Re: [PATCH] handle renamed init_level4_pgt -> init_top_pgt

[Dave Young <dyoung@redhat.com>]

On 12/08/17 at 08:15am, Atsushi Kumagai wrote:
> >>Linux 4.13 renamed init_level4_pgt to init_top_pgt in preparation for
> >>introducing 5-level page tables.  This patch follows the rename if
> >>the lookup for init_level4_pgt fails.  It also checks to see if
> >>5-level page tables are enabled and bails if it discovers they are.
> >
> >Thanks Jeff, but could you rebase it on the current devel branch ?
> >vtop4 for x86_64 was modified in the commit below:
> >
> >commit 8c89727155f4994b4e75a659e28e5eff16ff6cbc
> >Author: Takao Indoh <indou.takao@jp.fujitsu.com>
> >Date:   Thu Oct 26 20:32:54 2017 +0900
> >
> >    [PATCH v3 2/4] Introduce vtop4_x86_64_pagetable
> >
> >Regards,
> >Atsushi Kumagai
> 
> I rebased that and updated the devel branch:
> 
> https://sourceforge.net/p/makedumpfile/code/ci/97e156b493c46fabfc4b136ab834a6495166ac66/
> 
> I'll merge it into v1.6.3 if you have no comment.

[dyoung@dhcp-*-* makedumpfile]$ sudo ./makedumpfile -l -d 31 /mnt/vmcore/vmcore /tmp/vmcore.1
The kernel version is not supported.
The makedumpfile operation may be incomplete.
Checking for memory holes                         : [100.0 %] |                  __vtop4_x86_64: Can't get a valid pte.
readmem: Can't convert a virtual address(ffff88007ebb1000) to physical address.
readmem: type_addr: 0, addr:ffff88007ebb1000, size:32768
__exclude_unnecessary_pages: Can't read the buffer of struct page.
create_2nd_bitmap: Can't exclude unnecessary pages.

makedumpfile Failed.

If you need the vmcore for debugging please let me know, my test is just
a normal test in kvm guest.

> 
> Thanks,
> Atsushi Kumagai
> 
> >>Signed-off-by: Jeff Mahoney <jeffm@suse.com>
> >>---
> >> arch/x86_64.c  | 24 +++++++++++++++++++++---
> >> makedumpfile.c |  6 ++++++
> >> makedumpfile.h |  2 ++
> >> 3 files changed, 29 insertions(+), 3 deletions(-)
> >>
> >>diff --git a/arch/x86_64.c b/arch/x86_64.c
> >>index 08dd6b2..9b09035 100644
> >>--- a/arch/x86_64.c
> >>+++ b/arch/x86_64.c
> >>@@ -259,16 +259,26 @@ vtop4_x86_64(unsigned long vaddr)
> >> {
> >> 	unsigned long page_dir, pml4, pgd_paddr, pgd_pte, pmd_paddr, pmd_pte;
> >> 	unsigned long pte_paddr, pte;
> >>+	unsigned long init_level4_pgt;
> >>
> >>-	if (SYMBOL(init_level4_pgt) == NOT_FOUND_SYMBOL) {
> >>+	if (SYMBOL(init_level4_pgt) != NOT_FOUND_SYMBOL)
> >>+		init_level4_pgt = SYMBOL(init_level4_pgt);
> >>+	else if (SYMBOL(init_top_pgt) != NOT_FOUND_SYMBOL)
> >>+		init_level4_pgt = SYMBOL(init_top_pgt);
> >>+	else {
> >> 		ERRMSG("Can't get the symbol of init_level4_pgt.\n");
> >> 		return NOT_PADDR;
> >> 	}
> >>
> >>+	if (SYMBOL(level4_kernel_pgt) != NOT_FOUND_SYMBOL) {
> >>+		ERRMSG("Kernel is built with 5-level page tables\n");
> >>+		return NOT_PADDR;
> >>+	}
> >>+
> >> 	/*
> >> 	 * Get PGD.
> >> 	 */
> >>-	page_dir = SYMBOL(init_level4_pgt) - __START_KERNEL_map + info->phys_base;
> >>+	page_dir = init_level4_pgt - __START_KERNEL_map + info->phys_base;
> >> 	if (is_xen_memory()) {
> >> 		page_dir = ptom_xen(page_dir);
> >> 		if (page_dir == NOT_PADDR)
> >>@@ -549,8 +559,16 @@ find_vmemmap_x86_64()
> >> 	struct vmap_pfns *vmapp, *vmaphead = NULL, *cur, *tail;
> >>
> >> 	init_level4_pgt = SYMBOL(init_level4_pgt);
> >>+	if (init_level4_pgt == NOT_FOUND_SYMBOL)
> >>+		init_level4_pgt = SYMBOL(init_top_pgt);
> >>+
> >> 	if (init_level4_pgt == NOT_FOUND_SYMBOL) {
> >>-		ERRMSG("init_level4_pgt not found\n");
> >>+		ERRMSG("init_level4_pgt/init_top_pgt not found\n");
> >>+		return FAILED;
> >>+	}
> >>+
> >>+	if (SYMBOL(level4_kernel_pgt) != NOT_FOUND_SYMBOL) {
> >>+		ERRMSG("kernel is configured for 5-level page tables\n");
> >> 		return FAILED;
> >> 	}
> >> 	pagestructsize = size_table.page;
> >>diff --git a/makedumpfile.c b/makedumpfile.c
> >>index f85003a..6e5ec34 100644
> >>--- a/makedumpfile.c
> >>+++ b/makedumpfile.c
> >>@@ -1486,6 +1486,8 @@ get_symbol_info(void)
> >> 	SYMBOL_INIT(_stext, "_stext");
> >> 	SYMBOL_INIT(swapper_pg_dir, "swapper_pg_dir");
> >> 	SYMBOL_INIT(init_level4_pgt, "init_level4_pgt");
> >>+	SYMBOL_INIT(level4_kernel_pgt, "level4_kernel_pgt");
> >>+	SYMBOL_INIT(init_top_pgt, "init_top_pgt");
> >> 	SYMBOL_INIT(vmlist, "vmlist");
> >> 	SYMBOL_INIT(vmap_area_list, "vmap_area_list");
> >> 	SYMBOL_INIT(node_online_map, "node_online_map");
> >>@@ -2105,6 +2107,8 @@ write_vmcoreinfo_data(void)
> >> 	WRITE_SYMBOL("_stext", _stext);
> >> 	WRITE_SYMBOL("swapper_pg_dir", swapper_pg_dir);
> >> 	WRITE_SYMBOL("init_level4_pgt", init_level4_pgt);
> >>+	WRITE_SYMBOL("level4_kernel_pgt", level4_kernel_pgt);
> >>+	WRITE_SYMBOL("init_top_pgt", init_top_pgt);
> >> 	WRITE_SYMBOL("vmlist", vmlist);
> >> 	WRITE_SYMBOL("vmap_area_list", vmap_area_list);
> >> 	WRITE_SYMBOL("node_online_map", node_online_map);
> >>@@ -2500,6 +2504,8 @@ read_vmcoreinfo(void)
> >> 	READ_SYMBOL("_stext", _stext);
> >> 	READ_SYMBOL("swapper_pg_dir", swapper_pg_dir);
> >> 	READ_SYMBOL("init_level4_pgt", init_level4_pgt);
> >>+	READ_SYMBOL("level4_kernel_pgt", level4_kernel_pgt);
> >>+	READ_SYMBOL("init_top_pgt", init_top_pgt);
> >> 	READ_SYMBOL("vmlist", vmlist);
> >> 	READ_SYMBOL("vmap_area_list", vmap_area_list);
> >> 	READ_SYMBOL("node_online_map", node_online_map);
> >>diff --git a/makedumpfile.h b/makedumpfile.h
> >>index 8a05794..9357e47 100644
> >>--- a/makedumpfile.h
> >>+++ b/makedumpfile.h
> >>@@ -1517,6 +1517,8 @@ struct symbol_table {
> >> 	unsigned long long	_stext;
> >> 	unsigned long long	swapper_pg_dir;
> >> 	unsigned long long	init_level4_pgt;
> >>+	unsigned long long	level4_kernel_pgt;
> >>+	unsigned long long	init_top_pgt;
> >> 	unsigned long long	vmlist;
> >> 	unsigned long long	vmap_area_list;
> >> 	unsigned long long	phys_base;
> >>
> >>
> >>--
> >>Jeff Mahoney
> >>SUSE Labs
> >
> >
> >
> >_______________________________________________
> >kexec mailing list
> >kexec@lists.infradead.org
> >http://lists.infradead.org/mailman/listinfo/kexec
> 
> 
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Thanks
Dave

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