Merge tag 'v5.17-rc4' into for-linus

Merge with mainline to get the Intel ASoC generic helpers header and
other changes.

1 files changed, 126 insertions, 38 deletions

diff --git a/lib/stackdepot.c b/lib/stackdepot.c
index 0a2e417f83cb..bf5ba9af0500 100644
--- a/lib/stackdepot.c
+++ b/lib/stackdepot.c
@@ -20,10 +20,10 @@
  */
 
 #include <linux/gfp.h>
-#include <linux/interrupt.h>
 #include <linux/jhash.h>
 #include <linux/kernel.h>
 #include <linux/mm.h>
+#include <linux/mutex.h>
 #include <linux/percpu.h>
 #include <linux/printk.h>
 #include <linux/slab.h>
@@ -102,8 +102,8 @@ static bool init_stack_slab(void **prealloc)
 }
 
 /* Allocation of a new stack in raw storage */
-static struct stack_record *depot_alloc_stack(unsigned long *entries, int size,
-		u32 hash, void **prealloc, gfp_t alloc_flags)
+static struct stack_record *
+depot_alloc_stack(unsigned long *entries, int size, u32 hash, void **prealloc)
 {
 	struct stack_record *stack;
 	size_t required_size = struct_size(stack, entries, size);
@@ -162,18 +162,40 @@ static int __init is_stack_depot_disabled(char *str)
 }
 early_param("stack_depot_disable", is_stack_depot_disabled);
 
-int __init stack_depot_init(void)
+/*
+ * __ref because of memblock_alloc(), which will not be actually called after
+ * the __init code is gone, because at that point slab_is_available() is true
+ */
+__ref int stack_depot_init(void)
 {
-	if (!stack_depot_disable) {
+	static DEFINE_MUTEX(stack_depot_init_mutex);
+
+	mutex_lock(&stack_depot_init_mutex);
+	if (!stack_depot_disable && !stack_table) {
 		size_t size = (STACK_HASH_SIZE * sizeof(struct stack_record *));
 		int i;
 
-		stack_table = memblock_alloc(size, size);
-		for (i = 0; i < STACK_HASH_SIZE;  i++)
-			stack_table[i] = NULL;
+		if (slab_is_available()) {
+			pr_info("Stack Depot allocating hash table with kvmalloc\n");
+			stack_table = kvmalloc(size, GFP_KERNEL);
+		} else {
+			pr_info("Stack Depot allocating hash table with memblock_alloc\n");
+			stack_table = memblock_alloc(size, SMP_CACHE_BYTES);
+		}
+		if (stack_table) {
+			for (i = 0; i < STACK_HASH_SIZE;  i++)
+				stack_table[i] = NULL;
+		} else {
+			pr_err("Stack Depot hash table allocation failed, disabling\n");
+			stack_depot_disable = true;
+			mutex_unlock(&stack_depot_init_mutex);
+			return -ENOMEM;
+		}
 	}
+	mutex_unlock(&stack_depot_init_mutex);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(stack_depot_init);
 
 /* Calculate hash for a stack */
 static inline u32 hash_stack(unsigned long *entries, unsigned int size)
@@ -215,6 +237,49 @@ static inline struct stack_record *find_stack(struct stack_record *bucket,
 }
 
 /**
+ * stack_depot_snprint - print stack entries from a depot into a buffer
+ *
+ * @handle:	Stack depot handle which was returned from
+ *		stack_depot_save().
+ * @buf:	Pointer to the print buffer
+ *
+ * @size:	Size of the print buffer
+ *
+ * @spaces:	Number of leading spaces to print
+ *
+ * Return:	Number of bytes printed.
+ */
+int stack_depot_snprint(depot_stack_handle_t handle, char *buf, size_t size,
+		       int spaces)
+{
+	unsigned long *entries;
+	unsigned int nr_entries;
+
+	nr_entries = stack_depot_fetch(handle, &entries);
+	return nr_entries ? stack_trace_snprint(buf, size, entries, nr_entries,
+						spaces) : 0;
+}
+EXPORT_SYMBOL_GPL(stack_depot_snprint);
+
+/**
+ * stack_depot_print - print stack entries from a depot
+ *
+ * @stack:		Stack depot handle which was returned from
+ *			stack_depot_save().
+ *
+ */
+void stack_depot_print(depot_stack_handle_t stack)
+{
+	unsigned long *entries;
+	unsigned int nr_entries;
+
+	nr_entries = stack_depot_fetch(stack, &entries);
+	if (nr_entries > 0)
+		stack_trace_print(entries, nr_entries, 0);
+}
+EXPORT_SYMBOL_GPL(stack_depot_print);
+
+/**
  * stack_depot_fetch - Fetch stack entries from a depot
  *
  * @handle:		Stack depot handle which was returned from
@@ -232,6 +297,9 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle,
 	struct stack_record *stack;
 
 	*entries = NULL;
+	if (!handle)
+		return 0;
+
 	if (parts.slabindex > depot_index) {
 		WARN(1, "slab index %d out of bounds (%d) for stack id %08x\n",
 			parts.slabindex, depot_index, handle);
@@ -248,17 +316,31 @@ unsigned int stack_depot_fetch(depot_stack_handle_t handle,
 EXPORT_SYMBOL_GPL(stack_depot_fetch);
 
 /**
- * stack_depot_save - Save a stack trace from an array
+ * __stack_depot_save - Save a stack trace from an array
  *
  * @entries:		Pointer to storage array
  * @nr_entries:		Size of the storage array
  * @alloc_flags:	Allocation gfp flags
+ * @can_alloc:		Allocate stack slabs (increased chance of failure if false)
+ *
+ * Saves a stack trace from @entries array of size @nr_entries. If @can_alloc is
+ * %true, is allowed to replenish the stack slab pool in case no space is left
+ * (allocates using GFP flags of @alloc_flags). If @can_alloc is %false, avoids
+ * any allocations and will fail if no space is left to store the stack trace.
+ *
+ * If the stack trace in @entries is from an interrupt, only the portion up to
+ * interrupt entry is saved.
  *
- * Return: The handle of the stack struct stored in depot
+ * Context: Any context, but setting @can_alloc to %false is required if
+ *          alloc_pages() cannot be used from the current context. Currently
+ *          this is the case from contexts where neither %GFP_ATOMIC nor
+ *          %GFP_NOWAIT can be used (NMI, raw_spin_lock).
+ *
+ * Return: The handle of the stack struct stored in depot, 0 on failure.
  */
-depot_stack_handle_t stack_depot_save(unsigned long *entries,
-				      unsigned int nr_entries,
-				      gfp_t alloc_flags)
+depot_stack_handle_t __stack_depot_save(unsigned long *entries,
+					unsigned int nr_entries,
+					gfp_t alloc_flags, bool can_alloc)
 {
 	struct stack_record *found = NULL, **bucket;
 	depot_stack_handle_t retval = 0;
@@ -267,6 +349,16 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries,
 	unsigned long flags;
 	u32 hash;
 
+	/*
+	 * If this stack trace is from an interrupt, including anything before
+	 * interrupt entry usually leads to unbounded stackdepot growth.
+	 *
+	 * Because use of filter_irq_stacks() is a requirement to ensure
+	 * stackdepot can efficiently deduplicate interrupt stacks, always
+	 * filter_irq_stacks() to simplify all callers' use of stackdepot.
+	 */
+	nr_entries = filter_irq_stacks(entries, nr_entries);
+
 	if (unlikely(nr_entries == 0) || stack_depot_disable)
 		goto fast_exit;
 
@@ -291,7 +383,7 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries,
 	 * The smp_load_acquire() here pairs with smp_store_release() to
 	 * |next_slab_inited| in depot_alloc_stack() and init_stack_slab().
 	 */
-	if (unlikely(!smp_load_acquire(&next_slab_inited))) {
+	if (unlikely(can_alloc && !smp_load_acquire(&next_slab_inited))) {
 		/*
 		 * Zero out zone modifiers, as we don't have specific zone
 		 * requirements. Keep the flags related to allocation in atomic
@@ -309,9 +401,8 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries,
 
 	found = find_stack(*bucket, entries, nr_entries, hash);
 	if (!found) {
-		struct stack_record *new =
-			depot_alloc_stack(entries, nr_entries,
-					  hash, &prealloc, alloc_flags);
+		struct stack_record *new = depot_alloc_stack(entries, nr_entries, hash, &prealloc);
+
 		if (new) {
 			new->next = *bucket;
 			/*
@@ -340,27 +431,24 @@ exit:
 fast_exit:
 	return retval;
 }
-EXPORT_SYMBOL_GPL(stack_depot_save);
+EXPORT_SYMBOL_GPL(__stack_depot_save);
 
-static inline int in_irqentry_text(unsigned long ptr)
-{
-	return (ptr >= (unsigned long)&__irqentry_text_start &&
-		ptr < (unsigned long)&__irqentry_text_end) ||
-		(ptr >= (unsigned long)&__softirqentry_text_start &&
-		 ptr < (unsigned long)&__softirqentry_text_end);
-}
-
-unsigned int filter_irq_stacks(unsigned long *entries,
-					     unsigned int nr_entries)
+/**
+ * stack_depot_save - Save a stack trace from an array
+ *
+ * @entries:		Pointer to storage array
+ * @nr_entries:		Size of the storage array
+ * @alloc_flags:	Allocation gfp flags
+ *
+ * Context: Contexts where allocations via alloc_pages() are allowed.
+ *          See __stack_depot_save() for more details.
+ *
+ * Return: The handle of the stack struct stored in depot, 0 on failure.
+ */
+depot_stack_handle_t stack_depot_save(unsigned long *entries,
+				      unsigned int nr_entries,
+				      gfp_t alloc_flags)
 {
-	unsigned int i;
-
-	for (i = 0; i < nr_entries; i++) {
-		if (in_irqentry_text(entries[i])) {
-			/* Include the irqentry function into the stack. */
-			return i + 1;
-		}
-	}
-	return nr_entries;
+	return __stack_depot_save(entries, nr_entries, alloc_flags, true);
 }
-EXPORT_SYMBOL_GPL(filter_irq_stacks);
+EXPORT_SYMBOL_GPL(stack_depot_save);