diff options
Diffstat (limited to 'lib/stackdepot.c')
| -rw-r--r-- | lib/stackdepot.c | 72 |
1 files changed, 39 insertions, 33 deletions
diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 0a2e417f83cb..09485dc5bd12 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -20,7 +20,6 @@ */ #include <linux/gfp.h> -#include <linux/interrupt.h> #include <linux/jhash.h> #include <linux/kernel.h> #include <linux/mm.h> @@ -102,8 +101,8 @@ 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); @@ -248,17 +247,28 @@ 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. * - * 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; @@ -291,7 +301,7 @@ 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 +319,8 @@ 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 +349,24 @@ exit: fast_exit: return retval; } -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); -} +EXPORT_SYMBOL_GPL(__stack_depot_save); -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); |