When i execute a kexec -l (load, not execute) on my MT7621 (mips32r2) target running either the 5.4 or 5.10 kernel, i am getting a reported kernel bug that causes the kernel to panic and reboot. The error is the same on either 5.4 or 5.10. My target runs from flash, and the kernel .elf i am trying to kexec is the exact same kernel booted from flash. # kexec -l --append="console=ttyS0,115200 rootfstype=squashfs" /tmp/vmlinux.elf Modified cmdline:console=ttyS0,115200 rootfstype=squashfs Unable to find /proc/device-tree/chosen/[linux,]stdout-path, printing from purgatory is disabled [ 761.663355] kexec command line truncated to 256 bytes [ 761.668452] usercopy: Kernel memory overwrite attempt detected to kernel text (offset 81844, size 256)! [ 761.677856] Kernel bug detected[#1]: [ 761.681423] CPU: 2 PID: 1755 Comm: kexec Not tainted 5.10.43 #0 [ 761.687317] $ 0 : 00000000 00000001 0000005b 00988000 [ 761.692545] $ 4 : 805e4408 8101e378 810238f8 822e1ca8 [ 761.697770] $ 8 : 00000001 822e1cc0 00000000 000019c8 [ 761.702991] $12 : 74206465 ffffff7f 00000001 656b206f [ 761.708214] $16 : 800153b4 00000100 00000000 800154b4 [ 761.713435] $20 : 0041e02c 80010000 00000000 00000000 [ 761.718656] $24 : 00000000 80314988 [ 761.723877] $28 : 822e0000 822e1e50 80650000 801507e8 [ 761.729100] Hi : 00000125 [ 761.731964] Lo : 122f2000 [ 761.734845] epc : 801507e8 usercopy_abort+0x94/0x98 [ 761.739886] ra : 801507e8 usercopy_abort+0x94/0x98 [ 761.744913] Status: 1100fc03 KERNEL EXL IE [ 761.749097] Cause : 50800024 (ExcCode 09) [ 761.753086] PrId : 0001992f (MIPS 1004Kc) [ 761.757161] Modules linked in: mt7915e mt76 mac80211 cfg80211 hwmon crc_ccitt compat sha256_generic libsha256 seqiv jitterentropy_rng drbg hmac cmac leds_gpio gpio_button_hotplug zram zsmalloc [ 761.774316] Process kexec (pid: 1755, threadinfo=c9ceaefe, task=a03f7798, tls=77ef2ec8) [ 761.782284] Stack : 00000100 80568ddc 805b702c 80568f04 8055f414 8055f414 8055f414 00013fb4 [ 761.790642] 00000100 8237ce00 00000100 80150940 822e1eb4 80010000 0041e02c 80069818 [ 761.798997] 00000100 8237ce00 38e38e39 00000100 80015388 8237ce00 80010000 80014cb8 [ 761.807354] 822e1eb0 00000100 00000006 8054f4ba 8237ce00 00000000 807c8ee0 8237ce20 [ 761.815709] 00000000 00000003 00000000 800a4498 00000000 8012a078 00000000 815ba758 [ 761.824061] ... [ 761.826505] Call Trace: [ 761.828944] [<801507e8>] usercopy_abort+0x94/0x98 [ 761.833632] [<80150940>] __check_object_size+0x154/0x1c4 [ 761.838945] [<80014cb8>] machine_kexec_prepare+0x124/0x2c4 [ 761.844430] [<800a4498>] sys_kexec_load+0x258/0x388 [ 761.849293] [<800135f8>] syscall_common+0x34/0x58 [ 761.853980] [ 761.855461] Code: afa30010 0c01a5fe 24848e80 <000c000d> 3c02805d 8c4293fc 1c40006c 00000000 27bdffd0 [ 761.865209] [ 761.866973] ---[ end trace 8145ef41fc12390f ]--- [ 761.871748] Kernel panic - not syncing: Fatal exception [ 761.876984] Rebooting in 3 seconds.. Is this a problem with the kexec utility from kexec-tools or is it a kernel bug, as it appears to be? Or have i done something wrong? Steven
