在 2019年06月09日 11:45, lijiang 写道: > 在 2019年06月06日 00:04, Lendacky, Thomas 写道: >> On 6/4/19 7:56 PM, Baoquan He wrote: >>> On 06/04/19 at 03:56pm, Lendacky, Thomas wrote: >>>> On 6/4/19 8:49 AM, Baoquan He wrote: >>>>> Hi Tom, >>>>> >>>>> Lianbo reported kdump kernel can't boot well with 'nokaslr' added, and >>>>> have to enable KASLR in kdump kernel to make it boot successfully. This >>>>> blocked his work on enabling sme for kexec/kdump. And on some machines >>>>> SME kernel can't boot in 1st kernel. >>>>> >>>>> I checked code of SME implementation, and found out the root cause. The >>>>> above failures are caused by SME code, sme_encrypt_kernel(). In >>>>> sme_encrypt_kernel(), you get a 2M of encryption work area as intermediate >>>>> buffer to encrypt kernel in-place. And the work area is just after _end of >>>>> kernel. >>>> >>>> I remember worrying about something like this back when I was testing the >>>> kexec support. I had come up with a patch to address it, but never got the >>>> time to test and submit it. I've included it here if you'd like to test >>>> it (I haven't done run this patch in quite some time). If it works, we can >>>> think about submitting it. >>> >>> Thanks for your quick response and making this patch, Tom. >>> >>> Tested on a speedway machine, it entered into kernel, but failed in >>> below stage. Tested two times, always happened. >> >> Is this the initial kernel boot or the kexec kernel boot? >> >> It looks like this is related to the initrd/initramfs decryption. Not >> sure what could be happening there. I just tried the patch on my Naples >> system and a 5.2.0-rc3 kernel and have been able to repeatedly kexec boot >> a number of times so far. >> > > I used the hacked kexec-tools(by Baoquan) to test it, the kexec-d kernel and > kdump kernel worked well. But Tom's patch only worked for the kexec-d kernel, > and the kdump kernel did not work(kdump kernel could not successfully boot). > What's the difference between them? > After applied Tom's patch, i changed the reserved memory(for crash kernel) to the above 256M(>256M), such as crashkernel=320M or 384M,512M..., the kdump kernel can work and successfully dump the vmcore. But the kdump kernel always happened the panic or could not boot successfully in the 256M(<= 256M) case, and on HP machine, i noticed that it printed OOM, the kdump kernel was too smaller memory. But i never see the OOM on speedway machine(probably related to the earlyprintk, it doesn't work and it loses many logs). After removing the option 'CONFIG_DEBUG_INFO' from .config, i tested again, the kdump kernel did not happen the panic in the 256M(crashkernel=256M), the kdump kernel can work and succeed to dump the vmcore on HP machine or speedway machine. It seems that the small memory caused the previous failure in kdump kernel. I would suggest to post this patch to upstream. What's your opinion? Tom, Baoquan and other people. Or do you have any comment? Thanks. Lianbo > Thanks > Lianbo > >> Thanks, >> Tom >> >>> >>> >>> [ 4.978521] Freeing unused decrypted memory: 2040K >>> [ 4.983800] Freeing unused kernel image memory: 2344K >>> [ 4.988943] Write protecting the kernel read-only data: 18432k >>> [ 4.995306] Freeing unused kernel image memory: 2012K >>> [ 5.000488] Freeing unused kernel image memory: 256K >>> [ 5.005540] Run /init as init process >>> [ 5.009443] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00007f00 >>> [ 5.017230] CPU: 0 PID: 1 Comm: init Not tainted 5.2.0-rc2+ #38 >>> [ 5.023251] Hardware name: AMD Corporation Speedway/Speedway, BIOS RSW1004B 10/18/2017 >>> [ 5.031299] Call Trace: >>> [ 5.033793] dump_stack+0x46/0x60 >>> [ 5.037169] panic+0xfb/0x2cb >>> [ 5.040191] do_exit.cold.21+0x59/0x81 >>> [ 5.044004] do_group_exit+0x3a/0xa0 >>> [ 5.047640] __x64_sys_exit_group+0x14/0x20 >>> [ 5.051899] do_syscall_64+0x55/0x1c0 >>> [ 5.055627] entry_SYSCALL_64_after_hwframe+0x44/0xa9 >>> [ 5.060764] RIP: 0033:0x7fa1b1fc9e2e >>> [ 5.064404] Code: Bad RIP value. >>> [ 5.067687] RSP: 002b:00007fffc5abb778 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 >>> [ 5.075296] RAX: ffffffffffffffda RBX: 00007fa1b1fd2528 RCX: 00007fa1b1fc9e2e >>> [ 5.082625] RDX: 000000000000007f RSI: 000000000000003c RDI: 000000000000007f >>> [ 5.089879] RBP: 00007fa1b21d8d00 R08: 00000000000000e7 R09: 00007fffc5abb688 >>> [ 5.097134] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 >>> [ 5.104386] R13: 0000000000000001 R14: 00007fa1b21d8d40 R15: 00007fa1b21d8d30 >>> [ 5.111645] Kernel Offset: disabled >>> [ 5.423002] Rebooting in 10 seconds.. >>> [ 15.429641] ACPI MEMORY or I/O RESET_REG. >>> _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec