kernel/git/stable/linux.git/arch/arm64/include, branch linux-5.18.y

kexec_file: drop weak attribute from functions

2022-08-17T12:42:23+00:00

[ Upstream commit 65d9a9a60fd71be964effb2e94747a6acb6e7015 ] As requested (http://lkml.kernel.org/r/87ee0q7b92.fsf@email.froward.int.ebiederm.org), this series converts weak functions in kexec to use the #ifdef approach. Quoting the 3e35142ef99fe ("kexec_file: drop weak attribute from arch_kexec_apply_relocations[_add]") changelog: : Since commit d1bcae833b32f1 ("ELF: Don't generate unused section symbols") : [1], binutils (v2.36+) started dropping section symbols that it thought : were unused. This isn't an issue in general, but with kexec_file.c, gcc : is placing kexec_arch_apply_relocations[_add] into a separate : .text.unlikely section and the section symbol ".text.unlikely" is being : dropped. Due to this, recordmcount is unable to find a non-weak symbol in : .text.unlikely to generate a relocation record against. This patch (of 2); Drop __weak attribute from functions in kexec_file.c: - arch_kexec_kernel_image_probe() - arch_kimage_file_post_load_cleanup() - arch_kexec_kernel_image_load() - arch_kexec_locate_mem_hole() - arch_kexec_kernel_verify_sig() arch_kexec_kernel_image_load() calls into kexec_image_load_default(), so drop the static attribute for the latter. arch_kexec_kernel_verify_sig() is not overridden by any architecture, so drop the __weak attribute. Link: https://lkml.kernel.org/r/cover.1656659357.git.naveen.n.rao@linux.vnet.ibm.com Link: https://lkml.kernel.org/r/2cd7ca1fe4d6bb6ca38e3283c717878388ed6788.1656659357.git.naveen.n.rao@linux.vnet.ibm.com Signed-off-by: Naveen N. Rao Suggested-by: Eric Biederman Signed-off-by: Andrew Morton Signed-off-by: Mimi Zohar Signed-off-by: Sasha Levin

arm64: Expand ESR_ELx_WFx_ISS_TI to match its ARMv8.7 definition

2022-08-17T12:40:42+00:00

[ Upstream commit 6a437208cb942a2dd98f7e1c3fd347ed3d425ffc ] Starting with FEAT_WFXT in ARMv8.7, the TI field in the ISS that is reported on a WFx trap is expanded by one bit to allow the description of WFET and WFIT. Special care is taken to exclude the WFxT bit from the mask used to match WFI so that it also matches WFIT when trapped from EL0. Reviewed-by: Joey Gouly Signed-off-by: Marc Zyngier Acked-by: Catalin Marinas Link: https://lore.kernel.org/r/20220419182755.601427-2-maz@kernel.org Signed-off-by: Sasha Levin

arm64: Do not forget syscall when starting a new thread.

2022-08-17T12:40:20+00:00

[ Upstream commit de6921856f99c11d3986c6702d851e1328d4f7f6 ] Enable tracing of the execve*() system calls with the syscalls:sys_exit_execve tracepoint by removing the call to forget_syscall() when starting a new thread and preserving the value of regs->syscallno across exec. Signed-off-by: Francis Laniel Link: https://lore.kernel.org/r/20220608162447.666494-2-flaniel@linux.microsoft.com Signed-off-by: Will Deacon Signed-off-by: Sasha Levin

arm64: set UXN on swapper page tables

2022-08-11T11:20:42+00:00

[ This issue was fixed upstream by accident in c3cee924bd85 ("arm64: head: cover entire kernel image in initial ID map") as part of a large refactoring of the arm64 boot flow. This simple fix is therefore preferred for -stable backporting ] On a system that implements FEAT_EPAN, read/write access to the idmap is denied because UXN is not set on the swapper PTEs. As a result, idmap_kpti_install_ng_mappings panics the kernel when accessing __idmap_kpti_flag. Fix it by setting UXN on these PTEs. Fixes: 18107f8a2df6 ("arm64: Support execute-only permissions with Enhanced PAN") Cc: # 5.15 Link: https://linux-review.googlesource.com/id/Ic452fa4b4f74753e54f71e61027e7222a0fae1b1 Signed-off-by: Peter Collingbourne Acked-by: Will Deacon Cc: Ard Biesheuvel Cc: Catalin Marinas Link: https://lore.kernel.org/r/20220719234909.1398992-1-pcc@google.com Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman

irqchip/gic-v3: Refactor ISB + EOIR at ack time

2022-06-09T08:30:14+00:00

[ Upstream commit 6efb50923771f392122f5ce69dfc43b08f16e449 ] There are cases where a context synchronization event is necessary between an IRQ being raised and being handled, and there are races such that we cannot rely upon the exception entry being subsequent to the interrupt being raised. To fix this, we place an ISB between a read of IAR and the subsequent invocation of an IRQ handler. When EOI mode 1 is in use, we need to EOI an interrupt prior to invoking its handler, and we have a write to EOIR for this. As this write to EOIR requires an ISB, and this is provided by the gic_write_eoir() helper, we omit the usual ISB in this case, with the logic being: | if (static_branch_likely(&supports_deactivate_key)) | gic_write_eoir(irqnr); | else | isb(); This is somewhat opaque, and it would be a little clearer if there were an unconditional ISB, with only the write to EOIR being conditional, e.g. | if (static_branch_likely(&supports_deactivate_key)) | write_gicreg(irqnr, ICC_EOIR1_EL1); | | isb(); This patch rewrites the code that way, with this logic factored into a new helper function with comments explaining what the ISB is for, as were originally laid out in commit: 39a06b67c2c1256b ("irqchip/gic: Ensure we have an ISB between ack and ->handle_irq") Note that since then, we removed the IAR polling in commit: 342677d70ab92142 ("irqchip/gic-v3: Remove acknowledge loop") ... which removed one of the two race conditions. For consistency, other portions of the driver are made to manipulate EOIR using write_gicreg() and explcit ISBs, and the gic_write_eoir() helper function is removed. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Marc Zyngier Cc: Thomas Gleixner Cc: Will Deacon Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220513133038.226182-3-mark.rutland@arm.com Signed-off-by: Sasha Levin

arm64: stackleak: fix current_top_of_stack()

2022-06-09T08:30:08+00:00

[ Upstream commit e85094c31ddb794ac41c299a5a7a68243148f829 ] Due to some historical confusion, arm64's current_top_of_stack() isn't what the stackleak code expects. This could in theory result in a number of problems, and practically results in an unnecessary performance hit. We can avoid this by aligning the arm64 implementation with the x86 implementation. The arm64 implementation of current_top_of_stack() was added specifically for stackleak in commit: 0b3e336601b82c6a ("arm64: Add support for STACKLEAK gcc plugin") This was intended to be equivalent to the x86 implementation, but the implementation, semantics, and performance characteristics differ wildly: * On x86, current_top_of_stack() returns the top of the current task's task stack, regardless of which stack is in active use. The implementation accesses a percpu variable which the x86 entry code maintains, and returns the location immediately above the pt_regs on the task stack (above which x86 has some padding). * On arm64 current_top_of_stack() returns the top of the stack in active use (i.e. the one which is currently being used). The implementation checks the SP against a number of potentially-accessible stacks, and will BUG() if no stack is found. The core stackleak_erase() code determines the upper bound of stack to erase with: | if (on_thread_stack()) | boundary = current_stack_pointer; | else | boundary = current_top_of_stack(); On arm64 stackleak_erase() is always called on a task stack, and on_thread_stack() should always be true. On x86, stackleak_erase() is mostly called on a trampoline stack, and is sometimes called on a task stack. Currently, this results in a lot of unnecessary code being generated for arm64 for the impossible !on_thread_stack() case. Some of this is inlined, bloating stackleak_erase(), while portions of this are left out-of-line and permitted to be instrumented (which would be a functional problem if that code were reachable). As a first step towards improving this, this patch aligns arm64's implementation of current_top_of_stack() with x86's, always returning the top of the current task's stack. With GCC 11.1.0 this results in the bulk of the unnecessary code being removed, including all of the out-of-line instrumentable code. While I don't believe there's a functional problem in practice I've marked this as a fix since the semantic was clearly wrong, the fix itself is simple, and other code might rely upon this in future. Fixes: 0b3e336601b82c6a ("arm64: Add support for STACKLEAK gcc plugin") Signed-off-by: Mark Rutland Cc: Alexander Popov Cc: Andrew Morton Cc: Andy Lutomirski Cc: Catalin Marinas Cc: Kees Cook Cc: Will Deacon Acked-by: Catalin Marinas Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20220427173128.2603085-2-mark.rutland@arm.com Signed-off-by: Sasha Levin

Merge tag 'mm-hotfixes-stable-2022-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2022-05-13T17:22:37+00:00

Pull misc fixes from Andrew Morton: "Seven MM fixes, three of which address issues added in the most recent merge window, four of which are cc:stable. Three non-MM fixes, none very serious" [ And yes, that's a real pull request from Andrew, not me creating a branch from emailed patches. Woo-hoo! ] * tag 'mm-hotfixes-stable-2022-05-11' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: MAINTAINERS: add a mailing list for DAMON development selftests: vm: Makefile: rename TARGETS to VMTARGETS mm/kfence: reset PG_slab and memcg_data before freeing __kfence_pool mailmap: add entry for martyna.szapar-mudlaw@intel.com arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map procfs: prevent unprivileged processes accessing fdinfo dir mm: mremap: fix sign for EFAULT error return value mm/hwpoison: use pr_err() instead of dump_page() in get_any_page() mm/huge_memory: do not overkill when splitting huge_zero_page Revert "mm/memory-failure.c: skip huge_zero_page in memory_failure()"

arm[64]/memremap: don't abuse pfn_valid() to ensure presence of linear map

2022-05-10T00:34:28+00:00

The semantics of pfn_valid() is to check presence of the memory map for a PFN and not whether a PFN is covered by the linear map. The memory map may be present for NOMAP memory regions, but they won't be mapped in the linear mapping. Accessing such regions via __va() when they are memremap()'ed will cause a crash. On v5.4.y the crash happens on qemu-arm with UEFI [1]: <1>[ 0.084476] 8<--- cut here --- <1>[ 0.084595] Unable to handle kernel paging request at virtual address dfb76000 <1>[ 0.084938] pgd = (ptrval) <1>[ 0.085038] [dfb76000] *pgd=5f7fe801, *pte=00000000, *ppte=00000000 ... <4>[ 0.093923] [] (memcpy) from [] (dmi_setup+0x60/0x418) <4>[ 0.094204] [] (dmi_setup) from [] (arm_dmi_init+0x8/0x10) <4>[ 0.094408] [] (arm_dmi_init) from [] (do_one_initcall+0x50/0x228) <4>[ 0.094619] [] (do_one_initcall) from [] (kernel_init_freeable+0x15c/0x1f8) <4>[ 0.094841] [] (kernel_init_freeable) from [] (kernel_init+0x8/0x10c) <4>[ 0.095057] [] (kernel_init) from [] (ret_from_fork+0x14/0x2c) On kernels v5.10.y and newer the same crash won't reproduce on ARM because commit b10d6bca8720 ("arch, drivers: replace for_each_membock() with for_each_mem_range()") changed the way memory regions are registered in the resource tree, but that merely covers up the problem. On ARM64 memory resources registered in yet another way and there the issue of wrong usage of pfn_valid() to ensure availability of the linear map is also covered. Implement arch_memremap_can_ram_remap() on ARM and ARM64 to prevent access to NOMAP regions via the linear mapping in memremap(). Link: https://lore.kernel.org/all/Yl65zxGgFzF1Okac@sirena.org.uk Link: https://lkml.kernel.org/r/20220426060107.7618-1-rppt@kernel.org Signed-off-by: Mike Rapoport Reported-by: "kernelci.org bot" Tested-by: Mark Brown Reviewed-by: Ard Biesheuvel Acked-by: Catalin Marinas Cc: Greg Kroah-Hartman Cc: Mark Brown Cc: Mark-PK Tsai Cc: Russell King Cc: Tony Lindgren Cc: Will Deacon Cc: [5.4+] Signed-off-by: Andrew Morton

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2022-05-01T18:49:32+00:00

Pull kvm fixes from Paolo Bonzini: "ARM: - Take care of faults occuring between the PARange and IPA range by injecting an exception - Fix S2 faults taken from a host EL0 in protected mode - Work around Oops caused by a PMU access from a 32bit guest when PMU has been created. This is a temporary bodge until we fix it for good. x86: - Fix potential races when walking host page table - Fix shadow page table leak when KVM runs nested - Work around bug in userspace when KVM synthesizes leaf 0x80000021 on older (pre-EPYC) or Intel processors Generic (but affects only RISC-V): - Fix bad user ABI for KVM_EXIT_SYSTEM_EVENT" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: KVM: x86: work around QEMU issue with synthetic CPUID leaves Revert "x86/mm: Introduce lookup_address_in_mm()" KVM: x86/mmu: fix potential races when walking host page table KVM: fix bad user ABI for KVM_EXIT_SYSTEM_EVENT KVM: x86/mmu: Do not create SPTEs for GFNs that exceed host.MAXPHYADDR KVM: arm64: Inject exception on out-of-IPA-range translation fault KVM/arm64: Don't emulate a PMU for 32-bit guests if feature not set KVM: arm64: Handle host stage-2 faults from 32-bit EL0

Merge tag 'kvmarm-fixes-5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

2022-04-29T16:32:14+00:00

KVM/arm64 fixes for 5.18, take #2 - Take care of faults occuring between the PARange and IPA range by injecting an exception - Fix S2 faults taken from a host EL0 in protected mode - Work around Oops caused by a PMU access from a 32bit guest when PMU has been created. This is a temporary bodge until we fix it for good.