From 09a0de491c5ec0e40f8f9d21b13af306667360f4 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 3 Aug 2018 14:44:59 +0200 Subject: genirq: Make force irq threading setup more robust commit d1f0301b3333eef5efbfa1fe0f0edbea01863d5d upstream. The support of force threading interrupts which are set up with both a primary and a threaded handler wreckaged the setup of regular requested threaded interrupts (primary handler == NULL). The reason is that it does not check whether the primary handler is set to the default handler which wakes the handler thread. Instead it replaces the thread handler with the primary handler as it would do with force threaded interrupts which have been requested via request_irq(). So both the primary and the thread handler become the same which then triggers the warnon that the thread handler tries to wakeup a not configured secondary thread. Fortunately this only happens when the driver omits the IRQF_ONESHOT flag when requesting the threaded interrupt, which is normaly caught by the sanity checks when force irq threading is disabled. Fix it by skipping the force threading setup when a regular threaded interrupt is requested. As a consequence the interrupt request which lacks the IRQ_ONESHOT flag is rejected correctly instead of silently wreckaging it. Fixes: 2a1d3ab8986d ("genirq: Handle force threading of irqs with primary and thread handler") Reported-by: Kurt Kanzenbach Signed-off-by: Thomas Gleixner Tested-by: Kurt Kanzenbach Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- kernel/irq/manage.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 5f55a8bf5264..0df2b44dac7c 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1012,6 +1012,13 @@ static int irq_setup_forced_threading(struct irqaction *new) if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT)) return 0; + /* + * No further action required for interrupts which are requested as + * threaded interrupts already + */ + if (new->handler == irq_default_primary_handler) + return 0; + new->flags |= IRQF_ONESHOT; /* @@ -1019,7 +1026,7 @@ static int irq_setup_forced_threading(struct irqaction *new) * thread handler. We force thread them as well by creating a * secondary action. */ - if (new->handler != irq_default_primary_handler && new->thread_fn) { + if (new->handler && new->thread_fn) { /* Allocate the secondary action */ new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL); if (!new->secondary) -- cgit v1.2.3 From 0a022859e2304b21a6cd620c2eb008cc60de0ab8 Mon Sep 17 00:00:00 2001 From: Anna-Maria Gleixner Date: Tue, 31 Jul 2018 18:13:58 +0200 Subject: nohz: Fix local_timer_softirq_pending() commit 80d20d35af1edd632a5e7a3b9c0ab7ceff92769e upstream. local_timer_softirq_pending() checks whether the timer softirq is pending with: local_softirq_pending() & TIMER_SOFTIRQ. This is wrong because TIMER_SOFTIRQ is the softirq number and not a bitmask. So the test checks for the wrong bit. Use BIT(TIMER_SOFTIRQ) instead. Fixes: 5d62c183f9e9 ("nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()") Signed-off-by: Anna-Maria Gleixner Signed-off-by: Thomas Gleixner Reviewed-by: Paul E. McKenney Reviewed-by: Daniel Bristot de Oliveira Acked-by: Frederic Weisbecker Cc: bigeasy@linutronix.de Cc: peterz@infradead.org Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20180731161358.29472-1-anna-maria@linutronix.de Signed-off-by: Greg Kroah-Hartman --- kernel/time/tick-sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index e5d228f7224c..5ad2e852e9f6 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -570,7 +570,7 @@ static void tick_nohz_restart(struct tick_sched *ts, ktime_t now) static inline bool local_timer_softirq_pending(void) { - return local_softirq_pending() & TIMER_SOFTIRQ; + return local_softirq_pending() & BIT(TIMER_SOFTIRQ); } static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts, -- cgit v1.2.3 From 731ccd90b8dc6697fefb62f43ed6f8d253d7fd5b Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 14 Jul 2018 01:28:15 +0900 Subject: ring_buffer: tracing: Inherit the tracing setting to next ring buffer commit 73c8d8945505acdcbae137c2e00a1232e0be709f upstream. Maintain the tracing on/off setting of the ring_buffer when switching to the trace buffer snapshot. Taking a snapshot is done by swapping the backup ring buffer (max_tr_buffer). But since the tracing on/off setting is defined by the ring buffer, when swapping it, the tracing on/off setting can also be changed. This causes a strange result like below: /sys/kernel/debug/tracing # cat tracing_on 1 /sys/kernel/debug/tracing # echo 0 > tracing_on /sys/kernel/debug/tracing # cat tracing_on 0 /sys/kernel/debug/tracing # echo 1 > snapshot /sys/kernel/debug/tracing # cat tracing_on 1 /sys/kernel/debug/tracing # echo 1 > snapshot /sys/kernel/debug/tracing # cat tracing_on 0 We don't touch tracing_on, but snapshot changes tracing_on setting each time. This is an anomaly, because user doesn't know that each "ring_buffer" stores its own tracing-enable state and the snapshot is done by swapping ring buffers. Link: http://lkml.kernel.org/r/153149929558.11274.11730609978254724394.stgit@devbox Cc: Ingo Molnar Cc: Shuah Khan Cc: Tom Zanussi Cc: Hiraku Toyooka Cc: stable@vger.kernel.org Fixes: debdd57f5145 ("tracing: Make a snapshot feature available from userspace") Signed-off-by: Masami Hiramatsu [ Updated commit log and comment in the code ] Signed-off-by: Steven Rostedt (VMware) Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman --- kernel/trace/ring_buffer.c | 16 ++++++++++++++++ kernel/trace/trace.c | 6 ++++++ 2 files changed, 22 insertions(+) (limited to 'kernel') diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index d9cd6191760b..fdaa88f38aec 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -3141,6 +3141,22 @@ int ring_buffer_record_is_on(struct ring_buffer *buffer) return !atomic_read(&buffer->record_disabled); } +/** + * ring_buffer_record_is_set_on - return true if the ring buffer is set writable + * @buffer: The ring buffer to see if write is set enabled + * + * Returns true if the ring buffer is set writable by ring_buffer_record_on(). + * Note that this does NOT mean it is in a writable state. + * + * It may return true when the ring buffer has been disabled by + * ring_buffer_record_disable(), as that is a temporary disabling of + * the ring buffer. + */ +int ring_buffer_record_is_set_on(struct ring_buffer *buffer) +{ + return !(atomic_read(&buffer->record_disabled) & RB_BUFFER_OFF); +} + /** * ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer * @buffer: The ring buffer to stop writes to. diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8aef4e63ac57..1b980a8ef791 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1088,6 +1088,12 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) arch_spin_lock(&tr->max_lock); + /* Inherit the recordable setting from trace_buffer */ + if (ring_buffer_record_is_set_on(tr->trace_buffer.buffer)) + ring_buffer_record_on(tr->max_buffer.buffer); + else + ring_buffer_record_off(tr->max_buffer.buffer); + buf = tr->trace_buffer.buffer; tr->trace_buffer.buffer = tr->max_buffer.buffer; tr->max_buffer.buffer = buf; -- cgit v1.2.3