linux-kernel - [PATCH] [7/31] Extract page table dumping code from i386 fault handler into dump

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Message-Id: <20080114221639.31FC714F83@wotan.suse.de>
Date:	Mon, 14 Jan 2008 23:16:39 +0100 (CET)
From:	Andi Kleen <ak@...e.de>
To:	linux-kernel@...r.kernel.org, jbeulich@...ell.com, mingo@...e.hu,
	tglx@...utronix.de
Subject: [PATCH] [7/31] Extract page table dumping code from i386 fault handler into dump_pagetable()


Similar to x86-64. This is useful in other situations where we want
the page table dumped too.

Besides anything that makes i386 do_page_fault shorter is good.

Signed-off-by: Andi Kleen <ak@...e.de>

---
 arch/x86/mm/fault_32.c |   72 ++++++++++++++++++++++++++-----------------------
 1 file changed, 39 insertions(+), 33 deletions(-)

Index: linux/arch/x86/mm/fault_32.c
===================================================================
--- linux.orig/arch/x86/mm/fault_32.c
+++ linux/arch/x86/mm/fault_32.c
@@ -28,6 +28,44 @@
 #include <asm/desc.h>
 #include <asm/segment.h>
 
+void dump_pagetable(unsigned long address)
+{
+	typeof(pte_val(__pte(0))) page;
+
+	page = read_cr3();
+	page = ((__typeof__(page) *) __va(page))[address >> PGDIR_SHIFT];
+#ifdef CONFIG_X86_PAE
+	printk("*pdpt = %016Lx ", page);
+	if ((page >> PAGE_SHIFT) < max_low_pfn
+	    && page & _PAGE_PRESENT) {
+		page &= PAGE_MASK;
+		page = ((__typeof__(page) *) __va(page))[(address >> PMD_SHIFT)
+							 & (PTRS_PER_PMD - 1)];
+		printk(KERN_CONT "*pde = %016Lx ", page);
+		page &= ~_PAGE_NX;
+	}
+#else
+	printk("*pde = %08lx ", page);
+#endif
+
+	/*
+	 * We must not directly access the pte in the highpte
+	 * case if the page table is located in highmem.
+	 * And let's rather not kmap-atomic the pte, just in case
+	 * it's allocated already.
+	 */
+	if ((page >> PAGE_SHIFT) < max_low_pfn
+	    && (page & _PAGE_PRESENT)
+	    && !(page & _PAGE_PSE)) {
+		page &= PAGE_MASK;
+		page = ((__typeof__(page) *) __va(page))[(address >> PAGE_SHIFT)
+							 & (PTRS_PER_PTE - 1)];
+		printk("*pte = %0*Lx ", sizeof(page)*2, (u64)page);
+	}
+
+	printk("\n");
+}
+
 /*
  * Page fault error code bits
  *	bit 0 == 0 means no page found, 1 means protection fault
@@ -530,7 +568,6 @@ no_context:
 	bust_spinlocks(1);
 
 	if (oops_may_print()) {
-		__typeof__(pte_val(__pte(0))) page;
 
 #ifdef CONFIG_X86_PAE
 		if (error_code & PF_INSTR) {
@@ -551,38 +588,7 @@ no_context:
 		printk(" at virtual address %08lx\n", address);
 		printk(KERN_ALERT "printing ip: %08lx ", regs->ip);
 
-		page = read_cr3();
-		page = ((__typeof__(page) *) __va(page))[address >> PGDIR_SHIFT];
-#ifdef CONFIG_X86_PAE
-		printk("*pdpt = %016Lx ", page);
-		if ((page >> PAGE_SHIFT) < max_low_pfn
-		    && page & _PAGE_PRESENT) {
-			page &= PAGE_MASK;
-			page = ((__typeof__(page) *) __va(page))[(address >> PMD_SHIFT)
-			                                         & (PTRS_PER_PMD - 1)];
-			printk(KERN_CONT "*pde = %016Lx ", page);
-			page &= ~_PAGE_NX;
-		}
-#else
-		printk("*pde = %08lx ", page);
-#endif
-
-		/*
-		 * We must not directly access the pte in the highpte
-		 * case if the page table is located in highmem.
-		 * And let's rather not kmap-atomic the pte, just in case
-		 * it's allocated already.
-		 */
-		if ((page >> PAGE_SHIFT) < max_low_pfn
-		    && (page & _PAGE_PRESENT)
-		    && !(page & _PAGE_PSE)) {
-			page &= PAGE_MASK;
-			page = ((__typeof__(page) *) __va(page))[(address >> PAGE_SHIFT)
-			                                         & (PTRS_PER_PTE - 1)];
-			printk("*pte = %0*Lx ", sizeof(page)*2, (u64)page);
-		}
-
-		printk("\n");
+		dump_pagetable(address);
 	}
 
 	tsk->thread.cr2 = address;
--
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