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From:   "Rafael J. Wysocki" <rjw@rjwysocki.net>
To:     Linux PM <linux-pm@vger.kernel.org>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Kees Cook <keescook@chromium.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: [PATCH] PM: core: Do not randomize struct dev_pm_ops layout
Date:   Thu, 04 Aug 2022 19:15:08 +0200
Message-ID: <2643836.mvXUDI8C0e@kreacher>
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From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Because __rpm_get_callback() uses offsetof() to compute the address of
the callback in question in struct dev_pm_ops, randomizing the layout
of the latter leads to interesting, but unfortunately also undesirable
results in some cases.

Prevent that from happening by using the __no_randomize_layout
annotation on struct dev_pm_ops.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 include/linux/pm.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux-pm/include/linux/pm.h
===================================================================
--- linux-pm.orig/include/linux/pm.h
+++ linux-pm/include/linux/pm.h
@@ -307,7 +307,7 @@ struct dev_pm_ops {
 	int (*runtime_suspend)(struct device *dev);
 	int (*runtime_resume)(struct device *dev);
 	int (*runtime_idle)(struct device *dev);
-};
+} __no_randomize_layout;
 
 #define SYSTEM_SLEEP_PM_OPS(suspend_fn, resume_fn) \
 	.suspend = pm_sleep_ptr(suspend_fn), \