[PATCH 2/3] makedumpfile: Introduce vtop4_x86_64_pagetable

[Takao Indoh]

This patch introduces new function vtop4_x86_64_pagetable
to translate virtual address to physical address. Unlike vtop4_x86_64,
vtop4_x86_64_pagetable need a pointer of top of pagetable like CR3.

Current vtop4_x86_64 implementation uses symbol value of
init_level4_pgt, therefore vtop4_x86_64 does not work for sadump
dumpfile of kaslr enabled kernel because it does not have vmcoreinfo to
correct address of init_level4_pgt. vtop4_x86_64_pagetable requires
pagetable address instead of init_level4_pgt and sadump dumpfile can
pass CR3 value which is included in dump header.

Signed-off-by: Takao Indoh <indou.takao at jp.fujitsu.com>
---
 arch/x86_64.c  | 30 +++++++++++++++++++++++-------
 makedumpfile.h |  1 +
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/arch/x86_64.c b/arch/x86_64.c
index 08dd6b2..33621f1 100644
--- a/arch/x86_64.c
+++ b/arch/x86_64.c
@@ -255,20 +255,15 @@ get_versiondep_info_x86_64(void)
  * Translate a virtual address to a physical address by using 4 levels paging.
  */
 unsigned long long
-vtop4_x86_64(unsigned long vaddr)
+__vtop4_x86_64(unsigned long vaddr, unsigned long pagetable)
 {
 	unsigned long page_dir, pml4, pgd_paddr, pgd_pte, pmd_paddr, pmd_pte;
 	unsigned long pte_paddr, pte;
 
-	if (SYMBOL(init_level4_pgt) == NOT_FOUND_SYMBOL) {
-		ERRMSG("Can't get the symbol of init_level4_pgt.\n");
-		return NOT_PADDR;
-	}
-
 	/*
 	 * Get PGD.
 	 */
-	page_dir = SYMBOL(init_level4_pgt) - __START_KERNEL_map + info->phys_base;
+	page_dir = pagetable;
 	if (is_xen_memory()) {
 		page_dir = ptom_xen(page_dir);
 		if (page_dir == NOT_PADDR)
@@ -346,6 +341,27 @@ vtop4_x86_64(unsigned long vaddr)
 	return (pte & ENTRY_MASK) + PAGEOFFSET(vaddr);
 }
 
+unsigned long long
+vtop4_x86_64(unsigned long vaddr)
+{
+	unsigned long pagetable;
+
+	if (SYMBOL(init_level4_pgt) == NOT_FOUND_SYMBOL) {
+		ERRMSG("Can't get the symbol of init_level4_pgt.\n");
+		return NOT_PADDR;
+	}
+
+	pagetable = SYMBOL(init_level4_pgt) - __START_KERNEL_map + info->phys_base;
+
+	return __vtop4_x86_64(vaddr, pagetable);
+}
+
+unsigned long long
+vtop4_x86_64_pagetable(unsigned long vaddr, unsigned long pagetable)
+{
+	return __vtop4_x86_64(vaddr, pagetable);
+}
+
 /*
  * for Xen extraction
  */
diff --git a/makedumpfile.h b/makedumpfile.h
index 704a6bc..f48dc0b 100644
--- a/makedumpfile.h
+++ b/makedumpfile.h
@@ -978,6 +978,7 @@ int get_phys_base_x86_64(void);
 int get_machdep_info_x86_64(void);
 int get_versiondep_info_x86_64(void);
 unsigned long long vtop4_x86_64(unsigned long vaddr);
+unsigned long long vtop4_x86_64_pagetable(unsigned long vaddr, unsigned long pagetable);
 #define find_vmemmap()		find_vmemmap_x86_64()
 #define get_phys_base()		get_phys_base_x86_64()
 #define get_machdep_info()	get_machdep_info_x86_64()
-- 
2.9.5