| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * C++ stream style string builder used in KUnit for building messages. |
| * |
| * Copyright (C) 2019, Google LLC. |
| * Author: Brendan Higgins <brendanhiggins@google.com> |
| */ |
| |
| #include <linux/list.h> |
| #include <linux/slab.h> |
| #include <kunit/string-stream.h> |
| |
| int string_stream_vadd(struct string_stream *this, |
| const char *fmt, |
| va_list args) |
| { |
| struct string_stream_fragment *frag_container; |
| int len; |
| va_list args_for_counting; |
| unsigned long flags; |
| |
| /* Make a copy because `vsnprintf` could change it */ |
| va_copy(args_for_counting, args); |
| |
| /* Need space for null byte. */ |
| len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1; |
| |
| va_end(args_for_counting); |
| |
| frag_container = kmalloc(sizeof(*frag_container), GFP_KERNEL); |
| if (!frag_container) |
| return -ENOMEM; |
| |
| frag_container->fragment = kmalloc(len, GFP_KERNEL); |
| if (!frag_container->fragment) { |
| kfree(frag_container); |
| return -ENOMEM; |
| } |
| |
| len = vsnprintf(frag_container->fragment, len, fmt, args); |
| spin_lock_irqsave(&this->lock, flags); |
| this->length += len; |
| list_add_tail(&frag_container->node, &this->fragments); |
| spin_unlock_irqrestore(&this->lock, flags); |
| return 0; |
| } |
| |
| int string_stream_add(struct string_stream *this, const char *fmt, ...) |
| { |
| va_list args; |
| int result; |
| |
| va_start(args, fmt); |
| result = string_stream_vadd(this, fmt, args); |
| va_end(args); |
| return result; |
| } |
| |
| void string_stream_clear(struct string_stream *this) |
| { |
| struct string_stream_fragment *frag_container, *frag_container_safe; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&this->lock, flags); |
| list_for_each_entry_safe(frag_container, |
| frag_container_safe, |
| &this->fragments, |
| node) { |
| list_del(&frag_container->node); |
| kfree(frag_container->fragment); |
| kfree(frag_container); |
| } |
| this->length = 0; |
| spin_unlock_irqrestore(&this->lock, flags); |
| } |
| |
| char *string_stream_get_string(struct string_stream *this) |
| { |
| struct string_stream_fragment *frag_container; |
| size_t buf_len = this->length + 1; /* +1 for null byte. */ |
| char *buf; |
| unsigned long flags; |
| |
| buf = kzalloc(buf_len, GFP_KERNEL); |
| if (!buf) |
| return NULL; |
| |
| spin_lock_irqsave(&this->lock, flags); |
| list_for_each_entry(frag_container, &this->fragments, node) |
| strlcat(buf, frag_container->fragment, buf_len); |
| spin_unlock_irqrestore(&this->lock, flags); |
| |
| return buf; |
| } |
| |
| bool string_stream_is_empty(struct string_stream *this) |
| { |
| bool is_empty; |
| unsigned long flags; |
| |
| spin_lock_irqsave(&this->lock, flags); |
| is_empty = list_empty(&this->fragments); |
| spin_unlock_irqrestore(&this->lock, flags); |
| |
| return is_empty; |
| } |
| |
| void destroy_string_stream(struct string_stream *stream) |
| { |
| string_stream_clear(stream); |
| kfree(stream); |
| } |
| |
| static void string_stream_destroy(struct kref *kref) |
| { |
| struct string_stream *stream = container_of(kref, |
| struct string_stream, |
| refcount); |
| destroy_string_stream(stream); |
| } |
| |
| struct string_stream *new_string_stream(void) |
| { |
| struct string_stream *stream = kzalloc(sizeof(*stream), GFP_KERNEL); |
| |
| if (!stream) |
| return NULL; |
| |
| INIT_LIST_HEAD(&stream->fragments); |
| spin_lock_init(&stream->lock); |
| kref_init(&stream->refcount); |
| return stream; |
| } |
| |
| void string_stream_get(struct string_stream *stream) |
| { |
| kref_get(&stream->refcount); |
| } |
| |
| int string_stream_put(struct string_stream *stream) |
| { |
| return kref_put(&stream->refcount, &string_stream_destroy); |
| } |