Re: [patch] MCA recovery verify pfn_valid

[Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>]

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How about this?

Thanks,
H.Seto

Verify the pfn is valid before calling pfn_to_page(),
and cut isolation message if nothing was done.

Signed-off-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com>

Russ Anderson wrote:
> Jack Steiner wrote:
>>
>>Perhaps another status should be returned.
> 
> In this case, is any message really needed?  As you say, success is
> is misleading because nothing was done.  Failure is not accurate
> because it didn't fail.  So perhaps a third status that does not
> print any page isolation message is the best solution.

[-- Attachment #2: mca_drv_pfnverify.patch --]
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 arch/ia64/kernel/mca_drv.c |   21 +++++++++++++++------
 1 files changed, 15 insertions(+), 6 deletions(-)

Index: build/arch/ia64/kernel/mca_drv.c
===================================================================
--- build.orig/arch/ia64/kernel/mca_drv.c
+++ build/arch/ia64/kernel/mca_drv.c
@@ -56,8 +56,9 @@ static struct page *page_isolate[MAX_PAG
 static int num_page_isolate = 0;
 
 typedef enum {
-	ISOLATE_NG = 0,
-	ISOLATE_OK = 1
+	ISOLATE_NG,
+	ISOLATE_OK,
+	ISOLATE_NONE
 } isolate_status_t;
 
 /*
@@ -74,7 +75,7 @@ static struct {
  * @paddr:	poisoned memory location
  *
  * Return value:
- *	ISOLATE_OK / ISOLATE_NG
+ *	one of isolate_status_t, ISOLATE_OK/NG/NONE.
  */
 
 static isolate_status_t
@@ -85,7 +86,10 @@ mca_page_isolate(unsigned long paddr)
 
 	/* whether physical address is valid or not */
 	if (!ia64_phys_addr_valid(paddr))
-		return ISOLATE_NG;
+		return ISOLATE_NONE;
+
+	if (!pfn_valid(paddr))
+		return ISOLATE_NONE;
 
 	/* convert physical address to physical page number */
 	p = pfn_to_page(paddr>>PAGE_SHIFT);
@@ -122,10 +126,15 @@ mca_handler_bh(unsigned long paddr)
 		current->pid, current->comm);
 
 	spin_lock(&mca_bh_lock);
-	if (mca_page_isolate(paddr) == ISOLATE_OK) {
+	switch (mca_page_isolate(paddr)) {
+	case ISOLATE_OK:
 		printk(KERN_DEBUG "Page isolation: ( %lx ) success.\n", paddr);
-	} else {
+		break;
+	case ISOLATE_NG:
 		printk(KERN_DEBUG "Page isolation: ( %lx ) failure.\n", paddr);
+		break;
+	default:
+		break;
 	}
 	spin_unlock(&mca_bh_lock);