tracing: Don't use out-of-sync va_list in event printing
If trace_seq becomes full, trace_seq_vprintf() no longer consumes arguments from va_list, making va_list out of sync with format processing by trace_check_vprintf(). This causes va_arg() in trace_check_vprintf() to return wrong positional argument, which results into a WARN_ON_ONCE() hit. ftrace_stress_test from LTP triggers this situation. Fix it by explicitly avoiding further use if va_list at the point when it's consistency can no longer be guaranteed. Link: https://lkml.kernel.org/r/20211118145516.13219-1-nikita.yushchenko@virtuozzo.com Signed-off-by:Nikita Yushchenko <nikita.yushchenko@virtuozzo.com> Signed-off-by:
Steven Rostedt (VMware) <rostedt@goodmis.org>
parent
c4c1dbcc
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