in the kernel. The splice logic wants a full page from the ring buffer
but the ring_buffer_wait() returns when there's any data in the ring buffer.
The splice code would then continue the loop waiting for a full page.
But if a full page never happens, the splice code will never sleep and
just continue to loop.
There's another case that Rabin fixed that could loop if there's no memory
and kmalloc() constantly returns NULL.
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Merge tag 'trace-fixes-v3.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Rabin Vincent found a way that tracing could cause an infinite loop in
the kernel. The splice logic wants a full page from the ring buffer
but the ring_buffer_wait() returns when there's any data in the ring
buffer. The splice code would then continue the loop waiting for a
full page. But if a full page never happens, the splice code will
never sleep and just continue to loop.
There's another case that Rabin fixed that could loop if there's no
memory and kmalloc() constantly returns NULL"
* tag 'trace-fixes-v3.18-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Do not risk busy looping in buffer splice
tracing: Do not busy wait in buffer splice
15e5cda9e6