• Andrey Ryabinin's avatar
    module: fix types of device tables aliases · 6301939d
    Andrey Ryabinin authored
    
    
    MODULE_DEVICE_TABLE() macro used to create aliases to device tables.
    Normally alias should have the same type as aliased symbol.
    
    Device tables are arrays, so they have 'struct type##_device_id[x]'
    types. Alias created by MODULE_DEVICE_TABLE() will have non-array type -
    	'struct type##_device_id'.
    
    This inconsistency confuses compiler, it could make a wrong assumption
    about variable's size which leads KASan to produce a false positive report
    about out of bounds access.
    
    For every global variable compiler calls __asan_register_globals() passing
    information about global variable (address, size, size with redzone, name
    ...) __asan_register_globals() poison symbols redzone to detect possible
    out of bounds accesses.
    
    When symbol has an alias __asan_register_globals() will be called as for
    symbol so for alias.  Compiler determines size of variable by size of
    variable's type.  Alias and symbol have the same address, so if alias have
    the wrong size part of memory that actually belongs to the symbol could be
    poisoned as redzone of alias symbol.
    
    By fixing type of alias symbol we will fix size of it, so
    __asan_register_globals() will not poison valid memory.
    Signed-off-by: default avatarAndrey 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: default avatarAndrey 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: default avatarAndrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    6301939d