Hi, * Aaro Koskinen <aaro.koskinen@xxxxxx> [190524 22:07]: > Hi, > > Noticed today that booting omap2plus_defconfig on N8x0 crashes > early. Disabling CONFIG_SMP makes it work. OK. It sure used to work when I last tested but that's been quite a while now. Any ideas which commit caused the ldrexd regression? Regards, Tony > Uncompressing Linux... done, booting the kernel. > [ 0.000000] Booting Linux on physical CPU 0x0 > [ 0.000000] Linux version 5.2.0-rc1-n8x0-los_925980+-00233-g0a72ef899014 (aaro@amd-fx-6350) (gcc version 8.3.0 (GCC)) #2 SMP Fri May 24 23:55:08 EEST 2019 > [ 0.000000] CPU: ARMv6-compatible processor [4107b362] revision 2 (ARMv6TEJ), cr=00c5387d > [ 0.000000] CPU: VIPT aliasing data cache, VIPT aliasing instruction cache > [ 0.000000] OF: fdt: Machine model: Nokia N810 > [ 0.000000] printk: bootconsole [earlycon0] enabled > [ 0.000000] Memory policy: Data cache writeback > [ 0.000000] CPU: All CPU(s) started in SVC mode. > [ 0.000000] OMAP2420 > [ 0.000000] percpu: Embedded 16 pages/cpu s33996 r8192 d23348 u65536 > [ 0.000000] Built 1 zonelists, mobility grouping on. Total pages: 32512 > [ 0.000000] Kernel command line: console=ttyO2,115200 earlyprintk > [ 0.000000] Dentry cache hash table entries: 16384 (order: 4, 65536 bytes) > [ 0.000000] Inode-cache hash table entries: 8192 (order: 3, 32768 bytes) > [ 0.000000] Memory: 119992K/131072K available (4717K kernel code, 153K rwdata, 1488K rodata, 2080K init, 1128K bss, 11080K reserved, 0K cma-reserved, 0K highmem) > [ 0.000000] SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1 > [ 0.000000] rcu: Hierarchical RCU implementation. > [ 0.000000] rcu: RCU restricting CPUs from NR_CPUS=4 to nr_cpu_ids=1. > [ 0.000000] rcu: RCU calculated value of scheduler-enlistment delay is 10 jiffies. > [ 0.000000] rcu: Adjusting geometry for rcu_fanout_leaf=16, nr_cpu_ids=1 > [ 0.000000] NR_IRQS: 16, nr_irqs: 16, preallocated irqs: 16 > [ 0.000000] IRQ: Found an INTC at 0x(ptrval) (revision 2.0) with 96 interrupts > [ 0.000000] random: get_random_bytes called from start_kernel+0x250/0x424 with crng_init=0 > [ 0.000000] Clocking rate (Crystal/DPLL/MPU): 19.2/658/329 MHz > [ 0.000000] OMAP clockevent source: timer1 at 32768 Hz > [ 0.000000] clocksource: 32k_counter: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_ns: 58327039986419 ns > [ 0.000030] sched_clock: 32 bits at 32kHz, resolution 30517ns, wraps every 65535999984741ns > [ 0.008605] OMAP clocksource: 32k_counter at 32768 Hz > [ 0.014007] hw-breakpoint: CPUID feature registers not supported. Assuming v6 debug is present. > [ 0.023468] Console: colour dummy device 80x30 > [ 0.028137] Calibrating delay loop... 326.86 BogoMIPS (lpj=1634304) > [ 0.088439] pid_max: default: 32768 minimum: 301 > [ 0.093658] Mount-cache hash table entries: 1024 (order: 0, 4096 bytes) > [ 0.100494] Mountpoint-cache hash table entries: 1024 (order: 0, 4096 bytes) > [ 0.108276] Internal error: Oops - undefined instruction: 0 [#1] SMP ARM > [ 0.115203] Modules linked in: > [ 0.118377] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.2.0-rc1-n8x0-los_925980+-00233-g0a72ef899014 #2 > [ 0.128021] Hardware name: Generic OMAP2420 (Flattened Device Tree) > [ 0.134521] PC is at lockref_get+0x2c/0xd0 > [ 0.138732] LR is at 0x0 > [ 0.141357] pc : [<c023701c>] lr : [<00000000>] psr: 60000053 > [ 0.147796] sp : c0843ea0 ip : 00000001 fp : c0666a38 > [ 0.153198] r10: 00000001 r9 : c0868700 r8 : c0669624 > [ 0.158569] r7 : 00000000 r6 : c00de694 r5 : 00000002 r4 : 00010001 > [ 0.165283] r3 : 00000001 r2 : 00010001 r1 : 00010001 r0 : c7402050 > [ 0.172027] Flags: nZCv IRQs on FIQs off Mode SVC_32 ISA ARM Segment none > [ 0.179473] Control: 00c5387d Table: 80004000 DAC: 00000051 > [ 0.185394] Process swapper/0 (pid: 0, stack limit = 0x(ptrval)) > [ 0.191558] Stack: (0xc0843ea0 to 0xc0844000) > [ 0.196075] 3ea0: c7402000 00000000 c00de694 00000000 c0669624 c0122f4c 00000000 c0843ee8 > [ 0.204528] 3ec0: c04b9c20 c7825600 c00de890 00000000 00000004 c0154c00 c7825600 00000000 > [ 0.212951] 3ee0: 00000000 c0121b88 c05a91bc 00000002 c7825600 00000000 00000000 c0669624 > [ 0.221405] 3f00: c0868700 c0141e2c c7825600 c0141eb4 00000000 c0970728 c0842000 c0141f00 > [ 0.229858] 3f20: 00000000 c064b73c c00de8a0 c014031c c0847388 00000000 00000000 c063b070 > [ 0.238281] 3f40: c0847388 c064f8f8 00000004 c0847388 c0847390 00000000 00000000 00000001 > [ 0.246734] 3f60: c0666a38 c024af58 00000000 9ac7f44c 00000000 c0847360 00000021 c0847080 > [ 0.255187] 3f80: c0868700 c064f590 0000002c 00000024 00000000 00000000 c086874c c086874c > [ 0.263610] 3fa0: ffffffff c063ac94 ffffffff ffffffff 00000000 c063a584 00000000 c7ffcd80 > [ 0.272064] 3fc0: 00000000 c0666a38 9ac2f64c 00000000 00000000 c063a330 00000051 00c0387d > [ 0.280487] 3fe0: ffffffff 82009000 4107b362 00c5387d 00000000 00000000 00000000 00000000 > [ 0.288970] [<c023701c>] (lockref_get) from [<c0122f4c>] (mount_nodev+0x6c/0x94) > [ 0.296600] [<c0122f4c>] (mount_nodev) from [<c0154c00>] (legacy_get_tree+0x28/0x54) > [ 0.304595] [<c0154c00>] (legacy_get_tree) from [<c0121b88>] (vfs_get_tree+0x24/0xf8) > [ 0.312713] [<c0121b88>] (vfs_get_tree) from [<c0141e2c>] (fc_mount+0xc/0x30) > [ 0.320068] [<c0141e2c>] (fc_mount) from [<c0141eb4>] (vfs_kern_mount.part.3+0x64/0x80) > [ 0.328338] [<c0141eb4>] (vfs_kern_mount.part.3) from [<c0141f00>] (kern_mount+0x1c/0x34) > [ 0.336791] [<c0141f00>] (kern_mount) from [<c064b73c>] (shmem_init+0x64/0xb4) > [ 0.344268] [<c064b73c>] (shmem_init) from [<c063b070>] (init_rootfs+0x44/0x88) > [ 0.351837] [<c063b070>] (init_rootfs) from [<c064f8f8>] (mnt_init+0x104/0x268) > [ 0.359374] [<c064f8f8>] (mnt_init) from [<c064f590>] (vfs_caches_init+0x6c/0x88) > [ 0.367095] [<c064f590>] (vfs_caches_init) from [<c063ac94>] (start_kernel+0x368/0x424) > [ 0.375366] [<c063ac94>] (start_kernel) from [<00000000>] (0x0) > [ 0.381469] Code: e3a0e000 e1a04001 e28c5001 f5d0f000 (e1b06f9f) > [ 0.387786] ---[ end trace 57f1c61709eb3312 ]--- > [ 0.392547] Kernel panic - not syncing: Attempted to kill the idle task! > [ 0.399475] ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]--- > > It seems lockref_get+0x2c is __cmpxchg64: > > c0236ff0 <lockref_get>: > [...] > __asm__ __volatile__( > c023701c: e1b06f9f ldrexd r6, [r0] > c0237020: e1360002 teq r6, r2 > c0237024: 01370003 teqeq r7, r3 > c0237028: 1a000002 bne c0237038 <lockref_get+0x48> > c023702c: e1a01f94 strexd r1, r4, [r0] > c0237030: e3310000 teq r1, #0 > c0237034: 1afffff8 bne c023701c <lockref_get+0x2c> > > and ldrexd is not supported on ARMv6. > > A.
