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-rw-r--r--kernel/dma/debug.c9
-rw-r--r--kernel/dma/direct.h7
-rw-r--r--kernel/dma/mapping.c6
-rw-r--r--kernel/dma/swiotlb.c21
-rw-r--r--kernel/futex/core.c2
-rw-r--r--kernel/futex/pi.c3
-rw-r--r--kernel/futex/syscalls.c8
-rw-r--r--kernel/power/main.c2
-rw-r--r--kernel/power/snapshot.c11
-rw-r--r--kernel/rcu/rcu.h9
-rw-r--r--kernel/rcu/srcutiny.c19
-rw-r--r--kernel/rcu/srcutree.c211
-rw-r--r--kernel/sysctl.c2
-rw-r--r--kernel/time/alarmtimer.c2
-rw-r--r--kernel/trace/trace_events_trigger.c79
-rw-r--r--kernel/trace/trace_osnoise.c10
16 files changed, 259 insertions, 142 deletions
diff --git a/kernel/dma/debug.c b/kernel/dma/debug.c
index 86f87e43438c..0677918f06a8 100644
--- a/kernel/dma/debug.c
+++ b/kernel/dma/debug.c
@@ -453,7 +453,7 @@ static int active_cacheline_set_overlap(phys_addr_t cln, int overlap)
return overlap;
}
-static void active_cacheline_inc_overlap(phys_addr_t cln)
+static void active_cacheline_inc_overlap(phys_addr_t cln, bool is_cache_clean)
{
int overlap = active_cacheline_read_overlap(cln);
@@ -462,7 +462,7 @@ static void active_cacheline_inc_overlap(phys_addr_t cln)
/* If we overflowed the overlap counter then we're potentially
* leaking dma-mappings.
*/
- WARN_ONCE(overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
+ WARN_ONCE(!is_cache_clean && overlap > ACTIVE_CACHELINE_MAX_OVERLAP,
pr_fmt("exceeded %d overlapping mappings of cacheline %pa\n"),
ACTIVE_CACHELINE_MAX_OVERLAP, &cln);
}
@@ -495,7 +495,7 @@ static int active_cacheline_insert(struct dma_debug_entry *entry,
if (rc == -EEXIST) {
struct dma_debug_entry *existing;
- active_cacheline_inc_overlap(cln);
+ active_cacheline_inc_overlap(cln, entry->is_cache_clean);
existing = radix_tree_lookup(&dma_active_cacheline, cln);
/* A lookup failure here after we got -EEXIST is unexpected. */
WARN_ON(!existing);
@@ -601,7 +601,8 @@ static void add_dma_entry(struct dma_debug_entry *entry, unsigned long attrs)
unsigned long flags;
int rc;
- entry->is_cache_clean = !!(attrs & DMA_ATTR_CPU_CACHE_CLEAN);
+ entry->is_cache_clean = attrs & (DMA_ATTR_DEBUGGING_IGNORE_CACHELINES |
+ DMA_ATTR_REQUIRE_COHERENT);
bucket = get_hash_bucket(entry, &flags);
hash_bucket_add(bucket, entry);
diff --git a/kernel/dma/direct.h b/kernel/dma/direct.h
index e89f175e9c2d..6184ff303f08 100644
--- a/kernel/dma/direct.h
+++ b/kernel/dma/direct.h
@@ -84,7 +84,7 @@ static inline dma_addr_t dma_direct_map_phys(struct device *dev,
dma_addr_t dma_addr;
if (is_swiotlb_force_bounce(dev)) {
- if (attrs & DMA_ATTR_MMIO)
+ if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT))
return DMA_MAPPING_ERROR;
return swiotlb_map(dev, phys, size, dir, attrs);
@@ -98,7 +98,8 @@ static inline dma_addr_t dma_direct_map_phys(struct device *dev,
dma_addr = phys_to_dma(dev, phys);
if (unlikely(!dma_capable(dev, dma_addr, size, true)) ||
dma_kmalloc_needs_bounce(dev, size, dir)) {
- if (is_swiotlb_active(dev))
+ if (is_swiotlb_active(dev) &&
+ !(attrs & DMA_ATTR_REQUIRE_COHERENT))
return swiotlb_map(dev, phys, size, dir, attrs);
goto err_overflow;
@@ -123,7 +124,7 @@ static inline void dma_direct_unmap_phys(struct device *dev, dma_addr_t addr,
{
phys_addr_t phys;
- if (attrs & DMA_ATTR_MMIO)
+ if (attrs & (DMA_ATTR_MMIO | DMA_ATTR_REQUIRE_COHERENT))
/* nothing to do: uncached and no swiotlb */
return;
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 3928a509c44c..6d3dd0bd3a88 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -164,6 +164,9 @@ dma_addr_t dma_map_phys(struct device *dev, phys_addr_t phys, size_t size,
if (WARN_ON_ONCE(!dev->dma_mask))
return DMA_MAPPING_ERROR;
+ if (!dev_is_dma_coherent(dev) && (attrs & DMA_ATTR_REQUIRE_COHERENT))
+ return DMA_MAPPING_ERROR;
+
if (dma_map_direct(dev, ops) ||
(!is_mmio && arch_dma_map_phys_direct(dev, phys + size)))
addr = dma_direct_map_phys(dev, phys, size, dir, attrs);
@@ -235,6 +238,9 @@ static int __dma_map_sg_attrs(struct device *dev, struct scatterlist *sg,
BUG_ON(!valid_dma_direction(dir));
+ if (!dev_is_dma_coherent(dev) && (attrs & DMA_ATTR_REQUIRE_COHERENT))
+ return -EOPNOTSUPP;
+
if (WARN_ON_ONCE(!dev->dma_mask))
return 0;
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index d8e6f1d889d5..9fd73700ddcf 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -30,6 +30,7 @@
#include <linux/gfp.h>
#include <linux/highmem.h>
#include <linux/io.h>
+#include <linux/kmsan-checks.h>
#include <linux/iommu-helper.h>
#include <linux/init.h>
#include <linux/memblock.h>
@@ -901,10 +902,19 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
local_irq_save(flags);
page = pfn_to_page(pfn);
- if (dir == DMA_TO_DEVICE)
+ if (dir == DMA_TO_DEVICE) {
+ /*
+ * Ideally, kmsan_check_highmem_page()
+ * could be used here to detect infoleaks,
+ * but callers may map uninitialized buffers
+ * that will be written by the device,
+ * causing false positives.
+ */
memcpy_from_page(vaddr, page, offset, sz);
- else
+ } else {
+ kmsan_unpoison_memory(vaddr, sz);
memcpy_to_page(page, offset, vaddr, sz);
+ }
local_irq_restore(flags);
size -= sz;
@@ -913,8 +923,15 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
offset = 0;
}
} else if (dir == DMA_TO_DEVICE) {
+ /*
+ * Ideally, kmsan_check_memory() could be used here to detect
+ * infoleaks (uninitialized data being sent to device), but
+ * callers may map uninitialized buffers that will be written
+ * by the device, causing false positives.
+ */
memcpy(vaddr, phys_to_virt(orig_addr), size);
} else {
+ kmsan_unpoison_memory(vaddr, size);
memcpy(phys_to_virt(orig_addr), vaddr, size);
}
}
diff --git a/kernel/futex/core.c b/kernel/futex/core.c
index cf7e610eac42..31e83a09789e 100644
--- a/kernel/futex/core.c
+++ b/kernel/futex/core.c
@@ -342,7 +342,7 @@ static int __futex_key_to_node(struct mm_struct *mm, unsigned long addr)
if (!vma)
return FUTEX_NO_NODE;
- mpol = vma_policy(vma);
+ mpol = READ_ONCE(vma->vm_policy);
if (!mpol)
return FUTEX_NO_NODE;
diff --git a/kernel/futex/pi.c b/kernel/futex/pi.c
index bc1f7e83a37e..7808068fa59e 100644
--- a/kernel/futex/pi.c
+++ b/kernel/futex/pi.c
@@ -918,7 +918,7 @@ int fixup_pi_owner(u32 __user *uaddr, struct futex_q *q, int locked)
int futex_lock_pi(u32 __user *uaddr, unsigned int flags, ktime_t *time, int trylock)
{
struct hrtimer_sleeper timeout, *to;
- struct task_struct *exiting = NULL;
+ struct task_struct *exiting;
struct rt_mutex_waiter rt_waiter;
struct futex_q q = futex_q_init;
DEFINE_WAKE_Q(wake_q);
@@ -933,6 +933,7 @@ int futex_lock_pi(u32 __user *uaddr, unsigned int flags, ktime_t *time, int tryl
to = futex_setup_timer(time, &timeout, flags, 0);
retry:
+ exiting = NULL;
ret = get_futex_key(uaddr, flags, &q.key, FUTEX_WRITE);
if (unlikely(ret != 0))
goto out;
diff --git a/kernel/futex/syscalls.c b/kernel/futex/syscalls.c
index 743c7a728237..77ad9691f6a6 100644
--- a/kernel/futex/syscalls.c
+++ b/kernel/futex/syscalls.c
@@ -459,6 +459,14 @@ SYSCALL_DEFINE4(futex_requeue,
if (ret)
return ret;
+ /*
+ * For now mandate both flags are identical, like the sys_futex()
+ * interface has. If/when we merge the variable sized futex support,
+ * that patch can modify this test to allow a difference in size.
+ */
+ if (futexes[0].w.flags != futexes[1].w.flags)
+ return -EINVAL;
+
cmpval = futexes[0].w.val;
return futex_requeue(u64_to_user_ptr(futexes[0].w.uaddr), futexes[0].w.flags,
diff --git a/kernel/power/main.c b/kernel/power/main.c
index 5f8c9e12eaec..5429e9f19b65 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -40,7 +40,7 @@ void pm_restore_gfp_mask(void)
{
WARN_ON(!mutex_is_locked(&system_transition_mutex));
- if (WARN_ON(!saved_gfp_count) || --saved_gfp_count)
+ if (!saved_gfp_count || --saved_gfp_count)
return;
gfp_allowed_mask = saved_gfp_mask;
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 6e1321837c66..a564650734dc 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -2855,6 +2855,17 @@ int snapshot_write_finalize(struct snapshot_handle *handle)
{
int error;
+ /*
+ * Call snapshot_write_next() to drain any trailing zero pages,
+ * but make sure we're in the data page region first.
+ * This function can return PAGE_SIZE if the kernel was expecting
+ * another copy page. Return -ENODATA in that situation.
+ */
+ if (handle->cur > nr_meta_pages + 1) {
+ error = snapshot_write_next(handle);
+ if (error)
+ return error > 0 ? -ENODATA : error;
+ }
copy_last_highmem_page();
error = hibernate_restore_protect_page(handle->buffer);
/* Do that only if we have loaded the image entirely */
diff --git a/kernel/rcu/rcu.h b/kernel/rcu/rcu.h
index dc5d614b372c..9b10b57b79ad 100644
--- a/kernel/rcu/rcu.h
+++ b/kernel/rcu/rcu.h
@@ -502,6 +502,15 @@ do { \
___locked; \
})
+#define raw_spin_trylock_irqsave_rcu_node(p, flags) \
+({ \
+ bool ___locked = raw_spin_trylock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \
+ \
+ if (___locked) \
+ smp_mb__after_unlock_lock(); \
+ ___locked; \
+})
+
#define raw_lockdep_assert_held_rcu_node(p) \
lockdep_assert_held(&ACCESS_PRIVATE(p, lock))
diff --git a/kernel/rcu/srcutiny.c b/kernel/rcu/srcutiny.c
index 3450c3751ef7..a2e2d516e51b 100644
--- a/kernel/rcu/srcutiny.c
+++ b/kernel/rcu/srcutiny.c
@@ -9,6 +9,7 @@
*/
#include <linux/export.h>
+#include <linux/irq_work.h>
#include <linux/mutex.h>
#include <linux/preempt.h>
#include <linux/rcupdate_wait.h>
@@ -41,6 +42,7 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp)
ssp->srcu_idx_max = 0;
INIT_WORK(&ssp->srcu_work, srcu_drive_gp);
INIT_LIST_HEAD(&ssp->srcu_work.entry);
+ init_irq_work(&ssp->srcu_irq_work, srcu_tiny_irq_work);
return 0;
}
@@ -84,6 +86,7 @@ EXPORT_SYMBOL_GPL(init_srcu_struct);
void cleanup_srcu_struct(struct srcu_struct *ssp)
{
WARN_ON(ssp->srcu_lock_nesting[0] || ssp->srcu_lock_nesting[1]);
+ irq_work_sync(&ssp->srcu_irq_work);
flush_work(&ssp->srcu_work);
WARN_ON(ssp->srcu_gp_running);
WARN_ON(ssp->srcu_gp_waiting);
@@ -177,6 +180,20 @@ void srcu_drive_gp(struct work_struct *wp)
}
EXPORT_SYMBOL_GPL(srcu_drive_gp);
+/*
+ * Use an irq_work to defer schedule_work() to avoid acquiring the workqueue
+ * pool->lock while the caller might hold scheduler locks, causing lockdep
+ * splats due to workqueue_init() doing a wakeup.
+ */
+void srcu_tiny_irq_work(struct irq_work *irq_work)
+{
+ struct srcu_struct *ssp;
+
+ ssp = container_of(irq_work, struct srcu_struct, srcu_irq_work);
+ schedule_work(&ssp->srcu_work);
+}
+EXPORT_SYMBOL_GPL(srcu_tiny_irq_work);
+
static void srcu_gp_start_if_needed(struct srcu_struct *ssp)
{
unsigned long cookie;
@@ -189,7 +206,7 @@ static void srcu_gp_start_if_needed(struct srcu_struct *ssp)
WRITE_ONCE(ssp->srcu_idx_max, cookie);
if (!READ_ONCE(ssp->srcu_gp_running)) {
if (likely(srcu_init_done))
- schedule_work(&ssp->srcu_work);
+ irq_work_queue(&ssp->srcu_irq_work);
else if (list_empty(&ssp->srcu_work.entry))
list_add(&ssp->srcu_work.entry, &srcu_boot_list);
}
diff --git a/kernel/rcu/srcutree.c b/kernel/rcu/srcutree.c
index aef8e91ad33e..0d01cd8c4b4a 100644
--- a/kernel/rcu/srcutree.c
+++ b/kernel/rcu/srcutree.c
@@ -19,6 +19,7 @@
#include <linux/mutex.h>
#include <linux/percpu.h>
#include <linux/preempt.h>
+#include <linux/irq_work.h>
#include <linux/rcupdate_wait.h>
#include <linux/sched.h>
#include <linux/smp.h>
@@ -75,44 +76,9 @@ static bool __read_mostly srcu_init_done;
static void srcu_invoke_callbacks(struct work_struct *work);
static void srcu_reschedule(struct srcu_struct *ssp, unsigned long delay);
static void process_srcu(struct work_struct *work);
+static void srcu_irq_work(struct irq_work *work);
static void srcu_delay_timer(struct timer_list *t);
-/* Wrappers for lock acquisition and release, see raw_spin_lock_rcu_node(). */
-#define spin_lock_rcu_node(p) \
-do { \
- spin_lock(&ACCESS_PRIVATE(p, lock)); \
- smp_mb__after_unlock_lock(); \
-} while (0)
-
-#define spin_unlock_rcu_node(p) spin_unlock(&ACCESS_PRIVATE(p, lock))
-
-#define spin_lock_irq_rcu_node(p) \
-do { \
- spin_lock_irq(&ACCESS_PRIVATE(p, lock)); \
- smp_mb__after_unlock_lock(); \
-} while (0)
-
-#define spin_unlock_irq_rcu_node(p) \
- spin_unlock_irq(&ACCESS_PRIVATE(p, lock))
-
-#define spin_lock_irqsave_rcu_node(p, flags) \
-do { \
- spin_lock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \
- smp_mb__after_unlock_lock(); \
-} while (0)
-
-#define spin_trylock_irqsave_rcu_node(p, flags) \
-({ \
- bool ___locked = spin_trylock_irqsave(&ACCESS_PRIVATE(p, lock), flags); \
- \
- if (___locked) \
- smp_mb__after_unlock_lock(); \
- ___locked; \
-})
-
-#define spin_unlock_irqrestore_rcu_node(p, flags) \
- spin_unlock_irqrestore(&ACCESS_PRIVATE(p, lock), flags) \
-
/*
* Initialize SRCU per-CPU data. Note that statically allocated
* srcu_struct structures might already have srcu_read_lock() and
@@ -131,7 +97,7 @@ static void init_srcu_struct_data(struct srcu_struct *ssp)
*/
for_each_possible_cpu(cpu) {
sdp = per_cpu_ptr(ssp->sda, cpu);
- spin_lock_init(&ACCESS_PRIVATE(sdp, lock));
+ raw_spin_lock_init(&ACCESS_PRIVATE(sdp, lock));
rcu_segcblist_init(&sdp->srcu_cblist);
sdp->srcu_cblist_invoking = false;
sdp->srcu_gp_seq_needed = ssp->srcu_sup->srcu_gp_seq;
@@ -186,7 +152,7 @@ static bool init_srcu_struct_nodes(struct srcu_struct *ssp, gfp_t gfp_flags)
/* Each pass through this loop initializes one srcu_node structure. */
srcu_for_each_node_breadth_first(ssp, snp) {
- spin_lock_init(&ACCESS_PRIVATE(snp, lock));
+ raw_spin_lock_init(&ACCESS_PRIVATE(snp, lock));
BUILD_BUG_ON(ARRAY_SIZE(snp->srcu_have_cbs) !=
ARRAY_SIZE(snp->srcu_data_have_cbs));
for (i = 0; i < ARRAY_SIZE(snp->srcu_have_cbs); i++) {
@@ -242,7 +208,7 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static)
if (!ssp->srcu_sup)
return -ENOMEM;
if (!is_static)
- spin_lock_init(&ACCESS_PRIVATE(ssp->srcu_sup, lock));
+ raw_spin_lock_init(&ACCESS_PRIVATE(ssp->srcu_sup, lock));
ssp->srcu_sup->srcu_size_state = SRCU_SIZE_SMALL;
ssp->srcu_sup->node = NULL;
mutex_init(&ssp->srcu_sup->srcu_cb_mutex);
@@ -252,6 +218,7 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static)
mutex_init(&ssp->srcu_sup->srcu_barrier_mutex);
atomic_set(&ssp->srcu_sup->srcu_barrier_cpu_cnt, 0);
INIT_DELAYED_WORK(&ssp->srcu_sup->work, process_srcu);
+ init_irq_work(&ssp->srcu_sup->irq_work, srcu_irq_work);
ssp->srcu_sup->sda_is_static = is_static;
if (!is_static) {
ssp->sda = alloc_percpu(struct srcu_data);
@@ -263,9 +230,12 @@ static int init_srcu_struct_fields(struct srcu_struct *ssp, bool is_static)
ssp->srcu_sup->srcu_gp_seq_needed_exp = SRCU_GP_SEQ_INITIAL_VAL;
ssp->srcu_sup->srcu_last_gp_end = ktime_get_mono_fast_ns();
if (READ_ONCE(ssp->srcu_sup->srcu_size_state) == SRCU_SIZE_SMALL && SRCU_SIZING_IS_INIT()) {
- if (!init_srcu_struct_nodes(ssp, is_static ? GFP_ATOMIC : GFP_KERNEL))
+ if (!preemptible())
+ WRITE_ONCE(ssp->srcu_sup->srcu_size_state, SRCU_SIZE_ALLOC);
+ else if (init_srcu_struct_nodes(ssp, GFP_KERNEL))
+ WRITE_ONCE(ssp->srcu_sup->srcu_size_state, SRCU_SIZE_BIG);
+ else
goto err_free_sda;
- WRITE_ONCE(ssp->srcu_sup->srcu_size_state, SRCU_SIZE_BIG);
}
ssp->srcu_sup->srcu_ssp = ssp;
smp_store_release(&ssp->srcu_sup->srcu_gp_seq_needed,
@@ -394,20 +364,20 @@ static void srcu_transition_to_big(struct srcu_struct *ssp)
/* Double-checked locking on ->srcu_size-state. */
if (smp_load_acquire(&ssp->srcu_sup->srcu_size_state) != SRCU_SIZE_SMALL)
return;
- spin_lock_irqsave_rcu_node(ssp->srcu_sup, flags);
+ raw_spin_lock_irqsave_rcu_node(ssp->srcu_sup, flags);
if (smp_load_acquire(&ssp->srcu_sup->srcu_size_state) != SRCU_SIZE_SMALL) {
- spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
+ raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
return;
}
__srcu_transition_to_big(ssp);
- spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
+ raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
}
/*
* Check to see if the just-encountered contention event justifies
* a transition to SRCU_SIZE_BIG.
*/
-static void spin_lock_irqsave_check_contention(struct srcu_struct *ssp)
+static void raw_spin_lock_irqsave_check_contention(struct srcu_struct *ssp)
{
unsigned long j;
@@ -429,16 +399,16 @@ static void spin_lock_irqsave_check_contention(struct srcu_struct *ssp)
* to SRCU_SIZE_BIG. But only if the srcutree.convert_to_big module
* parameter permits this.
*/
-static void spin_lock_irqsave_sdp_contention(struct srcu_data *sdp, unsigned long *flags)
+static void raw_spin_lock_irqsave_sdp_contention(struct srcu_data *sdp, unsigned long *flags)
{
struct srcu_struct *ssp = sdp->ssp;
- if (spin_trylock_irqsave_rcu_node(sdp, *flags))
+ if (raw_spin_trylock_irqsave_rcu_node(sdp, *flags))
return;
- spin_lock_irqsave_rcu_node(ssp->srcu_sup, *flags);
- spin_lock_irqsave_check_contention(ssp);
- spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, *flags);
- spin_lock_irqsave_rcu_node(sdp, *flags);
+ raw_spin_lock_irqsave_rcu_node(ssp->srcu_sup, *flags);
+ raw_spin_lock_irqsave_check_contention(ssp);
+ raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, *flags);
+ raw_spin_lock_irqsave_rcu_node(sdp, *flags);
}
/*
@@ -447,12 +417,12 @@ static void spin_lock_irqsave_sdp_contention(struct srcu_data *sdp, unsigned lon
* to SRCU_SIZE_BIG. But only if the srcutree.convert_to_big module
* parameter permits this.
*/
-static void spin_lock_irqsave_ssp_contention(struct srcu_struct *ssp, unsigned long *flags)
+static void raw_spin_lock_irqsave_ssp_contention(struct srcu_struct *ssp, unsigned long *flags)
{
- if (spin_trylock_irqsave_rcu_node(ssp->srcu_sup, *flags))
+ if (raw_spin_trylock_irqsave_rcu_node(ssp->srcu_sup, *flags))
return;
- spin_lock_irqsave_rcu_node(ssp->srcu_sup, *flags);
- spin_lock_irqsave_check_contention(ssp);
+ raw_spin_lock_irqsave_rcu_node(ssp->srcu_sup, *flags);
+ raw_spin_lock_irqsave_check_contention(ssp);
}
/*
@@ -470,13 +440,13 @@ static void check_init_srcu_struct(struct srcu_struct *ssp)
/* The smp_load_acquire() pairs with the smp_store_release(). */
if (!rcu_seq_state(smp_load_acquire(&ssp->srcu_sup->srcu_gp_seq_needed))) /*^^^*/
return; /* Already initialized. */
- spin_lock_irqsave_rcu_node(ssp->srcu_sup, flags);
+ raw_spin_lock_irqsave_rcu_node(ssp->srcu_sup, flags);
if (!rcu_seq_state(ssp->srcu_sup->srcu_gp_seq_needed)) {
- spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
+ raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
return;
}
init_srcu_struct_fields(ssp, true);
- spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
+ raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
}
/*
@@ -742,13 +712,15 @@ void cleanup_srcu_struct(struct srcu_struct *ssp)
unsigned long delay;
struct srcu_usage *sup = ssp->srcu_sup;
- spin_lock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_lock_irq_rcu_node(ssp->srcu_sup);
delay = srcu_get_delay(ssp);
- spin_unlock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_unlock_irq_rcu_node(ssp->srcu_sup);
if (WARN_ON(!delay))
return; /* Just leak it! */
if (WARN_ON(srcu_readers_active(ssp)))
return; /* Just leak it! */
+ /* Wait for irq_work to finish first as it may queue a new work. */
+ irq_work_sync(&sup->irq_work);
flush_delayed_work(&sup->work);
for_each_possible_cpu(cpu) {
struct srcu_data *sdp = per_cpu_ptr(ssp->sda, cpu);
@@ -960,7 +932,7 @@ static void srcu_gp_end(struct srcu_struct *ssp)
mutex_lock(&sup->srcu_cb_mutex);
/* End the current grace period. */
- spin_lock_irq_rcu_node(sup);
+ raw_spin_lock_irq_rcu_node(sup);
idx = rcu_seq_state(sup->srcu_gp_seq);
WARN_ON_ONCE(idx != SRCU_STATE_SCAN2);
if (srcu_gp_is_expedited(ssp))
@@ -971,7 +943,7 @@ static void srcu_gp_end(struct srcu_struct *ssp)
gpseq = rcu_seq_current(&sup->srcu_gp_seq);
if (ULONG_CMP_LT(sup->srcu_gp_seq_needed_exp, gpseq))
WRITE_ONCE(sup->srcu_gp_seq_needed_exp, gpseq);
- spin_unlock_irq_rcu_node(sup);
+ raw_spin_unlock_irq_rcu_node(sup);
mutex_unlock(&sup->srcu_gp_mutex);
/* A new grace period can start at this point. But only one. */
@@ -983,7 +955,7 @@ static void srcu_gp_end(struct srcu_struct *ssp)
} else {
idx = rcu_seq_ctr(gpseq) % ARRAY_SIZE(snp->srcu_have_cbs);
srcu_for_each_node_breadth_first(ssp, snp) {
- spin_lock_irq_rcu_node(snp);
+ raw_spin_lock_irq_rcu_node(snp);
cbs = false;
last_lvl = snp >= sup->level[rcu_num_lvls - 1];
if (last_lvl)
@@ -998,7 +970,7 @@ static void srcu_gp_end(struct srcu_struct *ssp)
else
mask = snp->srcu_data_have_cbs[idx];
snp->srcu_data_have_cbs[idx] = 0;
- spin_unlock_irq_rcu_node(snp);
+ raw_spin_unlock_irq_rcu_node(snp);
if (cbs)
srcu_schedule_cbs_snp(ssp, snp, mask, cbdelay);
}
@@ -1008,27 +980,27 @@ static void srcu_gp_end(struct srcu_struct *ssp)
if (!(gpseq & counter_wrap_check))
for_each_possible_cpu(cpu) {
sdp = per_cpu_ptr(ssp->sda, cpu);
- spin_lock_irq_rcu_node(sdp);
+ raw_spin_lock_irq_rcu_node(sdp);
if (ULONG_CMP_GE(gpseq, sdp->srcu_gp_seq_needed + 100))
sdp->srcu_gp_seq_needed = gpseq;
if (ULONG_CMP_GE(gpseq, sdp->srcu_gp_seq_needed_exp + 100))
sdp->srcu_gp_seq_needed_exp = gpseq;
- spin_unlock_irq_rcu_node(sdp);
+ raw_spin_unlock_irq_rcu_node(sdp);
}
/* Callback initiation done, allow grace periods after next. */
mutex_unlock(&sup->srcu_cb_mutex);
/* Start a new grace period if needed. */
- spin_lock_irq_rcu_node(sup);
+ raw_spin_lock_irq_rcu_node(sup);
gpseq = rcu_seq_current(&sup->srcu_gp_seq);
if (!rcu_seq_state(gpseq) &&
ULONG_CMP_LT(gpseq, sup->srcu_gp_seq_needed)) {
srcu_gp_start(ssp);
- spin_unlock_irq_rcu_node(sup);
+ raw_spin_unlock_irq_rcu_node(sup);
srcu_reschedule(ssp, 0);
} else {
- spin_unlock_irq_rcu_node(sup);
+ raw_spin_unlock_irq_rcu_node(sup);
}
/* Transition to big if needed. */
@@ -1059,19 +1031,19 @@ static void srcu_funnel_exp_start(struct srcu_struct *ssp, struct srcu_node *snp
if (WARN_ON_ONCE(rcu_seq_done(&ssp->srcu_sup->srcu_gp_seq, s)) ||
(!srcu_invl_snp_seq(sgsne) && ULONG_CMP_GE(sgsne, s)))
return;
- spin_lock_irqsave_rcu_node(snp, flags);
+ raw_spin_lock_irqsave_rcu_node(snp, flags);
sgsne = snp->srcu_gp_seq_needed_exp;
if (!srcu_invl_snp_seq(sgsne) && ULONG_CMP_GE(sgsne, s)) {
- spin_unlock_irqrestore_rcu_node(snp, flags);
+ raw_spin_unlock_irqrestore_rcu_node(snp, flags);
return;
}
WRITE_ONCE(snp->srcu_gp_seq_needed_exp, s);
- spin_unlock_irqrestore_rcu_node(snp, flags);
+ raw_spin_unlock_irqrestore_rcu_node(snp, flags);
}
- spin_lock_irqsave_ssp_contention(ssp, &flags);
+ raw_spin_lock_irqsave_ssp_contention(ssp, &flags);
if (ULONG_CMP_LT(ssp->srcu_sup->srcu_gp_seq_needed_exp, s))
WRITE_ONCE(ssp->srcu_sup->srcu_gp_seq_needed_exp, s);
- spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
+ raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
}
/*
@@ -1109,12 +1081,12 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp,
for (snp = snp_leaf; snp != NULL; snp = snp->srcu_parent) {
if (WARN_ON_ONCE(rcu_seq_done(&sup->srcu_gp_seq, s)) && snp != snp_leaf)
return; /* GP already done and CBs recorded. */
- spin_lock_irqsave_rcu_node(snp, flags);
+ raw_spin_lock_irqsave_rcu_node(snp, flags);
snp_seq = snp->srcu_have_cbs[idx];
if (!srcu_invl_snp_seq(snp_seq) && ULONG_CMP_GE(snp_seq, s)) {
if (snp == snp_leaf && snp_seq == s)
snp->srcu_data_have_cbs[idx] |= sdp->grpmask;
- spin_unlock_irqrestore_rcu_node(snp, flags);
+ raw_spin_unlock_irqrestore_rcu_node(snp, flags);
if (snp == snp_leaf && snp_seq != s) {
srcu_schedule_cbs_sdp(sdp, do_norm ? SRCU_INTERVAL : 0);
return;
@@ -1129,11 +1101,11 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp,
sgsne = snp->srcu_gp_seq_needed_exp;
if (!do_norm && (srcu_invl_snp_seq(sgsne) || ULONG_CMP_LT(sgsne, s)))
WRITE_ONCE(snp->srcu_gp_seq_needed_exp, s);
- spin_unlock_irqrestore_rcu_node(snp, flags);
+ raw_spin_unlock_irqrestore_rcu_node(snp, flags);
}
/* Top of tree, must ensure the grace period will be started. */
- spin_lock_irqsave_ssp_contention(ssp, &flags);
+ raw_spin_lock_irqsave_ssp_contention(ssp, &flags);
if (ULONG_CMP_LT(sup->srcu_gp_seq_needed, s)) {
/*
* Record need for grace period s. Pair with load
@@ -1154,13 +1126,17 @@ static void srcu_funnel_gp_start(struct srcu_struct *ssp, struct srcu_data *sdp,
// it isn't. And it does not have to be. After all, it
// can only be executed during early boot when there is only
// the one boot CPU running with interrupts still disabled.
+ //
+ // Use an irq_work here to avoid acquiring runqueue lock with
+ // srcu rcu_node::lock held. BPF instrument could introduce the
+ // opposite dependency, hence we need to break the possible
+ // locking dependency here.
if (likely(srcu_init_done))
- queue_delayed_work(rcu_gp_wq, &sup->work,
- !!srcu_get_delay(ssp));
+ irq_work_queue(&sup->irq_work);
else if (list_empty(&sup->work.work.entry))
list_add(&sup->work.work.entry, &srcu_boot_list);
}
- spin_unlock_irqrestore_rcu_node(sup, flags);
+ raw_spin_unlock_irqrestore_rcu_node(sup, flags);
}
/*
@@ -1172,9 +1148,9 @@ static bool try_check_zero(struct srcu_struct *ssp, int idx, int trycount)
{
unsigned long curdelay;
- spin_lock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_lock_irq_rcu_node(ssp->srcu_sup);
curdelay = !srcu_get_delay(ssp);
- spin_unlock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_unlock_irq_rcu_node(ssp->srcu_sup);
for (;;) {
if (srcu_readers_active_idx_check(ssp, idx))
@@ -1285,12 +1261,12 @@ static bool srcu_should_expedite(struct srcu_struct *ssp)
return false;
/* If the local srcu_data structure has callbacks, not idle. */
sdp = raw_cpu_ptr(ssp->sda);
- spin_lock_irqsave_rcu_node(sdp, flags);
+ raw_spin_lock_irqsave_rcu_node(sdp, flags);
if (rcu_segcblist_pend_cbs(&sdp->srcu_cblist)) {
- spin_unlock_irqrestore_rcu_node(sdp, flags);
+ raw_spin_unlock_irqrestore_rcu_node(sdp, flags);
return false; /* Callbacks already present, so not idle. */
}
- spin_unlock_irqrestore_rcu_node(sdp, flags);
+ raw_spin_unlock_irqrestore_rcu_node(sdp, flags);
/*
* No local callbacks, so probabilistically probe global state.
@@ -1350,7 +1326,7 @@ static unsigned long srcu_gp_start_if_needed(struct srcu_struct *ssp,
sdp = per_cpu_ptr(ssp->sda, get_boot_cpu_id());
else
sdp = raw_cpu_ptr(ssp->sda);
- spin_lock_irqsave_sdp_contention(sdp, &flags);
+ raw_spin_lock_irqsave_sdp_contention(sdp, &flags);
if (rhp)
rcu_segcblist_enqueue(&sdp->srcu_cblist, rhp);
/*
@@ -1410,7 +1386,7 @@ static unsigned long srcu_gp_start_if_needed(struct srcu_struct *ssp,
sdp->srcu_gp_seq_needed_exp = s;
needexp = true;
}
- spin_unlock_irqrestore_rcu_node(sdp, flags);
+ raw_spin_unlock_irqrestore_rcu_node(sdp, flags);
/* Ensure that snp node tree is fully initialized before traversing it */
if (ss_state < SRCU_SIZE_WAIT_BARRIER)
@@ -1522,7 +1498,7 @@ static void __synchronize_srcu(struct srcu_struct *ssp, bool do_norm)
/*
* Make sure that later code is ordered after the SRCU grace
- * period. This pairs with the spin_lock_irq_rcu_node()
+ * period. This pairs with the raw_spin_lock_irq_rcu_node()
* in srcu_invoke_callbacks(). Unlike Tree RCU, this is needed
* because the current CPU might have been totally uninvolved with
* (and thus unordered against) that grace period.
@@ -1701,7 +1677,7 @@ static void srcu_barrier_cb(struct rcu_head *rhp)
*/
static void srcu_barrier_one_cpu(struct srcu_struct *ssp, struct srcu_data *sdp)
{
- spin_lock_irq_rcu_node(sdp);
+ raw_spin_lock_irq_rcu_node(sdp);
atomic_inc(&ssp->srcu_sup->srcu_barrier_cpu_cnt);
sdp->srcu_barrier_head.func = srcu_barrier_cb;
debug_rcu_head_queue(&sdp->srcu_barrier_head);
@@ -1710,7 +1686,7 @@ static void srcu_barrier_one_cpu(struct srcu_struct *ssp, struct srcu_data *sdp)
debug_rcu_head_unqueue(&sdp->srcu_barrier_head);
atomic_dec(&ssp->srcu_sup->srcu_barrier_cpu_cnt);
}
- spin_unlock_irq_rcu_node(sdp);
+ raw_spin_unlock_irq_rcu_node(sdp);
}
/**
@@ -1761,7 +1737,7 @@ static void srcu_expedite_current_cb(struct rcu_head *rhp)
bool needcb = false;
struct srcu_data *sdp = container_of(rhp, struct srcu_data, srcu_ec_head);
- spin_lock_irqsave_sdp_contention(sdp, &flags);
+ raw_spin_lock_irqsave_sdp_contention(sdp, &flags);
if (sdp->srcu_ec_state == SRCU_EC_IDLE) {
WARN_ON_ONCE(1);
} else if (sdp->srcu_ec_state == SRCU_EC_PENDING) {
@@ -1771,7 +1747,7 @@ static void srcu_expedite_current_cb(struct rcu_head *rhp)
sdp->srcu_ec_state = SRCU_EC_PENDING;
needcb = true;
}
- spin_unlock_irqrestore_rcu_node(sdp, flags);
+ raw_spin_unlock_irqrestore_rcu_node(sdp, flags);
// If needed, requeue ourselves as an expedited SRCU callback.
if (needcb)
__call_srcu(sdp->ssp, &sdp->srcu_ec_head, srcu_expedite_current_cb, false);
@@ -1795,7 +1771,7 @@ void srcu_expedite_current(struct srcu_struct *ssp)
migrate_disable();
sdp = this_cpu_ptr(ssp->sda);
- spin_lock_irqsave_sdp_contention(sdp, &flags);
+ raw_spin_lock_irqsave_sdp_contention(sdp, &flags);
if (sdp->srcu_ec_state == SRCU_EC_IDLE) {
sdp->srcu_ec_state = SRCU_EC_PENDING;
needcb = true;
@@ -1804,7 +1780,7 @@ void srcu_expedite_current(struct srcu_struct *ssp)
} else {
WARN_ON_ONCE(sdp->srcu_ec_state != SRCU_EC_REPOST);
}
- spin_unlock_irqrestore_rcu_node(sdp, flags);
+ raw_spin_unlock_irqrestore_rcu_node(sdp, flags);
// If needed, queue an expedited SRCU callback.
if (needcb)
__call_srcu(ssp, &sdp->srcu_ec_head, srcu_expedite_current_cb, false);
@@ -1848,17 +1824,17 @@ static void srcu_advance_state(struct srcu_struct *ssp)
*/
idx = rcu_seq_state(smp_load_acquire(&ssp->srcu_sup->srcu_gp_seq)); /* ^^^ */
if (idx == SRCU_STATE_IDLE) {
- spin_lock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_lock_irq_rcu_node(ssp->srcu_sup);
if (ULONG_CMP_GE(ssp->srcu_sup->srcu_gp_seq, ssp->srcu_sup->srcu_gp_seq_needed)) {
WARN_ON_ONCE(rcu_seq_state(ssp->srcu_sup->srcu_gp_seq));
- spin_unlock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_unlock_irq_rcu_node(ssp->srcu_sup);
mutex_unlock(&ssp->srcu_sup->srcu_gp_mutex);
return;
}
idx = rcu_seq_state(READ_ONCE(ssp->srcu_sup->srcu_gp_seq));
if (idx == SRCU_STATE_IDLE)
srcu_gp_start(ssp);
- spin_unlock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_unlock_irq_rcu_node(ssp->srcu_sup);
if (idx != SRCU_STATE_IDLE) {
mutex_unlock(&ssp->srcu_sup->srcu_gp_mutex);
return; /* Someone else started the grace period. */
@@ -1872,10 +1848,10 @@ static void srcu_advance_state(struct srcu_struct *ssp)
return; /* readers present, retry later. */
}
srcu_flip(ssp);
- spin_lock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_lock_irq_rcu_node(ssp->srcu_sup);
rcu_seq_set_state(&ssp->srcu_sup->srcu_gp_seq, SRCU_STATE_SCAN2);
ssp->srcu_sup->srcu_n_exp_nodelay = 0;
- spin_unlock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_unlock_irq_rcu_node(ssp->srcu_sup);
}
if (rcu_seq_state(READ_ONCE(ssp->srcu_sup->srcu_gp_seq)) == SRCU_STATE_SCAN2) {
@@ -1913,7 +1889,7 @@ static void srcu_invoke_callbacks(struct work_struct *work)
ssp = sdp->ssp;
rcu_cblist_init(&ready_cbs);
- spin_lock_irq_rcu_node(sdp);
+ raw_spin_lock_irq_rcu_node(sdp);
WARN_ON_ONCE(!rcu_segcblist_segempty(&sdp->srcu_cblist, RCU_NEXT_TAIL));
rcu_segcblist_advance(&sdp->srcu_cblist,
rcu_seq_current(&ssp->srcu_sup->srcu_gp_seq));
@@ -1924,7 +1900,7 @@ static void srcu_invoke_callbacks(struct work_struct *work)
*/
if (sdp->srcu_cblist_invoking ||
!rcu_segcblist_ready_cbs(&sdp->srcu_cblist)) {
- spin_unlock_irq_rcu_node(sdp);
+ raw_spin_unlock_irq_rcu_node(sdp);
return; /* Someone else on the job or nothing to do. */
}
@@ -1932,7 +1908,7 @@ static void srcu_invoke_callbacks(struct work_struct *work)
sdp->srcu_cblist_invoking = true;
rcu_segcblist_extract_done_cbs(&sdp->srcu_cblist, &ready_cbs);
len = ready_cbs.len;
- spin_unlock_irq_rcu_node(sdp);
+ raw_spin_unlock_irq_rcu_node(sdp);
rhp = rcu_cblist_dequeue(&ready_cbs);
for (; rhp != NULL; rhp = rcu_cblist_dequeue(&ready_cbs)) {
debug_rcu_head_unqueue(rhp);
@@ -1947,11 +1923,11 @@ static void srcu_invoke_callbacks(struct work_struct *work)
* Update counts, accelerate new callbacks, and if needed,
* schedule another round of callback invocation.
*/
- spin_lock_irq_rcu_node(sdp);
+ raw_spin_lock_irq_rcu_node(sdp);
rcu_segcblist_add_len(&sdp->srcu_cblist, -len);
sdp->srcu_cblist_invoking = false;
more = rcu_segcblist_ready_cbs(&sdp->srcu_cblist);
- spin_unlock_irq_rcu_node(sdp);
+ raw_spin_unlock_irq_rcu_node(sdp);
/* An SRCU barrier or callbacks from previous nesting work pending */
if (more)
srcu_schedule_cbs_sdp(sdp, 0);
@@ -1965,7 +1941,7 @@ static void srcu_reschedule(struct srcu_struct *ssp, unsigned long delay)
{
bool pushgp = true;
- spin_lock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_lock_irq_rcu_node(ssp->srcu_sup);
if (ULONG_CMP_GE(ssp->srcu_sup->srcu_gp_seq, ssp->srcu_sup->srcu_gp_seq_needed)) {
if (!WARN_ON_ONCE(rcu_seq_state(ssp->srcu_sup->srcu_gp_seq))) {
/* All requests fulfilled, time to go idle. */
@@ -1975,7 +1951,7 @@ static void srcu_reschedule(struct srcu_struct *ssp, unsigned long delay)
/* Outstanding request and no GP. Start one. */
srcu_gp_start(ssp);
}
- spin_unlock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_unlock_irq_rcu_node(ssp->srcu_sup);
if (pushgp)
queue_delayed_work(rcu_gp_wq, &ssp->srcu_sup->work, delay);
@@ -1995,9 +1971,9 @@ static void process_srcu(struct work_struct *work)
ssp = sup->srcu_ssp;
srcu_advance_state(ssp);
- spin_lock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_lock_irq_rcu_node(ssp->srcu_sup);
curdelay = srcu_get_delay(ssp);
- spin_unlock_irq_rcu_node(ssp->srcu_sup);
+ raw_spin_unlock_irq_rcu_node(ssp->srcu_sup);
if (curdelay) {
WRITE_ONCE(sup->reschedule_count, 0);
} else {
@@ -2015,6 +1991,23 @@ static void process_srcu(struct work_struct *work)
srcu_reschedule(ssp, curdelay);
}
+static void srcu_irq_work(struct irq_work *work)
+{
+ struct srcu_struct *ssp;
+ struct srcu_usage *sup;
+ unsigned long delay;
+ unsigned long flags;
+
+ sup = container_of(work, struct srcu_usage, irq_work);
+ ssp = sup->srcu_ssp;
+
+ raw_spin_lock_irqsave_rcu_node(ssp->srcu_sup, flags);
+ delay = srcu_get_delay(ssp);
+ raw_spin_unlock_irqrestore_rcu_node(ssp->srcu_sup, flags);
+
+ queue_delayed_work(rcu_gp_wq, &sup->work, !!delay);
+}
+
void srcutorture_get_gp_data(struct srcu_struct *ssp, int *flags,
unsigned long *gp_seq)
{
diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index 9d3a666ffde1..c9efb17cc255 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -1118,7 +1118,7 @@ int proc_do_large_bitmap(const struct ctl_table *table, int dir,
unsigned long bitmap_len = table->maxlen;
unsigned long *bitmap = *(unsigned long **) table->data;
unsigned long *tmp_bitmap = NULL;
- char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c;
+ char tr_a[] = { '-', ',', '\n' }, tr_b[] = { ',', '\n', 0 }, c = 0;
if (!bitmap || !bitmap_len || !left || (*ppos && SYSCTL_KERN_TO_USER(dir))) {
*lenp = 0;
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 069d93bfb0c7..b64db405ba5c 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -540,7 +540,7 @@ static s64 alarm_timer_forward(struct k_itimer *timr, ktime_t now)
{
struct alarm *alarm = &timr->it.alarm.alarmtimer;
- return alarm_forward(alarm, timr->it_interval, now);
+ return alarm_forward(alarm, now, timr->it_interval);
}
/**
diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c
index d5230b759a2d..655db2e82513 100644
--- a/kernel/trace/trace_events_trigger.c
+++ b/kernel/trace/trace_events_trigger.c
@@ -22,6 +22,39 @@ static struct task_struct *trigger_kthread;
static struct llist_head trigger_data_free_list;
static DEFINE_MUTEX(trigger_data_kthread_mutex);
+static int trigger_kthread_fn(void *ignore);
+
+static void trigger_create_kthread_locked(void)
+{
+ lockdep_assert_held(&trigger_data_kthread_mutex);
+
+ if (!trigger_kthread) {
+ struct task_struct *kthread;
+
+ kthread = kthread_create(trigger_kthread_fn, NULL,
+ "trigger_data_free");
+ if (!IS_ERR(kthread))
+ WRITE_ONCE(trigger_kthread, kthread);
+ }
+}
+
+static void trigger_data_free_queued_locked(void)
+{
+ struct event_trigger_data *data, *tmp;
+ struct llist_node *llnodes;
+
+ lockdep_assert_held(&trigger_data_kthread_mutex);
+
+ llnodes = llist_del_all(&trigger_data_free_list);
+ if (!llnodes)
+ return;
+
+ tracepoint_synchronize_unregister();
+
+ llist_for_each_entry_safe(data, tmp, llnodes, llist)
+ kfree(data);
+}
+
/* Bulk garbage collection of event_trigger_data elements */
static int trigger_kthread_fn(void *ignore)
{
@@ -56,30 +89,50 @@ void trigger_data_free(struct event_trigger_data *data)
if (data->cmd_ops->set_filter)
data->cmd_ops->set_filter(NULL, data, NULL);
+ /*
+ * Boot-time trigger registration can fail before kthread creation
+ * works. Keep the deferred-free semantics during boot and let late
+ * init start the kthread to drain the list.
+ */
+ if (system_state == SYSTEM_BOOTING && !trigger_kthread) {
+ llist_add(&data->llist, &trigger_data_free_list);
+ return;
+ }
+
if (unlikely(!trigger_kthread)) {
guard(mutex)(&trigger_data_kthread_mutex);
+
+ trigger_create_kthread_locked();
/* Check again after taking mutex */
if (!trigger_kthread) {
- struct task_struct *kthread;
-
- kthread = kthread_create(trigger_kthread_fn, NULL,
- "trigger_data_free");
- if (!IS_ERR(kthread))
- WRITE_ONCE(trigger_kthread, kthread);
+ llist_add(&data->llist, &trigger_data_free_list);
+ /* Drain the queued frees synchronously if creation failed. */
+ trigger_data_free_queued_locked();
+ return;
}
}
- if (!trigger_kthread) {
- /* Do it the slow way */
- tracepoint_synchronize_unregister();
- kfree(data);
- return;
- }
-
llist_add(&data->llist, &trigger_data_free_list);
wake_up_process(trigger_kthread);
}
+static int __init trigger_data_free_init(void)
+{
+ guard(mutex)(&trigger_data_kthread_mutex);
+
+ if (llist_empty(&trigger_data_free_list))
+ return 0;
+
+ trigger_create_kthread_locked();
+ if (trigger_kthread)
+ wake_up_process(trigger_kthread);
+ else
+ trigger_data_free_queued_locked();
+
+ return 0;
+}
+late_initcall(trigger_data_free_init);
+
static inline void data_ops_trigger(struct event_trigger_data *data,
struct trace_buffer *buffer, void *rec,
struct ring_buffer_event *event)
diff --git a/kernel/trace/trace_osnoise.c b/kernel/trace/trace_osnoise.c
index dee610e465b9..be6cf0bb3c03 100644
--- a/kernel/trace/trace_osnoise.c
+++ b/kernel/trace/trace_osnoise.c
@@ -2073,8 +2073,8 @@ static void osnoise_hotplug_workfn(struct work_struct *dummy)
if (!osnoise_has_registered_instances())
return;
- guard(mutex)(&interface_lock);
guard(cpus_read_lock)();
+ guard(mutex)(&interface_lock);
if (!cpu_online(cpu))
return;
@@ -2237,11 +2237,11 @@ static ssize_t osnoise_options_write(struct file *filp, const char __user *ubuf,
if (running)
stop_per_cpu_kthreads();
- mutex_lock(&interface_lock);
/*
* avoid CPU hotplug operations that might read options.
*/
cpus_read_lock();
+ mutex_lock(&interface_lock);
retval = cnt;
@@ -2257,8 +2257,8 @@ static ssize_t osnoise_options_write(struct file *filp, const char __user *ubuf,
clear_bit(option, &osnoise_options);
}
- cpus_read_unlock();
mutex_unlock(&interface_lock);
+ cpus_read_unlock();
if (running)
start_per_cpu_kthreads();
@@ -2345,16 +2345,16 @@ osnoise_cpus_write(struct file *filp, const char __user *ubuf, size_t count,
if (running)
stop_per_cpu_kthreads();
- mutex_lock(&interface_lock);
/*
* osnoise_cpumask is read by CPU hotplug operations.
*/
cpus_read_lock();
+ mutex_lock(&interface_lock);
cpumask_copy(&osnoise_cpumask, osnoise_cpumask_new);
- cpus_read_unlock();
mutex_unlock(&interface_lock);
+ cpus_read_unlock();
if (running)
start_per_cpu_kthreads();
generated by cgit v1.2.3 (git 2.25.1) at 2026-05-06 11:41:18 +0000