Upstream commit bffa986c6f80e39d9903015fc7d0d99a66bbf559. Tag-based KASAN reuses a significant part of the generic KASAN code, so move the common parts to common.c without any functional changes. Link: http://lkml.kernel.org/r/114064d002356e03bb8cc91f7835e20dc61b51d9.1544099024.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Change-Id: I4e0a463cd0b9671cf9ce5ac27418894d45a06b80 Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Bug: 128674696tirimbino
Andrey Konovalov
6 years ago
committed by
Paul Lawrence
parent
06ba7b677f
commit
748038be9c
@ -1,11 +1,14 @@ |
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# SPDX-License-Identifier: GPL-2.0
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KASAN_SANITIZE := n
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UBSAN_SANITIZE_common.o := n
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UBSAN_SANITIZE_kasan.o := n
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KCOV_INSTRUMENT := n
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CFLAGS_REMOVE_kasan.o = -pg
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# Function splitter causes unnecessary splits in __asan_load1/__asan_store1
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# see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533
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CFLAGS_common.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
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CFLAGS_kasan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector)
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obj-y := kasan.o report.o kasan_init.o quarantine.o
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obj-y := common.o kasan.o report.o kasan_init.o quarantine.o
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@ -0,0 +1,603 @@ |
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/*
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* This file contains common generic and tag-based KASAN code. |
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* |
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* Copyright (c) 2014 Samsung Electronics Co., Ltd. |
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* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com> |
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* |
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* Some code borrowed from https://github.com/xairy/kasan-prototype by
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* Andrey Konovalov <andreyknvl@gmail.com> |
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* |
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* This program is free software; you can redistribute it and/or modify |
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* it under the terms of the GNU General Public License version 2 as |
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* published by the Free Software Foundation. |
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* |
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*/ |
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#include <linux/export.h> |
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#include <linux/interrupt.h> |
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#include <linux/init.h> |
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#include <linux/kasan.h> |
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#include <linux/kernel.h> |
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#include <linux/kmemleak.h> |
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#include <linux/linkage.h> |
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#include <linux/memblock.h> |
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#include <linux/memory.h> |
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#include <linux/mm.h> |
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#include <linux/module.h> |
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#include <linux/printk.h> |
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#include <linux/sched.h> |
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#include <linux/sched/task_stack.h> |
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#include <linux/slab.h> |
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#include <linux/stacktrace.h> |
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#include <linux/string.h> |
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#include <linux/types.h> |
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#include <linux/vmalloc.h> |
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#include <linux/bug.h> |
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#include "kasan.h" |
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#include "../slab.h" |
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static inline int in_irqentry_text(unsigned long ptr) |
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{ |
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return (ptr >= (unsigned long)&__irqentry_text_start && |
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ptr < (unsigned long)&__irqentry_text_end) || |
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(ptr >= (unsigned long)&__softirqentry_text_start && |
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ptr < (unsigned long)&__softirqentry_text_end); |
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} |
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static inline void filter_irq_stacks(struct stack_trace *trace) |
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{ |
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int i; |
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if (!trace->nr_entries) |
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return; |
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for (i = 0; i < trace->nr_entries; i++) |
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if (in_irqentry_text(trace->entries[i])) { |
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/* Include the irqentry function into the stack. */ |
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trace->nr_entries = i + 1; |
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break; |
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} |
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} |
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static inline depot_stack_handle_t save_stack(gfp_t flags) |
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{ |
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unsigned long entries[KASAN_STACK_DEPTH]; |
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struct stack_trace trace = { |
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.nr_entries = 0, |
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.entries = entries, |
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.max_entries = KASAN_STACK_DEPTH, |
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.skip = 0 |
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}; |
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save_stack_trace(&trace); |
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filter_irq_stacks(&trace); |
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if (trace.nr_entries != 0 && |
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trace.entries[trace.nr_entries-1] == ULONG_MAX) |
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trace.nr_entries--; |
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return depot_save_stack(&trace, flags); |
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} |
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static inline void set_track(struct kasan_track *track, gfp_t flags) |
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{ |
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track->pid = current->pid; |
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track->stack = save_stack(flags); |
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} |
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void kasan_enable_current(void) |
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{ |
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current->kasan_depth++; |
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} |
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void kasan_disable_current(void) |
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{ |
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current->kasan_depth--; |
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} |
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void kasan_check_read(const volatile void *p, unsigned int size) |
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{ |
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check_memory_region((unsigned long)p, size, false, _RET_IP_); |
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} |
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EXPORT_SYMBOL(kasan_check_read); |
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void kasan_check_write(const volatile void *p, unsigned int size) |
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{ |
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check_memory_region((unsigned long)p, size, true, _RET_IP_); |
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} |
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EXPORT_SYMBOL(kasan_check_write); |
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#undef memset |
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void *memset(void *addr, int c, size_t len) |
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{ |
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check_memory_region((unsigned long)addr, len, true, _RET_IP_); |
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return __memset(addr, c, len); |
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} |
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#undef memmove |
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void *memmove(void *dest, const void *src, size_t len) |
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{ |
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check_memory_region((unsigned long)src, len, false, _RET_IP_); |
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check_memory_region((unsigned long)dest, len, true, _RET_IP_); |
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return __memmove(dest, src, len); |
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} |
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#undef memcpy |
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void *memcpy(void *dest, const void *src, size_t len) |
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{ |
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check_memory_region((unsigned long)src, len, false, _RET_IP_); |
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check_memory_region((unsigned long)dest, len, true, _RET_IP_); |
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return __memcpy(dest, src, len); |
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} |
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/*
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* Poisons the shadow memory for 'size' bytes starting from 'addr'. |
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* Memory addresses should be aligned to KASAN_SHADOW_SCALE_SIZE. |
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*/ |
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void kasan_poison_shadow(const void *address, size_t size, u8 value) |
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{ |
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void *shadow_start, *shadow_end; |
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shadow_start = kasan_mem_to_shadow(address); |
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shadow_end = kasan_mem_to_shadow(address + size); |
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__memset(shadow_start, value, shadow_end - shadow_start); |
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} |
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void kasan_unpoison_shadow(const void *address, size_t size) |
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{ |
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kasan_poison_shadow(address, size, 0); |
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if (size & KASAN_SHADOW_MASK) { |
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u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); |
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*shadow = size & KASAN_SHADOW_MASK; |
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} |
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} |
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static void __kasan_unpoison_stack(struct task_struct *task, const void *sp) |
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{ |
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void *base = task_stack_page(task); |
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size_t size = sp - base; |
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kasan_unpoison_shadow(base, size); |
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} |
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/* Unpoison the entire stack for a task. */ |
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void kasan_unpoison_task_stack(struct task_struct *task) |
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{ |
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__kasan_unpoison_stack(task, task_stack_page(task) + THREAD_SIZE); |
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} |
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/* Unpoison the stack for the current task beyond a watermark sp value. */ |
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asmlinkage void kasan_unpoison_task_stack_below(const void *watermark) |
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{ |
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/*
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* Calculate the task stack base address. Avoid using 'current' |
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* because this function is called by early resume code which hasn't |
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* yet set up the percpu register (%gs). |
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*/ |
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void *base = (void *)((unsigned long)watermark & ~(THREAD_SIZE - 1)); |
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kasan_unpoison_shadow(base, watermark - base); |
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} |
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/*
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* Clear all poison for the region between the current SP and a provided |
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* watermark value, as is sometimes required prior to hand-crafted asm function |
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* returns in the middle of functions. |
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*/ |
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void kasan_unpoison_stack_above_sp_to(const void *watermark) |
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{ |
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const void *sp = __builtin_frame_address(0); |
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size_t size = watermark - sp; |
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if (WARN_ON(sp > watermark)) |
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return; |
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kasan_unpoison_shadow(sp, size); |
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} |
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void kasan_alloc_pages(struct page *page, unsigned int order) |
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{ |
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if (likely(!PageHighMem(page))) |
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kasan_unpoison_shadow(page_address(page), PAGE_SIZE << order); |
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} |
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void kasan_free_pages(struct page *page, unsigned int order) |
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{ |
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if (likely(!PageHighMem(page))) |
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kasan_poison_shadow(page_address(page), |
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PAGE_SIZE << order, |
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KASAN_FREE_PAGE); |
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} |
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/*
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* Adaptive redzone policy taken from the userspace AddressSanitizer runtime. |
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* For larger allocations larger redzones are used. |
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*/ |
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static inline unsigned int optimal_redzone(unsigned int object_size) |
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{ |
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return |
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object_size <= 64 - 16 ? 16 : |
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object_size <= 128 - 32 ? 32 : |
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object_size <= 512 - 64 ? 64 : |
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object_size <= 4096 - 128 ? 128 : |
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object_size <= (1 << 14) - 256 ? 256 : |
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object_size <= (1 << 15) - 512 ? 512 : |
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object_size <= (1 << 16) - 1024 ? 1024 : 2048; |
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} |
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void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, |
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unsigned long *flags) |
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{ |
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unsigned int orig_size = *size; |
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int redzone_adjust; |
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/* Add alloc meta. */ |
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cache->kasan_info.alloc_meta_offset = *size; |
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*size += sizeof(struct kasan_alloc_meta); |
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/* Add free meta. */ |
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if (cache->flags & SLAB_TYPESAFE_BY_RCU || cache->ctor || |
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cache->object_size < sizeof(struct kasan_free_meta)) { |
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cache->kasan_info.free_meta_offset = *size; |
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*size += sizeof(struct kasan_free_meta); |
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} |
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redzone_adjust = optimal_redzone(cache->object_size) - |
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(*size - cache->object_size); |
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if (redzone_adjust > 0) |
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*size += redzone_adjust; |
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*size = min_t(unsigned int, KMALLOC_MAX_SIZE, |
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max(*size, cache->object_size + |
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optimal_redzone(cache->object_size))); |
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/*
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* If the metadata doesn't fit, don't enable KASAN at all. |
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*/ |
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if (*size <= cache->kasan_info.alloc_meta_offset || |
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*size <= cache->kasan_info.free_meta_offset) { |
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cache->kasan_info.alloc_meta_offset = 0; |
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cache->kasan_info.free_meta_offset = 0; |
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*size = orig_size; |
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return; |
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} |
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*flags |= SLAB_KASAN; |
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} |
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size_t kasan_metadata_size(struct kmem_cache *cache) |
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{ |
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return (cache->kasan_info.alloc_meta_offset ? |
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sizeof(struct kasan_alloc_meta) : 0) + |
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(cache->kasan_info.free_meta_offset ? |
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sizeof(struct kasan_free_meta) : 0); |
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} |
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struct kasan_alloc_meta *get_alloc_info(struct kmem_cache *cache, |
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const void *object) |
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{ |
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BUILD_BUG_ON(sizeof(struct kasan_alloc_meta) > 32); |
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return (void *)object + cache->kasan_info.alloc_meta_offset; |
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} |
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struct kasan_free_meta *get_free_info(struct kmem_cache *cache, |
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const void *object) |
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{ |
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BUILD_BUG_ON(sizeof(struct kasan_free_meta) > 32); |
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return (void *)object + cache->kasan_info.free_meta_offset; |
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} |
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void kasan_poison_slab(struct page *page) |
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{ |
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kasan_poison_shadow(page_address(page), |
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PAGE_SIZE << compound_order(page), |
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KASAN_KMALLOC_REDZONE); |
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} |
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void kasan_unpoison_object_data(struct kmem_cache *cache, void *object) |
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{ |
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kasan_unpoison_shadow(object, cache->object_size); |
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} |
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void kasan_poison_object_data(struct kmem_cache *cache, void *object) |
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{ |
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kasan_poison_shadow(object, |
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round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE), |
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KASAN_KMALLOC_REDZONE); |
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} |
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void *kasan_init_slab_obj(struct kmem_cache *cache, const void *object) |
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{ |
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struct kasan_alloc_meta *alloc_info; |
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if (!(cache->flags & SLAB_KASAN)) |
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return (void *)object; |
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alloc_info = get_alloc_info(cache, object); |
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__memset(alloc_info, 0, sizeof(*alloc_info)); |
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return (void *)object; |
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} |
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void *kasan_slab_alloc(struct kmem_cache *cache, void *object, gfp_t flags) |
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{ |
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return kasan_kmalloc(cache, object, cache->object_size, flags); |
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} |
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static bool __kasan_slab_free(struct kmem_cache *cache, void *object, |
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unsigned long ip, bool quarantine) |
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{ |
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s8 shadow_byte; |
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unsigned long rounded_up_size; |
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if (unlikely(nearest_obj(cache, virt_to_head_page(object), object) != |
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object)) { |
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kasan_report_invalid_free(object, ip); |
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return true; |
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} |
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/* RCU slabs could be legally used after free within the RCU period */ |
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if (unlikely(cache->flags & SLAB_TYPESAFE_BY_RCU)) |
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return false; |
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shadow_byte = READ_ONCE(*(s8 *)kasan_mem_to_shadow(object)); |
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if (shadow_byte < 0 || shadow_byte >= KASAN_SHADOW_SCALE_SIZE) { |
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kasan_report_invalid_free(object, ip); |
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return true; |
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} |
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rounded_up_size = round_up(cache->object_size, KASAN_SHADOW_SCALE_SIZE); |
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kasan_poison_shadow(object, rounded_up_size, KASAN_KMALLOC_FREE); |
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if (!quarantine || unlikely(!(cache->flags & SLAB_KASAN))) |
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return false; |
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set_track(&get_alloc_info(cache, object)->free_track, GFP_NOWAIT); |
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quarantine_put(get_free_info(cache, object), cache); |
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return true; |
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} |
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bool kasan_slab_free(struct kmem_cache *cache, void *object, unsigned long ip) |
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{ |
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return __kasan_slab_free(cache, object, ip, true); |
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} |
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void *kasan_kmalloc(struct kmem_cache *cache, const void *object, size_t size, |
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gfp_t flags) |
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{ |
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unsigned long redzone_start; |
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unsigned long redzone_end; |
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if (gfpflags_allow_blocking(flags)) |
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quarantine_reduce(); |
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if (unlikely(object == NULL)) |
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return NULL; |
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redzone_start = round_up((unsigned long)(object + size), |
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KASAN_SHADOW_SCALE_SIZE); |
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redzone_end = round_up((unsigned long)object + cache->object_size, |
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KASAN_SHADOW_SCALE_SIZE); |
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kasan_unpoison_shadow(object, size); |
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kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start, |
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KASAN_KMALLOC_REDZONE); |
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if (cache->flags & SLAB_KASAN) |
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set_track(&get_alloc_info(cache, object)->alloc_track, flags); |
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return (void *)object; |
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} |
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EXPORT_SYMBOL(kasan_kmalloc); |
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void *kasan_kmalloc_large(const void *ptr, size_t size, gfp_t flags) |
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{ |
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struct page *page; |
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unsigned long redzone_start; |
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unsigned long redzone_end; |
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if (gfpflags_allow_blocking(flags)) |
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quarantine_reduce(); |
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if (unlikely(ptr == NULL)) |
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return NULL; |
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page = virt_to_page(ptr); |
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redzone_start = round_up((unsigned long)(ptr + size), |
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KASAN_SHADOW_SCALE_SIZE); |
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redzone_end = (unsigned long)ptr + (PAGE_SIZE << compound_order(page)); |
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kasan_unpoison_shadow(ptr, size); |
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kasan_poison_shadow((void *)redzone_start, redzone_end - redzone_start, |
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KASAN_PAGE_REDZONE); |
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return (void *)ptr; |
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} |
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void *kasan_krealloc(const void *object, size_t size, gfp_t flags) |
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{ |
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struct page *page; |
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if (unlikely(object == ZERO_SIZE_PTR)) |
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return (void *)object; |
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page = virt_to_head_page(object); |
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if (unlikely(!PageSlab(page))) |
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return kasan_kmalloc_large(object, size, flags); |
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else |
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return kasan_kmalloc(page->slab_cache, object, size, flags); |
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} |
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void kasan_poison_kfree(void *ptr, unsigned long ip) |
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{ |
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struct page *page; |
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page = virt_to_head_page(ptr); |
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if (unlikely(!PageSlab(page))) { |
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if (ptr != page_address(page)) { |
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kasan_report_invalid_free(ptr, ip); |
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return; |
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} |
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kasan_poison_shadow(ptr, PAGE_SIZE << compound_order(page), |
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KASAN_FREE_PAGE); |
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} else { |
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__kasan_slab_free(page->slab_cache, ptr, ip, false); |
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} |
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} |
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void kasan_kfree_large(void *ptr, unsigned long ip) |
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{ |
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if (ptr != page_address(virt_to_head_page(ptr))) |
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kasan_report_invalid_free(ptr, ip); |
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/* The object will be poisoned by page_alloc. */ |
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} |
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int kasan_module_alloc(void *addr, size_t size) |
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{ |
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void *ret; |
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size_t scaled_size; |
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size_t shadow_size; |
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unsigned long shadow_start; |
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shadow_start = (unsigned long)kasan_mem_to_shadow(addr); |
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scaled_size = (size + KASAN_SHADOW_MASK) >> KASAN_SHADOW_SCALE_SHIFT; |
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shadow_size = round_up(scaled_size, PAGE_SIZE); |
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if (WARN_ON(!PAGE_ALIGNED(shadow_start))) |
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return -EINVAL; |
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ret = __vmalloc_node_range(shadow_size, 1, shadow_start, |
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shadow_start + shadow_size, |
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GFP_KERNEL | __GFP_ZERO, |
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PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE, |
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__builtin_return_address(0)); |
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if (ret) { |
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find_vm_area(addr)->flags |= VM_KASAN; |
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kmemleak_ignore(ret); |
||||
return 0; |
||||
} |
||||
|
||||
return -ENOMEM; |
||||
} |
||||
|
||||
void kasan_free_shadow(const struct vm_struct *vm) |
||||
{ |
||||
if (vm->flags & VM_KASAN) |
||||
vfree(kasan_mem_to_shadow(vm->addr)); |
||||
} |
||||
|
||||
#ifdef CONFIG_MEMORY_HOTPLUG |
||||
static bool shadow_mapped(unsigned long addr) |
||||
{ |
||||
pgd_t *pgd = pgd_offset_k(addr); |
||||
p4d_t *p4d; |
||||
pud_t *pud; |
||||
pmd_t *pmd; |
||||
pte_t *pte; |
||||
|
||||
if (pgd_none(*pgd)) |
||||
return false; |
||||
p4d = p4d_offset(pgd, addr); |
||||
if (p4d_none(*p4d)) |
||||
return false; |
||||
pud = pud_offset(p4d, addr); |
||||
if (pud_none(*pud)) |
||||
return false; |
||||
|
||||
/*
|
||||
* We can't use pud_large() or pud_huge(), the first one is |
||||
* arch-specific, the last one depends on HUGETLB_PAGE. So let's abuse |
||||
* pud_bad(), if pud is bad then it's bad because it's huge. |
||||
*/ |
||||
if (pud_bad(*pud)) |
||||
return true; |
||||
pmd = pmd_offset(pud, addr); |
||||
if (pmd_none(*pmd)) |
||||
return false; |
||||
|
||||
if (pmd_bad(*pmd)) |
||||
return true; |
||||
pte = pte_offset_kernel(pmd, addr); |
||||
return !pte_none(*pte); |
||||
} |
||||
|
||||
static int __meminit kasan_mem_notifier(struct notifier_block *nb, |
||||
unsigned long action, void *data) |
||||
{ |
||||
struct memory_notify *mem_data = data; |
||||
unsigned long nr_shadow_pages, start_kaddr, shadow_start; |
||||
unsigned long shadow_end, shadow_size; |
||||
|
||||
nr_shadow_pages = mem_data->nr_pages >> KASAN_SHADOW_SCALE_SHIFT; |
||||
start_kaddr = (unsigned long)pfn_to_kaddr(mem_data->start_pfn); |
||||
shadow_start = (unsigned long)kasan_mem_to_shadow((void *)start_kaddr); |
||||
shadow_size = nr_shadow_pages << PAGE_SHIFT; |
||||
shadow_end = shadow_start + shadow_size; |
||||
|
||||
if (WARN_ON(mem_data->nr_pages % KASAN_SHADOW_SCALE_SIZE) || |
||||
WARN_ON(start_kaddr % (KASAN_SHADOW_SCALE_SIZE << PAGE_SHIFT))) |
||||
return NOTIFY_BAD; |
||||
|
||||
switch (action) { |
||||
case MEM_GOING_ONLINE: { |
||||
void *ret; |
||||
|
||||
/*
|
||||
* If shadow is mapped already than it must have been mapped |
||||
* during the boot. This could happen if we onlining previously |
||||
* offlined memory. |
||||
*/ |
||||
if (shadow_mapped(shadow_start)) |
||||
return NOTIFY_OK; |
||||
|
||||
ret = __vmalloc_node_range(shadow_size, PAGE_SIZE, shadow_start, |
||||
shadow_end, GFP_KERNEL, |
||||
PAGE_KERNEL, VM_NO_GUARD, |
||||
pfn_to_nid(mem_data->start_pfn), |
||||
__builtin_return_address(0)); |
||||
if (!ret) |
||||
return NOTIFY_BAD; |
||||
|
||||
kmemleak_ignore(ret); |
||||
return NOTIFY_OK; |
||||
} |
||||
case MEM_CANCEL_ONLINE: |
||||
case MEM_OFFLINE: { |
||||
struct vm_struct *vm; |
||||
|
||||
/*
|
||||
* shadow_start was either mapped during boot by kasan_init() |
||||
* or during memory online by __vmalloc_node_range(). |
||||
* In the latter case we can use vfree() to free shadow. |
||||
* Non-NULL result of the find_vm_area() will tell us if |
||||
* that was the second case. |
||||
* |
||||
* Currently it's not possible to free shadow mapped |
||||
* during boot by kasan_init(). It's because the code |
||||
* to do that hasn't been written yet. So we'll just |
||||
* leak the memory. |
||||
*/ |
||||
vm = find_vm_area((void *)shadow_start); |
||||
if (vm) |
||||
vfree((void *)shadow_start); |
||||
} |
||||
} |
||||
|
||||
return NOTIFY_OK; |
||||
} |
||||
|
||||
static int __init kasan_memhotplug_init(void) |
||||
{ |
||||
hotplug_memory_notifier(kasan_mem_notifier, 0); |
||||
|
||||
return 0; |
||||
} |
||||
|
||||
core_initcall(kasan_memhotplug_init); |
||||
#endif |
||||
Loading…
Reference in new issue