Hi memory tagging folks, While debugging something else, I ended up running v6.4 on an arm64 (v9) fastmodel with both CONFIG_SLUB_DEBUG_ON=y and CONFIG_KASAN_HW_TAGS=y. This makes the system pretty unusable, as I see a tonne of kmalloc Redzone corruption messages pretty much straight out of startup (example below). Please can you take a look? Cheers, Will --->8 [ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=8, Nodes=1 [ 0.000000] ============================================================================= [ 0.000000] BUG kmalloc-128 (Not tainted): kmalloc Redzone overwritten [ 0.000000] ----------------------------------------------------------------------------- [ 0.000000] [ 0.000000] 0xffff00080001a9b0-0xf1ff00080001a9ff @offset=2480. First byte 0x0 instead of 0xcc [ 0.000000] Allocated in apply_wqattrs_prepare+0x90/0x2a4 age=0 cpu=0 pid=0 [ 0.000000] kmalloc_trace+0x34/0x6c [ 0.000000] apply_wqattrs_prepare+0x90/0x2a4 [ 0.000000] apply_workqueue_attrs+0x5c/0xb4 [ 0.000000] alloc_workqueue+0x368/0x4f8 [ 0.000000] workqueue_init_early+0x2e8/0x3ac [ 0.000000] start_kernel+0x168/0x394 [ 0.000000] __primary_switched+0xbc/0xc4 [ 0.000000] Slab 0xfffffc0020000680 objects=21 used=8 fp=0xffff00080001ac80 flags=0xbfffc0000010200(slab|head|node=0|zone=2|lastcpupid=0xffff|kasantag=0x0) [ 0.000000] Object 0xf1ff00080001a980 @offset=17437937757178562944 fp=0x0000000000000000 [ 0.000000] [ 0.000000] Redzone ffff00080001a900: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................ [ 0.000000] Redzone ffff00080001a910: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................ [ 0.000000] Redzone ffff00080001a920: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................ [ 0.000000] Redzone ffff00080001a930: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................ [ 0.000000] Redzone ffff00080001a940: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................ [ 0.000000] Redzone ffff00080001a950: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................ [ 0.000000] Redzone ffff00080001a960: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................ [ 0.000000] Redzone ffff00080001a970: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc ................ [ 0.000000] Object ffff00080001a980: 00 00 00 00 00 00 00 00 ff 00 00 00 00 00 00 00 ................ [ 0.000000] Object ffff00080001a990: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 0.000000] Object ffff00080001a9a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 0.000000] Object ffff00080001a9b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 0.000000] Object ffff00080001a9c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 0.000000] Object ffff00080001a9d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 0.000000] Object ffff00080001a9e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 0.000000] Object ffff00080001a9f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [ 0.000000] Redzone ffff00080001aa00: cc cc cc cc cc cc cc cc ........ [ 0.000000] Padding ffff00080001aa54: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ [ 0.000000] Padding ffff00080001aa64: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZZZZZ [ 0.000000] Padding ffff00080001aa74: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZZZZZ [ 0.000000] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.4.0-00001-g56e11237836c #1 [ 0.000000] Hardware name: FVP Base RevC (DT) [ 0.000000] Call trace: [ 0.000000] dump_backtrace+0xec/0x108 [ 0.000000] show_stack+0x18/0x2c [ 0.000000] dump_stack_lvl+0x50/0x68 [ 0.000000] dump_stack+0x18/0x24 [ 0.000000] print_trailer+0x1ec/0x230 [ 0.000000] check_bytes_and_report+0x110/0x154 [ 0.000000] check_object+0x31c/0x360 [ 0.000000] free_to_partial_list+0x174/0x5d8 [ 0.000000] __slab_free+0x220/0x28c [ 0.000000] __kmem_cache_free+0x364/0x3dc [ 0.000000] kfree+0x50/0x70 [ 0.000000] apply_wqattrs_prepare+0x244/0x2a4 [ 0.000000] apply_workqueue_attrs+0x5c/0xb4 [ 0.000000] alloc_workqueue+0x368/0x4f8 [ 0.000000] workqueue_init_early+0x2e8/0x3ac [ 0.000000] start_kernel+0x168/0x394 [ 0.000000] __primary_switched+0xbc/0xc4 [ 0.000000] Disabling lock debugging due to kernel taint [ 0.000000] FIX kmalloc-128: Restoring kmalloc Redzone 0xffff00080001a9b0-0xf1ff00080001a9ff=0xcc [ 0.000000] FIX kmalloc-128: Object at 0xf1ff00080001a980 not freed
