[PATCH 06/10] [PATCH] uml - Fix x86_64 page leak

Chris Wright
2005-09-30T02:27:57Z

[-- Attachment #1: uml-fix-x86_64-page-leak.patch --]
[-- Type: text/plain, Size: 3595 bytes --]

-stable review patch. If anyone has any objections, please let us know.
------------------

We were leaking pmd pages when 3_LEVEL_PGTABLES was enabled. This fixes that,
has been well tested and is included in mainline tree. Please include in -stable
as well.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Chris Wright <chrisw@osdl.org>
---
arch/um/kernel/skas/include/mmu-skas.h | 4 ++++
arch/um/kernel/skas/mmu.c | 9 ++++++++-
include/asm-um/pgalloc.h | 12 +++++++-----
include/asm-um/pgtable-3level.h | 9 +++------
4 files changed, 22 insertions(+), 12 deletions(-)

Index: linux-2.6.13.y/arch/um/kernel/skas/include/mmu-skas.h
===================================================================
--- linux-2.6.13.y.orig/arch/um/kernel/skas/include/mmu-skas.h
+++ linux-2.6.13.y/arch/um/kernel/skas/include/mmu-skas.h
@@ -6,11 +6,15 @@
#ifndef __SKAS_MMU_H
#define __SKAS_MMU_H

+#include "linux/config.h"
#include "mm_id.h"

struct mmu_context_skas {
struct mm_id id;
unsigned long last_page_table;
+#ifdef CONFIG_3_LEVEL_PGTABLES
+ unsigned long last_pmd;
+#endif
};

extern void switch_mm_skas(struct mm_id * mm_idp);
Index: linux-2.6.13.y/arch/um/kernel/skas/mmu.c
===================================================================
--- linux-2.6.13.y.orig/arch/um/kernel/skas/mmu.c
+++ linux-2.6.13.y/arch/um/kernel/skas/mmu.c
@@ -56,6 +56,9 @@ static int init_stub_pte(struct mm_struc
*/

mm->context.skas.last_page_table = pmd_page_kernel(*pmd);
+#ifdef CONFIG_3_LEVEL_PGTABLES
+ mm->context.skas.last_pmd = (unsigned long) __va(pud_val(*pud));
+#endif

*pte = mk_pte(virt_to_page(kernel), __pgprot(_PAGE_PRESENT));
*pte = pte_mkexec(*pte);
@@ -140,6 +143,10 @@ void destroy_context_skas(struct mm_stru
else {
os_kill_ptraced_process(mmu->id.u.pid, 1);
free_page(mmu->id.stack);
- free_page(mmu->last_page_table);
+ pte_free_kernel((pte_t *) mmu->last_page_table);
+ dec_page_state(nr_page_table_pages);
+#ifdef CONFIG_3_LEVEL_PGTABLES
+ pmd_free((pmd_t *) mmu->last_pmd);
+#endif
}
}
Index: linux-2.6.13.y/include/asm-um/pgalloc.h
===================================================================
--- linux-2.6.13.y.orig/include/asm-um/pgalloc.h
+++ linux-2.6.13.y/include/asm-um/pgalloc.h
@@ -42,11 +42,13 @@ static inline void pte_free(struct page
#define __pte_free_tlb(tlb,pte) tlb_remove_page((tlb),(pte))

#ifdef CONFIG_3_LEVEL_PGTABLES
-/*
- * In the 3-level case we free the pmds as part of the pgd.
- */
-#define pmd_free(x) do { } while (0)
-#define __pmd_free_tlb(tlb,x) do { } while (0)
+
+extern __inline__ void pmd_free(pmd_t *pmd)
+{
+ free_page((unsigned long)pmd);
+}
+
+#define __pmd_free_tlb(tlb,x) tlb_remove_page((tlb),virt_to_page(x))
#endif

#define check_pgt_cache() do { } while (0)
Index: linux-2.6.13.y/include/asm-um/pgtable-3level.h
===================================================================
--- linux-2.6.13.y.orig/include/asm-um/pgtable-3level.h
+++ linux-2.6.13.y/include/asm-um/pgtable-3level.h
@@ -98,14 +98,11 @@ static inline pmd_t *pmd_alloc_one(struc
return pmd;
}

-static inline void pmd_free(pmd_t *pmd){
- free_page((unsigned long) pmd);
+extern inline void pud_clear (pud_t *pud)
+{
+ set_pud(pud, __pud(0));
}

-#define __pmd_free_tlb(tlb,x) do { } while (0)
-
-static inline void pud_clear (pud_t * pud) { }
-
#define pud_page(pud) \
((struct page *) __va(pud_val(pud) & PAGE_MASK))

--