From 15ef6a982f40a2b53b057dad24f00c3fb43e7e70 Mon Sep 17 00:00:00 2001 From: Andrey Konovalov Date: Fri, 10 Feb 2023 22:15:49 +0100 Subject: lib/stackdepot: put functions in logical order Patch series "lib/stackdepot: fixes and clean-ups", v2. A set of fixes, comments, and clean-ups I came up with while reading the stack depot code. This patch (of 18): Put stack depot functions' declarations and definitions in a more logical order: 1. Functions that save stack traces into stack depot. 2. Functions that fetch and print stack traces. 3. stack_depot_get_extra_bits that operates on stack depot handles and does not interact with the stack depot storage. No functional changes. Link: https://lkml.kernel.org/r/cover.1676063693.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/daca1319b665d826b94c596b992a8d8117846147.1676063693.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov Reviewed-by: Alexander Potapenko Cc: Evgenii Stepanov Cc: Marco Elver Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- lib/stackdepot.c | 314 +++++++++++++++++++++++++++---------------------------- 1 file changed, 157 insertions(+), 157 deletions(-) (limited to 'lib') diff --git a/lib/stackdepot.c b/lib/stackdepot.c index 79e894cf8406..4bfaf3bce619 100644 --- a/lib/stackdepot.c +++ b/lib/stackdepot.c @@ -79,84 +79,6 @@ static int next_slab_inited; static size_t depot_offset; static DEFINE_RAW_SPINLOCK(depot_lock); -unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle) -{ - union handle_parts parts = { .handle = handle }; - - return parts.extra; -} -EXPORT_SYMBOL(stack_depot_get_extra_bits); - -static bool init_stack_slab(void **prealloc) -{ - if (!*prealloc) - return false; - /* - * This smp_load_acquire() pairs with smp_store_release() to - * |next_slab_inited| below and in depot_alloc_stack(). - */ - if (smp_load_acquire(&next_slab_inited)) - return true; - if (stack_slabs[depot_index] == NULL) { - stack_slabs[depot_index] = *prealloc; - *prealloc = NULL; - } else { - /* If this is the last depot slab, do not touch the next one. */ - if (depot_index + 1 < STACK_ALLOC_MAX_SLABS) { - stack_slabs[depot_index + 1] = *prealloc; - *prealloc = NULL; - } - /* - * This smp_store_release pairs with smp_load_acquire() from - * |next_slab_inited| above and in stack_depot_save(). - */ - smp_store_release(&next_slab_inited, 1); - } - return true; -} - -/* Allocation of a new stack in raw storage */ -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); - - required_size = ALIGN(required_size, 1 << STACK_ALLOC_ALIGN); - - if (unlikely(depot_offset + required_size > STACK_ALLOC_SIZE)) { - if (unlikely(depot_index + 1 >= STACK_ALLOC_MAX_SLABS)) { - WARN_ONCE(1, "Stack depot reached limit capacity"); - return NULL; - } - depot_index++; - depot_offset = 0; - /* - * smp_store_release() here pairs with smp_load_acquire() from - * |next_slab_inited| in stack_depot_save() and - * init_stack_slab(). - */ - if (depot_index + 1 < STACK_ALLOC_MAX_SLABS) - smp_store_release(&next_slab_inited, 0); - } - init_stack_slab(prealloc); - if (stack_slabs[depot_index] == NULL) - return NULL; - - stack = stack_slabs[depot_index] + depot_offset; - - stack->hash = hash; - stack->size = size; - stack->handle.slabindex = depot_index; - stack->handle.offset = depot_offset >> STACK_ALLOC_ALIGN; - stack->handle.valid = 1; - stack->handle.extra = 0; - memcpy(stack->entries, entries, flex_array_size(stack, entries, size)); - depot_offset += required_size; - - return stack; -} - /* one hash table bucket entry per 16kB of memory */ #define STACK_HASH_SCALE 14 /* limited between 4k and 1M buckets */ @@ -270,6 +192,76 @@ int stack_depot_init(void) } EXPORT_SYMBOL_GPL(stack_depot_init); +static bool init_stack_slab(void **prealloc) +{ + if (!*prealloc) + return false; + /* + * This smp_load_acquire() pairs with smp_store_release() to + * |next_slab_inited| below and in depot_alloc_stack(). + */ + if (smp_load_acquire(&next_slab_inited)) + return true; + if (stack_slabs[depot_index] == NULL) { + stack_slabs[depot_index] = *prealloc; + *prealloc = NULL; + } else { + /* If this is the last depot slab, do not touch the next one. */ + if (depot_index + 1 < STACK_ALLOC_MAX_SLABS) { + stack_slabs[depot_index + 1] = *prealloc; + *prealloc = NULL; + } + /* + * This smp_store_release pairs with smp_load_acquire() from + * |next_slab_inited| above and in stack_depot_save(). + */ + smp_store_release(&next_slab_inited, 1); + } + return true; +} + +/* Allocation of a new stack in raw storage */ +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); + + required_size = ALIGN(required_size, 1 << STACK_ALLOC_ALIGN); + + if (unlikely(depot_offset + required_size > STACK_ALLOC_SIZE)) { + if (unlikely(depot_index + 1 >= STACK_ALLOC_MAX_SLABS)) { + WARN_ONCE(1, "Stack depot reached limit capacity"); + return NULL; + } + depot_index++; + depot_offset = 0; + /* + * smp_store_release() here pairs with smp_load_acquire() from + * |next_slab_inited| in stack_depot_save() and + * init_stack_slab(). + */ + if (depot_index + 1 < STACK_ALLOC_MAX_SLABS) + smp_store_release(&next_slab_inited, 0); + } + init_stack_slab(prealloc); + if (stack_slabs[depot_index] == NULL) + return NULL; + + stack = stack_slabs[depot_index] + depot_offset; + + stack->hash = hash; + stack->size = size; + stack->handle.slabindex = depot_index; + stack->handle.offset = depot_offset >> STACK_ALLOC_ALIGN; + stack->handle.valid = 1; + stack->handle.extra = 0; + memcpy(stack->entries, entries, flex_array_size(stack, entries, size)); + depot_offset += required_size; + + return stack; +} + /* Calculate hash for a stack */ static inline u32 hash_stack(unsigned long *entries, unsigned int size) { @@ -309,85 +301,6 @@ static inline struct stack_record *find_stack(struct stack_record *bucket, return NULL; } -/** - * 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 - * stack_depot_save(). - * @entries: Pointer to store the entries address - * - * Return: The number of trace entries for this depot. - */ -unsigned int stack_depot_fetch(depot_stack_handle_t handle, - unsigned long **entries) -{ - union handle_parts parts = { .handle = handle }; - void *slab; - size_t offset = parts.offset << STACK_ALLOC_ALIGN; - 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); - return 0; - } - slab = stack_slabs[parts.slabindex]; - if (!slab) - return 0; - stack = slab + offset; - - *entries = stack->entries; - return stack->size; -} -EXPORT_SYMBOL_GPL(stack_depot_fetch); - /** * __stack_depot_save - Save a stack trace from an array * @@ -533,3 +446,90 @@ depot_stack_handle_t stack_depot_save(unsigned long *entries, return __stack_depot_save(entries, nr_entries, 0, alloc_flags, true); } EXPORT_SYMBOL_GPL(stack_depot_save); + +/** + * stack_depot_fetch - Fetch stack entries from a depot + * + * @handle: Stack depot handle which was returned from + * stack_depot_save(). + * @entries: Pointer to store the entries address + * + * Return: The number of trace entries for this depot. + */ +unsigned int stack_depot_fetch(depot_stack_handle_t handle, + unsigned long **entries) +{ + union handle_parts parts = { .handle = handle }; + void *slab; + size_t offset = parts.offset << STACK_ALLOC_ALIGN; + 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); + return 0; + } + slab = stack_slabs[parts.slabindex]; + if (!slab) + return 0; + stack = slab + offset; + + *entries = stack->entries; + return stack->size; +} +EXPORT_SYMBOL_GPL(stack_depot_fetch); + +/** + * 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_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); + +unsigned int stack_depot_get_extra_bits(depot_stack_handle_t handle) +{ + union handle_parts parts = { .handle = handle }; + + return parts.extra; +} +EXPORT_SYMBOL(stack_depot_get_extra_bits); -- cgit v1.2.3