Re: kernel oops and panic in acpi_atomic_read under 2.6.39.3. call trace included

["Rafael J. Wysocki" <rjw@sisk.pl>]

Hi,

On Monday, August 22, 2011, Rick Warner wrote:
...
> Hi Rafael,
> 
> Thanks for the off-list help in getting you this info.
> 
> I had already rebuilt the kernel using the change I mentioned earlier (test on 
> !&g->error_status_address) since the call trace I got.
> 
> I luckily still had a copy of the kernel and modules I built previously using 
> just your patch, so I undid my change to the ghes.c source, leaving just your 
> patch but not mine so it would match the ghes.ko module I ran on.  This is the 
> output of gdb on that ghes.ko now:
> 
> (gdb) l *ghes_read_estatus+0x38
> 0x258 is in ghes_read_estatus (drivers/acpi/apei/ghes.c:296).
> warning: Source file is more recent than executable.
> 291             int rc;
> 292             if (!g)
> 293                     return -EINVAL;
> 294
> 295             rc = acpi_atomic_read(&buf_paddr, &g->error_status_address);
> 296             if (rc) {
> 297                     if (!silent && printk_ratelimit())
> 298                             pr_warning(FW_WARN GHES_PFX
> 299     "Failed to read error status block address for hardware error source: 
> %d.\n",
> 300                                        g->header.source_id);
> 
> The warning about the source being newer is because of the reverted change in 
> the ghes.c source mentioned above.

OK, since &buf_addr cannot be NULL, perhaps ghes is.  Please check if the
appended patch makes a difference.

Thanks,
Rafael

---
 drivers/acpi/apei/ghes.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

Index: linux/drivers/acpi/apei/ghes.c
===================================================================
--- linux.orig/drivers/acpi/apei/ghes.c
+++ linux/drivers/acpi/apei/ghes.c
@@ -393,11 +393,16 @@ static void ghes_copy_tofrom_phys(void *
 
 static int ghes_read_estatus(struct ghes *ghes, int silent)
 {
-	struct acpi_hest_generic *g = ghes->generic;
+	struct acpi_hest_generic *g;
 	u64 buf_paddr;
 	u32 len;
 	int rc;
 
+	if (!ghes || !ghes->generic)
+		return -EINVAL;
+
+	g = ghes->generic;
+
 	rc = acpi_atomic_read(&buf_paddr, &g->error_status_address);
 	if (rc) {
 		if (!silent && printk_ratelimit())