diff options
Diffstat (limited to 'lib/stackdepot.c')
| -rw-r--r-- | lib/stackdepot.c | 42 |
1 files changed, 33 insertions, 9 deletions
diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 4df162a84bfe..8c6e4e9cb535 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -357,7 +357,6 @@ static inline struct stack_record *find_stack(struct stack_record *bucket, * * @entries: Pointer to storage array * @nr_entries: Size of the storage array - * @extra_bits: Flags to store in unused bits of depot_stack_handle_t * @alloc_flags: Allocation gfp flags * @can_alloc: Allocate stack pools (increased chance of failure if false) * @@ -369,10 +368,6 @@ static inline struct stack_record *find_stack(struct stack_record *bucket, * If the stack trace in @entries is from an interrupt, only the portion up to * interrupt entry is saved. * - * Additional opaque flags can be passed in @extra_bits, stored in the unused - * bits of the stack handle, and retrieved using stack_depot_get_extra_bits() - * without calling stack_depot_fetch(). - * * 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 @@ -382,7 +377,6 @@ static inline struct stack_record *find_stack(struct stack_record *bucket, */ depot_stack_handle_t __stack_depot_save(unsigned long *entries, unsigned int nr_entries, - unsigned int extra_bits, gfp_t alloc_flags, bool can_alloc) { struct stack_record *found = NULL, **bucket; @@ -471,8 +465,6 @@ exit: if (found) retval.handle = found->handle.handle; fast_exit: - retval.extra = extra_bits; - return retval.handle; } EXPORT_SYMBOL_GPL(__stack_depot_save); @@ -493,7 +485,7 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries, unsigned int nr_entries, gfp_t alloc_flags) { - return __stack_depot_save(entries, nr_entries, 0, alloc_flags, true); + return __stack_depot_save(entries, nr_entries, alloc_flags, true); } EXPORT_SYMBOL_GPL(stack_depot_save); @@ -576,6 +568,38 @@ int stack_depot_snprint(depot_stack_handle_t handle, char *buf, size_t size, } EXPORT_SYMBOL_GPL(stack_depot_snprint); +/** + * stack_depot_set_extra_bits - Set extra bits in a stack depot handle + * + * @handle: Stack depot handle returned from stack_depot_save() + * @extra_bits: Value to set the extra bits + * + * Return: Stack depot handle with extra bits set + * + * Stack depot handles have a few unused bits, which can be used for storing + * user-specific information. These bits are transparent to the stack depot. + */ +depot_stack_handle_t __must_check stack_depot_set_extra_bits( + depot_stack_handle_t handle, unsigned int extra_bits) +{ + union handle_parts parts = { .handle = handle }; + + /* Don't set extra bits on empty handles. */ + if (!handle) + return 0; + + parts.extra = extra_bits; + return parts.handle; +} +EXPORT_SYMBOL(stack_depot_set_extra_bits); + +/** + * stack_depot_get_extra_bits - Retrieve extra bits from a stack depot handle + * + * @handle: Stack depot handle with extra bits saved + * + * Return: Extra bits retrieved from the stack depot handle + */ unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle) { union handle_parts parts = { .handle = handle }; |