Hi, > > > As you pointed out above, a wild pointer could cause a > > WARN from early_ioremap. We need to never follow the pointer in the > > first place after a kexec, unless we have some way to know that it's > > actually valid. > > So you assume that the information from ACPI is always correct then? > The pointer is correct, the information it points to is no longer. > > If we run always under EFI then it looks like the variable efi_setup > which is checked in efi_enter_virtual_mode() is 0 during normal boot > and != 0 on kexec entry. This hint is set via setup_data / SETUP_EFI > since commit 1fec053369 ("x86/efi: Pass necessary EFI data for kexec > via setup_data"). So maybe we could use this to check if we run under > kexec or not. Not sure if BGRT is useful in kexec kernel, it seems not worth to copy it between kernels. IMO just return in case if (efi_setup) is true make sense. Thanks Dave -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html