bebf56a1b1
This feature let us to detect accesses out of bounds of global variables. This will work as for globals in kernel image, so for globals in modules. Currently this won't work for symbols in user-specified sections (e.g. __init, __read_mostly, ...) The idea of this is simple. Compiler increases each global variable by redzone size and add constructors invoking __asan_register_globals() function. Information about global variable (address, size, size with redzone ...) passed to __asan_register_globals() so we could poison variable's redzone. This patch also forces module_alloc() to return 8*PAGE_SIZE aligned address making shadow memory handling ( kasan_module_alloc()/kasan_module_free() ) more simple. Such alignment guarantees that each shadow page backing modules address space correspond to only one module_alloc() allocation. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrey Konovalov <adech.fo@gmail.com> Cc: Yuri Gribov <tetra2005@gmail.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
76 lines
2.2 KiB
C
76 lines
2.2 KiB
C
#ifndef __MM_KASAN_KASAN_H
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#define __MM_KASAN_KASAN_H
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#include <linux/kasan.h>
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#define KASAN_SHADOW_SCALE_SIZE (1UL << KASAN_SHADOW_SCALE_SHIFT)
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#define KASAN_SHADOW_MASK (KASAN_SHADOW_SCALE_SIZE - 1)
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#define KASAN_FREE_PAGE 0xFF /* page was freed */
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#define KASAN_FREE_PAGE 0xFF /* page was freed */
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#define KASAN_PAGE_REDZONE 0xFE /* redzone for kmalloc_large allocations */
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#define KASAN_KMALLOC_REDZONE 0xFC /* redzone inside slub object */
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#define KASAN_KMALLOC_FREE 0xFB /* object was freed (kmem_cache_free/kfree) */
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#define KASAN_GLOBAL_REDZONE 0xFA /* redzone for global variable */
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/*
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* Stack redzone shadow values
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* (Those are compiler's ABI, don't change them)
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*/
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#define KASAN_STACK_LEFT 0xF1
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#define KASAN_STACK_MID 0xF2
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#define KASAN_STACK_RIGHT 0xF3
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#define KASAN_STACK_PARTIAL 0xF4
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/* Don't break randconfig/all*config builds */
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#ifndef KASAN_ABI_VERSION
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#define KASAN_ABI_VERSION 1
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#endif
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struct kasan_access_info {
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const void *access_addr;
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const void *first_bad_addr;
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size_t access_size;
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bool is_write;
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unsigned long ip;
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};
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/* The layout of struct dictated by compiler */
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struct kasan_source_location {
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const char *filename;
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int line_no;
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int column_no;
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};
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/* The layout of struct dictated by compiler */
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struct kasan_global {
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const void *beg; /* Address of the beginning of the global variable. */
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size_t size; /* Size of the global variable. */
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size_t size_with_redzone; /* Size of the variable + size of the red zone. 32 bytes aligned */
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const void *name;
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const void *module_name; /* Name of the module where the global variable is declared. */
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unsigned long has_dynamic_init; /* This needed for C++ */
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#if KASAN_ABI_VERSION >= 4
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struct kasan_source_location *location;
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#endif
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};
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void kasan_report_error(struct kasan_access_info *info);
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void kasan_report_user_access(struct kasan_access_info *info);
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static inline const void *kasan_shadow_to_mem(const void *shadow_addr)
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{
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return (void *)(((unsigned long)shadow_addr - KASAN_SHADOW_OFFSET)
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<< KASAN_SHADOW_SCALE_SHIFT);
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}
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static inline bool kasan_enabled(void)
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{
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return !current->kasan_depth;
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}
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void kasan_report(unsigned long addr, size_t size,
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bool is_write, unsigned long ip);
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#endif
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