From c100a583601d357f923c41af5434dc1f8d07890f Mon Sep 17 00:00:00 2001 From: Baoquan He Date: Fri, 2 Mar 2018 13:18:01 +0800 Subject: [PATCH] kdump, vmcoreinfo: Export pgtable_l5_enabled value User-space utilities examining crash-kernels need to know if the crashed kernel was in 5-level paging mode or not. So write 'pgtable_l5_enabled' to vmcoreinfo, which covers these three cases: pgtable_l5_enabled == 0 when: - Compiled with !CONFIG_X86_5LEVEL - Compiled with CONFIG_X86_5LEVEL=y while CPU has no 'la57' flag pgtable_l5_enabled != 0 when: - Compiled with CONFIG_X86_5LEVEL=y and CPU has 'la57' flag Signed-off-by: Baoquan He Acked-by: Kirill A. Shutemov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: douly.fnst@cn.fujitsu.com Cc: dyoung@redhat.com Cc: ebiederm@xmission.com Cc: kirill.shutemov@linux.intel.com Cc: vgoyal@redhat.com Link: http://lkml.kernel.org/r/20180302051801.19594-1-bhe@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/machine_kexec_64.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c index 3b7427aa7d85..02f913cb27b5 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -350,6 +350,7 @@ void arch_crash_save_vmcoreinfo(void) { VMCOREINFO_NUMBER(phys_base); VMCOREINFO_SYMBOL(init_top_pgt); + VMCOREINFO_NUMBER(pgtable_l5_enabled); #ifdef CONFIG_NUMA VMCOREINFO_SYMBOL(node_data);