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Date: Sat, 10 May 2008 17:33:08 +0200
From: Vegard Nossum <vegard.nossum@...il.com>
To: Ingo Molnar <mingo@...e.hu>, Pekka Enberg <penberg@...helsinki.fi>
Cc: Andi Kleen <andi@...stfloor.org>, linux-kernel@...r.kernel.org
Subject: [PATCH] kmemcheck: use set_memory_4k() instead of disabling PSE
Hi,
With this, we reduce the overall impact of kmemcheck by reverting some
earlier, now unnecessary, changes:
Documentation/kmemcheck.txt | 101 +++++
MAINTAINERS | 8 +
arch/x86/Kconfig.debug | 87 ++++
arch/x86/kernel/Makefile | 2 +
- arch/x86/kernel/cpu/common.c | 7 +
arch/x86/kernel/entry_32.S | 8 +-
arch/x86/kernel/entry_64.S | 4 +-
- arch/x86/kernel/head_32.S | 2 +-
- arch/x86/kernel/kmemcheck.c | 964 ++++++++++++++++++++++++++++++++++++++++++
+ arch/x86/kernel/kmemcheck.c | 963 ++++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/process.c | 2 +-
arch/x86/kernel/process_32.c | 4 +-
arch/x86/kernel/process_64.c | 12 +-
arch/x86/kernel/traps_32.c | 18 +-
arch/x86/kernel/traps_64.c | 16 +-
- arch/x86/mm/fault.c | 25 +-
- arch/x86/mm/init_32.c | 2 +-
+ arch/x86/mm/fault.c | 35 ++
include/asm-x86/kdebug.h | 3 +-
include/asm-x86/kmemcheck.h | 30 ++
include/asm-x86/pgtable.h | 4 +-
include/asm-x86/pgtable_32.h | 6 +
include/asm-x86/pgtable_64.h | 6 +
include/asm-x86/string_32.h | 8 +
include/asm-x86/string_64.h | 1 +
include/linux/gfp.h | 3 +-
include/linux/kmemcheck.h | 61 +++
include/linux/mm_types.h | 4 +
include/linux/slab.h | 7 +
include/linux/slab_def.h | 81 ++++
init/main.c | 2 +
kernel/fork.c | 16 +-
kernel/sysctl.c | 12 +
mm/Makefile | 2 +-
mm/kmemcheck.c | 97 +++++
mm/slab.c | 101 +----
mm/slub.c | 17 +-
- 35 files changed, 1601 insertions(+), 122 deletions(-)
+ 32 files changed, 1605 insertions(+), 116 deletions(-)
which is probably a good thing if it is ever merged into mainline :-)
See patch description for more info.
Vegard
>From 648611a899fd61df8f44b6f78c2700a460913d67 Mon Sep 17 00:00:00 2001
From: Vegard Nossum <vegard.nossum@...il.com>
Date: Sat, 10 May 2008 17:19:33 +0200
Subject: [PATCH] kmemcheck: use set_memory_4k() instead of disabling PSE
Thanks a bunch to Andi Kleen for this brilliant solution. Now all pages
that kmemcheck handle will be 4k in size, and we need no special-case code
to handle larger pages.
This will also greatly help the upcoming 64-bit support.
Signed-off-by: Vegard Nossum <vegard.nossum@...il.com>
---
arch/x86/kernel/cpu/common.c | 7 ------
arch/x86/kernel/head_32.S | 2 +-
arch/x86/kernel/kmemcheck.c | 9 +++----
arch/x86/mm/fault.c | 44 +++++++++++++++++++++++++++++------------
arch/x86/mm/init_32.c | 2 +-
5 files changed, 37 insertions(+), 27 deletions(-)
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 39933f6..35b4f6a 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -651,13 +651,6 @@ void __init early_cpu_init(void)
cpu_devs[cvdev->vendor] = cvdev->cpu_dev;
early_cpu_detect();
-
-#ifdef CONFIG_KMEMCHECK
- /*
- * We need 4K granular PTEs for kmemcheck:
- */
- setup_clear_cpu_cap(X86_FEATURE_PSE);
-#endif
}
/* Make sure %fs is initialized properly in idle threads */
diff --git a/arch/x86/kernel/head_32.S b/arch/x86/kernel/head_32.S
index c41ca7d..b2cc737 100644
--- a/arch/x86/kernel/head_32.S
+++ b/arch/x86/kernel/head_32.S
@@ -60,7 +60,7 @@ LOW_PAGES = 1<<(32-PAGE_SHIFT_asm)
* pagetables from above the 16MB DMA limit, so we'll have to set
* up pagetables 16MB more (worst-case):
*/
-#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
+#ifdef CONFIG_DEBUG_PAGEALLOC
LOW_PAGES = LOW_PAGES + 0x1000000
#endif
diff --git a/arch/x86/kernel/kmemcheck.c b/arch/x86/kernel/kmemcheck.c
index 7412a80..752a2d1 100644
--- a/arch/x86/kernel/kmemcheck.c
+++ b/arch/x86/kernel/kmemcheck.c
@@ -488,9 +488,7 @@ kmemcheck_show_pages(struct page *p, unsigned int n)
address = (unsigned long) page_address(&p[i]);
pte = lookup_address(address, &level);
BUG_ON(!pte);
-
- if (level != PG_LEVEL_4K)
- continue;
+ BUG_ON(level != PG_LEVEL_4K);
set_pte(pte, __pte(pte_val(*pte) | _PAGE_PRESENT));
set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_HIDDEN));
@@ -510,6 +508,8 @@ kmemcheck_hide_pages(struct page *p, unsigned int n)
{
unsigned int i;
+ set_memory_4k((unsigned long) page_address(p), n);
+
for (i = 0; i < n; ++i) {
unsigned long address;
pte_t *pte;
@@ -518,8 +518,7 @@ kmemcheck_hide_pages(struct page *p, unsigned int n)
address = (unsigned long) page_address(&p[i]);
pte = lookup_address(address, &level);
BUG_ON(!pte);
- if (level != PG_LEVEL_4K)
- continue;
+ BUG_ON(level != PG_LEVEL_4K);
set_pte(pte, __pte(pte_val(*pte) & ~_PAGE_PRESENT));
set_pte(pte, __pte(pte_val(*pte) | _PAGE_HIDDEN));
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 694a0b0..bde2361 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -492,8 +492,7 @@ static int spurious_fault(unsigned long address,
*
* This assumes no large pages in there.
*/
-static int vmalloc_fault(struct pt_regs *regs, unsigned long address,
- unsigned long error_code)
+static int vmalloc_fault(unsigned long address)
{
#ifdef CONFIG_X86_32
unsigned long pgd_paddr;
@@ -510,17 +509,10 @@ static int vmalloc_fault(struct pt_regs *regs, unsigned long address,
pmd_k = vmalloc_sync_one(__va(pgd_paddr), address);
if (!pmd_k)
return -1;
+
pte_k = pte_offset_kernel(pmd_k, address);
- if (!pte_present(*pte_k)) {
- if (!pte_hidden(*pte_k))
- return -1;
-
- if (error_code & 2)
- kmemcheck_access(regs, address, KMEMCHECK_WRITE);
- else
- kmemcheck_access(regs, address, KMEMCHECK_READ);
- kmemcheck_show(regs);
- }
+ if (!pte_present(*pte_k))
+ return -1;
return 0;
#else
pgd_t *pgd, *pgd_ref;
@@ -573,6 +565,29 @@ static int vmalloc_fault(struct pt_regs *regs, unsigned long address,
#endif
}
+static bool kmemcheck_fault(struct pt_regs *regs, unsigned long address,
+ unsigned long error_code)
+{
+ pte_t *pte;
+ unsigned int level;
+
+ pte = lookup_address(address, &level);
+ if (!pte)
+ return false;
+ if (level != PG_LEVEL_4K)
+ return false;
+ if (!pte_hidden(*pte))
+ return false;
+
+ if (error_code & 2)
+ kmemcheck_access(regs, address, KMEMCHECK_WRITE);
+ else
+ kmemcheck_access(regs, address, KMEMCHECK_READ);
+
+ kmemcheck_show(regs);
+ return true;
+}
+
int show_unhandled_signals = 1;
/*
@@ -638,7 +653,10 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
if (unlikely(address >= TASK_SIZE64)) {
#endif
if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) &&
- vmalloc_fault(regs, address, error_code) >= 0)
+ vmalloc_fault(address) >= 0)
+ return;
+
+ if (kmemcheck_fault(regs, address, error_code))
return;
/* Can handle a stale RO->RW TLB */
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index 806c6aa..de236e4 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -92,7 +92,7 @@ static pte_t * __init one_page_table_init(pmd_t *pmd)
if (!(pmd_val(*pmd) & _PAGE_PRESENT)) {
pte_t *page_table = NULL;
-#if defined(CONFIG_DEBUG_PAGEALLOC) || defined(CONFIG_KMEMCHECK)
+#ifdef CONFIG_DEBUG_PAGEALLOC
page_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
#endif
if (!page_table) {
--
1.5.4.1
--
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