On 06/06/2014 12:37 AM, Dave Young wrote: > On 06/05/14 at 11:01am, Vivek Goyal wrote: >> On Thu, Jun 05, 2014 at 04:31:34PM +0800, Dave Young wrote: >> >> [..] >>>> + ret = kexec_file_load(kernel_fd, info.initrd_fd, info.command_line, >>>> + info.command_line_len, info.kexec_flags); >>> >>> Vivek, >>> >>> I tried your patch on my uefi test machine, but kexec load fails like below: >>> >>> [root at localhost ~]# kexec -l /boot/vmlinuz-3.15.0-rc8+ --use-kexec2-syscall >>> Could not find a free area of memory of 0xa000 bytes ... >> >> Hi Dave, >> >> I think this message is coming from kexec-tools from old loading path. I >> think somehow new path did not even kick in. I tried above and I got >> -EBADF as I did not pass initrd. Can you run gdb on kexec and see if >> you are getting to syscall or run strace. > > Seems I can not reproduce the local hole fail issue but I'm sure it happens > before the new syscall callback. > > This time I got -ENOEXEC. It's caused by CONFIG_EFI_MIXED=y. In case EFI_MIXED > 64bit kernel runs on 32bit efi firmware thus XLF_CAN_BE_LOADED_ABOVE_4G is not > set thus bzImage probe will fail with NOEXEC. > OK... this is seriously problematic. #if defined(CONFIG_RELOCATABLE) && defined(CONFIG_X86_64) && \ !defined(CONFIG_EFI_MIXED) /* kernel/boot_param/ramdisk could be loaded above 4g */ # define XLF1 XLF_CAN_BE_LOADED_ABOVE_4G #else # define XLF1 0 #endif The fact that even compiling with CONFIG_EFI_MIXED disables XLF_CAN_BE_LOADED_ABOVE_4G is really not going to fly. We should expect CONFIG_EFI_MIXED to be the norm, but *also* should expect that there is a legitimate need to load above 4G. Matt, could you explain why this is necessary? We need to figure out a way around this. My thinking is that disabling this flag is unnecessary, since a 32-bit EFI loader should not load above the 4G mark anyway, but if I'm confused and there is a more fundamental requirement, then we need to consider that more carefully. -hpa
