Re: [PATCH v5 6/8] arm64/efi: move SetVirtualAddressMap() to UEFI stub

Steve Capper
2015-01-29T09:50:26Z

On 8 January 2015 at 18:48, Ard Biesheuvel <ard.biesheuvel@linaro.org> wrote:
> In order to support kexec, the kernel needs to be able to deal with the
> state of the UEFI firmware after SetVirtualAddressMap() has been called.
> To avoid having separate code paths for non-kexec and kexec, let's move
> the call to SetVirtualAddressMap() to the stub: this will guarantee us
> that it will only be called once (since the stub is not executed during
> kexec), and ensures that the UEFI state is identical between kexec and
> normal boot.
>
> This implies that the layout of the virtual mapping needs to be created
> by the stub as well. All regions are rounded up to a naturally aligned
> multiple of 64 KB (for compatibility with 64k pages kernels) and recorded
> in the UEFI memory map. The kernel proper reads those values and installs
> the mappings in a dedicated set of page tables that are swapped in during
> UEFI Runtime Services calls.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

Hi,
I've been testing out linux-next next-20150128 and have run into an
early bootup failure on Seattle.
Having done a bisect, this patch comes up as the first "bad" patch:
f3cdfd2 arm64/efi: move SetVirtualAddressMap() to UEFI stub

I've tried the defconfig with 4-levels 4KB and 2-levels 64KB pages and
the failure mode doesn't change.

The point of failure for me is in setup_arch, just after call to
local_async_enable.

I'm not very knowledgeable of EFI, my guess is that a System Error
occurs early (during the EFI stub activity?), then manifests once the
asynchronous aborts are enabled?

Cheers,
--
Steve

The full boot log:
EFI stub: Booting Linux Kernel...
EFI stub: Using DTB from configuration table
EFI stub: Exiting boot services and installing virtual address map...
Booting Linux on physical CPU 0x0
Initializing cgroup subsys cpu
Linux version 3.19.0-rc4+ (steven@capper-seattle) (gcc version 4.9.2
20141101 (Red Hat 4.9.2-1) (GCC) ) #42 SMP Thu Jan 29 09:28:34 GMT
2015
CPU: AArch64 Processor [410fd070] revision 0
Detected PIPT I-cache on CPU0
alternatives: enabling workaround for ARM erratum 832075
Early serial console at MMIO 0xe1010000 (options '')
bootconsole [uart0] enabled
Bad mode in Error handler detected, code 0xbf000000
CPU: 0 PID: 0 Comm: swapper Not tainted 3.19.0-rc4+ #42
Hardware name: amd,seattle (DT)
task: fffffe0000aaddf0 ti: fffffe0000a70000 task.ti: fffffe0000a70000
PC is at setup_arch+0x1f8/0x510
LR is at setup_arch+0x1f4/0x510
pc : [<fffffe00009b2818>] lr : [<fffffe00009b2814>] pstate: 000002c5
sp : fffffe0000a73f10
x29: fffffe0000a73f10 x28: 0000028001000000
x27: fffffe0000081230 x26: 0000008001c00000
x25: 0000008001be0000 x24: fffffe0000aa6000
x23: 0000000000000000 x22: fffffe0000aa6000
x21: fffffe0000a73fe8 x20: fffffe0000b60000
x19: fffffe0000080000 x18: 0000000000000000
x17: 0000000000000800 x16: 0000000000001000
x15: 0000000000001c00 x14: 0ffffffffffffffe
x13: 0000000000000001 x12: 0000000000000010
x11: 0000000000000007 x10: 0101010101010101
x9 : fffffffffffffffe x8 : 0000000000000008
x7 : 0000000000000006 x6 : 0000800000000000
x5 : 000000000000005f x4 : 0000000000000000
x3 : 0000000000000063 x2 : 0000000000000065
x1 : 0000000000000000 x0 : 0000000000000001

Internal error: Oops - bad mode: 0 [#1] SMP
Modules linked in:
CPU: 0 PID: 0 Comm: swapper Not tainted 3.19.0-rc4+ #42
Hardware name: amd,seattle (DT)
task: fffffe0000aaddf0 ti: fffffe0000a70000 task.ti: fffffe0000a70000
PC is at setup_arch+0x1f8/0x510
LR is at setup_arch+0x1f4/0x510
pc : [<fffffe00009b2818>] lr : [<fffffe00009b2814>] pstate: 000002c5
sp : fffffe0000a73f10
x29: fffffe0000a73f10 x28: 0000028001000000
x27: fffffe0000081230 x26: 0000008001c00000
x25: 0000008001be0000 x24: fffffe0000aa6000
x23: 0000000000000000 x22: fffffe0000aa6000
x21: fffffe0000a73fe8 x20: fffffe0000b60000
x19: fffffe0000080000 x18: 0000000000000000
x17: 0000000000000800 x16: 0000000000001000
x15: 0000000000001c00 x14: 0ffffffffffffffe
x13: 0000000000000001 x12: 0000000000000010
x11: 0000000000000007 x10: 0101010101010101
x9 : fffffffffffffffe x8 : 0000000000000008
x7 : 0000000000000006 x6 : 0000800000000000
x5 : 000000000000005f x4 : 0000000000000000
x3 : 0000000000000063 x2 : 0000000000000065
x1 : 0000000000000000 x0 : 0000000000000001

Process swapper (pid: 0, stack limit = 0xfffffe0000a70058)
Stack: (0xfffffe0000a73f10 to 0xfffffe0000a74000)
3f00: 00a73fa0 fffffe00 009b0688 fffffe00
3f20: 009ef3b8 fffffe00 00b60000 fffffe00 00b60000 fffffe00 00aa6000 fffffe00
3f40: 00000000 00000000 01000000 00000080 01be0000 00000080 01c00000 00000080
3f60: 00081230 fffffe00 00630088 fffffe00 00000001 00000000 1fe00000 00000080
3f80: 00b63870 fffffe00 00000002 00000000 00b6451a fffffe00 00000000 00000000
3fa0: 00000000 00000000 010906e0 00000080 f0f1e938 00000083 00000e12 00000000
3fc0: 1fe00000 00000080 410fd070 00000000 01ab0000 00000080 01000000 00000080
3fe0: 00000000 00000000 009ef3b8 fffffe00 00000000 00000000 00000000 00000000
Call trace:
[<fffffe00009b2818>] setup_arch+0x1f8/0x510
[<fffffe00009b0684>] start_kernel+0xa4/0x3a8
Code: 94000b2c 940009f7 97fff760 d50344ff (d00007f5)
---[ end trace cb88537fdc8fa200 ]---
Kernel panic - not syncing: Attempted to kill the idle task!
---[ end Kernel panic - not syncing: Attempted to kill the idle task!