Re: 2.6.35.5: hibernation broken... AGAIN
From: Rafael J. Wysocki
Date: Fri Nov 26 2010 - 18:11:20 EST
On Friday, November 26, 2010, Ondrej Zary wrote:
> On Thursday 18 November 2010, Hugh Dickins wrote:
> > On Wed, 17 Nov 2010, Ondrej Zary wrote:
> > > On Wednesday 17 November 2010 22:12:01 Rafael J. Wysocki wrote:
> > > > On Wednesday, November 17, 2010, Andrew Morton wrote:
> > > > > On Wed, 17 Nov 2010 21:53:52 +0100
> > > > >
> > > > > "Rafael J. Wysocki" <rjw@xxxxxxx> wrote:
> > > > > > On Wednesday, November 17, 2010, Ondrej Zary wrote:
> > > > > > > Hello,
> > > > > > > the nasty memory-corrupting hibernation bug
> > > > > > > https://bugzilla.kernel.org/show_bug.cgi?id=15753 is back since
> > > > > > > 2.6.35.5. 2.6.35.4 works fine, 2.6.35.5 crashes after two days.
> >
> > That's distressing, for both and all of us: I'm sorry.
> >
> > > > > > > It seems to be caused by
> > > > > > > b77c254d8d66e5e9aa81239fedba9f3d568097d9.
> > > > >
> > > > > commit b77c254d8d66e5e9aa81239fedba9f3d568097d9
> > > > > Author: Hugh Dickins <hughd@xxxxxxxxxx>
> > > > > Date: Thu Sep 9 16:38:09 2010 -0700
> > > > >
> > > > > swap: prevent reuse during hibernation
> >
> > Embarrassing: I suspect that I've been confused, not for the first
> > time, by the fork-like nature of hibernation and its images.
> > I wonder if this patch below fixes it, Ondrej?
> >
> > (And is it kernel swsusp or user swsusp that you're using? May not
> > matter at all, but will help us to think more clearly about it,
> > if the corruption remains after this patch.)
> >
> > Rafael, do you agree that this patch was actually required even for
> > your original commit 452aa6999e6703ffbddd7f6ea124d3968915f3e3
> > mm/pm: force GFP_NOIO during suspend/hibernation and resume?
> >
> > Or am I still just as confused? Or if not, are there more forking
> > places which require a similar patch?
> >
> > Not signing it off yet,
> > Hugh
>
> Could you please do that? The patch fixes the problem.
Can you check if the problem is also fixed by the patch below, please?
Rafael
---
kernel/power/hibernate.c | 36 ++++++++++++++++++++++++++----------
kernel/power/power.h | 1 +
kernel/power/user.c | 1 +
3 files changed, 28 insertions(+), 10 deletions(-)
Index: linux-2.6/kernel/power/hibernate.c
===================================================================
--- linux-2.6.orig/kernel/power/hibernate.c
+++ linux-2.6/kernel/power/hibernate.c
@@ -29,6 +29,21 @@
#include "power.h"
+static gfp_t saved_gfp_mask;
+
+static void hibernate_restrict_gfp_mask(void)
+{
+ saved_gfp_mask = clear_gfp_allowed_mask(GFP_IOFS);
+}
+
+void hibernate_restore_gfp_mask(void)
+{
+ if (saved_gfp_mask) {
+ set_gfp_allowed_mask(saved_gfp_mask);
+ saved_gfp_mask = 0;
+ }
+}
+
static int nocompress = 0;
static int noresume = 0;
static char resume_file[256] = CONFIG_PM_STD_PARTITION;
@@ -327,7 +342,6 @@ static int create_image(int platform_mod
int hibernation_snapshot(int platform_mode)
{
int error;
- gfp_t saved_mask;
error = platform_begin(platform_mode);
if (error)
@@ -339,7 +353,7 @@ int hibernation_snapshot(int platform_mo
goto Close;
suspend_console();
- saved_mask = clear_gfp_allowed_mask(GFP_IOFS);
+ hibernate_restrict_gfp_mask();
error = dpm_suspend_start(PMSG_FREEZE);
if (error)
goto Recover_platform;
@@ -348,7 +362,10 @@ int hibernation_snapshot(int platform_mo
goto Recover_platform;
error = create_image(platform_mode);
- /* Control returns here after successful restore */
+ /*
+ * Control returns here (1) after the image has been created or the
+ * image creation has failed and (2) after a successful restore.
+ */
Resume_devices:
/* We may need to release the preallocated image pages here. */
@@ -357,7 +374,10 @@ int hibernation_snapshot(int platform_mo
dpm_resume_end(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
- set_gfp_allowed_mask(saved_mask);
+
+ if (error || !in_suspend)
+ hibernate_restore_gfp_mask();
+
resume_console();
Close:
platform_end(platform_mode);
@@ -452,17 +472,16 @@ static int resume_target_kernel(bool pla
int hibernation_restore(int platform_mode)
{
int error;
- gfp_t saved_mask;
pm_prepare_console();
suspend_console();
- saved_mask = clear_gfp_allowed_mask(GFP_IOFS);
+ hibernate_restrict_gfp_mask();
error = dpm_suspend_start(PMSG_QUIESCE);
if (!error) {
error = resume_target_kernel(platform_mode);
dpm_resume_end(PMSG_RECOVER);
}
- set_gfp_allowed_mask(saved_mask);
+ hibernate_restore_gfp_mask();
resume_console();
pm_restore_console();
return error;
@@ -476,7 +495,6 @@ int hibernation_restore(int platform_mod
int hibernation_platform_enter(void)
{
int error;
- gfp_t saved_mask;
if (!hibernation_ops)
return -ENOSYS;
@@ -492,7 +510,6 @@ int hibernation_platform_enter(void)
entering_platform_hibernation = true;
suspend_console();
- saved_mask = clear_gfp_allowed_mask(GFP_IOFS);
error = dpm_suspend_start(PMSG_HIBERNATE);
if (error) {
if (hibernation_ops->recover)
@@ -536,7 +553,6 @@ int hibernation_platform_enter(void)
Resume_devices:
entering_platform_hibernation = false;
dpm_resume_end(PMSG_RESTORE);
- set_gfp_allowed_mask(saved_mask);
resume_console();
Close:
Index: linux-2.6/kernel/power/power.h
===================================================================
--- linux-2.6.orig/kernel/power/power.h
+++ linux-2.6/kernel/power/power.h
@@ -52,6 +52,7 @@ static inline char *check_image_kernel(s
extern int hibernation_snapshot(int platform_mode);
extern int hibernation_restore(int platform_mode);
extern int hibernation_platform_enter(void);
+extern void hibernate_restore_gfp_mask(void);
#else /* !CONFIG_HIBERNATION */
Index: linux-2.6/kernel/power/user.c
===================================================================
--- linux-2.6.orig/kernel/power/user.c
+++ linux-2.6/kernel/power/user.c
@@ -263,6 +263,7 @@ static long snapshot_ioctl(struct file *
case SNAPSHOT_UNFREEZE:
if (!data->frozen || data->ready)
break;
+ hibernate_restore_gfp_mask();
thaw_processes();
usermodehelper_enable();
data->frozen = 0;
--
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