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-rw-r--r--arch/x86/kernel/reboot.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
index 02693dd9a079..d64889aa2d46 100644
--- a/arch/x86/kernel/reboot.c
+++ b/arch/x86/kernel/reboot.c
@@ -718,6 +718,7 @@ static int crashing_cpu;
static nmi_shootdown_cb shootdown_callback;
static atomic_t waiting_for_crash_ipi;
+static int crash_ipi_issued;
static int crash_nmi_callback(unsigned int val, struct pt_regs *regs)
{
@@ -780,6 +781,9 @@ void nmi_shootdown_cpus(nmi_shootdown_cb callback)
smp_send_nmi_allbutself();
+ /* Kick CPUs looping in NMI context. */
+ WRITE_ONCE(crash_ipi_issued, 1);
+
msecs = 1000; /* Wait at most a second for the other cpus to stop */
while ((atomic_read(&waiting_for_crash_ipi) > 0) && msecs) {
mdelay(1);
@@ -788,9 +792,35 @@ void nmi_shootdown_cpus(nmi_shootdown_cb callback)
/* Leave the nmi callback set */
}
+
+/*
+ * Check if the crash dumping IPI got issued and if so, call its callback
+ * directly. This function is used when we have already been in NMI handler.
+ * It doesn't return.
+ */
+void run_crash_ipi_callback(struct pt_regs *regs)
+{
+ if (crash_ipi_issued)
+ crash_nmi_callback(0, regs);
+}
+
+/* Override the weak function in kernel/panic.c */
+void nmi_panic_self_stop(struct pt_regs *regs)
+{
+ while (1) {
+ /* If no CPU is preparing crash dump, we simply loop here. */
+ run_crash_ipi_callback(regs);
+ cpu_relax();
+ }
+}
+
#else /* !CONFIG_SMP */
void nmi_shootdown_cpus(nmi_shootdown_cb callback)
{
/* No other CPUs to shoot down */
}
+
+void run_crash_ipi_callback(struct pt_regs *regs)
+{
+}
#endif
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