From: Chao Fan <email@example.com> To: Dave Young <firstname.lastname@example.org> Cc: Junichi Nomura <email@example.com>, Borislav Petkov <firstname.lastname@example.org>, "email@example.com" <firstname.lastname@example.org>, "email@example.com" <firstname.lastname@example.org>, "email@example.com" <firstname.lastname@example.org>, "email@example.com" <firstname.lastname@example.org>, "email@example.com" <firstname.lastname@example.org> Subject: Re: [PATCH v2] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Date: Wed, 3 Apr 2019 16:23:06 +0800 [thread overview] Message-ID: <20190403082305.GG1555@localhost.localdomain> (raw) In-Reply-To: <20190403080846.GB2579@dhcp-128-65.nay.redhat.com> On Wed, Apr 03, 2019 at 04:09:16PM +0800, Dave Young wrote: >On 04/03/19 at 03:21pm, Chao Fan wrote: >> On Wed, Apr 03, 2019 at 01:53:40PM +0800, Dave Young wrote: >> >On 04/03/19 at 01:35pm, Chao Fan wrote: >> >> On Tue, Apr 02, 2019 at 08:03:19PM +0800, Dave Young wrote: >> >> >On 04/01/19 at 12:08am, Junichi Nomura wrote: >> >> >> Commit 3a63f70bf4c3a ("x86/boot: Early parse RSDP and save it in >> >> >> boot_params") broke kexec boot on EFI systems. efi_get_rsdp_addr() >> >> >> in the early parsing code tries to search RSDP from EFI table but >> >> >> that will crash because the table address is virtual when the kernel >> >> >> was booted by kexec. >> >> >> >> >> >> In the case of kexec, physical address of EFI tables is provided >> >> >> via efi_setup_data in boot_params, which is set up by kexec(1). >> >> >> >> >> >> Factor out the table parsing code and use different pointers depending >> >> >> on whether the kernel is booted by kexec or not. >> >> >> >> >> >> Fixes: 3a63f70bf4c3a ("x86/boot: Early parse RSDP and save it in boot_params") >> >> >> Signed-off-by: Jun'ichi Nomura <email@example.com> >> >> >> Acked-by: Baoquan He <firstname.lastname@example.org> >> >> >> Cc: Chao Fan <email@example.com> >> >> >> Cc: Borislav Petkov <firstname.lastname@example.org> >> >> >> Cc: Dave Young <email@example.com> >> >> [...] >> >> > >> >> >I failed to kexec reboot on my laptop, kernel panics too quick, I'm not sure this is >> >> >caused by your patch though. >> >> > >> >> >Actually there are something probably i915 changes break kexec, the >> >> >above test is with "nomodeset" which should work. >> >> > >> >> >Let me do more testing and update here tomorrow. >> >> > >> >> >> >> Hi Dave, >> >> >> >> Last day I was testing the normal kexec, today I have tested the kdump >> >> issue. Since the kdump has set "nokaslr" to cmdline, so I drop from >> >> KDUMP_COMMANDLINE_APPEND >> >> And it booted OK, so the PATCH works in both normal kexec and kdump. >> >> >> > >> >Actually I got some different kexec test results. >> > >> >Yesterday, with my installed kernel (based on git head several weeks >> >ago), kexec kernel panics. >> > >> >Then I tried latest mainline with git pull, everything works, (with or >> >without the patch, and can not reproduce the bug this patch is fixing) >> > >> >Today, test again, kexec reboot hangs (with or without your patch), but >> >kdump works always (with or without the patch) >> >> That's so strange, I'm puzzled by your test. >> Withour ant changes, just test again, the result of yesterday and today >> are different? >> >> > >> >It is weird to me. Probably I need find out why I can not reproduce the >> >bug this patch is addressing first. >> >> Hmm, is your laptop booted from EFI or legacy BIOS? > >EFI booted. > >> > >> >earlyprintk seems not working for me anymore, it is not easy to debug on >> >laptop now. >> >> Another computer can help print the console message. >> I remeber you are good at debug on two computers. > >I used to use earlyprintk, but seems earlyprintk can not work so early. >So I only can try to comment out code manually. Ah, I got it. If you want to use earlyprintk to print message of get_rsdp_addr(), you should change some code. Because get_rsdp_addr() is called before earlyprintk initialed. I am still testing, but in my debug stage, I change like this: diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index c0d6c560df69..dbbe8d9a5792 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -352,7 +352,6 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, boot_params->hdr.loadflags &= ~KASLR_FLAG; /* Save RSDP address for later use. */ - boot_params->acpi_rsdp_addr = get_rsdp_addr(); sanitize_boot_params(boot_params); @@ -368,6 +367,7 @@ asmlinkage __visible void *extract_kernel(void *rmode, memptr heap, cols = boot_params->screen_info.orig_video_cols; console_init(); + boot_params->acpi_rsdp_addr = get_rsdp_addr(); debug_putstr("early console in extract_kernel\n"); free_mem_ptr = heap; /* Heap */ Call this function after console_init(). That will make earlyprintk works. > >It seems to be still some bug in early acpi code because if I >return 0 in get rsdp function it just works. > >This guess make sense to me for now: >1. nokaslr does not work because it may only avoid randomization, but it >does not avoid running the early acpi parsing code. > >2. kexec does not work without the patch we talked about, because I just >reproduced Junichi reported bug, sometimes hang, or reset, it is >understandable. > >3. kexec does not work with the patch, so there is still bugs in the >code. > >So several things to do is: > >Fix 1. (separate issue), Baoquan or either of you may want to fix it :) For 1, I think it's not needed to fix. Since not only KASLR needs RSDP. So nokaslr should not stop the acpi parsing code. > >Fix 3. need more debugging, have you or Junichi run tests on more real >hardware, maybe it is easier to reproduce on real hardware, I'm glad to >help to try test patch or provide any help. I am still testing in real hardware. Thanks, Chao Fan > >Thanks >Dave > >
next prev parent reply other threads:[~2019-04-03 8:23 UTC|newest] Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-03-22 11:03 [PATCH] x86/boot: Use EFI setup data if provided Junichi Nomura 2019-03-22 15:23 ` Borislav Petkov 2019-03-25 0:27 ` Junichi Nomura 2019-03-25 6:01 ` Dave Young 2019-03-25 6:19 ` Dave Young 2019-03-25 6:45 ` Kairui Song 2019-03-25 6:47 ` Junichi Nomura 2019-03-25 6:59 ` Dave Young 2019-03-25 8:27 ` [PATCH v2] " Junichi Nomura 2019-03-25 8:54 ` Boris Petkov 2019-03-25 9:25 ` [PATCH v2] x86/boot: Don't try to search RSDP from EFI when kexec-booted Junichi Nomura 2019-03-25 10:15 ` [PATCH v2] x86/boot: Use EFI setup data if provided Dave Young 2019-03-25 10:36 ` Junichi Nomura 2019-03-25 11:16 ` Dave Young 2019-03-25 12:01 ` Borislav Petkov 2019-03-25 12:23 ` Dave Young 2019-03-25 12:32 ` Borislav Petkov 2019-03-25 23:10 ` Junichi Nomura 2019-03-26 12:46 ` Dave Young 2019-03-26 13:57 ` Borislav Petkov 2019-03-27 1:48 ` bhe 2019-03-27 12:14 ` Borislav Petkov 2019-03-28 4:17 ` Junichi Nomura 2019-03-28 6:26 ` Chao Fan 2019-03-28 6:43 ` bhe 2019-03-28 7:43 ` Junichi Nomura 2019-03-28 15:52 ` Borislav Petkov 2019-03-29 3:05 ` Junichi Nomura 2019-03-29 8:39 ` Borislav Petkov 2019-03-29 9:05 ` Chao Fan 2019-03-29 9:16 ` Borislav Petkov 2019-03-29 9:37 ` Junichi Nomura 2019-03-29 9:44 ` Chao Fan 2019-03-29 9:56 ` Junichi Nomura 2019-03-29 7:20 ` [PATCH] x86/boot: Use efi_setup_data for searching RSDP on kexec-ed kernel Junichi Nomura 2019-03-29 7:49 ` bhe 2019-03-29 8:29 ` Chao Fan 2019-03-29 8:39 ` Junichi Nomura 2019-03-29 9:18 ` Chao Fan 2019-03-29 9:16 ` bhe 2019-03-29 9:20 ` Chao Fan 2019-04-01 0:08 ` [PATCH v2] " Junichi Nomura 2019-04-02 9:41 ` Chao Fan 2019-04-02 9:53 ` Junichi Nomura 2019-04-02 11:06 ` Chao Fan 2019-04-02 10:22 ` Junichi Nomura 2019-04-02 12:03 ` Dave Young 2019-04-03 5:35 ` Chao Fan 2019-04-03 5:53 ` Dave Young 2019-04-03 6:39 ` Dave Young 2019-04-03 7:30 ` Chao Fan 2019-04-03 7:50 ` bhe 2019-04-03 8:23 ` Dave Young 2019-04-03 8:26 ` Dave Young 2019-04-03 16:14 ` Borislav Petkov 2019-04-04 1:02 ` Chao Fan 2019-04-03 9:28 ` Chao Fan 2019-04-03 7:21 ` Chao Fan 2019-04-03 8:09 ` Dave Young 2019-04-03 8:23 ` Chao Fan [this message] 2019-04-03 9:02 ` Chao Fan 2019-04-03 9:39 ` Chao Fan 2019-04-04 1:23 ` Junichi Nomura 2019-04-04 2:52 ` Dave Young 2019-04-04 3:00 ` bhe 2019-04-04 3:10 ` bhe 2019-04-04 3:22 ` Dave Young 2019-04-04 6:41 ` Dave Young 2019-04-04 7:20 ` Chao Fan 2019-04-04 7:41 ` Dave Young 2019-04-04 7:48 ` Chao Fan 2019-04-04 12:22 ` Borislav Petkov 2019-04-04 14:08 ` Dave Young 2019-04-03 8:18 ` Dave Young 2019-04-02 10:25 ` [PATCH v3] " Junichi Nomura 2019-04-04 7:32 ` Dave Young 2019-04-04 12:24 ` Borislav Petkov 2019-04-04 14:12 ` Dave Young 2019-04-04 14:41 ` Borislav Petkov 2019-04-05 1:36 ` Dave Young 2019-04-05 4:19 ` Junichi Nomura 2019-03-28 23:11 ` [PATCH v2] x86/boot: Use EFI setup data if provided bhe 2019-03-29 3:34 ` Junichi Nomura 2019-03-29 3:52 ` bhe 2019-03-29 5:16 ` Junichi Nomura 2019-03-25 7:27 ` [PATCH] " Baoquan He 2019-03-25 7:53 ` Borislav Petkov 2019-03-25 8:21 ` Baoquan He 2019-03-25 8:43 ` Thomas Gleixner 2019-03-25 9:03 ` Baoquan He
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