At the same time, IBPB can be set to conditional. However, this leads to the case where it's impossible to turn on IBPB for a process because in the PR_SPEC_DISABLE case in ib_prctl_set() the spectre_v2_user_stibp == SPECTRE_V2_USER_STRICT_PREFERRED condition leads to a return before the task flag is set. Similarly, ib_prctl_get() will return PR_SPEC_DISABLE even though IBPB is set to conditional. More generally, the following cases are possible: 1. STIBP = conditional && IBPB = on for spectre_v2_user=seccomp,ibpb 2. STIBP = on && IBPB = conditional for AMD CPUs with X86_FEATURE_AMD_STIBP_ALWAYS_ON The first case functions correctly today, but only because spectre_v2_user_ibpb isn't updated to reflect the IBPB mode. At a high level, this change does one thing. If either STIBP or IBPB is set to conditional, allow the prctl to change the task flag. Also, reflect that capability when querying the state. This isn't perfect since it doesn't take into account if only STIBP or IBPB is unconditionally on. But it allows the conditional feature to work as expected, without affecting the unconditional one. [ bp: Massage commit message and comment; space out statements for better readability. ] Fixes: 21998a351512 ("x86/speculation: Avoid force-disabling IBPB based on STIBP and enhanced IBRS.") Signed-off-by: Anand K Mistry <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Acked-by: Thomas Gleixner <[email protected]> Acked-by: Tom Lendacky <[email protected]> Link: https://lkml.kernel.org/r/20201105163246.v2.1.Ifd7243cd3e2c2206a893ad0a5b9a4f19549e22c6@changeid
2020-11-05Merge tag 'hyperv-fixes-signed' of ↵Linus Torvalds1-5/+9
git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux Pull hyperv fixes from Wei Liu: - clarify a comment (Michael Kelley) - change a pr_warn() to pr_info() (Olaf Hering) * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: x86/hyperv: Clarify comment on x2apic mode hv_balloon: disable warning when floor reached
2020-11-05RISC-V: Remove any memblock representing unusable memory areaAtish Patra1-11/+7
RISC-V limits the physical memory size by -PAGE_OFFSET. Any memory beyond that size from DRAM start is unusable. Just remove any memblock pointing to those memory region without worrying about computing the maximum size. Signed-off-by: Atish Patra <[email protected]> Reviewed-by: Mike Rapoport <[email protected]> Signed-off-by: Palmer Dabbelt <[email protected]>
2020-11-05powerpc/8xx: Manage _PAGE_ACCESSED through APG bits in L1 entryChristophe Leroy4-66/+28
When _PAGE_ACCESSED is not set, a minor fault is expected. To do this, TLB miss exception ANDs _PAGE_PRESENT and _PAGE_ACCESSED into the L2 entry valid bit. To simplify the processing and reduce the number of instructions in TLB miss exceptions, manage it as an APG bit and get it next to _PAGE_GUARDED bit to allow a copy in one go. Then declare the corresponding groups as handling all accesses as user accesses. As the PP bits always define user as No Access, it will generate a fault. Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/80f488db230c6b0e7b3b990d72bd94a8a069e93e.1602492856.git.christophe.leroy@csgroup.eu
2020-11-05powerpc/8xx: Always fault when _PAGE_ACCESSED is not setChristophe Leroy1-12/+2
The kernel expects pte_young() to work regardless of CONFIG_SWAP. Make sure a minor fault is taken to set _PAGE_ACCESSED when it is not already set, regardless of the selection of CONFIG_SWAP. This adds at least 3 instructions to the TLB miss exception handlers fast path. Following patch will reduce this overhead. Also update the rotation instruction to the correct number of bits to reflect all changes done to _PAGE_ACCESSED over time. Fixes: d069cb4373fe ("powerpc/8xx: Don't touch ACCESSED when no SWAP.") Fixes: 5f356497c384 ("powerpc/8xx: remove unused _PAGE_WRITETHRU") Fixes: e0a8e0d90a9f ("powerpc/8xx: Handle PAGE_USER via APG bits") Fixes: 5b2753fc3e8a ("powerpc/8xx: Implementation of PAGE_EXEC") Fixes: a891c43b97d3 ("powerpc/8xx: Prepare handlers for _PAGE_HUGE for 512k pages.") Cc: [email protected] Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/af834e8a0f1fa97bfae65664950f0984a70c4750.1602492856.git.christophe.leroy@csgroup.eu
2020-11-05powerpc/40x: Always fault when _PAGE_ACCESSED is not setChristophe Leroy1-8/+0
The kernel expects pte_young() to work regardless of CONFIG_SWAP. Make sure a minor fault is taken to set _PAGE_ACCESSED when it is not already set, regardless of the selection of CONFIG_SWAP. Fixes: 2c74e2586bb9 ("powerpc/40x: Rework 40x PTE access and TLB miss") Cc: [email protected] Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/b02ca2ed2d3676a096219b48c0f69ec982a75bcf.1602342801.git.christophe.leroy@csgroup.eu
2020-11-05powerpc/603: Always fault when _PAGE_ACCESSED is not setChristophe Leroy1-12/+0
The kernel expects pte_young() to work regardless of CONFIG_SWAP. Make sure a minor fault is taken to set _PAGE_ACCESSED when it is not already set, regardless of the selection of CONFIG_SWAP. Fixes: 84de6ab0e904 ("powerpc/603: don't handle PAGE_ACCESSED in TLB miss handlers.") Cc: [email protected] Signed-off-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/a44367744de54e2315b2f1a8cbbd7f88488072e0.1602342806.git.christophe.leroy@csgroup.eu
2020-11-05powerpc: Use asm_goto_volatile for put_user()Michael Ellerman1-2/+2
Andreas reported that commit ee0a49a6870e ("powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()") broke CLONE_CHILD_SETTID. Further inspection showed that the put_user() in schedule_tail() was missing entirely, the store not emitted by the compiler. <.schedule_tail>: mflr r0 std r0,16(r1) stdu r1,-112(r1) bl <.finish_task_switch> ld r9,2496(r3) cmpdi cr7,r9,0 bne cr7,<.schedule_tail+0x60> ld r3,392(r13) ld r9,1392(r3) cmpdi cr7,r9,0 beq cr7,<.schedule_tail+0x3c> li r4,0 li r5,0 bl <.__task_pid_nr_ns> nop bl <.calculate_sigpending> nop addi r1,r1,112 ld r0,16(r1) mtlr r0 blr nop nop nop bl <.__balance_callback> b <.schedule_tail+0x1c> Notice there are no stores other than to the stack. There should be a stw in there for the store to current->set_child_tid. This is only seen with GCC 4.9 era compilers (tested with 4.9.3 and 4.9.4), and only when CONFIG_PPC_KUAP is disabled. When CONFIG_PPC_KUAP=y, the inline asm that's part of the isync() and mtspr() inlined via allow_user_access() seems to be enough to avoid the bug. We already have a macro to work around this (or a similar bug), called asm_volatile_goto which includes an empty asm block to tickle the compiler into generating the right code. So use that. With this applied the code generation looks more like it will work: <.schedule_tail>: mflr r0 std r31,-8(r1) std r0,16(r1) stdu r1,-144(r1) std r3,112(r1) bl <._mcount> nop ld r3,112(r1) bl <.finish_task_switch> ld r9,2624(r3) cmpdi cr7,r9,0 bne cr7,<.schedule_tail+0xa0> ld r3,2408(r13) ld r31,1856(r3) cmpdi cr7,r31,0 beq cr7,<.schedule_tail+0x80> li r4,0 li r5,0 bl <.__task_pid_nr_ns> nop li r9,-1 clrldi r9,r9,12 cmpld cr7,r31,r9 bgt cr7,<.schedule_tail+0x80> lis r9,16 rldicr r9,r9,32,31 subf r9,r31,r9 cmpldi cr7,r9,3 ble cr7,<.schedule_tail+0x80> li r9,0 stw r3,0(r31) <-- stw nop bl <.calculate_sigpending> nop addi r1,r1,144 ld r0,16(r1) ld r31,-8(r1) mtlr r0 blr nop bl <.__balance_callback> b <.schedule_tail+0x30> Fixes: ee0a49a6870e ("powerpc/uaccess: Switch __put_user_size_allowed() to __put_user_asm_goto()") Reported-by: Andreas Schwab <[email protected]> Tested-by: Andreas Schwab <[email protected]> Suggested-by: Christophe Leroy <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-11-04risc-v: kernel: ftrace: Fixes improper SPDX comment styleRyan Kosta1-1/+1
Signed-off-by: Ryan Kosta <[email protected]> Signed-off-by: Palmer Dabbelt <[email protected]>
2020-11-04x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.SFangrui Song3-9/+3
Commit 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") added .weak directives to arch/x86/lib/mem*_64.S instead of changing the existing ENTRY macros to WEAK. This can lead to the assembly snippet .weak memcpy ... .globl memcpy which will produce a STB_WEAK memcpy with GNU as but STB_GLOBAL memcpy with LLVM's integrated assembler before LLVM 12. LLVM 12 (since https://reviews.llvm.org/D90108) will error on such an overridden symbol binding. Commit ef1e03152cb0 ("x86/asm: Make some functions local") changed ENTRY in arch/x86/lib/memcpy_64.S to SYM_FUNC_START_LOCAL, which was ineffective due to the preceding .weak directive. Use the appropriate SYM_FUNC_START_WEAK instead. Fixes: 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions") Fixes: ef1e03152cb0 ("x86/asm: Make some functions local") Reported-by: Sami Tolvanen <[email protected]> Signed-off-by: Fangrui Song <[email protected]> Signed-off-by: Borislav Petkov <[email protected]> Reviewed-by: Nick Desaulniers <[email protected]> Tested-by: Nathan Chancellor <[email protected]> Tested-by: Nick Desaulniers <[email protected]> Cc: <[email protected]> Link: https://lkml.kernel.org/r/[email protected]
2020-11-04ARM, xtensa: highmem: avoid clobbering non-page aligned memory reservationsArd Biesheuvel2-4/+4
free_highpages() iterates over the free memblock regions in high memory, and marks each page as available for the memory management system. Until commit cddb5ddf2b76 ("arm, xtensa: simplify initialization of high memory pages") it rounded beginning of each region upwards and end of each region downwards. However, after that commit free_highmem() rounds the beginning and end of each region downwards, and we may end up freeing a page that is memblock_reserve()d, resulting in memory corruption. Restore the original rounding of the region boundaries to avoid freeing reserved pages. Fixes: cddb5ddf2b76 ("arm, xtensa: simplify initialization of high memory pages") Link: https://lore.kernel.org/r/[email protected]/ Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Ard Biesheuvel <[email protected]> Co-developed-by: Mike Rapoport <[email protected]> Signed-off-by: Mike Rapoport <[email protected]> Acked-by: Max Filippov <[email protected]>
2020-11-03Merge tag 'x86_seves_for_v5.10_rc3' of ↵Linus Torvalds8-8/+167
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 SEV-ES fixes from Borislav Petkov: "A couple of changes to the SEV-ES code to perform more stringent hypervisor checks before enabling encryption (Joerg Roedel)" * tag 'x86_seves_for_v5.10_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/sev-es: Do not support MMIO to/from encrypted memory x86/head/64: Check SEV encryption before switching to kernel page-table x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path x86/boot/compressed/64: Sanity-check CPUID results in the early #VC handler x86/boot/compressed/64: Introduce sev_status
2020-11-03s390/pci: fix hot-plug of PCI function missing busNiklas Schnelle1-0/+4
Under some circumstances in particular with "Reconfigure I/O Path" a zPCI function may first appear in Standby through a PCI event with PEC 0x0302 which initially makes it visible to the zPCI subsystem, Only after that is it configured with a zPCI event with PEC 0x0301. If the zbus is still missing a PCI function zero (devfn == 0) when the PCI event 0x0301 is handled zdev->zbus->bus is still NULL and gets dereferenced in common code. Check for this case and enable but don't scan the zPCI function. This matches what would happen if we immediately got the 0x0301 configuration request or the function was included in CLP List PCI. In all cases the PCI functions with devfn != 0 will be scanned once function 0 appears. Fixes: 3047766bc6ec ("s390/pci: fix enabling a reserved PCI function") Cc: <[email protected]> # 5.8 Signed-off-by: Niklas Schnelle <[email protected]> Acked-by: Pierre Morel <[email protected]> Signed-off-by: Heiko Carstens <[email protected]>
2020-11-03s390/smp: move rcu_cpu_starting() earlierQian Cai1-1/+2
The call to rcu_cpu_starting() in smp_init_secondary() is not early enough in the CPU-hotplug onlining process, which results in lockdep splats as follows: WARNING: suspicious RCU usage ----------------------------- kernel/locking/lockdep.c:3497 RCU-list traversed in non-reader section!! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 no locks held by swapper/1/0. Call Trace: show_stack+0x158/0x1f0 dump_stack+0x1f2/0x238 __lock_acquire+0x2640/0x4dd0 lock_acquire+0x3a8/0xd08 _raw_spin_lock_irqsave+0xc0/0xf0 clockevents_register_device+0xa8/0x528 init_cpu_timer+0x33e/0x468 smp_init_secondary+0x11a/0x328 smp_start_secondary+0x82/0x88 This is avoided by moving the call to rcu_cpu_starting up near the beginning of the smp_init_secondary() function. Note that the raw_smp_processor_id() is required in order to avoid calling into lockdep before RCU has declared the CPU to be watched for readers. Link: https://lore.kernel.org/lkml/160223032121.7002.1269740091547117869.tip-bot2@tip-bot2/ Signed-off-by: Qian Cai <[email protected]> Acked-by: Paul E. McKenney <[email protected]> Signed-off-by: Heiko Carstens <[email protected]>
2020-11-03s390: update defconfigsHeiko Carstens3-9/+12
Signed-off-by: Heiko Carstens <[email protected]>
2020-11-03s390/vdso: remove unused constantsHeiko Carstens1-8/+0
Signed-off-by: Heiko Carstens <[email protected]>
2020-11-03s390/vdso: remove empty unused fileHeiko Carstens1-0/+0
Signed-off-by: Heiko Carstens <[email protected]>
2020-11-03s390/mm: make pmd/pud_deref() large page awareGerald Schaefer1-22/+30
pmd/pud_deref() assume that they will never operate on large pmd/pud entries, and therefore only use the non-large _xxx_ENTRY_ORIGIN mask. With commit 9ec8fa8dc331b ("s390/vmemmap: extend modify_pagetable() to handle vmemmap"), that assumption is no longer true, at least for pmd_deref(). In theory, we could end up with wrong addresses because some of the non-address bits of a large entry would not be masked out. In practice, this does not (yet) show any impact, because vmemmap_free() is currently never used for s390. Fix pmd/pud_deref() to check for the entry type and use the _xxx_ENTRY_ORIGIN_LARGE mask for large entries. While at it, also move pmd/pud_pfn() around, in order to avoid code duplication, because they do the same thing. Fixes: 9ec8fa8dc331b ("s390/vmemmap: extend modify_pagetable() to handle vmemmap") Cc: <[email protected]> # 5.9 Signed-off-by: Gerald Schaefer <[email protected]> Reviewed-by: Alexander Gordeev <[email protected]> Signed-off-by: Heiko Carstens <[email protected]>
2020-11-03arm64: kprobes: Use BRK instead of single-step when executing instructions ↵Jean-Philippe Brucker4-47/+27
out-of-line Commit 36dadef23fcc ("kprobes: Init kprobes in early_initcall") enabled using kprobes from early_initcall. Unfortunately at this point the hardware debug infrastructure is not operational. The OS lock may still be locked, and the hardware watchpoints may have unknown values when kprobe enables debug monitors to single-step instructions. Rather than using hardware single-step, append a BRK instruction after the instruction to be executed out-of-line. Fixes: 36dadef23fcc ("kprobes: Init kprobes in early_initcall") Suggested-by: Will Deacon <[email protected]> Signed-off-by: Jean-Philippe Brucker <[email protected]> Acked-by: Masami Hiramatsu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Will Deacon <[email protected]>
2020-11-03arm64: NUMA: Kconfig: Increase NODES_SHIFT to 4Vanshidhar Konda1-1/+1
The current arm64 default config limits max NUMA nodes available on system to 4 (NODES_SHIFT = 2). Today's arm64 systems can reach or exceed 16 NUMA nodes. To accomodate current hardware and to fit NODES_SHIFT within page flags on arm64, increase NODES_SHIFT to 4. Signed-off-by: Vanshidhar Konda <[email protected]> Acked-by: Catalin Marinas <[email protected]> Link: https://lore.kernel.org/r/[email protected]/ Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Will Deacon <[email protected]>
2020-11-02ARC: [plat-hsdk] Remap CCMs super early in asm boot trampolineVineet Gupta2-18/+16
ARC HSDK platform stopped booting on released v5.10-rc1, getting stuck in startup of non master SMP cores. This was bisected to upstream commit 7fef431be9c9ac25 "(mm/page_alloc: place pages to tail in __free_pages_core())" That commit itself is harmless, it just exposed a subtle assumption in our platform code (hence CC'ing linux-mm just as FYI in case some other arches / platforms trip on it). The upstream commit is semantically disruptive as it reverses the order of page allocations (actually it can be good test for hardware verification to exercise different memory patterns altogether). For ARC HSDK platform that meant a remapped memory region (pertaining to unused Closely Coupled Memory) started getting used early for dynamice allocations, while not effectively remapped on all the cores, triggering memory error exception on those cores. The fix is to move the CCM remapping from early platform code to to early core boot code. And while it is undesirable to riddle common boot code with platform quirks, there is no other way to do this since the faltering code involves setting up stack itself so even function calls are not allowed at that point. If anyone is interested, all the gory details can be found at Link below. Link: https://github.com/foss-for-synopsys-dwc-arc-processors/linux/issues/32 Cc: David Hildenbrand <[email protected]> Cc: [email protected] Signed-off-by: Vineet Gupta <[email protected]>
2020-11-02ARC: stack unwinding: avoid indefinite loopingVineet Gupta1-1/+6
Currently stack unwinder is a while(1) loop which relies on the dwarf unwinder to signal termination, which in turn relies on dwarf info to do so. This in theory could cause an infinite loop if the dwarf info was somehow messed up or the register contents were etc. This fix thus detects the excessive looping and breaks the loop. | Mem: 26184K used, 1009136K free, 0K shrd, 0K buff, 14416K cached | CPU: 0.0% usr 72.8% sys 0.0% nic 27.1% idle 0.0% io 0.0% irq 0.0% sirq | Load average: 4.33 2.60 1.11 2/74 139 | PID PPID USER STAT VSZ %VSZ CPU %CPU COMMAND | 133 2 root SWN 0 0.0 3 22.9 [rcu_torture_rea] | 132 2 root SWN 0 0.0 0 22.0 [rcu_torture_rea] | 131 2 root SWN 0 0.0 3 21.5 [rcu_torture_rea] | 126 2 root RW 0 0.0 2 5.4 [rcu_torture_wri] | 129 2 root SWN 0 0.0 0 0.2 [rcu_torture_fak] | 137 2 root SW 0 0.0 0 0.2 [rcu_torture_cbf] | 127 2 root SWN 0 0.0 0 0.1 [rcu_torture_fak] | 138 115 root R 1464 0.1 2 0.1 top | 130 2 root SWN 0 0.0 0 0.1 [rcu_torture_fak] | 128 2 root SWN 0 0.0 0 0.1 [rcu_torture_fak] | 115 1 root S 1472 0.1 1 0.0 -/bin/sh | 104 1 root S 1464 0.1 0 0.0 inetd | 1 0 root S 1456 0.1 2 0.0 init | 78 1 root S 1456 0.1 0 0.0 syslogd -O /var/log/messages | 134 2 root SW 0 0.0 2 0.0 [rcu_torture_sta] | 10 2 root IW 0 0.0 1 0.0 [rcu_preempt] | 88 2 root IW 0 0.0 1 0.0 [kworker/1:1-eve] | 66 2 root IW 0 0.0 2 0.0 [kworker/2:2-eve] | 39 2 root IW 0 0.0 2 0.0 [kworker/2:1-eve] | unwinder looping too long, aborting ! Cc: <[email protected]> Signed-off-by: Vineet Gupta <[email protected]>
2020-11-02powerpc/smp: Call rcu_cpu_starting() earlierQian Cai1-1/+2
The call to rcu_cpu_starting() in start_secondary() is not early enough in the CPU-hotplug onlining process, which results in lockdep splats as follows (with CONFIG_PROVE_RCU_LIST=y): WARNING: suspicious RCU usage ----------------------------- kernel/locking/lockdep.c:3497 RCU-list traversed in non-reader section!! other info that might help us debug this: RCU used illegally from offline CPU! rcu_scheduler_active = 1, debug_locks = 1 no locks held by swapper/1/0. Call Trace: dump_stack+0xec/0x144 (unreliable) lockdep_rcu_suspicious+0x128/0x14c __lock_acquire+0x1060/0x1c60 lock_acquire+0x140/0x5f0 _raw_spin_lock_irqsave+0x64/0xb0 clockevents_register_device+0x74/0x270 register_decrementer_clockevent+0x94/0x110 start_secondary+0x134/0x800 start_secondary_prolog+0x10/0x14 This is avoided by adding a call to rcu_cpu_starting() near the beginning of the start_secondary() function. Note that the raw_smp_processor_id() is required in order to avoid calling into lockdep before RCU has declared the CPU to be watched for readers. It's safe to call rcu_cpu_starting() in the arch code as well as later in generic code, as explained by Paul: It uses a per-CPU variable so that RCU pays attention only to the first call to rcu_cpu_starting() if there is more than one of them. This is even intentional, due to there being a generic arch-independent call to rcu_cpu_starting() in notify_cpu_starting(). So multiple calls to rcu_cpu_starting() are fine by design. Fixes: 4d004099a668 ("lockdep: Fix lockdep recursion") Signed-off-by: Qian Cai <[email protected]> Acked-by: Paul E. McKenney <[email protected]> [mpe: Add Fixes tag, reword slightly & expand change log] Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
2020-11-02powerpc/eeh_cache: Fix a possible debugfs deadlockQian Cai1-2/+3
Lockdep complains that a possible deadlock below in eeh_addr_cache_show() because it is acquiring a lock with IRQ enabled, but eeh_addr_cache_insert_dev() needs to acquire the same lock with IRQ disabled. Let's just make eeh_addr_cache_show() acquire the lock with IRQ disabled as well. CPU0 CPU1 ---- ---- lock(&pci_io_addr_cache_root.piar_lock); local_irq_disable(); lock(&tp->lock); lock(&pci_io_addr_cache_root.piar_lock); <Interrupt> lock(&tp->lock); *** DEADLOCK *** lock_acquire+0x140/0x5f0 _raw_spin_lock_irqsave+0x64/0xb0 eeh_addr_cache_insert_dev+0x48/0x390 eeh_probe_device+0xb8/0x1a0 pnv_pcibios_bus_add_device+0x3c/0x80 pcibios_bus_add_device+0x118/0x290 pci_bus_add_device+0x28/0xe0 pci_bus_add_devices+0x54/0xb0 pcibios_init+0xc4/0x124 do_one_initcall+0xac/0x528 kernel_init_freeable+0x35c/0x3fc kernel_init+0x24/0x148 ret_from_kernel_thread+0x5c/0x80 lock_acquire+0x140/0x5f0 _raw_spin_lock+0x4c/0x70 eeh_addr_cache_show+0x38/0x110 seq_read+0x1a0/0x660 vfs_read+0xc8/0x1f0 ksys_read+0x74/0x130 system_call_exception+0xf8/0x1d0 system_call_common+0xe8/0x218 Fixes: 5ca85ae6318d ("powerpc/eeh_cache: Add a way to dump the EEH address cache") Signed-off-by: Qian Cai <[email protected]> Reviewed-by: Oliver O'Halloran <[email protected]> Signed-off-by: Michael Ellerman <[email protected]> Link: https://lore.kernel.org/r/[email protected]
Powered by cgit, Gruvboxed by Blaster4385.