2013-04-11 18:56:39

by Dave Jones

Subject: print out hardware name & modules list when we encounter bad page tables.

Given we have been seeing a lot of reports of page table corruption
for a while now, perhaps if we print out the hardware name, and list
of modules loaded, we might see some patterns emerging.

Signed-off-by: Dave Jones <[email protected]>

diff -durpN '--exclude-from=/home/davej/.exclude' /home/davej/src/kernel/git-trees/linux/include/asm-generic/bug.h linux-dj/include/asm-generic/bug.h
--- linux/include/asm-generic/bug.h 2013-01-04 18:57:12.604282214 -0500
+++ linux-dj/include/asm-generic/bug.h 2013-02-28 20:04:37.649304147 -0500
@@ -55,6 +55,8 @@ struct bug_entry {
#define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while(0)
#endif

+void print_hardware_dmi_name(void);
+
/*
* WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
* significant issues that need prompt attention if they should ever
diff -durpN '--exclude-from=/home/davej/.exclude' /home/davej/src/kernel/git-trees/linux/kernel/panic.c linux-dj/kernel/panic.c
--- linux/kernel/panic.c 2013-02-26 14:41:18.544116674 -0500
+++ linux-dj/kernel/panic.c 2013-02-28 20:04:37.666304115 -0500
@@ -397,16 +397,22 @@ struct slowpath_args {
va_list args;
};

-static void warn_slowpath_common(const char *file, int line, void *caller,
- unsigned taint, struct slowpath_args *args)
+void print_hardware_dmi_name(void)
{
const char *board;

- printk(KERN_WARNING "------------[ cut here ]------------\n");
- printk(KERN_WARNING "WARNING: at %s:%d %pS()\n", file, line, caller);
board = dmi_get_system_info(DMI_PRODUCT_NAME);
if (board)
printk(KERN_WARNING "Hardware name: %s\n", board);
+}
+
+static void warn_slowpath_common(const char *file, int line, void *caller,
+ unsigned taint, struct slowpath_args *args)
+{
+ printk(KERN_WARNING "------------[ cut here ]------------\n");
+ printk(KERN_WARNING "WARNING: at %s:%d %pS()\n", file, line, caller);
+
+ print_hardware_dmi_name();

if (args)
vprintk(args->fmt, args->args);
diff -durpN '--exclude-from=/home/davej/.exclude' /home/davej/src/kernel/git-trees/linux/mm/memory.c linux-dj/mm/memory.c
--- linux/mm/memory.c 2013-02-26 14:41:18.591116577 -0500
+++ linux-dj/mm/memory.c 2013-02-28 20:04:37.678304092 -0500
@@ -57,6 +57,7 @@
#include <linux/swapops.h>
#include <linux/elf.h>
#include <linux/gfp.h>
+#include <linux/module.h>
#include <linux/migrate.h>
#include <linux/string.h>

@@ -705,6 +706,9 @@ static void print_bad_pte(struct vm_area
"BUG: Bad page map in process %s pte:%08llx pmd:%08llx\n",
current->comm,
(long long)pte_val(pte), (long long)pmd_val(*pmd));
+ print_hardware_dmi_name();
+ print_modules();
+
if (page)
dump_page(page);
printk(KERN_ALERT
--- linux-dj/mm/page_alloc.c~ 2013-04-11 11:47:12.536675503 -0400
+++ linux-dj/mm/page_alloc.c 2013-04-11 11:47:16.416667806 -0400
@@ -321,6 +321,7 @@ static void bad_page(struct page *page)
current->comm, page_to_pfn(page));
dump_page(page);

+ print_hardware_dmi_name();
print_modules();
dump_stack();
out:

2013-04-16 12:21:49

by Josh Boyer

Subject: Re: print out hardware name & modules list when we encounter bad page tables.

On Thu, Apr 11, 2013 at 2:56 PM, Dave Jones <[email protected]> wrote:
> Given we have been seeing a lot of reports of page table corruption
> for a while now, perhaps if we print out the hardware name, and list
> of modules loaded, we might see some patterns emerging.
>
> Signed-off-by: Dave Jones <[email protected]>
>
> diff -durpN '--exclude-from=/home/davej/.exclude' /home/davej/src/kernel/git-trees/linux/include/asm-generic/bug.h linux-dj/include/asm-generic/bug.h
> --- linux/include/asm-generic/bug.h 2013-01-04 18:57:12.604282214 -0500
> +++ linux-dj/include/asm-generic/bug.h 2013-02-28 20:04:37.649304147 -0500
> @@ -55,6 +55,8 @@ struct bug_entry {
> #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while(0)
> #endif
>
> +void print_hardware_dmi_name(void);
> +
> /*
> * WARN(), WARN_ON(), WARN_ON_ONCE, and so on can be used to report
> * significant issues that need prompt attention if they should ever
> diff -durpN '--exclude-from=/home/davej/.exclude' /home/davej/src/kernel/git-trees/linux/kernel/panic.c linux-dj/kernel/panic.c
> --- linux/kernel/panic.c 2013-02-26 14:41:18.544116674 -0500
> +++ linux-dj/kernel/panic.c 2013-02-28 20:04:37.666304115 -0500
> @@ -397,16 +397,22 @@ struct slowpath_args {
> va_list args;
> };
>
> -static void warn_slowpath_common(const char *file, int line, void *caller,
> - unsigned taint, struct slowpath_args *args)
> +void print_hardware_dmi_name(void)
> {

This fails to build on arches that define __WARN_TAINT. Just move the
new function definition above the WANT_WARN_ON_SLOWPATH define and it
should be fine.

josh