diff options
| -rw-r--r-- | include/linux/ring_buffer.h | 6 | ||||
| -rw-r--r-- | kernel/trace/ring_buffer.c | 35 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 2 |
3 files changed, 34 insertions, 9 deletions
diff --git a/include/linux/ring_buffer.h b/include/linux/ring_buffer.h index 8de035f4f0d9..019b59a0bbc9 100644 --- a/include/linux/ring_buffer.h +++ b/include/linux/ring_buffer.h @@ -92,9 +92,11 @@ __ring_buffer_alloc(unsigned long size, unsigned flags, struct lock_class_key *k 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); bool ring_buffer_last_boot_delta(struct trace_buffer *buffer, unsigned long *kaslr_addr); +void *ring_buffer_meta_scratch(struct trace_buffer *buffer, unsigned int *size); /* * Because the ring buffer is generic, if other users of the ring buffer get @@ -112,11 +114,11 @@ bool ring_buffer_last_boot_delta(struct trace_buffer *buffer, unsigned long *kas * traced by ftrace, it can produce lockdep warnings. We need to keep each * ring buffer's lock class separate. */ -#define ring_buffer_alloc_range(size, flags, order, start, range_size) \ +#define ring_buffer_alloc_range(size, flags, order, start, range_size, s_size) \ ({ \ static struct lock_class_key __key; \ __ring_buffer_alloc_range((size), (flags), (order), (start), \ - (range_size), &__key); \ + (range_size), (s_size), &__key); \ }) typedef bool (*ring_buffer_cond_fn)(void *data); diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index 0304e431604d..c511b3283dc6 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1678,7 +1678,7 @@ 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) +static bool rb_meta_init(struct trace_buffer *buffer, int scratch_size) { unsigned long ptr = buffer->range_addr_start; struct ring_buffer_meta *bmeta; @@ -1696,6 +1696,7 @@ static bool rb_meta_init(struct trace_buffer *buffer) /* 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"); @@ -1730,6 +1731,9 @@ static bool rb_meta_init(struct trace_buffer *buffer) 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; } @@ -1954,7 +1958,7 @@ static void rb_meta_init_text_addr(struct ring_buffer_cpu_meta *meta) #endif } -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_cpu_meta *meta; struct ring_buffer_meta *bmeta; @@ -1969,7 +1973,7 @@ static void rb_range_meta_init(struct trace_buffer *buffer, int nr_pages) 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)) + if (rb_meta_init(buffer, scratch_size)) valid = true; bmeta = buffer->meta; @@ -2367,6 +2371,7 @@ 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; @@ -2416,10 +2421,15 @@ static struct trace_buffer *alloc_buffer(unsigned long size, unsigned flags, /* 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; @@ -2456,7 +2466,7 @@ 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 */ @@ -2509,7 +2519,7 @@ 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); @@ -2521,6 +2531,7 @@ 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 @@ -2531,9 +2542,11 @@ 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); } /** @@ -2557,6 +2570,16 @@ bool ring_buffer_last_boot_delta(struct trace_buffer *buffer, unsigned long *kas return true; } +void *ring_buffer_meta_scratch(struct trace_buffer *buffer, unsigned int *size) +{ + if (!buffer || !buffer->meta) + return NULL; + + *size = PAGE_SIZE - sizeof(*buffer->meta); + + return (void *)buffer->meta + sizeof(*buffer->meta); +} + /** * ring_buffer_free - free a ring buffer. * @buffer: the buffer to free. diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 934658cda570..73c8df12c33c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9218,7 +9218,7 @@ allocate_trace_buffer(struct trace_array *tr, struct array_buffer *buf, int size if (tr->range_addr_start && tr->range_addr_size) { buf->buffer = ring_buffer_alloc_range(size, rb_flags, 0, tr->range_addr_start, - tr->range_addr_size); + tr->range_addr_size, 0); #ifdef CONFIG_RANDOMIZE_BASE if (ring_buffer_last_boot_delta(buf->buffer, &tr->kaslr_addr)) |