X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=lib%2Fringbuffer%2Fring_buffer_backend.c;fp=lib%2Fringbuffer%2Fring_buffer_backend.c;h=0000000000000000000000000000000000000000;hb=cfa6cc1d0f01c2cfcc1a679abf3a6572d411c309;hp=d6547d7de9c9cef6f45a6fb426c864a1b8ee3347;hpb=cd4486798c2b046ea93b89439cd705e93c40b349;p=lttng-modules.git diff --git a/lib/ringbuffer/ring_buffer_backend.c b/lib/ringbuffer/ring_buffer_backend.c deleted file mode 100644 index d6547d7d..00000000 --- a/lib/ringbuffer/ring_buffer_backend.c +++ /dev/null @@ -1,1124 +0,0 @@ -/* SPDX-License-Identifier: (GPL-2.0-only OR LGPL-2.1-only) - * - * ring_buffer_backend.c - * - * Copyright (C) 2005-2012 Mathieu Desnoyers - */ - -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include /* for wrapper_vmalloc_sync_mappings() */ -#include -#include -#include - -/** - * lib_ring_buffer_backend_allocate - allocate a channel buffer - * @config: ring buffer instance configuration - * @buf: the buffer struct - * @size: total size of the buffer - * @num_subbuf: number of subbuffers - * @extra_reader_sb: need extra subbuffer for reader - */ -static -int lib_ring_buffer_backend_allocate(const struct lib_ring_buffer_config *config, - struct lib_ring_buffer_backend *bufb, - size_t size, size_t num_subbuf, - int extra_reader_sb) -{ - struct channel_backend *chanb = &bufb->chan->backend; - unsigned long j, num_pages, num_pages_per_subbuf, page_idx = 0; - unsigned long subbuf_size, mmap_offset = 0; - unsigned long num_subbuf_alloc; - struct page **pages; - unsigned long i; - - num_pages = size >> PAGE_SHIFT; - - /* - * Verify that there is enough free pages available on the system for - * the current allocation request. - * wrapper_check_enough_free_pages uses si_mem_available() if available - * and returns if there should be enough free pages based on the - * current estimate. - */ - if (!wrapper_check_enough_free_pages(num_pages)) - goto not_enough_pages; - - /* - * Set the current user thread as the first target of the OOM killer. - * If the estimate received by si_mem_available() was off, and we do - * end up running out of memory because of this buffer allocation, we - * want to kill the offending app first. - */ - wrapper_set_current_oom_origin(); - - num_pages_per_subbuf = num_pages >> get_count_order(num_subbuf); - subbuf_size = chanb->subbuf_size; - num_subbuf_alloc = num_subbuf; - - if (extra_reader_sb) { - num_pages += num_pages_per_subbuf; /* Add pages for reader */ - num_subbuf_alloc++; - } - - pages = vmalloc_node(ALIGN(sizeof(*pages) * num_pages, - 1 << INTERNODE_CACHE_SHIFT), - cpu_to_node(max(bufb->cpu, 0))); - if (unlikely(!pages)) - goto pages_error; - - bufb->array = lttng_kvmalloc_node(ALIGN(sizeof(*bufb->array) - * num_subbuf_alloc, - 1 << INTERNODE_CACHE_SHIFT), - GFP_KERNEL | __GFP_NOWARN, - cpu_to_node(max(bufb->cpu, 0))); - if (unlikely(!bufb->array)) - goto array_error; - - for (i = 0; i < num_pages; i++) { - pages[i] = alloc_pages_node(cpu_to_node(max(bufb->cpu, 0)), - GFP_KERNEL | __GFP_NOWARN | __GFP_ZERO, 0); - if (unlikely(!pages[i])) - goto depopulate; - } - bufb->num_pages_per_subbuf = num_pages_per_subbuf; - - /* Allocate backend pages array elements */ - for (i = 0; i < num_subbuf_alloc; i++) { - bufb->array[i] = - lttng_kvzalloc_node(ALIGN( - sizeof(struct lib_ring_buffer_backend_pages) + - sizeof(struct lib_ring_buffer_backend_page) - * num_pages_per_subbuf, - 1 << INTERNODE_CACHE_SHIFT), - GFP_KERNEL | __GFP_NOWARN, - cpu_to_node(max(bufb->cpu, 0))); - if (!bufb->array[i]) - goto free_array; - } - - /* Allocate write-side subbuffer table */ - bufb->buf_wsb = lttng_kvzalloc_node(ALIGN( - sizeof(struct lib_ring_buffer_backend_subbuffer) - * num_subbuf, - 1 << INTERNODE_CACHE_SHIFT), - GFP_KERNEL | __GFP_NOWARN, - cpu_to_node(max(bufb->cpu, 0))); - if (unlikely(!bufb->buf_wsb)) - goto free_array; - - for (i = 0; i < num_subbuf; i++) - bufb->buf_wsb[i].id = subbuffer_id(config, 0, 1, i); - - /* Assign read-side subbuffer table */ - if (extra_reader_sb) - bufb->buf_rsb.id = subbuffer_id(config, 0, 1, - num_subbuf_alloc - 1); - else - bufb->buf_rsb.id = subbuffer_id(config, 0, 1, 0); - - /* Allocate subbuffer packet counter table */ - bufb->buf_cnt = lttng_kvzalloc_node(ALIGN( - sizeof(struct lib_ring_buffer_backend_counts) - * num_subbuf, - 1 << INTERNODE_CACHE_SHIFT), - GFP_KERNEL | __GFP_NOWARN, - cpu_to_node(max(bufb->cpu, 0))); - if (unlikely(!bufb->buf_cnt)) - goto free_wsb; - - /* Assign pages to page index */ - for (i = 0; i < num_subbuf_alloc; i++) { - for (j = 0; j < num_pages_per_subbuf; j++) { - CHAN_WARN_ON(chanb, page_idx > num_pages); - bufb->array[i]->p[j].virt = page_address(pages[page_idx]); - bufb->array[i]->p[j].pfn = page_to_pfn(pages[page_idx]); - page_idx++; - } - if (config->output == RING_BUFFER_MMAP) { - bufb->array[i]->mmap_offset = mmap_offset; - mmap_offset += subbuf_size; - } - } - - /* - * If kmalloc ever uses vmalloc underneath, make sure the buffer pages - * will not fault. - */ - wrapper_vmalloc_sync_mappings(); - wrapper_clear_current_oom_origin(); - vfree(pages); - return 0; - -free_wsb: - lttng_kvfree(bufb->buf_wsb); -free_array: - for (i = 0; (i < num_subbuf_alloc && bufb->array[i]); i++) - lttng_kvfree(bufb->array[i]); -depopulate: - /* Free all allocated pages */ - for (i = 0; (i < num_pages && pages[i]); i++) - __free_page(pages[i]); - lttng_kvfree(bufb->array); -array_error: - vfree(pages); -pages_error: - wrapper_clear_current_oom_origin(); -not_enough_pages: - return -ENOMEM; -} - -int lib_ring_buffer_backend_create(struct lib_ring_buffer_backend *bufb, - struct channel_backend *chanb, int cpu) -{ - const struct lib_ring_buffer_config *config = &chanb->config; - - bufb->chan = container_of(chanb, struct channel, backend); - bufb->cpu = cpu; - - return lib_ring_buffer_backend_allocate(config, bufb, chanb->buf_size, - chanb->num_subbuf, - chanb->extra_reader_sb); -} - -void lib_ring_buffer_backend_free(struct lib_ring_buffer_backend *bufb) -{ - struct channel_backend *chanb = &bufb->chan->backend; - unsigned long i, j, num_subbuf_alloc; - - num_subbuf_alloc = chanb->num_subbuf; - if (chanb->extra_reader_sb) - num_subbuf_alloc++; - - lttng_kvfree(bufb->buf_wsb); - lttng_kvfree(bufb->buf_cnt); - for (i = 0; i < num_subbuf_alloc; i++) { - for (j = 0; j < bufb->num_pages_per_subbuf; j++) - __free_page(pfn_to_page(bufb->array[i]->p[j].pfn)); - lttng_kvfree(bufb->array[i]); - } - lttng_kvfree(bufb->array); - bufb->allocated = 0; -} - -void lib_ring_buffer_backend_reset(struct lib_ring_buffer_backend *bufb) -{ - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - unsigned long num_subbuf_alloc; - unsigned int i; - - num_subbuf_alloc = chanb->num_subbuf; - if (chanb->extra_reader_sb) - num_subbuf_alloc++; - - for (i = 0; i < chanb->num_subbuf; i++) - bufb->buf_wsb[i].id = subbuffer_id(config, 0, 1, i); - if (chanb->extra_reader_sb) - bufb->buf_rsb.id = subbuffer_id(config, 0, 1, - num_subbuf_alloc - 1); - else - bufb->buf_rsb.id = subbuffer_id(config, 0, 1, 0); - - for (i = 0; i < num_subbuf_alloc; i++) { - /* Don't reset mmap_offset */ - v_set(config, &bufb->array[i]->records_commit, 0); - v_set(config, &bufb->array[i]->records_unread, 0); - bufb->array[i]->data_size = 0; - /* Don't reset backend page and virt addresses */ - } - /* Don't reset num_pages_per_subbuf, cpu, allocated */ - v_set(config, &bufb->records_read, 0); -} - -/* - * The frontend is responsible for also calling ring_buffer_backend_reset for - * each buffer when calling channel_backend_reset. - */ -void channel_backend_reset(struct channel_backend *chanb) -{ - struct channel *chan = container_of(chanb, struct channel, backend); - const struct lib_ring_buffer_config *config = &chanb->config; - - /* - * Don't reset buf_size, subbuf_size, subbuf_size_order, - * num_subbuf_order, buf_size_order, extra_reader_sb, num_subbuf, - * priv, notifiers, config, cpumask and name. - */ - chanb->start_tsc = config->cb.ring_buffer_clock_read(chan); -} - -#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) - -/* - * No need to implement a "dead" callback to do a buffer switch here, - * because it will happen when tracing is stopped, or will be done by - * switch timer CPU DEAD callback. - * We don't free buffers when CPU go away, because it would make trace - * data vanish, which is unwanted. - */ -int lttng_cpuhp_rb_backend_prepare(unsigned int cpu, - struct lttng_cpuhp_node *node) -{ - struct channel_backend *chanb = container_of(node, - struct channel_backend, cpuhp_prepare); - const struct lib_ring_buffer_config *config = &chanb->config; - struct lib_ring_buffer *buf; - int ret; - - CHAN_WARN_ON(chanb, config->alloc == RING_BUFFER_ALLOC_GLOBAL); - - buf = per_cpu_ptr(chanb->buf, cpu); - ret = lib_ring_buffer_create(buf, chanb, cpu); - if (ret) { - printk(KERN_ERR - "ring_buffer_cpu_hp_callback: cpu %d " - "buffer creation failed\n", cpu); - return ret; - } - return 0; -} -EXPORT_SYMBOL_GPL(lttng_cpuhp_rb_backend_prepare); - -#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */ - -#ifdef CONFIG_HOTPLUG_CPU - -/** - * lib_ring_buffer_cpu_hp_callback - CPU hotplug callback - * @nb: notifier block - * @action: hotplug action to take - * @hcpu: CPU number - * - * Returns the success/failure of the operation. (%NOTIFY_OK, %NOTIFY_BAD) - */ -static -int lib_ring_buffer_cpu_hp_callback(struct notifier_block *nb, - unsigned long action, - void *hcpu) -{ - unsigned int cpu = (unsigned long)hcpu; - struct channel_backend *chanb = container_of(nb, struct channel_backend, - cpu_hp_notifier); - const struct lib_ring_buffer_config *config = &chanb->config; - struct lib_ring_buffer *buf; - int ret; - - CHAN_WARN_ON(chanb, config->alloc == RING_BUFFER_ALLOC_GLOBAL); - - switch (action) { - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - buf = per_cpu_ptr(chanb->buf, cpu); - ret = lib_ring_buffer_create(buf, chanb, cpu); - if (ret) { - printk(KERN_ERR - "ring_buffer_cpu_hp_callback: cpu %d " - "buffer creation failed\n", cpu); - return NOTIFY_BAD; - } - break; - case CPU_DEAD: - case CPU_DEAD_FROZEN: - /* No need to do a buffer switch here, because it will happen - * when tracing is stopped, or will be done by switch timer CPU - * DEAD callback. */ - break; - } - return NOTIFY_OK; -} - -#endif - -#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */ - -/** - * channel_backend_init - initialize a channel backend - * @chanb: channel backend - * @name: channel name - * @config: client ring buffer configuration - * @priv: client private data - * @parent: dentry of parent directory, %NULL for root directory - * @subbuf_size: size of sub-buffers (> PAGE_SIZE, power of 2) - * @num_subbuf: number of sub-buffers (power of 2) - * - * Returns channel pointer if successful, %NULL otherwise. - * - * Creates per-cpu channel buffers using the sizes and attributes - * specified. The created channel buffer files will be named - * name_0...name_N-1. File permissions will be %S_IRUSR. - * - * Called with CPU hotplug disabled. - */ -int channel_backend_init(struct channel_backend *chanb, - const char *name, - const struct lib_ring_buffer_config *config, - void *priv, size_t subbuf_size, size_t num_subbuf) -{ - struct channel *chan = container_of(chanb, struct channel, backend); - unsigned int i; - int ret; - - if (!name) - return -EPERM; - - /* Check that the subbuffer size is larger than a page. */ - if (subbuf_size < PAGE_SIZE) - return -EINVAL; - - /* - * Make sure the number of subbuffers and subbuffer size are - * power of 2 and nonzero. - */ - if (!subbuf_size || (subbuf_size & (subbuf_size - 1))) - return -EINVAL; - if (!num_subbuf || (num_subbuf & (num_subbuf - 1))) - return -EINVAL; - /* - * Overwrite mode buffers require at least 2 subbuffers per - * buffer. - */ - if (config->mode == RING_BUFFER_OVERWRITE && num_subbuf < 2) - return -EINVAL; - - ret = subbuffer_id_check_index(config, num_subbuf); - if (ret) - return ret; - - chanb->priv = priv; - chanb->buf_size = num_subbuf * subbuf_size; - chanb->subbuf_size = subbuf_size; - chanb->buf_size_order = get_count_order(chanb->buf_size); - chanb->subbuf_size_order = get_count_order(subbuf_size); - chanb->num_subbuf_order = get_count_order(num_subbuf); - chanb->extra_reader_sb = - (config->mode == RING_BUFFER_OVERWRITE) ? 1 : 0; - chanb->num_subbuf = num_subbuf; - strlcpy(chanb->name, name, NAME_MAX); - memcpy(&chanb->config, config, sizeof(chanb->config)); - - if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) { - if (!zalloc_cpumask_var(&chanb->cpumask, GFP_KERNEL)) - return -ENOMEM; - } - - if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) { - /* Allocating the buffer per-cpu structures */ - chanb->buf = alloc_percpu(struct lib_ring_buffer); - if (!chanb->buf) - goto free_cpumask; - -#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) - chanb->cpuhp_prepare.component = LTTNG_RING_BUFFER_BACKEND; - ret = cpuhp_state_add_instance(lttng_rb_hp_prepare, - &chanb->cpuhp_prepare.node); - if (ret) - goto free_bufs; -#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */ - - { - /* - * In case of non-hotplug cpu, if the ring-buffer is allocated - * in early initcall, it will not be notified of secondary cpus. - * In that off case, we need to allocate for all possible cpus. - */ -#ifdef CONFIG_HOTPLUG_CPU - /* - * buf->backend.allocated test takes care of concurrent CPU - * hotplug. - * Priority higher than frontend, so we create the ring buffer - * before we start the timer. - */ - chanb->cpu_hp_notifier.notifier_call = - lib_ring_buffer_cpu_hp_callback; - chanb->cpu_hp_notifier.priority = 5; - register_hotcpu_notifier(&chanb->cpu_hp_notifier); - - get_online_cpus(); - for_each_online_cpu(i) { - ret = lib_ring_buffer_create(per_cpu_ptr(chanb->buf, i), - chanb, i); - if (ret) - goto free_bufs; /* cpu hotplug locked */ - } - put_online_cpus(); -#else - for_each_possible_cpu(i) { - ret = lib_ring_buffer_create(per_cpu_ptr(chanb->buf, i), - chanb, i); - if (ret) - goto free_bufs; - } -#endif - } -#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */ - } else { - chanb->buf = kzalloc(sizeof(struct lib_ring_buffer), GFP_KERNEL); - if (!chanb->buf) - goto free_cpumask; - ret = lib_ring_buffer_create(chanb->buf, chanb, -1); - if (ret) - goto free_bufs; - } - chanb->start_tsc = config->cb.ring_buffer_clock_read(chan); - - return 0; - -free_bufs: - if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) { -#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) - /* - * Teardown of lttng_rb_hp_prepare instance - * on "add" error is handled within cpu hotplug, - * no teardown to do from the caller. - */ -#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */ -#ifdef CONFIG_HOTPLUG_CPU - put_online_cpus(); - unregister_hotcpu_notifier(&chanb->cpu_hp_notifier); -#endif -#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */ - for_each_possible_cpu(i) { - struct lib_ring_buffer *buf = - per_cpu_ptr(chanb->buf, i); - - if (!buf->backend.allocated) - continue; - lib_ring_buffer_free(buf); - } - free_percpu(chanb->buf); - } else - kfree(chanb->buf); -free_cpumask: - if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) - free_cpumask_var(chanb->cpumask); - return -ENOMEM; -} - -/** - * channel_backend_unregister_notifiers - unregister notifiers - * @chan: the channel - * - * Holds CPU hotplug. - */ -void channel_backend_unregister_notifiers(struct channel_backend *chanb) -{ - const struct lib_ring_buffer_config *config = &chanb->config; - - if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) { -#if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) - int ret; - - ret = cpuhp_state_remove_instance(lttng_rb_hp_prepare, - &chanb->cpuhp_prepare.node); - WARN_ON(ret); -#else /* #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */ - unregister_hotcpu_notifier(&chanb->cpu_hp_notifier); -#endif /* #else #if (LINUX_VERSION_CODE >= KERNEL_VERSION(4,10,0)) */ - } -} - -/** - * channel_backend_free - destroy the channel - * @chan: the channel - * - * Destroy all channel buffers and frees the channel. - */ -void channel_backend_free(struct channel_backend *chanb) -{ - const struct lib_ring_buffer_config *config = &chanb->config; - unsigned int i; - - if (config->alloc == RING_BUFFER_ALLOC_PER_CPU) { - for_each_possible_cpu(i) { - struct lib_ring_buffer *buf = per_cpu_ptr(chanb->buf, i); - - if (!buf->backend.allocated) - continue; - lib_ring_buffer_free(buf); - } - free_cpumask_var(chanb->cpumask); - free_percpu(chanb->buf); - } else { - struct lib_ring_buffer *buf = chanb->buf; - - CHAN_WARN_ON(chanb, !buf->backend.allocated); - lib_ring_buffer_free(buf); - kfree(buf); - } -} - -/** - * lib_ring_buffer_write - write data to a ring_buffer buffer. - * @bufb : buffer backend - * @offset : offset within the buffer - * @src : source address - * @len : length to write - * @pagecpy : page size copied so far - */ -void _lib_ring_buffer_write(struct lib_ring_buffer_backend *bufb, size_t offset, - const void *src, size_t len, size_t pagecpy) -{ - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - size_t sbidx, index; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; - - do { - len -= pagecpy; - src += pagecpy; - offset += pagecpy; - sbidx = offset >> chanb->subbuf_size_order; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - - /* - * Underlying layer should never ask for writes across - * subbuffers. - */ - CHAN_WARN_ON(chanb, offset >= chanb->buf_size); - - pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK)); - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - lib_ring_buffer_do_copy(config, - rpages->p[index].virt - + (offset & ~PAGE_MASK), - src, pagecpy); - } while (unlikely(len != pagecpy)); -} -EXPORT_SYMBOL_GPL(_lib_ring_buffer_write); - - -/** - * lib_ring_buffer_memset - write len bytes of c to a ring_buffer buffer. - * @bufb : buffer backend - * @offset : offset within the buffer - * @c : the byte to write - * @len : length to write - * @pagecpy : page size copied so far - */ -void _lib_ring_buffer_memset(struct lib_ring_buffer_backend *bufb, - size_t offset, - int c, size_t len, size_t pagecpy) -{ - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - size_t sbidx, index; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; - - do { - len -= pagecpy; - offset += pagecpy; - sbidx = offset >> chanb->subbuf_size_order; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - - /* - * Underlying layer should never ask for writes across - * subbuffers. - */ - CHAN_WARN_ON(chanb, offset >= chanb->buf_size); - - pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK)); - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - lib_ring_buffer_do_memset(rpages->p[index].virt - + (offset & ~PAGE_MASK), - c, pagecpy); - } while (unlikely(len != pagecpy)); -} -EXPORT_SYMBOL_GPL(_lib_ring_buffer_memset); - -/** - * lib_ring_buffer_strcpy - write string data to a ring_buffer buffer. - * @bufb : buffer backend - * @offset : offset within the buffer - * @src : source address - * @len : length to write - * @pagecpy : page size copied so far - * @pad : character to use for padding - */ -void _lib_ring_buffer_strcpy(struct lib_ring_buffer_backend *bufb, - size_t offset, const char *src, size_t len, - size_t pagecpy, int pad) -{ - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - size_t sbidx, index; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; - int src_terminated = 0; - - CHAN_WARN_ON(chanb, !len); - offset += pagecpy; - do { - len -= pagecpy; - if (!src_terminated) - src += pagecpy; - sbidx = offset >> chanb->subbuf_size_order; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - - /* - * Underlying layer should never ask for writes across - * subbuffers. - */ - CHAN_WARN_ON(chanb, offset >= chanb->buf_size); - - pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK)); - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - - if (likely(!src_terminated)) { - size_t count, to_copy; - - to_copy = pagecpy; - if (pagecpy == len) - to_copy--; /* Final '\0' */ - count = lib_ring_buffer_do_strcpy(config, - rpages->p[index].virt - + (offset & ~PAGE_MASK), - src, to_copy); - offset += count; - /* Padding */ - if (unlikely(count < to_copy)) { - size_t pad_len = to_copy - count; - - /* Next pages will have padding */ - src_terminated = 1; - lib_ring_buffer_do_memset(rpages->p[index].virt - + (offset & ~PAGE_MASK), - pad, pad_len); - offset += pad_len; - } - } else { - size_t pad_len; - - pad_len = pagecpy; - if (pagecpy == len) - pad_len--; /* Final '\0' */ - lib_ring_buffer_do_memset(rpages->p[index].virt - + (offset & ~PAGE_MASK), - pad, pad_len); - offset += pad_len; - } - } while (unlikely(len != pagecpy)); - /* Ending '\0' */ - lib_ring_buffer_do_memset(rpages->p[index].virt + (offset & ~PAGE_MASK), - '\0', 1); -} -EXPORT_SYMBOL_GPL(_lib_ring_buffer_strcpy); - -/** - * lib_ring_buffer_copy_from_user_inatomic - write user data to a ring_buffer buffer. - * @bufb : buffer backend - * @offset : offset within the buffer - * @src : source address - * @len : length to write - * @pagecpy : page size copied so far - * - * This function deals with userspace pointers, it should never be called - * directly without having the src pointer checked with access_ok() - * previously. - */ -void _lib_ring_buffer_copy_from_user_inatomic(struct lib_ring_buffer_backend *bufb, - size_t offset, - const void __user *src, size_t len, - size_t pagecpy) -{ - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - size_t sbidx, index; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; - int ret; - - do { - len -= pagecpy; - src += pagecpy; - offset += pagecpy; - sbidx = offset >> chanb->subbuf_size_order; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - - /* - * Underlying layer should never ask for writes across - * subbuffers. - */ - CHAN_WARN_ON(chanb, offset >= chanb->buf_size); - - pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK)); - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - ret = lib_ring_buffer_do_copy_from_user_inatomic(rpages->p[index].virt - + (offset & ~PAGE_MASK), - src, pagecpy) != 0; - if (ret > 0) { - /* Copy failed. */ - _lib_ring_buffer_memset(bufb, offset, 0, len, 0); - break; /* stop copy */ - } - } while (unlikely(len != pagecpy)); -} -EXPORT_SYMBOL_GPL(_lib_ring_buffer_copy_from_user_inatomic); - -/** - * lib_ring_buffer_strcpy_from_user_inatomic - write userspace string data to a ring_buffer buffer. - * @bufb : buffer backend - * @offset : offset within the buffer - * @src : source address - * @len : length to write - * @pagecpy : page size copied so far - * @pad : character to use for padding - * - * This function deals with userspace pointers, it should never be called - * directly without having the src pointer checked with access_ok() - * previously. - */ -void _lib_ring_buffer_strcpy_from_user_inatomic(struct lib_ring_buffer_backend *bufb, - size_t offset, const char __user *src, size_t len, - size_t pagecpy, int pad) -{ - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - size_t sbidx, index; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; - int src_terminated = 0; - - offset += pagecpy; - do { - len -= pagecpy; - if (!src_terminated) - src += pagecpy; - sbidx = offset >> chanb->subbuf_size_order; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - - /* - * Underlying layer should never ask for writes across - * subbuffers. - */ - CHAN_WARN_ON(chanb, offset >= chanb->buf_size); - - pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK)); - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - - if (likely(!src_terminated)) { - size_t count, to_copy; - - to_copy = pagecpy; - if (pagecpy == len) - to_copy--; /* Final '\0' */ - count = lib_ring_buffer_do_strcpy_from_user_inatomic(config, - rpages->p[index].virt - + (offset & ~PAGE_MASK), - src, to_copy); - offset += count; - /* Padding */ - if (unlikely(count < to_copy)) { - size_t pad_len = to_copy - count; - - /* Next pages will have padding */ - src_terminated = 1; - lib_ring_buffer_do_memset(rpages->p[index].virt - + (offset & ~PAGE_MASK), - pad, pad_len); - offset += pad_len; - } - } else { - size_t pad_len; - - pad_len = pagecpy; - if (pagecpy == len) - pad_len--; /* Final '\0' */ - lib_ring_buffer_do_memset(rpages->p[index].virt - + (offset & ~PAGE_MASK), - pad, pad_len); - offset += pad_len; - } - } while (unlikely(len != pagecpy)); - /* Ending '\0' */ - lib_ring_buffer_do_memset(rpages->p[index].virt + (offset & ~PAGE_MASK), - '\0', 1); -} -EXPORT_SYMBOL_GPL(_lib_ring_buffer_strcpy_from_user_inatomic); - -/** - * lib_ring_buffer_read - read data from ring_buffer_buffer. - * @bufb : buffer backend - * @offset : offset within the buffer - * @dest : destination address - * @len : length to copy to destination - * - * Should be protected by get_subbuf/put_subbuf. - * Returns the length copied. - */ -size_t lib_ring_buffer_read(struct lib_ring_buffer_backend *bufb, size_t offset, - void *dest, size_t len) -{ - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - size_t index, pagecpy, orig_len; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; - - orig_len = len; - offset &= chanb->buf_size - 1; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - if (unlikely(!len)) - return 0; - for (;;) { - pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK)); - id = bufb->buf_rsb.id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - memcpy(dest, rpages->p[index].virt + (offset & ~PAGE_MASK), - pagecpy); - len -= pagecpy; - if (likely(!len)) - break; - dest += pagecpy; - offset += pagecpy; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - /* - * Underlying layer should never ask for reads across - * subbuffers. - */ - CHAN_WARN_ON(chanb, offset >= chanb->buf_size); - } - return orig_len; -} -EXPORT_SYMBOL_GPL(lib_ring_buffer_read); - -/** - * __lib_ring_buffer_copy_to_user - read data from ring_buffer to userspace - * @bufb : buffer backend - * @offset : offset within the buffer - * @dest : destination userspace address - * @len : length to copy to destination - * - * Should be protected by get_subbuf/put_subbuf. - * access_ok() must have been performed on dest addresses prior to call this - * function. - * Returns -EFAULT on error, 0 if ok. - */ -int __lib_ring_buffer_copy_to_user(struct lib_ring_buffer_backend *bufb, - size_t offset, void __user *dest, size_t len) -{ - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - size_t index; - ssize_t pagecpy; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; - - offset &= chanb->buf_size - 1; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - if (unlikely(!len)) - return 0; - for (;;) { - pagecpy = min_t(size_t, len, PAGE_SIZE - (offset & ~PAGE_MASK)); - id = bufb->buf_rsb.id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - if (__copy_to_user(dest, - rpages->p[index].virt + (offset & ~PAGE_MASK), - pagecpy)) - return -EFAULT; - len -= pagecpy; - if (likely(!len)) - break; - dest += pagecpy; - offset += pagecpy; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - /* - * Underlying layer should never ask for reads across - * subbuffers. - */ - CHAN_WARN_ON(chanb, offset >= chanb->buf_size); - } - return 0; -} -EXPORT_SYMBOL_GPL(__lib_ring_buffer_copy_to_user); - -/** - * lib_ring_buffer_read_cstr - read a C-style string from ring_buffer. - * @bufb : buffer backend - * @offset : offset within the buffer - * @dest : destination address - * @len : destination's length - * - * Return string's length, or -EINVAL on error. - * Should be protected by get_subbuf/put_subbuf. - * Destination length should be at least 1 to hold '\0'. - */ -int lib_ring_buffer_read_cstr(struct lib_ring_buffer_backend *bufb, size_t offset, - void *dest, size_t len) -{ - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - size_t index; - ssize_t pagecpy, pagelen, strpagelen, orig_offset; - char *str; - struct lib_ring_buffer_backend_pages *rpages; - unsigned long sb_bindex, id; - - offset &= chanb->buf_size - 1; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - orig_offset = offset; - if (unlikely(!len)) - return -EINVAL; - for (;;) { - id = bufb->buf_rsb.id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - str = (char *)rpages->p[index].virt + (offset & ~PAGE_MASK); - pagelen = PAGE_SIZE - (offset & ~PAGE_MASK); - strpagelen = strnlen(str, pagelen); - if (len) { - pagecpy = min_t(size_t, len, strpagelen); - if (dest) { - memcpy(dest, str, pagecpy); - dest += pagecpy; - } - len -= pagecpy; - } - offset += strpagelen; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - if (strpagelen < pagelen) - break; - /* - * Underlying layer should never ask for reads across - * subbuffers. - */ - CHAN_WARN_ON(chanb, offset >= chanb->buf_size); - } - if (dest && len) - ((char *)dest)[0] = 0; - return offset - orig_offset; -} -EXPORT_SYMBOL_GPL(lib_ring_buffer_read_cstr); - -/** - * lib_ring_buffer_read_get_pfn - Get a page frame number to read from - * @bufb : buffer backend - * @offset : offset within the buffer - * @virt : pointer to page address (output) - * - * Should be protected by get_subbuf/put_subbuf. - * Returns the pointer to the page frame number unsigned long. - */ -unsigned long *lib_ring_buffer_read_get_pfn(struct lib_ring_buffer_backend *bufb, - size_t offset, void ***virt) -{ - size_t index; - struct lib_ring_buffer_backend_pages *rpages; - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - unsigned long sb_bindex, id; - - offset &= chanb->buf_size - 1; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - id = bufb->buf_rsb.id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - *virt = &rpages->p[index].virt; - return &rpages->p[index].pfn; -} -EXPORT_SYMBOL_GPL(lib_ring_buffer_read_get_pfn); - -/** - * lib_ring_buffer_read_offset_address - get address of a buffer location - * @bufb : buffer backend - * @offset : offset within the buffer. - * - * Return the address where a given offset is located (for read). - * Should be used to get the current subbuffer header pointer. Given we know - * it's never on a page boundary, it's safe to read/write directly - * from/to this address, as long as the read/write is never bigger than a - * page size. - */ -void *lib_ring_buffer_read_offset_address(struct lib_ring_buffer_backend *bufb, - size_t offset) -{ - size_t index; - struct lib_ring_buffer_backend_pages *rpages; - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - unsigned long sb_bindex, id; - - offset &= chanb->buf_size - 1; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - id = bufb->buf_rsb.id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - return rpages->p[index].virt + (offset & ~PAGE_MASK); -} -EXPORT_SYMBOL_GPL(lib_ring_buffer_read_offset_address); - -/** - * lib_ring_buffer_offset_address - get address of a location within the buffer - * @bufb : buffer backend - * @offset : offset within the buffer. - * - * Return the address where a given offset is located. - * Should be used to get the current subbuffer header pointer. Given we know - * it's always at the beginning of a page, it's safe to write directly to this - * address, as long as the write is never bigger than a page size. - */ -void *lib_ring_buffer_offset_address(struct lib_ring_buffer_backend *bufb, - size_t offset) -{ - size_t sbidx, index; - struct lib_ring_buffer_backend_pages *rpages; - struct channel_backend *chanb = &bufb->chan->backend; - const struct lib_ring_buffer_config *config = &chanb->config; - unsigned long sb_bindex, id; - - offset &= chanb->buf_size - 1; - sbidx = offset >> chanb->subbuf_size_order; - index = (offset & (chanb->subbuf_size - 1)) >> PAGE_SHIFT; - id = bufb->buf_wsb[sbidx].id; - sb_bindex = subbuffer_id_get_index(config, id); - rpages = bufb->array[sb_bindex]; - CHAN_WARN_ON(chanb, config->mode == RING_BUFFER_OVERWRITE - && subbuffer_id_is_noref(config, id)); - return rpages->p[index].virt + (offset & ~PAGE_MASK); -} -EXPORT_SYMBOL_GPL(lib_ring_buffer_offset_address);