| Message ID | 20170705140520.4948-1-jgross@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 07/05/2017 10:05 AM, Juergen Gross wrote: > Commit dc6416f1d711eb4c1726e845d653235dcaae12e1 ("xen/x86: Call > cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()") > introduced an error leading to a stack overflow of the idle task when > a cpu was brought offline/online many times: by calling > cpu_startup_entry() instead of returning at the end of xen_play_dead() > do_idle() would be entered again and again. > > Don't use cpu_startup_entry(), but cpuhp_online_idle() instead allowing > to return from xen_play_dead(). > > Cc: <stable@vger.kernel.org> # 4.12 > Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c index aae32535f4ec..3e71246da5fe 100644 --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -19,6 +19,7 @@ #include <linux/irq_work.h> #include <linux/tick.h> #include <linux/nmi.h> +#include <linux/cpuhotplug.h> #include <asm/paravirt.h> #include <asm/desc.h> @@ -417,7 +418,7 @@ static void xen_pv_play_dead(void) /* used only with HOTPLUG_CPU */ */ tick_nohz_idle_enter(); - cpu_startup_entry(CPUHP_AP_ONLINE_IDLE); + cpuhp_online_idle(CPUHP_AP_ONLINE_IDLE); } #else /* !CONFIG_HOTPLUG_CPU */
Commit dc6416f1d711eb4c1726e845d653235dcaae12e1 ("xen/x86: Call cpu_startup_entry(CPUHP_AP_ONLINE_IDLE) from xen_play_dead()") introduced an error leading to a stack overflow of the idle task when a cpu was brought offline/online many times: by calling cpu_startup_entry() instead of returning at the end of xen_play_dead() do_idle() would be entered again and again. Don't use cpu_startup_entry(), but cpuhp_online_idle() instead allowing to return from xen_play_dead(). Cc: <stable@vger.kernel.org> # 4.12 Signed-off-by: Juergen Gross <jgross@suse.com> --- For 4.11 the patch has to be backported. --- arch/x86/xen/smp_pv.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)