kernel.git/arch/arm64/include/asm/thread_info.h, branch linux-5.16.y

Merge tag 'cpu-to-thread_info-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2021-11-02T00:00:05Z

Pull thread_info update to move 'cpu' back from task_struct from Kees Cook: "Cross-architecture update to move task_struct::cpu back into thread_info on arm64, x86, s390, powerpc, and riscv. All Acked by arch maintainers. Quoting Ard Biesheuvel: 'Move task_struct::cpu back into thread_info Keeping CPU in task_struct is problematic for architectures that define raw_smp_processor_id() in terms of this field, as it requires linux/sched.h to be included, which causes a lot of pain in terms of circular dependencies (aka 'header soup') This series moves it back into thread_info (where it came from) for all architectures that enable THREAD_INFO_IN_TASK, addressing the header soup issue as well as some pointless differences in the implementations of task_cpu() and set_task_cpu()'" * tag 'cpu-to-thread_info-v5.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: riscv: rely on core code to keep thread_info::cpu updated powerpc: smp: remove hack to obtain offset of task_struct::cpu sched: move CPU field back into thread_info if THREAD_INFO_IN_TASK=y powerpc: add CPU field to struct thread_info s390: add CPU field to struct thread_info x86: add CPU field to struct thread_info arm64: add CPU field to struct thread_info

arm64/sve: Track vector lengths for tasks in an array

2021-10-21T09:18:17Z

As for SVE we will track a per task SME vector length for tasks. Convert the existing storage for the vector length into an array and update fpsimd_flush_task() to initialise this in a function. Signed-off-by: Mark Brown Link: https://lore.kernel.org/r/20211019172247.3045838-10-broonie@kernel.org Signed-off-by: Will Deacon

arm64: add CPU field to struct thread_info

2021-09-30T12:39:43Z

The CPU field will be moved back into thread_info even when THREAD_INFO_IN_TASK is enabled, so add it back to arm64's definition of struct thread_info. Note that arm64 always has CONFIG_SMP=y so there is no point in guarding the CPU field with an #ifdef. Signed-off-by: Ard Biesheuvel Acked-by: Catalin Marinas Acked-by: Mark Rutland

arm64/process.c: fix Wmissing-prototypes build warnings

2021-03-25T09:50:16Z

Fix GCC warnings reported when building with "-Wmissing-prototypes": arch/arm64/kernel/process.c:261:6: warning: no previous prototype for '__show_regs' [-Wmissing-prototypes] 261 | void __show_regs(struct pt_regs *regs) | ^~~~~~~~~~~ arch/arm64/kernel/process.c:307:6: warning: no previous prototype for '__show_regs_alloc_free' [-Wmissing-prototypes] 307 | void __show_regs_alloc_free(struct pt_regs *regs) | ^~~~~~~~~~~~~~~~~~~~~~ arch/arm64/kernel/process.c:365:5: warning: no previous prototype for 'arch_dup_task_struct' [-Wmissing-prototypes] 365 | int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) | ^~~~~~~~~~~~~~~~~~~~ arch/arm64/kernel/process.c:546:41: warning: no previous prototype for '__switch_to' [-Wmissing-prototypes] 546 | __notrace_funcgraph struct task_struct *__switch_to(struct task_struct *prev, | ^~~~~~~~~~~ arch/arm64/kernel/process.c:710:25: warning: no previous prototype for 'arm64_preempt_schedule_irq' [-Wmissing-prototypes] 710 | asmlinkage void __sched arm64_preempt_schedule_irq(void) | ^~~~~~~~~~~~~~~~~~~~~~~~~~ Link: https://lore.kernel.org/lkml/202103192250.AennsfXM-lkp@intel.com Reported-by: kernel test robot Signed-off-by: Maninder Singh Link: https://lore.kernel.org/r/1616568899-986-1-git-send-email-maninder1.s@samsung.com Signed-off-by: Will Deacon

arm64: make _TIF_WORK_MASK bits contiguous

2020-12-16T22:08:47Z

We need the bits of _TIF_WORK_MASK to be contiguous in order to to use this as an immediate argument to an AND instruction in entry.S. We happened to change these bits in commits: b5a5a01d8e9a ("arm64: uaccess: remove addr_limit_user_check()") 192caabd4dd9 ("arm64: add support for TIF_NOTIFY_SIGNAL") which each worked in isolation, but the merge resolution in commit: 005b2a9dc819 ("Merge tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block") happened to make the bits non-contiguous. Fix this by moving TIF_NOTIFY_SIGNAL to be bit 6, which is contiguous with the rest of _TIF_WORK_MASK. Otherwise, we'll get a build-time failure as below: arch/arm64/kernel/entry.S: Assembler messages: arch/arm64/kernel/entry.S:733: Error: immediate out of range at operand 3 -- `and x2,x19,#((1<<1)|(1<<0)|(1<<2)|(1<<3)|(1<<4)|(1<<5)|(1<<7))' scripts/Makefile.build:360: recipe for target 'arch/arm64/kernel/entry.o' failed Fixes: 005b2a9dc819a126 ("Merge tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block") Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Will Deacon Signed-off-by: Linus Torvalds

Merge tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block

2020-12-16T20:33:35Z

Pull TIF_NOTIFY_SIGNAL updates from Jens Axboe: "This sits on top of of the core entry/exit and x86 entry branch from the tip tree, which contains the generic and x86 parts of this work. Here we convert the rest of the archs to support TIF_NOTIFY_SIGNAL. With that done, we can get rid of JOBCTL_TASK_WORK from task_work and signal.c, and also remove a deadlock work-around in io_uring around knowing that signal based task_work waking is invoked with the sighand wait queue head lock. The motivation for this work is to decouple signal notify based task_work, of which io_uring is a heavy user of, from sighand. The sighand lock becomes a huge contention point, particularly for threaded workloads where it's shared between threads. Even outside of threaded applications it's slower than it needs to be. Roman Gershman reported that his networked workload dropped from 1.6M QPS at 80% CPU to 1.0M QPS at 100% CPU after io_uring was changed to use TIF_NOTIFY_SIGNAL. The time was all spent hammering on the sighand lock, showing 57% of the CPU time there [1]. There are further cleanups possible on top of this. One example is TIF_PATCH_PENDING, where a patch already exists to use TIF_NOTIFY_SIGNAL instead. Hopefully this will also lead to more consolidation, but the work stands on its own as well" [1] https://github.com/axboe/liburing/issues/215 * tag 'tif-task_work.arch-2020-12-14' of git://git.kernel.dk/linux-block: (28 commits) io_uring: remove 'twa_signal_ok' deadlock work-around kernel: remove checking for TIF_NOTIFY_SIGNAL signal: kill JOBCTL_TASK_WORK io_uring: JOBCTL_TASK_WORK is no longer used by task_work task_work: remove legacy TWA_SIGNAL path sparc: add support for TIF_NOTIFY_SIGNAL riscv: add support for TIF_NOTIFY_SIGNAL nds32: add support for TIF_NOTIFY_SIGNAL ia64: add support for TIF_NOTIFY_SIGNAL h8300: add support for TIF_NOTIFY_SIGNAL c6x: add support for TIF_NOTIFY_SIGNAL alpha: add support for TIF_NOTIFY_SIGNAL xtensa: add support for TIF_NOTIFY_SIGNAL arm: add support for TIF_NOTIFY_SIGNAL microblaze: add support for TIF_NOTIFY_SIGNAL hexagon: add support for TIF_NOTIFY_SIGNAL csky: add support for TIF_NOTIFY_SIGNAL openrisc: add support for TIF_NOTIFY_SIGNAL sh: add support for TIF_NOTIFY_SIGNAL um: add support for TIF_NOTIFY_SIGNAL ...

arm64: uaccess: remove addr_limit_user_check()

2020-12-02T19:49:11Z

Now that set_fs() is gone, addr_limit_user_check() is redundant. Remove the checks and associated thread flag. To ensure that _TIF_WORK_MASK can be used as an immediate value in an AND instruction (as it is in `ret_to_user`), TIF_MTE_ASYNC_FAULT is renumbered to keep the constituent bits of _TIF_WORK_MASK contiguous. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Christoph Hellwig Cc: James Morse Cc: Will Deacon Link: https://lore.kernel.org/r/20201202131558.39270-11-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: uaccess: remove set_fs()

2020-12-02T19:49:11Z

Now that the uaccess primitives dont take addr_limit into account, we have no need to manipulate this via set_fs() and get_fs(). Remove support for these, along with some infrastructure this renders redundant. We no longer need to flip UAO to access kernel memory under KERNEL_DS, and head.S unconditionally clears UAO for all kernel configurations via an ERET in init_kernel_el. Thus, we don't need to dynamically flip UAO, nor do we need to context-switch it. However, we still need to adjust PAN during SDEI entry. Masking of __user pointers no longer needs to use the dynamic value of addr_limit, and can use a constant derived from the maximum possible userspace task size. A new TASK_SIZE_MAX constant is introduced for this, which is also used by core code. In configurations supporting 52-bit VAs, this may include a region of unusable VA space above a 48-bit TTBR0 limit, but never includes any portion of TTBR1. Note that TASK_SIZE_MAX is an exclusive limit, while USER_DS and KERNEL_DS were inclusive limits, and is converted to a mask by subtracting one. As the SDEI entry code repurposes the otherwise unnecessary pt_regs::orig_addr_limit field to store the TTBR1 of the interrupted context, for now we rename that to pt_regs::sdei_ttbr1. In future we can consider factoring that out. Signed-off-by: Mark Rutland Acked-by: James Morse Cc: Christoph Hellwig Cc: Will Deacon Link: https://lore.kernel.org/r/20201202131558.39270-10-mark.rutland@arm.com Signed-off-by: Catalin Marinas

arm64: add support for TIF_NOTIFY_SIGNAL

2020-11-09T15:16:55Z

Wire up TIF_NOTIFY_SIGNAL handling for arm64. Cc: linux-arm-kernel@lists.infradead.org Acked-by: Will Deacon Acked-by: Catalin Marinas Signed-off-by: Jens Axboe

arm64: mte: Handle synchronous and asynchronous tag check faults

2020-09-04T11:46:06Z

The Memory Tagging Extension has two modes of notifying a tag check fault at EL0, configurable through the SCTLR_EL1.TCF0 field: 1. Synchronous raising of a Data Abort exception with DFSC 17. 2. Asynchronous setting of a cumulative bit in TFSRE0_EL1. Add the exception handler for the synchronous exception and handling of the asynchronous TFSRE0_EL1.TF0 bit setting via a new TIF flag in do_notify_resume(). On a tag check failure in user-space, whether synchronous or asynchronous, a SIGSEGV will be raised on the faulting thread. Signed-off-by: Vincenzo Frascino Co-developed-by: Catalin Marinas Signed-off-by: Catalin Marinas Cc: Will Deacon