When CONFIG_RANDOM_KMALLOC_CACHES or other randomization infrastructrue
enabled, the idle_task's stack may different between the booting kernel
and target kernel. So when resuming from hibernation, an ACTION_BOOT_CPU
IPI wakeup the idle instruction in arch_cpu_idle_dead() and jump to the
interrupt handler. But since the stack pointer is changed, the interrupt
handler cannot restore correct context.
So rename the current arch_cpu_idle_dead() to idle_play_dead(), make it
as the default version of play_dead(), and the new arch_cpu_idle_dead()
call play_dead() directly. For hibernation, implement an arch-specific
hibernate_resume_nonboot_cpu_disable() to use the polling version (idle
instruction is replace by nop, and irq is disabled) of play_dead(), i.e.
poll_play_dead(), to avoid IPI handler corrupting the idle_task's stack
when resuming from hibernation.
This solution is a little similar to commit 406f992e4a372dafbe3c ("x86 /
hibernate: Use hlt_play_dead() when resuming from hibernation").
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx>
---
arch/loongarch/kernel/smp.c | 40 ++++++++++++++++++++++++++++++++++++-
1 file changed, 39 insertions(+), 1 deletion(-)
diff --git a/arch/loongarch/kernel/smp.c b/arch/loongarch/kernel/smp.c
index fbf747447f13..308478f29278 100644
--- a/arch/loongarch/kernel/smp.c
+++ b/arch/loongarch/kernel/smp.c
@@ -19,6 +19,7 @@
#include <linux/smp.h>
#include <linux/threads.h>
#include <linux/export.h>
+#include <linux/suspend.h>
#include <linux/syscore_ops.h>
#include <linux/time.h>
#include <linux/tracepoint.h>
@@ -423,7 +424,7 @@ void loongson_cpu_die(unsigned int cpu)
mb();
}
-void __noreturn arch_cpu_idle_dead(void)
+static void __noreturn idle_play_dead(void)
{
register uint64_t addr;
register void (*init_fn)(void);
@@ -447,6 +448,43 @@ void __noreturn arch_cpu_idle_dead(void)
BUG();
}
+static void __noreturn poll_play_dead(void)
+{
+ register uint64_t addr;
+ register void (*init_fn)(void);
+
+ idle_task_exit();
+ __this_cpu_write(cpu_state, CPU_DEAD);
+
+ __smp_mb();
+ do {
+ __asm__ __volatile__("nop\n\t");
+ addr = iocsr_read64(LOONGARCH_IOCSR_MBUF0);
+ } while (addr == 0);
+
+ init_fn = (void *)TO_CACHE(addr);
+ iocsr_write32(0xffffffff, LOONGARCH_IOCSR_IPI_CLEAR);
+
+ init_fn();
+ BUG();
+}
+
+static void (*play_dead)(void) = idle_play_dead;
+
+void __noreturn arch_cpu_idle_dead(void)
+{
+ play_dead();
+ BUG(); /* play_dead() doesn't return */
+}
+
+#ifdef CONFIG_HIBERNATION
+int hibernate_resume_nonboot_cpu_disable(void)
+{
+ play_dead = poll_play_dead;
+ return suspend_disable_secondary_cpus();
+}
+#endif
+
#endif
/*
--
2.47.1
