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authorVegard Nossum <vegard.nossum@gmail.com>2008-04-04 00:51:41 +0200
committerVegard Nossum <vegard.nossum@gmail.com>2009-06-13 15:37:30 +0200
commitdfec072ecd35ba6ecad2d51dde325253ac9a2936 (patch)
treeccf682a631ef8edc0675d68d004bc3a80b34b648 /arch/x86/include
parente594c8de3bd4e7732ed3340fb01e18ec94b12df2 (diff)
kmemcheck: add the kmemcheck core
General description: kmemcheck is a patch to the linux kernel that detects use of uninitialized memory. It does this by trapping every read and write to memory that was allocated dynamically (e.g. using kmalloc()). If a memory address is read that has not previously been written to, a message is printed to the kernel log. Thanks to Andi Kleen for the set_memory_4k() solution. Andrew Morton suggested documenting the shadow member of struct page. Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> [export kmemcheck_mark_initialized] [build fix for setup_max_cpus] Signed-off-by: Ingo Molnar <mingo@elte.hu> [rebased for mainline inclusion] Signed-off-by: Vegard Nossum <vegardno@ifi.uio.no>
Diffstat (limited to 'arch/x86/include')
-rw-r--r--arch/x86/include/asm/kmemcheck.h42
-rw-r--r--arch/x86/include/asm/pgtable.h9
-rw-r--r--arch/x86/include/asm/pgtable_types.h4
3 files changed, 53 insertions, 2 deletions
diff --git a/arch/x86/include/asm/kmemcheck.h b/arch/x86/include/asm/kmemcheck.h
new file mode 100644
index 00000000000..ed01518f297
--- /dev/null
+++ b/arch/x86/include/asm/kmemcheck.h
@@ -0,0 +1,42 @@
+#ifndef ASM_X86_KMEMCHECK_H
+#define ASM_X86_KMEMCHECK_H
+
+#include <linux/types.h>
+#include <asm/ptrace.h>
+
+#ifdef CONFIG_KMEMCHECK
+bool kmemcheck_active(struct pt_regs *regs);
+
+void kmemcheck_show(struct pt_regs *regs);
+void kmemcheck_hide(struct pt_regs *regs);
+
+bool kmemcheck_fault(struct pt_regs *regs,
+ unsigned long address, unsigned long error_code);
+bool kmemcheck_trap(struct pt_regs *regs);
+#else
+static inline bool kmemcheck_active(struct pt_regs *regs)
+{
+ return false;
+}
+
+static inline void kmemcheck_show(struct pt_regs *regs)
+{
+}
+
+static inline void kmemcheck_hide(struct pt_regs *regs)
+{
+}
+
+static inline bool kmemcheck_fault(struct pt_regs *regs,
+ unsigned long address, unsigned long error_code)
+{
+ return false;
+}
+
+static inline bool kmemcheck_trap(struct pt_regs *regs)
+{
+ return false;
+}
+#endif /* CONFIG_KMEMCHECK */
+
+#endif
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 18ef7ebf263..c5a08079ad5 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -317,6 +317,15 @@ static inline int pte_present(pte_t a)
return pte_flags(a) & (_PAGE_PRESENT | _PAGE_PROTNONE);
}
+static inline int pte_hidden(pte_t x)
+{
+#ifdef CONFIG_KMEMCHECK
+ return pte_flags(x) & _PAGE_HIDDEN;
+#else
+ return 0;
+#endif
+}
+
static inline int pmd_present(pmd_t pmd)
{
return pmd_flags(pmd) & _PAGE_PRESENT;
diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h
index 4d258ad76a0..9b5c92140aa 100644
--- a/arch/x86/include/asm/pgtable_types.h
+++ b/arch/x86/include/asm/pgtable_types.h
@@ -18,7 +18,7 @@
#define _PAGE_BIT_GLOBAL 8 /* Global TLB entry PPro+ */
#define _PAGE_BIT_UNUSED1 9 /* available for programmer */
#define _PAGE_BIT_IOMAP 10 /* flag used to indicate IO mapping */
-#define _PAGE_BIT_UNUSED3 11
+#define _PAGE_BIT_HIDDEN 11 /* hidden by kmemcheck */
#define _PAGE_BIT_PAT_LARGE 12 /* On 2MB or 1GB pages */
#define _PAGE_BIT_SPECIAL _PAGE_BIT_UNUSED1
#define _PAGE_BIT_CPA_TEST _PAGE_BIT_UNUSED1
@@ -41,7 +41,7 @@
#define _PAGE_GLOBAL (_AT(pteval_t, 1) << _PAGE_BIT_GLOBAL)
#define _PAGE_UNUSED1 (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED1)
#define _PAGE_IOMAP (_AT(pteval_t, 1) << _PAGE_BIT_IOMAP)
-#define _PAGE_UNUSED3 (_AT(pteval_t, 1) << _PAGE_BIT_UNUSED3)
+#define _PAGE_HIDDEN (_AT(pteval_t, 1) << _PAGE_BIT_HIDDEN)
#define _PAGE_PAT (_AT(pteval_t, 1) << _PAGE_BIT_PAT)
#define _PAGE_PAT_LARGE (_AT(pteval_t, 1) << _PAGE_BIT_PAT_LARGE)
#define _PAGE_SPECIAL (_AT(pteval_t, 1) << _PAGE_BIT_SPECIAL)