arm64 crashkernel fails to boot on acpi-only machines due to ACPI regions being no longer mapped as NOMAP
Bhupesh SHARMA
bhupesh.linux at gmail.com
Mon Dec 18 00:59:05 PST 2017
On Mon, Dec 18, 2017 at 11:24 AM, AKASHI Takahiro
<takahiro.akashi at linaro.org> wrote:
> On Mon, Dec 18, 2017 at 01:16:57PM +0800, Dave Young wrote:
>> kexec at fedoraproject... is for Fedora kexec scripts discussion, changed it
>> to kexec at lists.infradead.org
>>
>> Also add linux-acpi list
>
> Thank you.
>
>> On 12/18/17 at 02:31am, Bhupesh Sharma wrote:
>> > On Fri, Dec 15, 2017 at 3:05 PM, Ard Biesheuvel
>> > <ard.biesheuvel at linaro.org> wrote:
>> > > On 15 December 2017 at 09:59, AKASHI Takahiro
>> > > <takahiro.akashi at linaro.org> wrote:
>> > >> On Wed, Dec 13, 2017 at 12:17:22PM +0000, Ard Biesheuvel wrote:
>> > >>> On 13 December 2017 at 12:16, AKASHI Takahiro
>> > >>> <takahiro.akashi at linaro.org> wrote:
>> > >>> > On Wed, Dec 13, 2017 at 10:49:27AM +0000, Ard Biesheuvel wrote:
>> > >>> >> On 13 December 2017 at 10:26, AKASHI Takahiro
>> > >>> >> <takahiro.akashi at linaro.org> wrote:
>> > >>> >> > Bhupesh, Ard,
>> > >>> >> >
>> > >>> >> > On Wed, Dec 13, 2017 at 03:21:59AM +0530, Bhupesh Sharma wrote:
>> > >>> >> >> Hi Ard, Akashi
>> > >>> >> >>
>> > >>> >> > (snip)
>> > >>> >> >
>> > >>> >> >> Looking deeper into the issue, since the arm64 kexec-tools uses the
>> > >>> >> >> 'linux,usable-memory-range' dt property to allow crash dump kernel to
>> > >>> >> >> identify its own usable memory and exclude, at its boot time, any
>> > >>> >> >> other memory areas that are part of the panicked kernel's memory.
>> > >>> >> >> (see https://www.kernel.org/doc/Documentation/devicetree/bindings/chosen.txt
>> > >>> >> >> , for details)
>> > >>> >> >
>> > >>> >> > Right.
>> > >>> >> >
>> > >>> >> >> 1). Now when 'kexec -p' is executed, this node is patched up only
>> > >>> >> >> with the crashkernel memory range:
>> > >>> >> >>
>> > >>> >> >> /* add linux,usable-memory-range */
>> > >>> >> >> nodeoffset = fdt_path_offset(new_buf, "/chosen");
>> > >>> >> >> result = fdt_setprop_range(new_buf, nodeoffset,
>> > >>> >> >> PROP_USABLE_MEM_RANGE, &crash_reserved_mem,
>> > >>> >> >> address_cells, size_cells);
>> > >>> >> >>
>> > >>> >> >> (see https://git.kernel.org/pub/scm/utils/kernel/kexec/kexec-tools.git/tree/kexec/arch/arm64/kexec-arm64.c#n465
>> > >>> >> >> , for details)
>> > >>> >> >>
>> > >>> >> >> 2). This excludes the ACPI reclaim regions irrespective of whether
>> > >>> >> >> they are marked as System RAM or as RESERVED. As,
>> > >>> >> >> 'linux,usable-memory-range' dt node is patched up only with
>> > >>> >> >> 'crash_reserved_mem' and not 'system_memory_ranges'
>> > >>> >> >>
>> > >>> >> >> 3). As a result when the crashkernel boots up it doesn't find this
>> > >>> >> >> ACPI memory and crashes while trying to access the same:
>> > >>> >> >>
>> > >>> >> >> # kexec -p /boot/vmlinuz-`uname -r` --initrd=/boot/initramfs-`uname
>> > >>> >> >> -r`.img --reuse-cmdline -d
>> > >>> >> >>
>> > >>> >> >> [snip..]
>> > >>> >> >>
>> > >>> >> >> Reserved memory range
>> > >>> >> >> 000000000e800000-000000002e7fffff (0)
>> > >>> >> >>
>> > >>> >> >> Coredump memory ranges
>> > >>> >> >> 0000000000000000-000000000e7fffff (0)
>> > >>> >> >> 000000002e800000-000000003961ffff (0)
>> > >>> >> >> 0000000039d40000-000000003ed2ffff (0)
>> > >>> >> >> 000000003ed60000-000000003fbfffff (0)
>> > >>> >> >> 0000001040000000-0000001ffbffffff (0)
>> > >>> >> >> 0000002000000000-0000002ffbffffff (0)
>> > >>> >> >> 0000009000000000-0000009ffbffffff (0)
>> > >>> >> >> 000000a000000000-000000affbffffff (0)
>> > >>> >> >>
>> > >>> >> >> 4). So if we revert Ard's patch or just comment the fixing up of the
>> > >>> >> >> memory cap'ing passed to the crash kernel inside
>> > >>> >> >> 'arch/arm64/mm/init.c' (see below):
>> > >>> >> >>
>> > >>> >> >> static void __init fdt_enforce_memory_region(void)
>> > >>> >> >> {
>> > >>> >> >> struct memblock_region reg = {
>> > >>> >> >> .size = 0,
>> > >>> >> >> };
>> > >>> >> >>
>> > >>> >> >> of_scan_flat_dt(early_init_dt_scan_usablemem, ®);
>> > >>> >> >>
>> > >>> >> >> if (reg.size)
>> > >>> >> >> //memblock_cap_memory_range(reg.base, reg.size); /*
>> > >>> >> >> comment this out */
>> > >>> >> >> }
>> > >>> >> >
>> > >>> >> > Please just don't do that. It can cause a fatal damage on
>> > >>> >> > memory contents of the *crashed* kernel.
>> > >>> >> >
>> > >>> >> >> 5). Both the above temporary solutions fix the problem.
>> > >>> >> >>
>> > >>> >> >> 6). However exposing all System RAM regions to the crashkernel is not
>> > >>> >> >> advisable and may cause the crashkernel or some crashkernel drivers to
>> > >>> >> >> fail.
>> > >>> >> >>
>> > >>> >> >> 6a). I am trying an approach now, where the ACPI reclaim regions are
>> > >>> >> >> added to '/proc/iomem' separately as ACPI reclaim regions by the
>> > >>> >> >> kernel code and on the other hand the user-space 'kexec-tools' will
>> > >>> >> >> pick up the ACPI reclaim regions from '/proc/iomem' and add it to the
>> > >>> >> >> dt node 'linux,usable-memory-range'
>> > >>> >> >
>> > >>> >> > I still don't understand why we need to carry over the information
>> > >>> >> > about "ACPI Reclaim memory" to crash dump kernel. In my understandings,
>> > >>> >> > such regions are free to be reused by the kernel after some point of
>> > >>> >> > initialization. Why does crash dump kernel need to know about them?
>> > >>> >> >
>> > >>> >>
>> > >>> >> Not really. According to the UEFI spec, they can be reclaimed after
>> > >>> >> the OS has initialized, i.e., when it has consumed the ACPI tables and
>> > >>> >> no longer needs them. Of course, in order to be able to boot a kexec
>> > >>> >> kernel, those regions needs to be preserved, which is why they are
>> > >>> >> memblock_reserve()'d now.
>> > >>> >
>> > >>> > For my better understandings, who is actually accessing such regions
>> > >>> > during boot time, uefi itself or efistub?
>> > >>> >
>> > >>>
>> > >>> No, only the kernel. This is where the ACPI tables are stored. For
>> > >>> instance, on QEMU we have
>> > >>>
>> > >>> ACPI: RSDP 0x0000000078980000 000024 (v02 BOCHS )
>> > >>> ACPI: XSDT 0x0000000078970000 000054 (v01 BOCHS BXPCFACP 00000001
>> > >>> 01000013)
>> > >>> ACPI: FACP 0x0000000078930000 00010C (v05 BOCHS BXPCFACP 00000001
>> > >>> BXPC 00000001)
>> > >>> ACPI: DSDT 0x0000000078940000 0011DA (v02 BOCHS BXPCDSDT 00000001
>> > >>> BXPC 00000001)
>> > >>> ACPI: APIC 0x0000000078920000 000140 (v03 BOCHS BXPCAPIC 00000001
>> > >>> BXPC 00000001)
>> > >>> ACPI: GTDT 0x0000000078910000 000060 (v02 BOCHS BXPCGTDT 00000001
>> > >>> BXPC 00000001)
>> > >>> ACPI: MCFG 0x0000000078900000 00003C (v01 BOCHS BXPCMCFG 00000001
>> > >>> BXPC 00000001)
>> > >>> ACPI: SPCR 0x00000000788F0000 000050 (v02 BOCHS BXPCSPCR 00000001
>> > >>> BXPC 00000001)
>> > >>> ACPI: IORT 0x00000000788E0000 00007C (v00 BOCHS BXPCIORT 00000001
>> > >>> BXPC 00000001)
>> > >>>
>> > >>> covered by
>> > >>>
>> > >>> efi: 0x0000788e0000-0x00007894ffff [ACPI Reclaim Memory ...]
>> > >>> ...
>> > >>> efi: 0x000078970000-0x00007898ffff [ACPI Reclaim Memory ...]
>> > >>
>> > >> OK. I mistakenly understood those regions could be freed after exiting
>> > >> UEFI boot services.
>> > >>
>> > >>>
>> > >>> >> So it seems that kexec does not honour the memblock_reserve() table
>> > >>> >> when booting the next kernel.
>> > >>> >
>> > >>> > not really.
>> > >>> >
>> > >>> >> > (In other words, can or should we skip some part of ACPI-related init code
>> > >>> >> > on crash dump kernel?)
>> > >>> >> >
>> > >>> >>
>> > >>> >> I don't think so. And the change to the handling of ACPI reclaim
>> > >>> >> regions only revealed the bug, not created it (given that other
>> > >>> >> memblock_reserve regions may be affected as well)
>> > >>> >
>> > >>> > As whether we should honor such reserved regions over kexec'ing
>> > >>> > depends on each one's specific nature, we will have to take care one-by-one.
>> > >>> > As a matter of fact, no information about "reserved" memblocks is
>> > >>> > exposed to user space (via proc/iomem).
>> > >>> >
>> > >>>
>> > >>> That is why I suggested (somewhere in this thread?) to not expose them
>> > >>> as 'System RAM'. Do you think that could solve this?
>> > >>
>> > >> Memblock-reserv'ing them is necessary to prevent their corruption and
>> > >> marking them under another name in /proc/iomem would also be good in order
>> > >> not to allocate them as part of crash kernel's memory.
>> > >>
>> > >
>> > > I agree. However, this may not be entirely trivial, since iterating
>> > > over the memblock_reserved table and creating iomem entries may result
>> > > in collisions.
>> >
>> > I found a method (using the patch I shared earlier in this thread) to mark these
>> > entries as 'ACPI reclaim memory' ranges rather than System RAM or
>> > reserved regions.
>> >
>> > >> But I'm not still convinced that we should export them in useable-
>> > >> memory-range to crash dump kernel. They will be accessed through
>> > >> acpi_os_map_memory() and so won't be required to be part of system ram
>> > >> (or memblocks), I guess.
>> > >
>> > > Agreed. They will be covered by the linear mapping in the boot kernel,
>> > > and be mapped explicitly via ioremap_cache() in the kexec kernel,
>> > > which is exactly what we want in this case.
>> >
>> > Now this is what is confusing me. I don't see the above happening.
>> >
>> > I see that the primary kernel boots up and adds the ACPI regions via:
>> > acpi_os_ioremap
>> > -> ioremap_cache
>> >
>> > But during the crashkernel boot, ''acpi_os_ioremap' calls
>> > 'ioremap' for the ACPI Reclaim Memory regions and not the _cache
>> > variant.
>
> It is natural if that region is out of memblocks.
Thanks for the confirmation. This was my understanding as well.
>> > And it fails while accessing the ACPI tables:
>> >
>> > [ 0.039205] ACPI: Core revision 20170728
>> > pud=000000002e7d0003, *pmd=000000002e7c0003, *pte=00e8000039710707
>> > [ 0.095098] Internal error: Oops: 96000021 [#1] SMP
>
> this (ESR = 0x96000021) means that Data Abort and Alignment fault happened.
> As ioremap() makes the mapping as "Device memory", unaligned memory
> access won't be allowed.
>
>> > [ 0.100022] Modules linked in:
>> > [ 0.103102] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.14.0-rc6 #1
>> > [ 0.109432] task: ffff000008d05180 task.stack: ffff000008cc0000
>> > [ 0.115414] PC is at acpi_ns_lookup+0x25c/0x3c0
>> > [ 0.119987] LR is at acpi_ds_load1_begin_op+0xa4/0x294
>> > [ 0.125175] pc : [<ffff0000084a6764>] lr : [<ffff00000849b4f8>]
>> > pstate: 60000045
>> > [ 0.132647] sp : ffff000008ccfb40
>> > [ 0.135989] x29: ffff000008ccfb40 x28: ffff000008a9f2a4
>> > [ 0.141354] x27: ffff0000088be820 x26: 0000000000000000
>> > [ 0.146718] x25: 000000000000001b x24: 0000000000000001
>> > [ 0.152083] x23: 0000000000000001 x22: ffff000009710027
>> > [ 0.157447] x21: ffff000008ccfc50 x20: 0000000000000001
>> > [ 0.162812] x19: 000000000000001b x18: 0000000000000005
>> > [ 0.168176] x17: 0000000000000000 x16: 0000000000000000
>> > [ 0.173541] x15: 0000000000000000 x14: 000000000000038e
>> > [ 0.178905] x13: ffffffff00000000 x12: ffffffffffffffff
>> > [ 0.184270] x11: 0000000000000006 x10: 00000000ffffff76
>> > [ 0.189634] x9 : 000000000000005f x8 : ffff8000126d0140
>> > [ 0.194998] x7 : 0000000000000000 x6 : ffff000008ccfc50
>> > [ 0.200362] x5 : ffff80000fe62c00 x4 : 0000000000000001
>> > [ 0.205727] x3 : ffff000008ccfbe0 x2 : ffff0000095e3980
>> > [ 0.211091] x1 : ffff000009710027 x0 : 0000000000000000
>> > [ 0.216456] Process swapper/0 (pid: 0, stack limit = 0xffff000008cc0000)
>> > [ 0.223224] Call trace:
>> > [ 0.225688] Exception stack(0xffff000008ccfa00 to 0xffff000008ccfb40)
>> > [ 0.232194] fa00: 0000000000000000 ffff000009710027
>> > ffff0000095e3980 ffff000008ccfbe0
>> > [ 0.240106] fa20: 0000000000000001 ffff80000fe62c00
>> > ffff000008ccfc50 0000000000000000
>> > [ 0.248018] fa40: ffff8000126d0140 000000000000005f
>> > 00000000ffffff76 0000000000000006
>> > [ 0.255931] fa60: ffffffffffffffff ffffffff00000000
>> > 000000000000038e 0000000000000000
>> > [ 0.263843] fa80: 0000000000000000 0000000000000000
>> > 0000000000000005 000000000000001b
>> > [ 0.271754] faa0: 0000000000000001 ffff000008ccfc50
>> > ffff000009710027 0000000000000001
>> > [ 0.279667] fac0: 0000000000000001 000000000000001b
>> > 0000000000000000 ffff0000088be820
>> > [ 0.287579] fae0: ffff000008a9f2a4 ffff000008ccfb40
>> > ffff00000849b4f8 ffff000008ccfb40
>> > [ 0.295491] fb00: ffff0000084a6764 0000000060000045
>> > ffff000008ccfb40 ffff000008260a18
>> > [ 0.303403] fb20: ffffffffffffffff ffff0000087f3fb0
>> > ffff000008ccfb40 ffff0000084a6764
>> > [ 0.311316] [<ffff0000084a6764>] acpi_ns_lookup+0x25c/0x3c0
>> > [ 0.316943] [<ffff00000849b4f8>] acpi_ds_load1_begin_op+0xa4/0x294
>> > [ 0.323186] [<ffff0000084ad4ac>] acpi_ps_build_named_op+0xc4/0x198
>> > [ 0.329428] [<ffff0000084ad6cc>] acpi_ps_create_op+0x14c/0x270
>> > [ 0.335319] [<ffff0000084acfa8>] acpi_ps_parse_loop+0x188/0x5c8
>> > [ 0.341298] [<ffff0000084ae048>] acpi_ps_parse_aml+0xb0/0x2b8
>> > [ 0.347101] [<ffff0000084a8e10>] acpi_ns_one_complete_parse+0x144/0x184
>> > [ 0.353783] [<ffff0000084a8e98>] acpi_ns_parse_table+0x48/0x68
>> > [ 0.359675] [<ffff0000084a82cc>] acpi_ns_load_table+0x4c/0xdc
>> > [ 0.365479] [<ffff0000084b32f8>] acpi_tb_load_namespace+0xe4/0x264
>> > [ 0.371723] [<ffff000008baf9b4>] acpi_load_tables+0x48/0xc0
>> > [ 0.377350] [<ffff000008badc20>] acpi_early_init+0x9c/0xd0
>> > [ 0.382891] [<ffff000008b70d50>] start_kernel+0x3b4/0x43c
>> > [ 0.388343] Code: b9008fb9 2a000318 36380054 32190318 (b94002c0)
>> > [ 0.394500] ---[ end trace c46ed37f9651c58e ]---
>> > [ 0.399160] Kernel panic - not syncing: Fatal exception
>> > [ 0.404437] Rebooting in 10 seconds.
>> >
>> > So, I think the linear mapping done by the primary kernel does not
>> > make these accessible in the crash kernel directly.
>> >
>> > Any pointers?
>>
>> Can you get the code line number for acpi_ns_lookup+0x25c?
>
> So should we always avoid ioremap() in acpi_os_ioremap() entirely, or
> modify acpi_ns_lookup() (or any acpi functions') to prevent unaligned
> accesses?
> (I didn't find out how unaligned accesses could happen there.)
>
Right. Like I captured somewhere in this thread (perhaps the first
email on this subject),
this is indeed an unaligned address access.
Now, modifying acpi_os_ioremap() to not ioremap() and thus avoiding
assigning this memory range
as device memory doesn't seem a neat solution as it means we are not
marking some thing with the right memory attribute and we can fall in
similar/related issues later.
Regarding the later suggestion, what I am seeing now is that the acpi
table access functions are perhaps reused from the earlier x86
implementation, but on the arm64 (or even arm) arch we should not be
allowing unaligned accesses which might cause UNDEFINED behaviour and
resultant crash.
So I can try going this approach and see if it works for me.
However, I am still not very sure as to why the crashkernel ranges
historically do not include the System RAM regions (which may include
the ACPI regions as well). These regions are available for the kernel
usage and perhaps should be exported to the crashkernel as well.
I am not fully aware of the previous discussions on capp'ing the
crashkernel memory being passed to the kdump kernel, but did we run
into any issues while doing so?
Also, even if I extend the kexec-tools to modify the
linux,usable-memory-range and add the ACPI regions to it, the
crashkernel fails to boot with the below message (I have added some
logic to print the DTB on the crash kernel boot start):
[ 0.000000] chosen {
[ 0.000000] linux,usable-memory-range
[ 0.000000] = <
[ 0.000000] 0x00000000
[ 0.000000] 0x0e800000
[ 0.000000] 0x00000000
[ 0.000000] 0x20000000
[ 0.000000] 0x00000000
[ 0.000000] 0x396c0000
[ 0.000000] 0x00000000
[ 0.000000] 0x000a0000
[ 0.000000] 0x00000000
[ 0.000000] 0x39770000
[ 0.000000] 0x00000000
[ 0.000000] 0x00040000
[ 0.000000] 0x00000000
[ 0.000000] 0x398a0000
[ 0.000000] 0x00000000
[ 0.000000] 0x00020000
[ 0.000000] >
[ 0.000000] ;
[snip..]
[ 0.000000] linux,usable-memory-range base e800000, size 20000000
[ 0.000000] - e800000 , 20000000
[ 0.000000] linux,usable-memory-range base 396c0000, size a0000
[ 0.000000] - 396c0000 , a0000
[ 0.000000] linux,usable-memory-range base 39770000, size 40000
[ 0.000000] - 39770000 , 40000
[ 0.000000] linux,usable-memory-range base 398a0000, size 20000
[ 0.000000] - 398a0000 , 20000
[ 0.000000] initrd not fully accessible via the linear mapping --
please check your bootloader ...
[ 0.000000] ------------[ cut here ]------------
[ 0.000000] WARNING: CPU: 0 PID: 0 at arch/arm64/mm/init.c:597
arm64_memblock_init+0x210/0x484
[ 0.000000] Modules linked in:
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.14.0+ #7
[ 0.000000] task: ffff000008d05580 task.stack: ffff000008cc0000
[ 0.000000] PC is at arm64_memblock_init+0x210/0x484
[ 0.000000] LR is at arm64_memblock_init+0x210/0x484
[ 0.000000] pc : [<ffff000008b76984>] lr : [<ffff000008b76984>]
pstate: 600000c5
[ 0.000000] sp : ffff000008ccfe80
[ 0.000000] x29: ffff000008ccfe80 x28: 000000000f370018
[ 0.000000] x27: 0000000011230000 x26: 00000000013b0000
[ 0.000000] x25: 000000000fe80000 x24: ffff000008cf3000
[ 0.000000] x23: ffff000008ec0000 x22: ffff000009680000
[ 0.000000] x21: ffff000008afa000 x20: ffff000008080000
[ 0.000000] x19: ffff000008afa000 x18: 000000000c283806
[ 0.000000] x17: 0000000000000000 x16: ffff000008d05580
[ 0.000000] x15: 000000002be00842 x14: 79206b6365686320
[ 0.000000] x13: 657361656c70202d x12: 2d20676e69707061
[ 0.000000] x11: 6d207261656e696c x10: 2065687420616976
[ 0.000000] x9 : 00000000000000f4 x8 : ffff000008517414
[ 0.000000] x7 : 746f6f622072756f x6 : 000000000000000d
[ 0.000000] x5 : ffff000008c96360 x4 : 0000000000000001
[ 0.000000] x3 : 0000000000000000 x2 : 0000000000000000
[ 0.000000] x1 : 0000000000000000 x0 : 0000000000000056
[ 0.000000] Call trace:
[ 0.000000] Exception stack(0xffff000008ccfd40 to 0xffff000008ccfe80)
[ 0.000000] fd40: 0000000000000056 0000000000000000
0000000000000000 0000000000000000
[ 0.000000] fd60: 0000000000000001 ffff000008c96360
000000000000000d 746f6f622072756f
[ 0.000000] fd80: ffff000008517414 00000000000000f4
2065687420616976 6d207261656e696c
[ 0.000000] fda0: 2d20676e69707061 657361656c70202d
79206b6365686320 000000002be00842
[ 0.000000] fdc0: ffff000008d05580 0000000000000000
000000000c283806 ffff000008afa000
[ 0.000000] fde0: ffff000008080000 ffff000008afa000
ffff000009680000 ffff000008ec0000
[ 0.000000] fe00: ffff000008cf3000 000000000fe80000
00000000013b0000 0000000011230000
[ 0.000000] fe20: 000000000f370018 ffff000008ccfe80
ffff000008b76984 ffff000008ccfe80
[ 0.000000] fe40: ffff000008b76984 00000000600000c5
ffff00000959b7a8 ffff000008ec0000
[ 0.000000] fe60: ffffffffffffffff 0000000000000005
ffff000008ccfe80 ffff000008b76984
[ 0.000000] [<ffff000008b76984>] arm64_memblock_init+0x210/0x484
[ 0.000000] [<ffff000008b7398c>] setup_arch+0x1b8/0x5f4
[ 0.000000] [<ffff000008b70a10>] start_kernel+0x74/0x43c
[ 0.000000] random: get_random_bytes called from
print_oops_end_marker+0x50/0x6c with crng_init=0
[ 0.000000] ---[ end trace 0000000000000000 ]---
[ 0.000000] Reserving 4KB of memory at 0x2e7f0000 for elfcorehdr
[ 0.000000] cma: Failed to reserve 512 MiB
[ 0.000000] Kernel panic - not syncing: ERROR: Failed to allocate
0x0000000000010000 bytes below 0x0000000000000000.
[ 0.000000]
[ 0.000000] CPU: 0 PID: 0 Comm: swapper Tainted: G W
------------ 4.14.0+ #7
[ 0.000000] Call trace:
[ 0.000000] [<ffff000008088da8>] dump_backtrace+0x0/0x23c
[ 0.000000] [<ffff000008089008>] show_stack+0x24/0x2c
[ 0.000000] [<ffff0000087f647c>] dump_stack+0x84/0xa8
[ 0.000000] [<ffff0000080cfd44>] panic+0x138/0x2a0
[ 0.000000] [<ffff000008b95c88>] memblock_alloc_base+0x44/0x4c
[ 0.000000] [<ffff000008b95cbc>] memblock_alloc+0x2c/0x38
[ 0.000000] [<ffff000008b772dc>] early_pgtable_alloc+0x20/0x74
[ 0.000000] [<ffff000008b7755c>] paging_init+0x28/0x544
[ 0.000000] [<ffff000008b73990>] setup_arch+0x1bc/0x5f4
[ 0.000000] [<ffff000008b70a10>] start_kernel+0x74/0x43c
[ 0.000000] ---[ end Kernel panic - not syncing: ERROR: Failed to
allocate 0x0000000000010000 bytes below 0x0000000000000000.
[ 0.000000]
I guess it is because of the 1G alignment requirement between the
kernel image and the initrd and how we populate the holes between the
kernel image, segments (including dtb) and the initrd from the
kexec-tools.
Akashi, any pointers on this will be helpful as well.
Regards,
Bhupesh
>> >
>> > Regards,
>> > Bhupesh
>> >
>> > >> Just FYI, on x86, ACPI tables seems to be exposed to crash dump kernel
>> > >> via a kernel command line parameter, "memmap=".
>> > >>
>> > _______________________________________________
>> > kexec mailing list -- kexec at lists.fedoraproject.org
>> > To unsubscribe send an email to kexec-leave at lists.fedoraproject.org
More information about the linux-arm-kernel
mailing list