On 07/24/23 at 10:18am, Jiri Olsa wrote: > On Mon, Jul 24, 2023 at 04:08:41PM +0800, Baoquan He wrote: > > On 07/24/23 at 08:23am, David Hildenbrand wrote: > > > Hi, > > > > > > > > > > > I met this too when I executed below command to trigger a kcore reading. > > > > I wanted to do a simple testing during system running and got this. > > > > > > > > makedumpfile --mem-usage /proc/kcore > > > > > > > > Later I tried your above objdump testing, it corrupted system too. > > > > > > > > > > What do you mean with "corrupted system too" -- did it not only fail to > > > dump the system, but also actually harmed the system? > > > > From my testing, reading kcore will cause system panic, then reboot. Not > > sure if Jiri saw the same phenomenon. > > it did not crash for me, just the read error > could you get console output from that? I got a new arm64 machine, then executing "makedumpfile --mem-usage /proc/kcore" won't trigger panic, your objdump command can trigger panic. The call trace is pasted at below. It's the same as the panic and call trace I met on my last arm64 machine. [13270.314323] Mem abort info: [13270.317162] ESR = 0x0000000096000007 [13270.320901] EC = 0x25: DABT (current EL), IL = 32 bits [13270.326217] SET = 0, FnV = 0 [13270.329261] EA = 0, S1PTW = 0 [13270.332390] FSC = 0x07: level 3 translation fault [13270.337270] Data abort info: [13270.340139] ISV = 0, ISS = 0x00000007, ISS2 = 0x00000000 [13270.345626] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [13270.350666] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [13270.355981] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000400651d64000 [13270.362672] [ffffdc9cf3ea0000] pgd=1000401ffffff003, p4d=1000401ffffff003, pud=1000401fffffe003, pmd=1000401fffffd003, pte=0000000000000000 [13270.375367] Internal error: Oops: 0000000096000007 [#4] SMP [13270.380934] Modules linked in: mlx5_ib ib_uverbs ib_core rfkill vfat fat joydev cdc_ether usbnet mii mlx5_core acpi_ipmi mlxfw ipmi_ssif psample tls ipmi_devintf pci_hyperv_intf arm_spe_pmu ipmi_msghandler arm_cmn arm_dmc620_pmu arm_dsu_pmu cppc_cpufreq acpi_tad fuse zram xfs crct10dif_ce polyval_ce polyval_generic ghash_ce uas sbsa_gwdt nvme nvme_core ast usb_storage nvme_common i2c_algo_bit xgene_hwmon [13270.416751] CPU: 15 PID: 8803 Comm: objdump Tainted: G D 6.5.0-rc3 #1 [13270.424570] Hardware name: WIWYNN Mt.Jade Server System B81.030Z1.0007/Mt.Jade Motherboard, BIOS 2.10.20220531 (SCP: 2.10.20220531) 2022/05/31 [13270.437337] pstate: 20400009 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [13270.444289] pc : __arch_copy_to_user+0x180/0x240 [13270.448910] lr : _copy_to_iter+0x11c/0x5d0 [13270.453002] sp : ffff8000b15a37c0 [13270.456306] x29: ffff8000b15a37c0 x28: ffffdc9cf3ea0000 x27: ffffdc9cf6938158 [13270.463431] x26: ffff8000b15a3ba8 x25: 0000000000000690 x24: ffff8000b15a3b80 [13270.470556] x23: 00000000000038ac x22: ffffdc9cf3ea0000 x21: ffff8000b15a3b80 [13270.477682] x20: ffffdc9cf64fdf00 x19: 0000000000000400 x18: 0000000000000000 [13270.484806] x17: 0000000000000000 x16: 0000000000000000 x15: ffffdc9cf3ea0000 [13270.491931] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 [13270.499056] x11: 0001000000000000 x10: ffffdc9cf64fdf00 x9 : 0000000000000690 [13270.506182] x8 : 000000007c000000 x7 : 0000fd007e000000 x6 : 000000000eee0b60 [13270.513306] x5 : 000000000eee0f60 x4 : 0000000000000000 x3 : 0000000000000400 [13270.520431] x2 : 0000000000000380 x1 : ffffdc9cf3ea0000 x0 : 000000000eee0b60 [13270.527556] Call trace: [13270.529992] __arch_copy_to_user+0x180/0x240 [13270.534250] read_kcore_iter+0x718/0x878 [13270.538167] proc_reg_read_iter+0x8c/0xe8 [13270.542168] vfs_read+0x214/0x2c0 [13270.545478] ksys_read+0x78/0x118 [13270.548782] __arm64_sys_read+0x24/0x38 [13270.552608] invoke_syscall+0x78/0x108 [13270.556351] el0_svc_common.constprop.0+0x4c/0xf8 [13270.561044] do_el0_svc+0x34/0x50 [13270.564347] el0_svc+0x34/0x108 [13270.567482] el0t_64_sync_handler+0x100/0x130 [13270.571829] el0t_64_sync+0x194/0x198 [13270.575483] Code: d503201f d503201f d503201f d503201f (a8c12027) [13270.581567] ---[ end trace 0000000000000000 ]---
