From: Sven Schnelle svens@stackframe.org
[ Upstream commit 66e29fcda1824f0427966fbee2bd2c85bf362c82 ]
With idle polling, IPIs are not sent when a CPU idle, but queued and run later from do_idle(). The default kgdb_call_nmi_hook() implementation gets the pointer to struct pt_regs from get_irq_reqs(), which doesn't work in that case because it was not called from the IPI interrupt handler. Fix it by defining our own kgdb_roundup() function which sents an IPI_ENTER_KGDB. When that IPI is received on the target CPU kgdb_nmicallback() is called.
Signed-off-by: Sven Schnelle svens@stackframe.org Signed-off-by: Helge Deller deller@gmx.de Signed-off-by: Sasha Levin sashal@kernel.org --- arch/parisc/kernel/smp.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-)
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c index 75dab2871346c..af966c1c922ff 100644 --- a/arch/parisc/kernel/smp.c +++ b/arch/parisc/kernel/smp.c @@ -32,6 +32,7 @@ #include <linux/bitops.h> #include <linux/ftrace.h> #include <linux/cpu.h> +#include <linux/kgdb.h>
#include <linux/atomic.h> #include <asm/current.h> @@ -74,7 +75,10 @@ enum ipi_message_type { IPI_CALL_FUNC, IPI_CPU_START, IPI_CPU_STOP, - IPI_CPU_TEST + IPI_CPU_TEST, +#ifdef CONFIG_KGDB + IPI_ENTER_KGDB, +#endif };
@@ -170,7 +174,12 @@ ipi_interrupt(int irq, void *dev_id) case IPI_CPU_TEST: smp_debug(100, KERN_DEBUG "CPU%d is alive!\n", this_cpu); break; - +#ifdef CONFIG_KGDB + case IPI_ENTER_KGDB: + smp_debug(100, KERN_DEBUG "CPU%d ENTER_KGDB\n", this_cpu); + kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs()); + break; +#endif default: printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n", this_cpu, which); @@ -226,6 +235,12 @@ send_IPI_allbutself(enum ipi_message_type op) } }
+#ifdef CONFIG_KGDB +void kgdb_roundup_cpus(void) +{ + send_IPI_allbutself(IPI_ENTER_KGDB); +} +#endif
inline void smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); }