From: Hugh Dickins <hugh@veritas.com>
Date: Sun, 7 Sep 2008 08:51:33 +0000 (-0700)
Subject: x86: add periodic corruption check
X-Git-Tag: v2.6.28-rc1~699^2^6~12
X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=bb577f980ef35e2b0d00aeed566724e5032aa5eb;p=linux-2.6-omap-h63xx.git

x86: add periodic corruption check

Perodically check for corruption in low phusical memory.  Don't bother
checking at fault time, since it won't show anything useful.

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index ee89ebc5aab..c239b378097 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -623,6 +623,7 @@ static void __init setup_bios_corruption_check(void)
 }
 
 static int __read_mostly bios_corruption_check = 1;
+static struct timer_list periodic_check_timer;
 
 void check_for_bios_corruption(void)
 {
@@ -650,6 +651,22 @@ void check_for_bios_corruption(void)
 		dump_stack();
 }
 
+static void periodic_check_for_corruption(unsigned long data)
+{
+	check_for_bios_corruption();
+	mod_timer(&periodic_check_timer, jiffies + 60*HZ);
+}
+
+void start_periodic_check_for_corruption(void)
+{
+	if (!bios_corruption_check)
+		return;
+
+	init_timer(&periodic_check_timer);
+	periodic_check_timer.function = &periodic_check_for_corruption;
+	periodic_check_for_corruption(0);
+}
+
 static int set_bios_corruption_check(char *arg)
 {
 	char *end;
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 5140bdf0302..455f3fe67b4 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -848,8 +848,6 @@ no_context:
  * Oops. The kernel tried to access some bad page. We'll have to
  * terminate things with extreme prejudice.
  */
-	check_for_bios_corruption();
-
 #ifdef CONFIG_X86_32
 	bust_spinlocks(1);
 #else
diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c
index d37f29376b0..657a16ad61b 100644
--- a/arch/x86/mm/init_32.c
+++ b/arch/x86/mm/init_32.c
@@ -907,6 +907,8 @@ void __init mem_init(void)
 	int codesize, reservedpages, datasize, initsize;
 	int tmp;
 
+	start_periodic_check_for_corruption();
+
 #ifdef CONFIG_FLATMEM
 	BUG_ON(!mem_map);
 #endif
diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c
index d3746efb060..f4db5276fa2 100644
--- a/arch/x86/mm/init_64.c
+++ b/arch/x86/mm/init_64.c
@@ -769,6 +769,8 @@ void __init mem_init(void)
 {
 	long codesize, reservedpages, datasize, initsize;
 
+	start_periodic_check_for_corruption();
+
 	pci_iommu_alloc();
 
 	/* clear_bss() already clear the empty_zero_page */
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 8017129e6b6..00bb251c645 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -246,6 +246,7 @@ extern int root_mountflags;
  * able to scatter it around anywhere in the kernel.
  */
 void check_for_bios_corruption(void);
+void start_periodic_check_for_corruption(void);
 #else
 static inline void check_for_bios_corruption(void)
 {