diff options
Diffstat (limited to 'kernel/trace/ring_buffer.c')
| -rw-r--r-- | kernel/trace/ring_buffer.c | 267 |
1 files changed, 166 insertions, 101 deletions
diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index b8e0ae15ca5b..d8d7b28e2c2f 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -31,6 +31,7 @@ #include <asm/local64.h> #include <asm/local.h> +#include <asm/setup.h> #include "trace.h" @@ -48,9 +49,12 @@ static void update_pages_handler(struct work_struct *work); struct ring_buffer_meta { int magic; - int struct_size; - unsigned long text_addr; - unsigned long data_addr; + int struct_sizes; + unsigned long total_size; + unsigned long buffers_offset; +}; + +struct ring_buffer_cpu_meta { unsigned long first_buffer; unsigned long head_buffer; unsigned long commit_buffer; @@ -517,7 +521,7 @@ struct ring_buffer_per_cpu { struct mutex mapping_lock; unsigned long *subbuf_ids; /* ID to subbuf VA */ struct trace_buffer_meta *meta_page; - struct ring_buffer_meta *ring_meta; + struct ring_buffer_cpu_meta *ring_meta; /* ring buffer pages to update, > 0 to add, < 0 to remove */ long nr_pages_to_update; @@ -550,8 +554,7 @@ struct trace_buffer { unsigned long range_addr_start; unsigned long range_addr_end; - long last_text_delta; - long last_data_delta; + struct ring_buffer_meta *meta; unsigned int subbuf_size; unsigned int subbuf_order; @@ -1271,7 +1274,7 @@ static void rb_head_page_activate(struct ring_buffer_per_cpu *cpu_buffer) rb_set_list_to_head(head->list.prev); if (cpu_buffer->ring_meta) { - struct ring_buffer_meta *meta = cpu_buffer->ring_meta; + struct ring_buffer_cpu_meta *meta = cpu_buffer->ring_meta; meta->head_buffer = (unsigned long)head->page; } } @@ -1569,7 +1572,7 @@ out_locked: static unsigned long rb_range_align_subbuf(unsigned long addr, int subbuf_size, int nr_subbufs) { - addr += sizeof(struct ring_buffer_meta) + + addr += sizeof(struct ring_buffer_cpu_meta) + sizeof(int) * nr_subbufs; return ALIGN(addr, subbuf_size); } @@ -1580,19 +1583,22 @@ rb_range_align_subbuf(unsigned long addr, int subbuf_size, int nr_subbufs) static void *rb_range_meta(struct trace_buffer *buffer, int nr_pages, int cpu) { int subbuf_size = buffer->subbuf_size + BUF_PAGE_HDR_SIZE; - unsigned long ptr = buffer->range_addr_start; - struct ring_buffer_meta *meta; + struct ring_buffer_cpu_meta *meta; + struct ring_buffer_meta *bmeta; + unsigned long ptr; int nr_subbufs; - if (!ptr) + bmeta = buffer->meta; + if (!bmeta) return NULL; + ptr = (unsigned long)bmeta + bmeta->buffers_offset; + meta = (struct ring_buffer_cpu_meta *)ptr; + /* When nr_pages passed in is zero, the first meta has already been initialized */ if (!nr_pages) { - meta = (struct ring_buffer_meta *)ptr; nr_subbufs = meta->nr_subbufs; } else { - meta = NULL; /* Include the reader page */ nr_subbufs = nr_pages + 1; } @@ -1624,7 +1630,7 @@ 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_meta *meta) +static void *rb_subbufs_from_meta(struct ring_buffer_cpu_meta *meta) { int subbuf_size = meta->subbuf_size; unsigned long ptr; @@ -1640,7 +1646,7 @@ static void *rb_subbufs_from_meta(struct ring_buffer_meta *meta) */ static void *rb_range_buffer(struct ring_buffer_per_cpu *cpu_buffer, int idx) { - struct ring_buffer_meta *meta; + struct ring_buffer_cpu_meta *meta; unsigned long ptr; int subbuf_size; @@ -1666,13 +1672,77 @@ static void *rb_range_buffer(struct ring_buffer_per_cpu *cpu_buffer, int idx) } /* + * See if the existing memory contains a valid meta section. + * if so, use that, otherwise initialize it. + */ +static bool rb_meta_init(struct trace_buffer *buffer, int scratch_size) +{ + unsigned long ptr = buffer->range_addr_start; + struct ring_buffer_meta *bmeta; + unsigned long total_size; + int struct_sizes; + + bmeta = (struct ring_buffer_meta *)ptr; + buffer->meta = bmeta; + + total_size = buffer->range_addr_end - buffer->range_addr_start; + + struct_sizes = sizeof(struct ring_buffer_cpu_meta); + struct_sizes |= sizeof(*bmeta) << 16; + + /* The first buffer will start word size after the meta page */ + ptr += sizeof(*bmeta); + ptr = ALIGN(ptr, sizeof(long)); + ptr += scratch_size; + + if (bmeta->magic != RING_BUFFER_META_MAGIC) { + pr_info("Ring buffer boot meta mismatch of magic\n"); + goto init; + } + + if (bmeta->struct_sizes != struct_sizes) { + pr_info("Ring buffer boot meta mismatch of struct size\n"); + goto init; + } + + if (bmeta->total_size != total_size) { + pr_info("Ring buffer boot meta mismatch of total size\n"); + goto init; + } + + if (bmeta->buffers_offset > bmeta->total_size) { + pr_info("Ring buffer boot meta mismatch of offset outside of total size\n"); + goto init; + } + + if (bmeta->buffers_offset != (void *)ptr - (void *)bmeta) { + pr_info("Ring buffer boot meta mismatch of first buffer offset\n"); + goto init; + } + + return true; + + init: + bmeta->magic = RING_BUFFER_META_MAGIC; + bmeta->struct_sizes = struct_sizes; + bmeta->total_size = total_size; + bmeta->buffers_offset = (void *)ptr - (void *)bmeta; + + /* Zero out the scatch pad */ + memset((void *)bmeta + sizeof(*bmeta), 0, bmeta->buffers_offset - sizeof(*bmeta)); + + return false; +} + +/* * See if the existing memory contains valid ring buffer data. * As the previous kernel must be the same as this kernel, all * the calculations (size of buffers and number of buffers) * must be the same. */ -static bool rb_meta_valid(struct ring_buffer_meta *meta, int cpu, - struct trace_buffer *buffer, int nr_pages) +static bool rb_cpu_meta_valid(struct ring_buffer_cpu_meta *meta, int cpu, + struct trace_buffer *buffer, int nr_pages, + unsigned long *subbuf_mask) { int subbuf_size = PAGE_SIZE; struct buffer_data_page *subbuf; @@ -1680,19 +1750,8 @@ static bool rb_meta_valid(struct ring_buffer_meta *meta, int cpu, unsigned long buffers_end; int i; - /* Check the meta magic and meta struct size */ - if (meta->magic != RING_BUFFER_META_MAGIC || - meta->struct_size != sizeof(*meta)) { - pr_info("Ring buffer boot meta[%d] mismatch of magic or struct size\n", cpu); + if (!subbuf_mask) return false; - } - - /* The subbuffer's size and number of subbuffers must match */ - if (meta->subbuf_size != subbuf_size || - meta->nr_subbufs != nr_pages + 1) { - pr_info("Ring buffer boot meta [%d] mismatch of subbuf_size/nr_pages\n", cpu); - return false; - } buffers_start = meta->first_buffer; buffers_end = meta->first_buffer + (subbuf_size * meta->nr_subbufs); @@ -1712,6 +1771,8 @@ static bool rb_meta_valid(struct ring_buffer_meta *meta, int cpu, subbuf = rb_subbufs_from_meta(meta); + bitmap_clear(subbuf_mask, 0, meta->nr_subbufs); + /* Is the meta buffers and the subbufs themselves have correct data? */ for (i = 0; i < meta->nr_subbufs; i++) { if (meta->buffers[i] < 0 || @@ -1725,13 +1786,19 @@ static bool rb_meta_valid(struct ring_buffer_meta *meta, int cpu, return false; } + if (test_bit(meta->buffers[i], subbuf_mask)) { + pr_info("Ring buffer boot meta [%d] array has duplicates\n", cpu); + return false; + } + + set_bit(meta->buffers[i], subbuf_mask); subbuf = (void *)subbuf + subbuf_size; } return true; } -static int rb_meta_subbuf_idx(struct ring_buffer_meta *meta, void *subbuf); +static int rb_meta_subbuf_idx(struct ring_buffer_cpu_meta *meta, void *subbuf); static int rb_read_data_buffer(struct buffer_data_page *dpage, int tail, int cpu, unsigned long long *timestamp, u64 *delta_ptr) @@ -1798,7 +1865,7 @@ static int rb_validate_buffer(struct buffer_data_page *dpage, int cpu) /* If the meta data has been validated, now validate the events */ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer) { - struct ring_buffer_meta *meta = cpu_buffer->ring_meta; + struct ring_buffer_cpu_meta *meta = cpu_buffer->ring_meta; struct buffer_page *head_page; unsigned long entry_bytes = 0; unsigned long entries = 0; @@ -1838,6 +1905,11 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer) cpu_buffer->cpu); goto invalid; } + + /* If the buffer has content, update pages_touched */ + if (ret) + local_inc(&cpu_buffer->pages_touched); + entries += ret; entry_bytes += local_read(&head_page->page->commit); local_set(&cpu_buffer->head_page->entries, ret); @@ -1874,40 +1946,35 @@ static void rb_meta_validate_events(struct ring_buffer_per_cpu *cpu_buffer) } } -/* Used to calculate data delta */ -static char rb_data_ptr[] = ""; - -#define THIS_TEXT_PTR ((unsigned long)rb_meta_init_text_addr) -#define THIS_DATA_PTR ((unsigned long)rb_data_ptr) - -static void rb_meta_init_text_addr(struct ring_buffer_meta *meta) -{ - meta->text_addr = THIS_TEXT_PTR; - meta->data_addr = THIS_DATA_PTR; -} - -static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages) +static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages, int scratch_size) { - struct ring_buffer_meta *meta; + struct ring_buffer_cpu_meta *meta; + unsigned long *subbuf_mask; unsigned long delta; void *subbuf; + bool valid = false; int cpu; int i; + /* Create a mask to test the subbuf array */ + subbuf_mask = bitmap_alloc(nr_pages + 1, GFP_KERNEL); + /* If subbuf_mask fails to allocate, then rb_meta_valid() will return false */ + + if (rb_meta_init(buffer, scratch_size)) + valid = true; + for (cpu = 0; cpu < nr_cpu_ids; cpu++) { void *next_meta; meta = rb_range_meta(buffer, nr_pages, cpu); - if (rb_meta_valid(meta, cpu, buffer, nr_pages)) { + if (valid && rb_cpu_meta_valid(meta, cpu, buffer, nr_pages, subbuf_mask)) { /* Make the mappings match the current address */ subbuf = rb_subbufs_from_meta(meta); delta = (unsigned long)subbuf - meta->first_buffer; meta->first_buffer += delta; meta->head_buffer += delta; meta->commit_buffer += delta; - buffer->last_text_delta = THIS_TEXT_PTR - meta->text_addr; - buffer->last_data_delta = THIS_DATA_PTR - meta->data_addr; continue; } @@ -1918,16 +1985,12 @@ static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages) memset(meta, 0, next_meta - (void *)meta); - meta->magic = RING_BUFFER_META_MAGIC; - meta->struct_size = sizeof(*meta); - meta->nr_subbufs = nr_pages + 1; meta->subbuf_size = PAGE_SIZE; subbuf = rb_subbufs_from_meta(meta); meta->first_buffer = (unsigned long)subbuf; - rb_meta_init_text_addr(meta); /* * The buffers[] array holds the order of the sub-buffers @@ -1943,12 +2006,13 @@ static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages) subbuf += meta->subbuf_size; } } + bitmap_free(subbuf_mask); } static void *rbm_start(struct seq_file *m, loff_t *pos) { struct ring_buffer_per_cpu *cpu_buffer = m->private; - struct ring_buffer_meta *meta = cpu_buffer->ring_meta; + struct ring_buffer_cpu_meta *meta = cpu_buffer->ring_meta; unsigned long val; if (!meta) @@ -1973,7 +2037,7 @@ static void *rbm_next(struct seq_file *m, void *v, loff_t *pos) static int rbm_show(struct seq_file *m, void *v) { struct ring_buffer_per_cpu *cpu_buffer = m->private; - struct ring_buffer_meta *meta = cpu_buffer->ring_meta; + struct ring_buffer_cpu_meta *meta = cpu_buffer->ring_meta; unsigned long val = (unsigned long)v; if (val == 1) { @@ -2022,7 +2086,7 @@ int ring_buffer_meta_seq_init(struct file *file, struct trace_buffer *buffer, in static void rb_meta_buffer_update(struct ring_buffer_per_cpu *cpu_buffer, struct buffer_page *bpage) { - struct ring_buffer_meta *meta = cpu_buffer->ring_meta; + struct ring_buffer_cpu_meta *meta = cpu_buffer->ring_meta; if (meta->head_buffer == (unsigned long)bpage->page) cpu_buffer->head_page = bpage; @@ -2037,7 +2101,7 @@ static int __rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, long nr_pages, struct list_head *pages) { struct trace_buffer *buffer = cpu_buffer->buffer; - struct ring_buffer_meta *meta = NULL; + struct ring_buffer_cpu_meta *meta = NULL; struct buffer_page *bpage, *tmp; bool user_thread = current->mm != NULL; gfp_t mflags; @@ -2161,7 +2225,7 @@ static struct ring_buffer_per_cpu * rb_allocate_cpu_buffer(struct trace_buffer *buffer, long nr_pages, int cpu) { struct ring_buffer_per_cpu *cpu_buffer; - struct ring_buffer_meta *meta; + struct ring_buffer_cpu_meta *meta; struct buffer_page *bpage; struct page *page; int ret; @@ -2290,6 +2354,7 @@ static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer) static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, int order, unsigned long start, unsigned long end, + unsigned long scratch_size, struct lock_class_key *key) { struct trace_buffer *buffer; @@ -2332,10 +2397,23 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, /* If start/end are specified, then that overrides size */ if (start && end) { + unsigned long buffers_start; unsigned long ptr; int n; - size = end - start; + /* Make sure that start is word aligned */ + start = ALIGN(start, sizeof(long)); + + /* scratch_size needs to be aligned too */ + scratch_size = ALIGN(scratch_size, sizeof(long)); + + /* Subtract the buffer meta data and word aligned */ + buffers_start = start + sizeof(struct ring_buffer_cpu_meta); + buffers_start = ALIGN(buffers_start, sizeof(long)); + buffers_start += scratch_size; + + /* Calculate the size for the per CPU data */ + size = end - buffers_start; size = size / nr_cpu_ids; /* @@ -2345,7 +2423,7 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, * needed, plus account for the integer array index that * will be appended to the meta data. */ - nr_pages = (size - sizeof(struct ring_buffer_meta)) / + nr_pages = (size - sizeof(struct ring_buffer_cpu_meta)) / (subbuf_size + sizeof(int)); /* Need at least two pages plus the reader page */ if (nr_pages < 3) @@ -2353,8 +2431,8 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, again: /* Make sure that the size fits aligned */ - for (n = 0, ptr = start; n < nr_cpu_ids; n++) { - ptr += sizeof(struct ring_buffer_meta) + + for (n = 0, ptr = buffers_start; n < nr_cpu_ids; n++) { + ptr += sizeof(struct ring_buffer_cpu_meta) + sizeof(int) * nr_pages; ptr = ALIGN(ptr, subbuf_size); ptr += subbuf_size * nr_pages; @@ -2371,7 +2449,7 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, buffer->range_addr_start = start; buffer->range_addr_end = end; - rb_range_meta_init(buffer, nr_pages); + rb_range_meta_init(buffer, nr_pages, scratch_size); } else { /* need at least two pages */ @@ -2424,7 +2502,7 @@ struct trace_buffer *__ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *key) { /* Default buffer page size - one system page */ - return alloc_buffer(size, flags, 0, 0, 0,key); + return alloc_buffer(size, flags, 0, 0, 0, 0, key); } EXPORT_SYMBOL_GPL(__ring_buffer_alloc); @@ -2436,6 +2514,7 @@ EXPORT_SYMBOL_GPL(__ring_buffer_alloc); * @order: sub-buffer order * @start: start of allocated range * @range_size: size of allocated range + * @scratch_size: size of scratch area (for preallocated memory buffers) * @key: ring buffer reader_lock_key. * * Currently the only flag that is available is the RB_FL_OVERWRITE @@ -2446,32 +2525,29 @@ EXPORT_SYMBOL_GPL(__ring_buffer_alloc); struct trace_buffer *__ring_buffer_alloc_range(unsigned long size, unsigned flags, int order, unsigned long start, unsigned long range_size, + unsigned long scratch_size, struct lock_class_key *key) { - return alloc_buffer(size, flags, order, start, start + range_size, key); + return alloc_buffer(size, flags, order, start, start + range_size, + scratch_size, key); } -/** - * ring_buffer_last_boot_delta - return the delta offset from last boot - * @buffer: The buffer to return the delta from - * @text: Return text delta - * @data: Return data delta - * - * Returns: The true if the delta is non zero - */ -bool ring_buffer_last_boot_delta(struct trace_buffer *buffer, long *text, - long *data) +void *ring_buffer_meta_scratch(struct trace_buffer *buffer, unsigned int *size) { - if (!buffer) - return false; + struct ring_buffer_meta *meta; + void *ptr; - if (!buffer->last_text_delta) - return false; + if (!buffer || !buffer->meta) + return NULL; - *text = buffer->last_text_delta; - *data = buffer->last_data_delta; + meta = buffer->meta; - return true; + ptr = (void *)ALIGN((unsigned long)meta + sizeof(*meta), sizeof(long)); + + if (size) + *size = (void *)meta + meta->buffers_offset - ptr; + + return ptr; } /** @@ -3082,7 +3158,7 @@ static void rb_inc_iter(struct ring_buffer_iter *iter) } /* Return the index into the sub-buffers for a given sub-buffer */ -static int rb_meta_subbuf_idx(struct ring_buffer_meta *meta, void *subbuf) +static int rb_meta_subbuf_idx(struct ring_buffer_cpu_meta *meta, void *subbuf) { void *subbuf_array; @@ -3094,7 +3170,7 @@ static int rb_meta_subbuf_idx(struct ring_buffer_meta *meta, void *subbuf) static void rb_update_meta_head(struct ring_buffer_per_cpu *cpu_buffer, struct buffer_page *next_page) { - struct ring_buffer_meta *meta = cpu_buffer->ring_meta; + struct ring_buffer_cpu_meta *meta = cpu_buffer->ring_meta; unsigned long old_head = (unsigned long)next_page->page; unsigned long new_head; @@ -3111,7 +3187,7 @@ static void rb_update_meta_head(struct ring_buffer_per_cpu *cpu_buffer, static void rb_update_meta_reader(struct ring_buffer_per_cpu *cpu_buffer, struct buffer_page *reader) { - struct ring_buffer_meta *meta = cpu_buffer->ring_meta; + struct ring_buffer_cpu_meta *meta = cpu_buffer->ring_meta; void *old_reader = cpu_buffer->reader_page->page; void *new_reader = reader->page; int id; @@ -3740,7 +3816,7 @@ rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer) rb_page_write(cpu_buffer->commit_page)); rb_inc_page(&cpu_buffer->commit_page); if (cpu_buffer->ring_meta) { - struct ring_buffer_meta *meta = cpu_buffer->ring_meta; + struct ring_buffer_cpu_meta *meta = cpu_buffer->ring_meta; meta->commit_buffer = (unsigned long)cpu_buffer->commit_page->page; } /* add barrier to keep gcc from optimizing too much */ @@ -5295,7 +5371,7 @@ rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) * moving it. The page before the header page has the * flag bit '1' set if it is pointing to the page we want. * but if the writer is in the process of moving it - * than it will be '2' or already moved '0'. + * then it will be '2' or already moved '0'. */ ret = rb_head_page_replace(reader, cpu_buffer->reader_page); @@ -5993,7 +6069,7 @@ rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer) if (cpu_buffer->mapped) { rb_update_meta_page(cpu_buffer); if (cpu_buffer->ring_meta) { - struct ring_buffer_meta *meta = cpu_buffer->ring_meta; + struct ring_buffer_cpu_meta *meta = cpu_buffer->ring_meta; meta->commit_buffer = meta->head_buffer; } } @@ -6027,7 +6103,6 @@ static void reset_disabled_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer) void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu) { struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu]; - struct ring_buffer_meta *meta; if (!cpumask_test_cpu(cpu, buffer->cpumask)) return; @@ -6046,11 +6121,6 @@ void ring_buffer_reset_cpu(struct trace_buffer *buffer, int cpu) atomic_dec(&cpu_buffer->record_disabled); atomic_dec(&cpu_buffer->resize_disabled); - /* Make sure persistent meta now uses this buffer's addresses */ - meta = rb_range_meta(buffer, 0, cpu_buffer->cpu); - if (meta) - rb_meta_init_text_addr(meta); - mutex_unlock(&buffer->mutex); } EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu); @@ -6065,7 +6135,6 @@ EXPORT_SYMBOL_GPL(ring_buffer_reset_cpu); void ring_buffer_reset_online_cpus(struct trace_buffer *buffer) { struct ring_buffer_per_cpu *cpu_buffer; - struct ring_buffer_meta *meta; int cpu; /* prevent another thread from changing buffer sizes */ @@ -6093,11 +6162,6 @@ void ring_buffer_reset_online_cpus(struct trace_buffer *buffer) reset_disabled_cpu_buffer(cpu_buffer); - /* Make sure persistent meta now uses this buffer's addresses */ - meta = rb_range_meta(buffer, 0, cpu_buffer->cpu); - if (meta) - rb_meta_init_text_addr(meta); - atomic_dec(&cpu_buffer->record_disabled); atomic_sub(RESET_BIT, &cpu_buffer->resize_disabled); } @@ -7126,6 +7190,7 @@ int ring_buffer_map(struct trace_buffer *buffer, int cpu, kfree(cpu_buffer->subbuf_ids); cpu_buffer->subbuf_ids = NULL; rb_free_meta_page(cpu_buffer); + atomic_dec(&cpu_buffer->resize_disabled); } unlock: @@ -7387,9 +7452,9 @@ static __init int rb_write_something(struct rb_test_data *data, bool nested) /* Ignore dropped events before test starts. */ if (started) { if (nested) - data->bytes_dropped += len; - else data->bytes_dropped_nested += len; + else + data->bytes_dropped += len; } return len; } |