Sven Schnelle 6feeee8efc s390/ftrace: fix endless recursion in function_graph tracer ... The following sequence triggers a kernel stack overflow on s390x: mount -t tracefs tracefs /sys/kernel/tracing cd /sys/kernel/tracing echo function_graph > current_tracer [crash] This is because preempt_count_{add,sub} are in the list of traced functions, which can be demonstrated by: echo preempt_count_add >set_ftrace_filter echo function_graph > current_tracer [crash] The stack overflow happens because get_tod_clock_monotonic() gets called by ftrace but itself calls preempt_{disable,enable}(), which leads to a endless recursion. Fix this by using preempt_{disable,enable}_notrace(). Fixes: 011620688a ("s390/time: ensure get_clock_monotonic() returns monotonic values") Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>		2019-12-18 23:29:26 +01:00
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asm	s390/ftrace: fix endless recursion in function_graph tracer	2019-12-18 23:29:26 +01:00
uapi/asm	arch: ipcbuf.h: make uapi asm/ipcbuf.h self-contained	2019-12-04 19:44:14 -08:00