6.17-stable review patch. If anyone has any objections, please let me know.
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From: Marek Marczykowski-Górecki marmarek@invisiblethingslab.com
commit 9d52b0b41be5b932a0a929c10038f1bb04af4ca5 upstream.
Xen's do_suspend() calls dpm_suspend_start() without taking required system_transition_mutex. Since 12ffc3b1513eb moved the pm_restrict_gfp_mask() call, not taking that mutex results in a WARN.
Take the mutex in do_suspend(), and use mutex_trylock() to follow how enter_state() does this.
Suggested-by: Jürgen Groß jgross@suse.com Fixes: 12ffc3b1513eb "PM: Restrict swap use to later in the suspend sequence" Link: https://lore.kernel.org/xen-devel/aKiBJeqsYx_4Top5@mail-itl/ Signed-off-by: Marek Marczykowski-Górecki marmarek@invisiblethingslab.com Cc: stable@vger.kernel.org # v6.16+ Reviewed-by: Juergen Gross jgross@suse.com Signed-off-by: Juergen Gross jgross@suse.com Message-ID: 20250921162853.223116-1-marmarek@invisiblethingslab.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/xen/manage.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-)
--- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -11,6 +11,7 @@ #include <linux/reboot.h> #include <linux/sysrq.h> #include <linux/stop_machine.h> +#include <linux/suspend.h> #include <linux/freezer.h> #include <linux/syscore_ops.h> #include <linux/export.h> @@ -95,10 +96,16 @@ static void do_suspend(void)
shutting_down = SHUTDOWN_SUSPEND;
+ if (!mutex_trylock(&system_transition_mutex)) + { + pr_err("%s: failed to take system_transition_mutex\n", __func__); + goto out; + } + err = freeze_processes(); if (err) { pr_err("%s: freeze processes failed %d\n", __func__, err); - goto out; + goto out_unlock; }
err = freeze_kernel_threads(); @@ -154,6 +161,8 @@ out_resume:
out_thaw: thaw_processes(); +out_unlock: + mutex_unlock(&system_transition_mutex); out: shutting_down = SHUTDOWN_INVALID; }