On 29 January 2015 at 09:50, Steve Capper <steve.capper@xxxxxxxxxx> wrote: > On 8 January 2015 at 18:48, Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx> 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@xxxxxxxxxx> > > 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? > This is a known issue with older versions of the Seattle firmware, and a fix is available (ask Rutland) Basically, the firmware dereferences the virtual mapping while it is being installed, which is a violation of the spec. With the new code, the virtual mapping is not actually active at that time, which is why you are getting SErrors now. -- Ard. > 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! -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
