This is a note to let you know that I've just added the patch titled parisc/kgdb: add kgdb_roundup() to make kgdb work with idle polling to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: parisc-kgdb-add-kgdb_roundup-to-make-kgdb-work-with-.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit ecc1837652b0344ae9ee569421a11162638ff10e Author: Sven Schnelle <svens@xxxxxxxxxxxxxx> Date: Fri Oct 15 21:49:23 2021 +0200 parisc/kgdb: add kgdb_roundup() to make kgdb work with idle polling [ 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@xxxxxxxxxxxxxx> Signed-off-by: Helge Deller <deller@xxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c index 5e26dbede5fc2..ae4fc8769c38b 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); }