diff options
author | David S. Miller <davem@davemloft.net> | 2009-04-13 14:41:05 -0700 |
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committer | David S. Miller <davem@davemloft.net> | 2009-04-13 14:41:05 -0700 |
commit | 83400207a07584539366f6859362db6872809a12 (patch) | |
tree | fad187f8b3bebf1b387ec42ef8143e6f4e49a256 /kernel/trace/trace.c | |
parent | 0d489ffb76de0fe804cf06a9d4d11fa7342d74b9 (diff) | |
parent | 80a04d3f2f94fb68b5df05e3ac6697130bc3467a (diff) |
Merge branch 'master' of /home/davem/src/GIT/linux-2.6/
Conflicts:
MAINTAINERS
Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r-- | kernel/trace/trace.c | 36 |
1 files changed, 21 insertions, 15 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 9d28476a985..1ce5dc6372b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3277,19 +3277,13 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp) info->tr = &global_trace; info->cpu = cpu; - info->spare = ring_buffer_alloc_read_page(info->tr->buffer); + info->spare = NULL; /* Force reading ring buffer for first read */ info->read = (unsigned int)-1; - if (!info->spare) - goto out; filp->private_data = info; - return 0; - - out: - kfree(info); - return -ENOMEM; + return nonseekable_open(inode, filp); } static ssize_t @@ -3304,6 +3298,11 @@ tracing_buffers_read(struct file *filp, char __user *ubuf, if (!count) return 0; + if (!info->spare) + info->spare = ring_buffer_alloc_read_page(info->tr->buffer); + if (!info->spare) + return -ENOMEM; + /* Do we have previous read data to read? */ if (info->read < PAGE_SIZE) goto read; @@ -3342,7 +3341,8 @@ static int tracing_buffers_release(struct inode *inode, struct file *file) { struct ftrace_buffer_info *info = file->private_data; - ring_buffer_free_read_page(info->tr->buffer, info->spare); + if (info->spare) + ring_buffer_free_read_page(info->tr->buffer, info->spare); kfree(info); return 0; @@ -3428,14 +3428,19 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, int size, i; size_t ret; - /* - * We can't seek on a buffer input - */ - if (unlikely(*ppos)) - return -ESPIPE; + if (*ppos & (PAGE_SIZE - 1)) { + WARN_ONCE(1, "Ftrace: previous read must page-align\n"); + return -EINVAL; + } + if (len & (PAGE_SIZE - 1)) { + WARN_ONCE(1, "Ftrace: splice_read should page-align\n"); + if (len < PAGE_SIZE) + return -EINVAL; + len &= PAGE_MASK; + } - for (i = 0; i < PIPE_BUFFERS && len; i++, len -= size) { + for (i = 0; i < PIPE_BUFFERS && len; i++, len -= PAGE_SIZE) { struct page *page; int r; @@ -3474,6 +3479,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, spd.partial[i].offset = 0; spd.partial[i].private = (unsigned long)ref; spd.nr_pages++; + *ppos += PAGE_SIZE; } spd.nr_pages = i; |