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git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git
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Andrey Konovalov
51fb34de2a
Once tag-based KASAN modes start tagging vmalloc() allocations, kernel stacks start getting tagged if CONFIG_VMAP_STACK is enabled. Reset the tag of kernel stack pointers after allocation in arch_alloc_vmap_stack(). For SW_TAGS KASAN, when CONFIG_KASAN_STACK is enabled, the instrumentation can't handle the SP register being tagged. For HW_TAGS KASAN, there's no instrumentation-related issues. However, the impact of having a tagged SP register needs to be properly evaluated, so keep it non-tagged for now. Note, that the memory for the stack allocation still gets tagged to catch vmalloc-into-stack out-of-bounds accesses. [[email protected]: fix case when a stack is retrieved from cached_stacks] Link: https://lkml.kernel.org/r/f50c5f96ef896d7936192c888b0c0a7674e33184.1644943792.git.andreyknvl@google.com [[email protected]: remove unnecessary check in alloc_thread_stack_node()] Link: https://lkml.kernel.org/r/20220301080706.GB17208@kili Link: https://lkml.kernel.org/r/698c5ab21743c796d46c15d075b9481825973e34.1643047180.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <[email protected]> Signed-off-by: Dan Carpenter <[email protected]> Acked-by: Catalin Marinas <[email protected]> Acked-by: Marco Elver <[email protected]> Reviewed-by: Marco Elver <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Evgenii Stepanov <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Peter Collingbourne <[email protected]> Cc: Vincenzo Frascino <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
30 lines
739 B
C
30 lines
739 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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// Copyright (C) 2017 Arm Ltd.
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#ifndef __ASM_VMAP_STACK_H
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#define __ASM_VMAP_STACK_H
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#include <linux/bug.h>
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#include <linux/gfp.h>
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#include <linux/kconfig.h>
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#include <linux/vmalloc.h>
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#include <linux/pgtable.h>
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#include <asm/memory.h>
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#include <asm/thread_info.h>
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/*
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* To ensure that VMAP'd stack overflow detection works correctly, all VMAP'd
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* stacks need to have the same alignment.
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*/
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static inline unsigned long *arch_alloc_vmap_stack(size_t stack_size, int node)
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{
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void *p;
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BUILD_BUG_ON(!IS_ENABLED(CONFIG_VMAP_STACK));
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p = __vmalloc_node(stack_size, THREAD_ALIGN, THREADINFO_GFP, node,
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__builtin_return_address(0));
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return kasan_reset_tag(p);
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}
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#endif /* __ASM_VMAP_STACK_H */
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