On Wed, May 26, 2021 at 06:12:34PM +0530, Naresh Kamboju wrote: > While booting Linux next-20210526 tag on arm64 the following crash noticed. > > [ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd034] > [ 0.000000] Linux version 5.13.0-rc3-next-20210526 > (tuxmake@52aac593b9ff) (aarch64-linux-gnu-gcc (Debian 11.1.0-1) > 11.1.0, GNU ld (GNU Binutils for Debian) 2.36.1) #1 SMP PREEMPT Wed > May 26 08:29:48 UTC 2021 > [ 0.000000] Machine model: linux,dummy-virt > [ 0.000000] earlycon: pl11 at MMIO 0x0000000009000000 (options '') > [ 0.000000] printk: bootconsole [pl11] enabled > [ 0.000000] efi: UEFI not found. > [ 0.000000] NUMA: No NUMA configuration found > [ 0.000000] NUMA: Faking a node at [mem > 0x0000000040000000-0x00000000bfffffff] > [ 0.000000] NUMA: NODE_DATA [mem 0xbfc00d40-0xbfc03fff] > [ 0.000000] Zone ranges: > [ 0.000000] DMA [mem 0x0000000040000000-0x00000000bfffffff] > [ 0.000000] DMA32 empty > [ 0.000000] Normal empty > [ 0.000000] Device empty > [ 0.000000] Movable zone start for each node > [ 0.000000] Early memory node ranges > [ 0.000000] node 0: [mem 0x0000000040000000-0x00000000bfffffff] > [ 0.000000] Initmem setup node 0 [mem 0x0000000040000000-0x00000000bfffffff] > [ 0.000000] cma: Reserved 32 MiB at 0x00000000bb800000 > [ 0.000000] kasan: KernelAddressSanitizer initialized > [ 0.000000] psci: probing for conduit method from DT. > [ 0.000000] psci: PSCIv1.0 detected in firmware. > [ 0.000000] psci: Using standard PSCI v0.2 function IDs > [ 0.000000] psci: Trusted OS migration not required > [ 0.000000] psci: SMC Calling Convention v1.1 > [ 0.000000] percpu: Embedded 500 pages/cpu s2009624 r8192 d30184 u2048000 > [ 0.000000] ------------[ cut here ]------------ > [ 0.000000] kernel BUG at arch/arm64/kernel/traps.c:406! > [ 0.000000] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP > [ 0.000000] Modules linked in: > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G T > 5.13.0-rc3-next-20210526 #1 c8ad07b8a918e7b0a25b795f9cc1c902737164cf > [ 0.000000] Hardware name: linux,dummy-virt (DT) > [ 0.000000] pstate: 404000c5 (nZcv daIF +PAN -UAO -TCO BTYPE=--) > [ 0.000000] pc : do_undefinstr+0x88/0xc0 > [ 0.000000] lr : do_undefinstr+0x88/0xc0 > [ 0.000000] sp : ffff800014267be0 > [ 0.000000] x29: ffff800014267be0 x28: ffff80001429b040 x27: 0000000000000000 > [ 0.000000] x26: 0000000000000000 x25: 0000000000000000 x24: 0000000000000000 > [ 0.000000] x23: 00000000604000c5 x22: ffff800010038528 x21: 0000000002000000 > [ 0.000000] x20: 0000000000000005 x19: ffff800014267c50 x18: 0000000000000000 > [ 0.000000] x17: 000c0400bb44ffff x16: 00000032b5503510 x15: 0000000000000000 > [ 0.000000] x14: 00000000bfc12000 x13: 0000001000000000 x12: 00000000f1f1f1f1 > [ 0.000000] x11: dfff800000000000 x10: ffff70000284cf44 x9 : ffff8000128bf2e0 > [ 0.000000] x8 : ffff700002854905 x7 : 1ffff00002854904 x6 : ffff700002854904 > [ 0.000000] x5 : dfff800000000000 x4 : ffff8000142a4820 x3 : ffff80001429b040 > [ 0.000000] x2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000 > [ 0.000000] Call trace: > [ 0.000000] do_undefinstr+0x88/0xc0 > [ 0.000000] el1_undef+0x30/0x80 > [ 0.000000] el1_sync_handler+0xc0/0x140 > [ 0.000000] el1_sync+0x7c/0x100 > [ 0.000000] __cpuinfo_store_cpu+0xe8/0x440 > [ 0.000000] cpuinfo_store_boot_cpu+0x54/0xb4 > [ 0.000000] smp_prepare_boot_cpu+0x68/0x1a4 > [ 0.000000] start_kernel+0x128/0x870 > [ 0.000000] __primary_switched+0x94/0x98 > [ 0.000000] Code: aa1403e1 940dda91 b4000074 940dd94f (d4210000) > [ 0.000000] random: get_random_bytes called from > oops_exit+0x54/0xc0 with crng_init=0 > [ 0.000000] ---[ end trace 0000000000000000 ]--- > [ 0.000000] Kernel panic - not syncing: Oops - BUG: Fatal exception > [ 0.000000] ---[ end Kernel panic - not syncing: Oops - BUG: Fatal > exception ]--- I'm guessing that's due to the newly introduced read of GMID_EL1, which does indeed appear to be undefined on cpus without FEAT_MTE2. Catalin -- I'll drop your patches for now. Will