Currently, Crash only enable support for kernel-only 5-level page tables by entering the command line option "--machdep vm=5level". Since Linux 4.17, the Linux kernel can be both 4level and 5level page tables. This command line can't work well for this.
Using the "pgtable_l5_enabled" to detect whether the kernel proper for 5 level page tables automatically. Also move the 5-level paging setup from machdep_init(PRE_GDB) to machdep_init(POST_RELOC). Signed-off-by: Dave Anderson <[email protected]> Signed-off-by: Dou Liyang <[email protected]> --- Changelog v1 --> v2 1. Make it support live systems suggested by Dave 2. Using __pgtable_l5_enabled for check. 3. Do some tests in both kdump(5level and 4level) and virsh dump(5level and 4level) --- x86_64.c | 56 +++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 37 insertions(+), 19 deletions(-) diff --git a/x86_64.c b/x86_64.c index 6d1ae2f..07b6aa9 100644 --- a/x86_64.c +++ b/x86_64.c @@ -294,25 +294,6 @@ x86_64_init(int when) machdep->machspec->pgdir_shift = PGDIR_SHIFT; machdep->machspec->ptrs_per_pgd = PTRS_PER_PGD; break; - - case VM_5LEVEL: - machdep->machspec->userspace_top = USERSPACE_TOP_5LEVEL; - machdep->machspec->page_offset = PAGE_OFFSET_5LEVEL; - machdep->machspec->vmalloc_start_addr = VMALLOC_START_ADDR_5LEVEL; - machdep->machspec->vmalloc_end = VMALLOC_END_5LEVEL; - machdep->machspec->modules_vaddr = MODULES_VADDR_5LEVEL; - machdep->machspec->modules_end = MODULES_END_5LEVEL; - machdep->machspec->vmemmap_vaddr = VMEMMAP_VADDR_5LEVEL; - machdep->machspec->vmemmap_end = VMEMMAP_END_5LEVEL; - if (symbol_exists("vmemmap_populate")) - machdep->flags |= VMEMMAP; - machdep->machspec->physical_mask_shift = __PHYSICAL_MASK_SHIFT_5LEVEL; - machdep->machspec->pgdir_shift = PGDIR_SHIFT_5LEVEL; - machdep->machspec->ptrs_per_pgd = PTRS_PER_PGD_5LEVEL; - if ((machdep->machspec->p4d = (char *)malloc(PAGESIZE())) == NULL) - error(FATAL, "cannot malloc p4d space."); - machdep->machspec->last_p4d_read = 0; - machdep->uvtop = x86_64_uvtop_level4; /* 5-level is optional per-task */ } machdep->kvbase = (ulong)PAGE_OFFSET; machdep->identity_map_base = (ulong)PAGE_OFFSET; @@ -346,6 +327,43 @@ x86_64_init(int when) break; case POST_RELOC: + /* Check for 5-level paging */ + if (!(machdep->flags & VM_5LEVEL)) { + int l5_enabled; + if ((string = pc->read_vmcoreinfo("NUMBER(pgtable_l5_enabled)"))) { + l5_enabled = 1; + free(string); + } else if (kernel_symbol_exists("__pgtable_l5_enabled")) + readmem(symbol_value("__pgtable_l5_enabled"), KVADDR, + &l5_enabled, sizeof(int), "__pgtable_l5_enabled", + FAULT_ON_ERROR); + + if (l5_enabled) + machdep->flags |= VM_5LEVEL; + } + if (machdep->flags & VM_5LEVEL) { + machdep->machspec->userspace_top = USERSPACE_TOP_5LEVEL; + machdep->machspec->page_offset = PAGE_OFFSET_5LEVEL; + machdep->machspec->vmalloc_start_addr = VMALLOC_START_ADDR_5LEVEL; + machdep->machspec->vmalloc_end = VMALLOC_END_5LEVEL; + machdep->machspec->modules_vaddr = MODULES_VADDR_5LEVEL; + machdep->machspec->modules_end = MODULES_END_5LEVEL; + machdep->machspec->vmemmap_vaddr = VMEMMAP_VADDR_5LEVEL; + machdep->machspec->vmemmap_end = VMEMMAP_END_5LEVEL; + if (symbol_exists("vmemmap_populate")) + machdep->flags |= VMEMMAP; + machdep->machspec->physical_mask_shift = __PHYSICAL_MASK_SHIFT_5LEVEL; + machdep->machspec->pgdir_shift = PGDIR_SHIFT_5LEVEL; + machdep->machspec->ptrs_per_pgd = PTRS_PER_PGD_5LEVEL; + if ((machdep->machspec->p4d = (char *)malloc(PAGESIZE())) == NULL) + error(FATAL, "cannot malloc p4d space."); + machdep->machspec->last_p4d_read = 0; + machdep->uvtop = x86_64_uvtop_level4; /* 5-level is optional per-task */ + machdep->kvbase = (ulong)PAGE_OFFSET; + machdep->identity_map_base = (ulong)PAGE_OFFSET; + + } + /* * Check for CONFIG_RANDOMIZE_MEMORY, and set page_offset here. * The remainder of the virtual address range setups will get -- 2.14.3 -- Crash-utility mailing list [email protected] https://www.redhat.com/mailman/listinfo/crash-utility
