diff options
| author | Kunwu Chan <kunwu.chan@gmail.com> | 2026-09-14 17:34:19 +0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2026-10-01 17:21:08 -0700 |
| commit | 92747742d660f52ecccb71cd5f8ff93e27db265a (patch) | |
| tree | 1aa06a8da119358dbdb734192ab9ac593bfbbbaf /kernel | |
| parent | 7743179aaa22b6ecb499dbb7fdb4207c8fce6f3e (diff) | |
| download | linux-next-92747742d660f52ecccb71cd5f8ff93e27db265a.tar.gz linux-next-92747742d660f52ecccb71cd5f8ff93e27db265a.zip | |
rcutorture: Add atomic SRCU cross-CPU IRQ context mismatch test
Add testtype 7 to verify that lockdep detects an IRQ-context
mismatch when an atomic SRCU read-side critical section is held
with IRQs enabled on one CPU and synchronize_srcu_atomic() is
called from an IPI handler on another CPU.
This covers the cross-CPU case that cannot be detected by
checking the current task's held locks.
Co-developed-by: Zqiang <qiang.zhang@linux.dev>
Signed-off-by: Zqiang <qiang.zhang@linux.dev>
Signed-off-by: Kunwu Chan <kunwu.chan@gmail.com>
Acked-by: Boqun Feng <boqun@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/rcu/rcutorture.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 35dc61d871b9..968343be4e0d 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -4695,6 +4695,8 @@ DEFINE_STATIC_SRCU_ATOMIC(srcu7_atomic); DEFINE_STATIC_SRCU_ATOMIC(srcu8_atomic); DEFINE_STATIC_SRCU_ATOMIC(srcu9_atomic); +DEFINE_STATIC_SRCU_ATOMIC(srcu_irq); + static int srcu_lockdep_next(const char *f, const char *fl, const char *fs, const char *fu, int i, int cyclelen, int deadlock) { @@ -4709,6 +4711,11 @@ static int srcu_lockdep_next(const char *f, const char *fl, const char *fs, cons return j; } +static void srcu_sync_irq(void *unused) +{ + synchronize_srcu_atomic(&srcu_irq); +} + // Test lockdep on SRCU-based deadlock scenarios. static void rcu_torture_init_srcu_lockdep(void) { @@ -4892,13 +4899,31 @@ static void rcu_torture_init_srcu_lockdep(void) return; } + if (testtype == 7) { + int cpu; + + for (i = 0; i < cyclelen; i++) { + idx = srcu_read_lock_atomic(&srcu_irq); + cpu = cpumask_any_but(cpu_online_mask, + smp_processor_id()); + if (cpu < nr_cpu_ids) { + pr_info("%s: CPU%d sending IPI to CPU%d\n", + __func__, smp_processor_id(), cpu); + smp_call_function_single(cpu, srcu_sync_irq, + NULL, 1); + } + srcu_read_unlock_atomic(&srcu_irq, idx); + } + return; + } + err_out: pr_info("%s: test_srcu_lockdep = %05d does nothing.\n", __func__, test_srcu_lockdep); pr_info("%s: test_srcu_lockdep = DNNL.\n", __func__); pr_info("%s: D: Deadlock if nonzero.\n", __func__); pr_info("%s: NN: Test number, 0=SRCU, 1=SRCU/mutex, 2=SRCU/rwsem, 3=SRCU/Tasks Trace RCU, 4=SRCU_ATOMIC, ", __func__); - pr_cont("5=SRCU_ATOMIC/raw_spinlock, 6=synchronize_srcu_atomic inside rcu_read_lock.\n"); + pr_cont("5=SRCU_ATOMIC/raw_spinlock, 6=synchronize_srcu_atomic inside rcu_read_lock, 7=atomic SRCU cross-CPU IRQ context mismatch.\n"); pr_info("%s: L: Cycle length.\n", __func__); if (!IS_ENABLED(CONFIG_TASKS_TRACE_RCU)) pr_info("%s: NN=3 disallowed because kernel is built with CONFIG_TASKS_TRACE_RCU=n\n", __func__); |