Since arm64 supports 5-level page tables, we need to add this information to vmcoreinfo to make debug tools know if 5-level page table is enabled or not. Missing this information will break the debug tool like crash [1]. [1] https://github.com/crash-utility/crash Signed-off-by: Kuan-Ying Lee <kuan-ying.lee@xxxxxxxxxxxxx> --- Documentation/admin-guide/kdump/vmcoreinfo.rst | 6 ++++++ arch/arm64/kernel/vmcore_info.c | 3 +++ 2 files changed, 9 insertions(+) diff --git a/Documentation/admin-guide/kdump/vmcoreinfo.rst b/Documentation/admin-guide/kdump/vmcoreinfo.rst index 0f714fc945ac..557a1cbe5098 100644 --- a/Documentation/admin-guide/kdump/vmcoreinfo.rst +++ b/Documentation/admin-guide/kdump/vmcoreinfo.rst @@ -466,6 +466,12 @@ Used to get the correct ranges: VMALLOC_START ~ VMALLOC_END-1 : vmalloc() / ioremap() space. VMEMMAP_START ~ VMEMMAP_END-1 : vmemmap region, used for struct page array. +pgtable_l5_enabled +------------------ + +User-space tools need to know whether the crash kernel was in 5-level +paging mode. + arm === diff --git a/arch/arm64/kernel/vmcore_info.c b/arch/arm64/kernel/vmcore_info.c index b19d5d6cb8b3..be65d664bdb7 100644 --- a/arch/arm64/kernel/vmcore_info.c +++ b/arch/arm64/kernel/vmcore_info.c @@ -7,6 +7,7 @@ #include <linux/vmcore_info.h> #include <asm/cpufeature.h> #include <asm/memory.h> +#include <asm/pgtable.h> #include <asm/pgtable-hwdef.h> #include <asm/pointer_auth.h> @@ -36,4 +37,6 @@ void arch_crash_save_vmcoreinfo(void) vmcoreinfo_append_str("NUMBER(KERNELPACMASK)=0x%llx\n", system_supports_address_auth() ? ptrauth_kernel_pac_mask() : 0); + vmcoreinfo_append_str("NUMBER(pgtable_l5_enabled)=%d\n", + pgtable_l5_enabled()); } -- 2.43.0
