diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index 02bc502..bd76a16 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -866,8 +866,9 @@ unsigned long ftrace_get_addr_new(struct dyn_ftrace *rec); unsigned long ftrace_get_addr_curr(struct dyn_ftrace *rec); extern ftrace_func_t ftrace_trace_function; +struct trace_array; -int ftrace_regex_open(struct ftrace_ops *ops, int flag, +int ftrace_regex_open(struct trace_array *tr, struct ftrace_ops *ops, int flag, struct inode *inode, struct file *file); ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos); @@ -1077,7 +1078,7 @@ static inline unsigned long ftrace_location(unsigned long ip) * have them defined when ftrace is not enabled, but these * functions may still be called. Use a macro instead of inline. */ -#define ftrace_regex_open(ops, flag, inod, file) ({ -ENODEV; }) +#define ftrace_regex_open(tr, ops, flag, inode, file) ({ -ENODEV; }) #define ftrace_set_early_filter(ops, buf, enable) do { } while (0) #define ftrace_set_filter_ip(ops, ip, remove, reset) ({ -ENODEV; }) #define ftrace_set_filter_ips(ops, ips, cnt, remove, reset) ({ -ENODEV; }) diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index 0670742..afc7daa 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -218,14 +218,15 @@ bool ring_buffer_time_stamp_abs(struct trace_buffer *buffer); size_t ring_buffer_nr_dirty_pages(struct trace_buffer *buffer, int cpu); struct buffer_data_read_page; -struct buffer_data_read_page * -ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu); +int ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu, + struct buffer_data_read_page **rpage); void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, struct buffer_data_read_page *page); int ring_buffer_read_page(struct trace_buffer *buffer, struct buffer_data_read_page *data_page, size_t len, int cpu, int full); void *ring_buffer_read_page_data(struct buffer_data_read_page *page); +unsigned int ring_buffer_read_page_size(struct buffer_data_read_page *rpage); struct trace_seq; diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f9d80c7..53d5db6 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -75,6 +75,8 @@ .func_hash = &opsname.local_hash, \ .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), \ .subop_list = LIST_HEAD_INIT(opsname.subop_list), +/* Used only to synchronize the initialization of ftrace_ops */ +static DEFINE_MUTEX(ops_mutex); #else #define INIT_OPS_HASH(opsname) #endif @@ -159,11 +161,18 @@ const struct ftrace_ops ftrace_nop_ops = { static inline void ftrace_ops_init(struct ftrace_ops *ops) { #ifdef CONFIG_DYNAMIC_FTRACE - if (!(ops->flags & FTRACE_OPS_FL_INITIALIZED)) { + unsigned long flags = smp_load_acquire(&ops->flags); + + if (!(flags & FTRACE_OPS_FL_INITIALIZED)) { + guard(mutex)(&ops_mutex); + /* Could have been initialized before lock taken */ + if (unlikely(ops->flags & FTRACE_OPS_FL_INITIALIZED)) + return; mutex_init(&ops->local_hash.regex_lock); INIT_LIST_HEAD(&ops->subop_list); ops->func_hash = &ops->local_hash; - ops->flags |= FTRACE_OPS_FL_INITIALIZED; + flags = ops->flags | FTRACE_OPS_FL_INITIALIZED; + smp_store_release(&ops->flags, flags); } #endif } @@ -4677,7 +4686,8 @@ ftrace_avail_addrs_open(struct inode *inode, struct file *file) /** * ftrace_regex_open - initialize function tracer filter files - * @ops: The ftrace_ops that hold the hash filters + * @tr: The trace_array that holds the ftrace_ops [optional] + * @ops: The ftrace_ops that hold the hash filters [optional] * @flag: The type of filter to process * @inode: The inode, usually passed in to your open routine * @file: The file, usually passed in to your open routine @@ -4691,26 +4701,45 @@ ftrace_avail_addrs_open(struct inode *inode, struct file *file) * tracing_lseek() should be used as the lseek routine, and * release must call ftrace_regex_release(). * + * Note, If @tr is not NULL, its reference has to be taken before + * @ops may be referenced. + * If @ops is NULL and @tr is not, then @tr->ops is used. + * If @tr is NULL and @ops is not then @ops->private is uesd for @tr. + * If both @tr and @ops are NULL, then the &global_ops is + * to be used, and @tr will be the global_ops.private pointer. + * * Returns: 0 on success or a negative errno value on failure */ int -ftrace_regex_open(struct ftrace_ops *ops, int flag, +ftrace_regex_open(struct trace_array *tr, struct ftrace_ops *ops, int flag, struct inode *inode, struct file *file) { - struct ftrace_iterator *iter; + struct ftrace_iterator *iter = NULL; struct ftrace_hash *hash; struct list_head *mod_head; - struct trace_array *tr = ops->private; - int ret = -ENOMEM; - - ftrace_ops_init(ops); + int ret = -ENODEV; if (unlikely(ftrace_disabled)) return -ENODEV; + if (!tr) { + if (!ops) + ops = &global_ops; + tr = ops->private; + } + if (tracing_check_open_get_tr(tr)) return -ENODEV; + if (!ops) + ops = tr->ops; + + if (WARN_ON_ONCE(!ops)) + goto out; + + ftrace_ops_init(ops); + + ret = -ENOMEM; iter = kzalloc_obj(*iter); if (!iter) goto out; @@ -4788,21 +4817,19 @@ ftrace_regex_open(struct ftrace_ops *ops, int flag, static int ftrace_filter_open(struct inode *inode, struct file *file) { - struct ftrace_ops *ops = inode->i_private; + struct trace_array *tr = inode->i_private; - /* Checks for tracefs lockdown */ - return ftrace_regex_open(ops, - FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, - inode, file); + return ftrace_regex_open(tr, NULL, + FTRACE_ITER_FILTER | FTRACE_ITER_DO_PROBES, + inode, file); } static int ftrace_notrace_open(struct inode *inode, struct file *file) { - struct ftrace_ops *ops = inode->i_private; + struct trace_array *tr = inode->i_private; - /* Checks for tracefs lockdown */ - return ftrace_regex_open(ops, FTRACE_ITER_NOTRACE, + return ftrace_regex_open(tr, NULL, FTRACE_ITER_NOTRACE, inode, file); } @@ -7492,15 +7519,15 @@ static const struct file_operations ftrace_graph_notrace_fops = { }; #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ -void ftrace_create_filter_files(struct ftrace_ops *ops, +void ftrace_create_filter_files(struct trace_array *tr, struct dentry *parent) { trace_create_file("set_ftrace_filter", TRACE_MODE_WRITE, parent, - ops, &ftrace_filter_fops); + tr, &ftrace_filter_fops); trace_create_file("set_ftrace_notrace", TRACE_MODE_WRITE, parent, - ops, &ftrace_notrace_fops); + tr, &ftrace_notrace_fops); } /* @@ -7525,7 +7552,6 @@ void ftrace_destroy_filter_files(struct ftrace_ops *ops) static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) { - trace_create_file("available_filter_functions", TRACE_MODE_READ, d_tracer, NULL, &ftrace_avail_fops); @@ -7538,7 +7564,7 @@ static __init int ftrace_init_dyn_tracefs(struct dentry *d_tracer) trace_create_file("touched_functions", TRACE_MODE_READ, d_tracer, NULL, &ftrace_touched_fops); - ftrace_create_filter_files(&global_ops, d_tracer); + ftrace_create_filter_files(NULL, d_tracer); #ifdef CONFIG_FUNCTION_GRAPH_TRACER trace_create_file("set_graph_function", TRACE_MODE_WRITE, d_tracer, diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 9726413..9c03a55 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -330,6 +330,14 @@ struct buffer_data_read_page { struct buffer_data_page *data; /* actual data, stored in this page */ }; +static __always_inline unsigned int rb_read_page_capacity(struct buffer_data_read_page *rpage) +{ + return (PAGE_SIZE << rpage->order) - BUF_PAGE_HDR_SIZE; +} + +/* The number of bits for static buffer ids */ +#define RB_STATIC_BITS 30 + /* * Note, the buffer_page list must be first. The buffer pages * are allocated in cache lines, which means that each buffer @@ -345,7 +353,7 @@ struct buffer_page { local_t entries; /* entries on this page */ unsigned long real_end; /* real end of data */ unsigned order; /* order of the page */ - u32 id:30; /* ID for external mapping */ + u32 id:RB_STATIC_BITS; /* ID for external mapping */ u32 range:1; /* Mapped via a range */ struct buffer_data_page *page; /* Actual data page */ }; @@ -652,6 +660,15 @@ static bool rb_is_static(struct ring_buffer_per_cpu *cpu_buffer) return cpu_buffer->user_mapped || cpu_buffer->remote || cpu_buffer->ring_meta; } +static unsigned long rb_static_max_pages(void) +{ + /* + * Static ring buffers are using bpage::id and must account for the + * reader page. + */ + return (1UL << RB_STATIC_BITS) - 1; +} + struct ring_buffer_iter { struct ring_buffer_per_cpu *cpu_buffer; unsigned long head; @@ -1669,7 +1686,7 @@ out_locked: * This is used to help find the next per cpu subbuffer within a mapped range. */ static unsigned long -rb_range_align_subbuf(unsigned long addr, int subbuf_size, int nr_subbufs) +rb_range_align_subbuf(unsigned long addr, unsigned int subbuf_size, unsigned long nr_subbufs) { addr += sizeof(struct ring_buffer_cpu_meta) + sizeof(int) * nr_subbufs; @@ -1679,13 +1696,12 @@ rb_range_align_subbuf(unsigned long addr, int subbuf_size, int nr_subbufs) /* * Return the ring_buffer_meta for a given @cpu. */ -static void *rb_range_meta(struct trace_buffer *buffer, int nr_pages, int cpu) +static void *rb_range_meta(struct trace_buffer *buffer, unsigned long nr_pages, int cpu) { - int subbuf_size = rb_subbuf_size(buffer); + unsigned int subbuf_size = rb_subbuf_size(buffer); struct ring_buffer_cpu_meta *meta; struct ring_buffer_meta *bmeta; - unsigned long ptr; - int nr_subbufs; + unsigned long ptr, nr_subbufs; bmeta = buffer->meta; if (!bmeta) @@ -1731,7 +1747,7 @@ static void *rb_range_meta(struct trace_buffer *buffer, int nr_pages, int cpu) /* Return the start of subbufs given the meta pointer */ static void *rb_subbufs_from_meta(struct ring_buffer_cpu_meta *meta) { - int subbuf_size = meta->subbuf_size; + unsigned int subbuf_size = meta->subbuf_size; unsigned long ptr; ptr = (unsigned long)meta; @@ -1743,11 +1759,11 @@ static void *rb_subbufs_from_meta(struct ring_buffer_cpu_meta *meta) /* * Return a specific sub-buffer for a given @cpu defined by @idx. */ -static void *rb_range_buffer(struct ring_buffer_per_cpu *cpu_buffer, int idx) +static void *rb_range_buffer(struct ring_buffer_per_cpu *cpu_buffer, unsigned long idx) { struct ring_buffer_cpu_meta *meta; + unsigned int subbuf_size; unsigned long ptr; - int subbuf_size; meta = rb_range_meta(cpu_buffer->buffer, 0, cpu_buffer->cpu); if (!meta) @@ -1763,7 +1779,7 @@ static void *rb_range_buffer(struct ring_buffer_per_cpu *cpu_buffer, int idx) ptr = (unsigned long)rb_subbufs_from_meta(meta); - ptr += subbuf_size * idx; + ptr += (unsigned long)subbuf_size * idx; if (ptr + subbuf_size > cpu_buffer->buffer->range_addr_end) return NULL; @@ -1840,13 +1856,12 @@ static bool rb_meta_init(struct trace_buffer *buffer, int scratch_size) * must be the same. */ static bool rb_cpu_meta_valid(struct ring_buffer_cpu_meta *meta, int cpu, - struct trace_buffer *buffer, int nr_pages, + struct trace_buffer *buffer, unsigned long nr_pages, unsigned long *subbuf_mask) { - int subbuf_size = PAGE_SIZE; unsigned long buffers_start; unsigned long buffers_end; - int i; + unsigned long i; if (!subbuf_mask) return false; @@ -1856,8 +1871,13 @@ static bool rb_cpu_meta_valid(struct ring_buffer_cpu_meta *meta, int cpu, return false; } + if (meta->nr_subbufs != nr_pages + 1) { + pr_info("Ring buffer boot meta [%d] invalid nr_subbufs\n", cpu); + return false; + } + buffers_start = meta->first_buffer; - buffers_end = meta->first_buffer + (subbuf_size * meta->nr_subbufs); + buffers_end = meta->first_buffer + (meta->nr_subbufs * PAGE_SIZE); /* Is the head and commit buffers within the range of buffers? */ if (meta->head_buffer < buffers_start || @@ -2095,8 +2115,8 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer) struct buffer_page *head_page, *orig_head, *orig_reader; struct rb_validation_state state = { 0 }; bool skip = false; + unsigned long i; int ret; - int i; if (!meta || !meta->head_buffer) return; @@ -2147,7 +2167,7 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer) rb_validate_buffer(head_page, cpu_buffer, meta, &state, 0, state.ts); } if (i) - pr_info("Ring buffer [%d] rewound %d pages\n", cpu_buffer->cpu, i); + pr_info("Ring buffer [%d] rewound %lu pages\n", cpu_buffer->cpu, i); /* The last rewound page must be skipped. */ if (head_page != orig_head) @@ -2231,7 +2251,8 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer) } } -static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages, int scratch_size) +static void rb_range_meta_init(struct trace_buffer *buffer, unsigned long nr_pages, + int scratch_size) { struct ring_buffer_cpu_meta *meta; unsigned long *subbuf_mask; @@ -2331,8 +2352,8 @@ static int rbm_show(struct seq_file *m, void *v) rb_meta_subbuf_idx(meta, (void *)meta->head_buffer)); seq_printf(m, "commit_buffer: %d\n", rb_meta_subbuf_idx(meta, (void *)meta->commit_buffer)); - seq_printf(m, "subbuf_size: %d\n", meta->subbuf_size); - seq_printf(m, "nr_subbufs: %d\n", meta->nr_subbufs); + seq_printf(m, "subbuf_size: %u\n", meta->subbuf_size); + seq_printf(m, "nr_subbufs: %u\n", meta->nr_subbufs); return 0; } @@ -2417,7 +2438,7 @@ static void *ring_buffer_desc_page(struct ring_buffer_desc *desc, unsigned int p } static int __rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, - long nr_pages, struct list_head *pages) + unsigned long nr_pages, struct list_head *pages) { struct trace_buffer *buffer = cpu_buffer->buffer; struct ring_buffer_cpu_meta *meta = NULL; @@ -2545,7 +2566,7 @@ static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, } static struct ring_buffer_per_cpu * -rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu) +rb_allocate_cpu_buffer(struct trace_buffer *buffer, unsigned long nr_pages, int cpu) { struct ring_buffer_per_cpu *cpu_buffer __free(kfree) = alloc_cpu_buffer(cpu); @@ -2702,8 +2723,8 @@ static void rb_test_inject_invalid_pages(struct trace_buffer *buffer) struct ring_buffer_cpu_meta *meta; struct buffer_data_page *dpage; unsigned long entry_bytes = 0; + unsigned int subbuf_size; unsigned long ptr; - int subbuf_size; int invalid = 0; int cpu; int i; @@ -2773,8 +2794,8 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, struct ring_buffer_remote *remote) { struct trace_buffer *buffer __free(kfree) = NULL; - long nr_pages; - int subbuf_size; + unsigned int subbuf_size; + unsigned long nr_pages; int bsize; int cpu; int ret; @@ -2828,6 +2849,8 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, size = end - buffers_start; size = size / nr_cpu_ids; + if (size < sizeof(struct ring_buffer_cpu_meta)) + goto fail_free_buffers; /* * The number of sub-buffers (nr_pages) is determined by the * total size allocated minus the meta data size. @@ -2837,6 +2860,10 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, */ nr_pages = (size - sizeof(struct ring_buffer_cpu_meta)) / (subbuf_size + sizeof(int)); + + if (nr_pages > rb_static_max_pages()) + goto fail_free_buffers; + /* Need at least two pages plus the reader page */ if (nr_pages < 3) goto fail_free_buffers; @@ -2869,6 +2896,10 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, /* The writer is remote. This ring-buffer is read-only */ atomic_inc(&buffer->record_disabled); nr_pages = desc->nr_page_va - 1; + + if (nr_pages > rb_static_max_pages()) + goto fail_free_buffers; + if (nr_pages < 2) goto fail_free_buffers; } else { @@ -5853,12 +5884,12 @@ __rb_get_reader_page_from_remote(struct ring_buffer_per_cpu *cpu_buffer) static struct buffer_page * __rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) { - int max_loops = cpu_buffer->ring_meta ? cpu_buffer->nr_pages : 3; + unsigned long max_loops = cpu_buffer->ring_meta ? cpu_buffer->nr_pages : 3; struct buffer_page *reader = NULL; + unsigned long nr_loops = 0; unsigned long overwrite; unsigned long flags; int missed_events = 0; - int nr_loops = 0; bool ret; local_irq_save(flags); @@ -6176,8 +6207,8 @@ rb_iter_peek(struct ring_buffer_iter *iter, u64 *ts) struct trace_buffer *buffer; struct ring_buffer_per_cpu *cpu_buffer; struct ring_buffer_event *event; - int nr_loops = 0; - int max_loops; + unsigned long nr_loops = 0; + unsigned long max_loops; if (ts) *ts = 0; @@ -6993,56 +7024,78 @@ EXPORT_SYMBOL_GPL(ring_buffer_swap_cpu); * ring_buffer_alloc_read_page - allocate a page to read from buffer * @buffer: the buffer to allocate for. * @cpu: the cpu buffer to allocate. + * @rpage: pointer to pass in an already allocated page (can be NULL) + * and returns the allocated page. * - * This function is used in conjunction with ring_buffer_read_page. + * This function is used in conjunction with ring_buffer_read_page(). * When reading a full page from the ring buffer, these functions * can be used to speed up the process. The calling function should * allocate a few pages first with this function. Then when it * needs to get pages from the ring buffer, it passes the result - * of this function into ring_buffer_read_page, which will swap + * of this function into ring_buffer_read_page(), which will swap * the page that was allocated, with the read page of the buffer. * + * If @rpage is provided, and it has a different order than the current + * subbuffer order, its payload will be freed and re-allocated. If it + * already matches the order, it is simply returned. + * * Returns: - * The page allocated, or ERR_PTR + * 0 on success, < 0 on error */ -struct buffer_data_read_page * -ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu) +int ring_buffer_alloc_read_page(struct trace_buffer *buffer, int cpu, + struct buffer_data_read_page **rpage) { struct ring_buffer_per_cpu *cpu_buffer; - struct buffer_data_read_page *bpage = NULL; unsigned long flags; + unsigned int order; if (!cpumask_test_cpu(cpu, buffer->cpumask)) - return ERR_PTR(-ENODEV); + return -ENODEV; - bpage = kzalloc_obj(*bpage); - if (!bpage) - return ERR_PTR(-ENOMEM); + if (!rpage) + return -EINVAL; - bpage->order = buffer->subbuf_order; + order = READ_ONCE(buffer->subbuf_order); + + if (*rpage) { + if ((*rpage)->order == order) + return 0; + + /* We can reuse rpage, but we discard the payload */ + free_pages((unsigned long)(*rpage)->data, (*rpage)->order); + (*rpage)->data = NULL; + } else { + *rpage = kzalloc_obj(**rpage); + if (!*rpage) + return -ENOMEM; + } + + (*rpage)->order = order; cpu_buffer = buffer->buffers[cpu]; + local_irq_save(flags); arch_spin_lock(&cpu_buffer->lock); if (cpu_buffer->free_page.data) { - *bpage = cpu_buffer->free_page; + **rpage = cpu_buffer->free_page; cpu_buffer->free_page.data = NULL; } arch_spin_unlock(&cpu_buffer->lock); local_irq_restore(flags); - if (bpage->data) { - rb_init_data_page(bpage->data); + if ((*rpage)->data) { + rb_init_data_page((*rpage)->data); } else { - bpage->data = alloc_cpu_data(cpu, bpage->order); - if (!bpage->data) { - kfree(bpage); - return ERR_PTR(-ENOMEM); + (*rpage)->data = alloc_cpu_data(cpu, (*rpage)->order); + if (!(*rpage)->data) { + kfree(*rpage); + *rpage = NULL; + return -ENOMEM; } } - return bpage; + return 0; } EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page); @@ -7050,21 +7103,30 @@ EXPORT_SYMBOL_GPL(ring_buffer_alloc_read_page); * ring_buffer_free_read_page - free an allocated read page * @buffer: the buffer the page was allocate for * @cpu: the cpu buffer the page came from - * @data_page: the page to free + * @rpage: the buffer_data_read_page to free * * Free a page allocated from ring_buffer_alloc_read_page. */ void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, - struct buffer_data_read_page *data_page) + struct buffer_data_read_page *rpage) { struct ring_buffer_per_cpu *cpu_buffer; - struct buffer_data_page *dpage = data_page->data; - struct page *page = virt_to_page(dpage); + struct buffer_data_page *dpage; unsigned long flags; + struct page *page; if (!buffer || !buffer->buffers || !buffer->buffers[cpu]) return; + if (!rpage) + return; + + dpage = rpage->data; + if (!dpage) + goto out; + + page = virt_to_page(dpage); + cpu_buffer = buffer->buffers[cpu]; /* @@ -7072,14 +7134,14 @@ void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, * is different from the subbuffer order of the buffer - * we can't reuse it */ - if (page_ref_count(page) > 1 || data_page->order != buffer->subbuf_order) + if (page_ref_count(page) > 1 || rpage->order != READ_ONCE(buffer->subbuf_order)) goto out; local_irq_save(flags); arch_spin_lock(&cpu_buffer->lock); if (!cpu_buffer->free_page.data) { - cpu_buffer->free_page = *data_page; + cpu_buffer->free_page = *rpage; dpage = NULL; } @@ -7087,8 +7149,8 @@ void ring_buffer_free_read_page(struct trace_buffer *buffer, int cpu, local_irq_restore(flags); out: - free_pages((unsigned long)dpage, data_page->order); - kfree(data_page); + free_pages((unsigned long)dpage, rpage->order); + kfree(rpage); } EXPORT_SYMBOL_GPL(ring_buffer_free_read_page); @@ -7159,10 +7221,9 @@ int ring_buffer_read_page(struct trace_buffer *buffer, if (!dpage) return -1; - guard(raw_spinlock_irqsave)(&cpu_buffer->reader_lock); + len = min_t(size_t, len, rb_read_page_capacity(data_page)); - if (data_page->order != cpu_buffer->reader_page->order) - return -1; + guard(raw_spinlock_irqsave)(&cpu_buffer->reader_lock); reader = rb_get_reader_page(cpu_buffer); if (!reader) @@ -7177,31 +7238,26 @@ int ring_buffer_read_page(struct trace_buffer *buffer, /* Check if any events were dropped */ missed_events = cpu_buffer->lost_events; - /* - * If this page has been partially read or - * if len is not big enough to read the rest of the page or - * a writer is still on the page, then - * we must copy the data from the page to the buffer. - * Otherwise, we can simply swap the page with the one passed in. - */ + /* + * It is not possible to swap the reader page if: + * - It has been partially read + * - len is not big enough to read it entirely + * - A writer is still on it + * - The ring buffer is static + * - The order doesn't match + */ if (read || (len < (size - read)) || cpu_buffer->reader_page == cpu_buffer->commit_page || - rb_is_static(cpu_buffer)) { + rb_is_static(cpu_buffer) || + data_page->order != reader->order) { struct buffer_data_page *rpage = cpu_buffer->reader_page->page; unsigned int rpos = read; unsigned int pos = 0; unsigned int event_size; unsigned int flags = 0; - /* - * If a full page is expected, this can still be returned - * if there's been a previous partial read and the - * rest of the page can be read and the commit page is off - * the reader page. - */ - if (full && - (!read || (len < (size - read)) || - cpu_buffer->reader_page == cpu_buffer->commit_page)) + /* If a full page is requested, it cannot be the commit page */ + if (full && cpu_buffer->reader_page == cpu_buffer->commit_page) return -1; if (len > (size - read)) @@ -7287,7 +7343,7 @@ int ring_buffer_read_page(struct trace_buffer *buffer, * missed events, then record it there. */ if (missed_events > 0 && - rb_page_capacity(reader) - size >= sizeof(missed_events)) { + rb_read_page_capacity(data_page) - size >= sizeof(missed_events)) { memcpy(&dpage->data[size], &missed_events, sizeof(missed_events)); local_add(RB_MISSED_STORED, &dpage->commit); @@ -7307,8 +7363,8 @@ int ring_buffer_read_page(struct trace_buffer *buffer, /* * This page may be off to user land. Zero it out here. */ - if (size < rb_page_capacity(reader)) - memset(&dpage->data[size], 0, rb_page_capacity(reader) - size); + if (size < rb_read_page_capacity(data_page)) + memset(&dpage->data[size], 0, rb_read_page_capacity(data_page) - size); return read; } @@ -7327,6 +7383,18 @@ void *ring_buffer_read_page_data(struct buffer_data_read_page *page) EXPORT_SYMBOL_GPL(ring_buffer_read_page_data); /** + * ring_buffer_read_page_size - get size of the read page. + * @page: the page to get the size from + * + * Returns size of the page in bytes. + */ +unsigned int ring_buffer_read_page_size(struct buffer_data_read_page *rpage) +{ + return rpage ? PAGE_SIZE << rpage->order : 0; +} +EXPORT_SYMBOL_GPL(ring_buffer_read_page_size); + +/** * ring_buffer_subbuf_size_get - get size of the sub buffer. * @buffer: the buffer to get the sub buffer size from * @@ -7380,8 +7448,8 @@ int ring_buffer_subbuf_order_set(struct trace_buffer *buffer, int order) struct ring_buffer_per_cpu *cpu_buffer; struct buffer_page *bpage, *tmp; unsigned int old_capacity; + unsigned long nr_pages; int old_order; - int nr_pages; int psize; int err; int cpu; @@ -7411,7 +7479,7 @@ int ring_buffer_subbuf_order_set(struct trace_buffer *buffer, int order) /* Make sure all commits have finished */ synchronize_rcu(); - buffer->subbuf_order = order; + WRITE_ONCE(buffer->subbuf_order, order); /* Make sure all new buffers are allocated, before deleting the old ones */ for_each_buffer_cpu(buffer, cpu) { @@ -7515,7 +7583,7 @@ int ring_buffer_subbuf_order_set(struct trace_buffer *buffer, int order) return 0; error: - buffer->subbuf_order = old_order; + WRITE_ONCE(buffer->subbuf_order, old_order); atomic_dec(&buffer->record_disabled); @@ -7563,10 +7631,10 @@ static void rb_setup_ids_meta_page(struct ring_buffer_per_cpu *cpu_buffer, struct buffer_page **subbuf_ids) { struct trace_buffer_meta *meta = cpu_buffer->meta_page; - unsigned int nr_subbufs = cpu_buffer->nr_pages + 1; + unsigned long nr_subbufs = cpu_buffer->nr_pages + 1; struct buffer_page *first_subbuf, *subbuf; - int cnt = 0; - int id = 0; + unsigned int cnt = 0; + unsigned int id = 0; id = rb_page_id(cpu_buffer, cpu_buffer->reader_page, id); subbuf_ids[id++] = cpu_buffer->reader_page; @@ -7794,6 +7862,9 @@ int ring_buffer_map(struct trace_buffer *buffer, int cpu, /* prevent another thread from changing buffer/sub-buffer sizes */ guard(mutex)(&buffer->mutex); + if (cpu_buffer->nr_pages > rb_static_max_pages()) + return -E2BIG; + err = rb_alloc_meta_page(cpu_buffer); if (err) return err; diff --git a/kernel/trace/ring_buffer_benchmark.c b/kernel/trace/ring_buffer_benchmark.c index 593e3b5..c3d34c0 100644 --- a/kernel/trace/ring_buffer_benchmark.c +++ b/kernel/trace/ring_buffer_benchmark.c @@ -104,7 +104,7 @@ static enum event_status read_event(int cpu) static enum event_status read_page(int cpu) { - struct buffer_data_read_page *bpage; + struct buffer_data_read_page *bpage = NULL; struct ring_buffer_event *event; struct rb_page *rpage; unsigned long commit; @@ -114,8 +114,8 @@ static enum event_status read_page(int cpu) int inc; int i; - bpage = ring_buffer_alloc_read_page(buffer, cpu); - if (IS_ERR(bpage)) + ret = ring_buffer_alloc_read_page(buffer, cpu, &bpage); + if (ret < 0) return EVENT_DROPPED; page_size = ring_buffer_subbuf_size_get(buffer); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a946e01..8658cad 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -7082,8 +7082,8 @@ ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, { struct ftrace_buffer_info *info = filp->private_data; struct trace_iterator *iter = &info->iter; + unsigned int spare_size; void *trace_data; - int page_size; ssize_t ret = 0; ssize_t size; @@ -7093,36 +7093,22 @@ ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, if (iter->snapshot && tracer_uses_snapshot(iter->tr->current_trace)) return -EBUSY; - page_size = ring_buffer_subbuf_size_get(iter->array_buffer->buffer); + spare_size = ring_buffer_read_page_size(info->spare); - /* Make sure the spare matches the current sub buffer size */ - if (info->spare) { - if (page_size != info->spare_size) { - ring_buffer_free_read_page(iter->array_buffer->buffer, - info->spare_cpu, info->spare); - info->spare = NULL; - } - } +again: + /* Do we have previous read data to read? */ + if (info->read < spare_size) + goto read; - if (!info->spare) { - info->spare = ring_buffer_alloc_read_page(iter->array_buffer->buffer, - iter->cpu_file); - if (IS_ERR(info->spare)) { - ret = PTR_ERR(info->spare); - info->spare = NULL; - } else { - info->spare_cpu = iter->cpu_file; - info->spare_size = page_size; - } - } - if (!info->spare) + ret = ring_buffer_alloc_read_page(iter->array_buffer->buffer, iter->cpu_file, + &info->spare); + if (ret) return ret; - /* Do we have previous read data to read? */ - if (info->read < page_size) - goto read; + spare_size = ring_buffer_read_page_size(info->spare); + info->read = spare_size; + info->spare_cpu = iter->cpu_file; - again: trace_access_lock(iter->cpu_file); ret = ring_buffer_read_page(iter->array_buffer->buffer, info->spare, @@ -7148,8 +7134,9 @@ ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf, } info->read = 0; + read: - size = page_size - info->read; + size = spare_size - info->read; if (size > count) size = count; trace_data = ring_buffer_read_page_data(info->spare); @@ -7190,26 +7177,24 @@ int tracing_buffers_release(struct inode *inode, struct file *file) __trace_array_put(iter->tr); - if (info->spare) - ring_buffer_free_read_page(iter->array_buffer->buffer, - info->spare_cpu, info->spare); + ring_buffer_free_read_page(iter->array_buffer->buffer, info->spare_cpu, info->spare); kvfree(info); return 0; } struct buffer_ref { - struct trace_buffer *buffer; - void *page; - int cpu; - refcount_t refcount; + struct trace_buffer *buffer; + struct buffer_data_read_page *rpage; + int cpu; + refcount_t refcount; }; static void buffer_ref_release(struct buffer_ref *ref) { if (!refcount_dec_and_test(&ref->refcount)) return; - ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->page); + ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->rpage); kfree(ref); } @@ -7268,25 +7253,15 @@ ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, .ops = &buffer_pipe_buf_ops, .spd_release = buffer_spd_release, }; + unsigned int page_size = 0; struct buffer_ref *ref; bool woken = false; - int page_size; int entries, i; ssize_t ret = 0; if (iter->snapshot && tracer_uses_snapshot(iter->tr->current_trace)) return -EBUSY; - page_size = ring_buffer_subbuf_size_get(iter->array_buffer->buffer); - if (*ppos & (page_size - 1)) - return -EINVAL; - - if (len & (page_size - 1)) { - if (len < page_size) - return -EINVAL; - len &= (~(page_size - 1)); - } - if (splice_grow_spd(pipe, &spd)) return -ENOMEM; @@ -7306,25 +7281,39 @@ ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos, refcount_set(&ref->refcount, 1); ref->buffer = iter->array_buffer->buffer; - ref->page = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file); - if (IS_ERR(ref->page)) { - ret = PTR_ERR(ref->page); - ref->page = NULL; + + ret = ring_buffer_alloc_read_page(ref->buffer, iter->cpu_file, &ref->rpage); + if (ret) { kfree(ref); break; } ref->cpu = iter->cpu_file; - r = ring_buffer_read_page(ref->buffer, ref->page, - len, iter->cpu_file, 1); + page_size = ring_buffer_read_page_size(ref->rpage); + + r = -EINVAL; + if (IS_ALIGNED(*ppos, page_size) && len >= page_size) { + r = ring_buffer_read_page(ref->buffer, ref->rpage, len, iter->cpu_file, 1); + } else if (!i) { + /* + * If this fails to read on the first iteration, it + * means the length was too small and an error should + * be returned to user space. Otherwise, at least + * one sub-buffer was successfully read but this failed + * due to either the length was unaligned or the + * subbuf order changed. Either case, do not report + * an error. + */ + ret = -EINVAL; + } + if (r < 0) { - ring_buffer_free_read_page(ref->buffer, ref->cpu, - ref->page); + ring_buffer_free_read_page(ref->buffer, ref->cpu, ref->rpage); kfree(ref); break; } - page = virt_to_page(ring_buffer_read_page_data(ref->page)); + page = virt_to_page(ring_buffer_read_page_data(ref->rpage)); spd.pages[i] = page; spd.partial[i].len = page_size; @@ -7842,11 +7831,70 @@ trace_options_core_write(struct file *filp, const char __user *ubuf, size_t cnt, return cnt; } +/* + * The tr_index is the address of a trace_array->trace_flags_index[] + * element that holds the index of the trace flag. But since the + * trace_array reference has not been taken yet, it cannot be referenced + * as it could have been freed by a rmdir of the instance the trace_array + * represents. + * + * Search the list of trace_arrays and compare the tr_index to the + * address of the entire trace_array trace_flags_index array for each + * trace_array in the list. If one is matched, then take the reference + * and return it. If not, the trace_array no longer exits. + */ +static int trace_array_options_get(void *tr_index) +{ + struct trace_array *tr; + int ret; + + ret = security_locked_down(LOCKDOWN_TRACEFS); + if (ret) + return ret; + + if (tracing_disabled) + return -ENODEV; + + guard(mutex)(&trace_types_lock); + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (tr_index >= (void *)&tr->trace_flags_index[0] && + tr_index < (void *)&tr->trace_flags_index[TRACE_FLAGS_MAX_SIZE]) + return __trace_array_get(tr); + } + return -ENODEV; +} + +static int trace_options_open(struct inode *inode, struct file *filp) +{ + void *tr_index = inode->i_private; + + if (trace_array_options_get(tr_index) < 0) + return -ENODEV; + + filp->private_data = tr_index; + + return 0; +} + +static int trace_options_release(struct inode *inode, struct file *filp) +{ + void *tr_index = filp->private_data; + struct trace_array *tr; + unsigned int index; + + get_tr_index(tr_index, &tr, &index); + + trace_array_put(tr); + + return 0; +} + static const struct file_operations trace_options_core_fops = { - .open = tracing_open_generic, - .read = trace_options_core_read, - .write = trace_options_core_write, - .llseek = generic_file_llseek, + .open = trace_options_open, + .read = trace_options_core_read, + .write = trace_options_core_write, + .llseek = generic_file_llseek, + .release = trace_options_release, }; struct dentry *trace_create_file(const char *name, @@ -9651,6 +9699,11 @@ __init static void enable_instances(void) if (flag_delim) *flag_delim++ = '\0'; + if (trace_array_find(name)) { + pr_warn("Tracing: Instance %s already exists\n", name); + continue; + } + if (backup) { if (backup_instance_area(backup, &addr, &size) < 0) continue; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 74a7a50..5e76f94 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -745,11 +745,10 @@ static inline int tracing_get_cpu(struct inode *inode) void tracing_reset_cpu(struct array_buffer *buf, int cpu); struct ftrace_buffer_info { - struct trace_iterator iter; - void *spare; - unsigned int spare_cpu; - unsigned int spare_size; - unsigned int read; + struct trace_iterator iter; + struct buffer_data_read_page *spare; + unsigned int spare_cpu; + unsigned int read; }; /** @@ -1340,7 +1339,7 @@ extern void clear_ftrace_function_probes(struct trace_array *tr); int register_ftrace_command(struct ftrace_func_command *cmd); int unregister_ftrace_command(struct ftrace_func_command *cmd); -void ftrace_create_filter_files(struct ftrace_ops *ops, +void ftrace_create_filter_files(struct trace_array *tr, struct dentry *parent); void ftrace_destroy_filter_files(struct ftrace_ops *ops); @@ -1363,11 +1362,12 @@ static inline void clear_ftrace_function_probes(struct trace_array *tr) { } +static inline void ftrace_create_filter_files(struct trace_array *tr, + struct dentry *parent) { } /* * The ops parameter passed in is usually undefined. * This must be a macro. */ -#define ftrace_create_filter_files(ops, parent) do { } while (0) #define ftrace_destroy_filter_files(ops) do { } while (0) #endif /* CONFIG_FUNCTION_TRACER && CONFIG_DYNAMIC_FTRACE */ diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 1d39eaf..9dbc244 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2736,14 +2736,14 @@ static const struct file_operations ftrace_show_event_filters_fops = { .open = ftrace_event_show_filters_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release, + .release = ftrace_event_release, }; static const struct file_operations ftrace_show_event_triggers_fops = { .open = ftrace_event_show_triggers_open, .read = seq_read, .llseek = seq_lseek, - .release = seq_release, + .release = ftrace_event_release, }; static const struct file_operations ftrace_set_event_pid_fops = { @@ -2908,7 +2908,17 @@ ftrace_event_set_open(struct inode *inode, struct file *file) static int ftrace_event_show_filters_open(struct inode *inode, struct file *file) { - return ftrace_event_open(inode, file, &show_show_event_filters_seq_ops); + struct trace_array *tr = inode->i_private; + int ret; + + ret = tracing_check_open_get_tr(tr); + if (ret) + return ret; + + ret = ftrace_event_open(inode, file, &show_show_event_filters_seq_ops); + if (ret < 0) + trace_array_put(tr); + return ret; } /** @@ -2922,7 +2932,17 @@ ftrace_event_show_filters_open(struct inode *inode, struct file *file) static int ftrace_event_show_triggers_open(struct inode *inode, struct file *file) { - return ftrace_event_open(inode, file, &show_show_event_triggers_seq_ops); + struct trace_array *tr = inode->i_private; + int ret; + + ret = tracing_check_open_get_tr(tr); + if (ret) + return ret; + + ret = ftrace_event_open(inode, file, &show_show_event_triggers_seq_ops); + if (ret < 0) + trace_array_put(tr); + return ret; } static int diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index cd37f20..c879d43 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -101,7 +101,7 @@ int ftrace_create_function_files(struct trace_array *tr, return ret; } - ftrace_create_filter_files(tr->ops, parent); + ftrace_create_filter_files(tr, parent); return 0; } diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 0aa2514..e7f4e52 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -499,7 +499,7 @@ stack_trace_filter_open(struct inode *inode, struct file *file) struct ftrace_ops *ops = inode->i_private; /* Checks for tracefs lockdown */ - return ftrace_regex_open(ops, FTRACE_ITER_FILTER, + return ftrace_regex_open(NULL, ops, FTRACE_ITER_FILTER, inode, file); }