Masami added a wrapper to be able to unhash trace event pointers
as they are only read by root anyway, and they can also be extracted
by the raw trace data buffers. But this wrapper utilized the iterator
to have a temporary buffer to manipulate the text with.
tp_printk is a kernel command line option that will send the trace
output of a trace event to the console on boot up (useful when the
system crashes before finishing the boot). But the code used the same
wrapper that Masami added, and its iterator did not have a buffer,
and this caused the system to crash.
Have the wrapper just print the trace event normally if the iterator
has no temporary buffer.
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Merge tag 'trace-v5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Fix tp_printk command line and trace events
Masami added a wrapper to be able to unhash trace event pointers as
they are only read by root anyway, and they can also be extracted by
the raw trace data buffers. But this wrapper utilized the iterator to
have a temporary buffer to manipulate the text with.
tp_printk is a kernel command line option that will send the trace
output of a trace event to the console on boot up (useful when the
system crashes before finishing the boot). But the code used the same
wrapper that Masami added, and its iterator did not have a buffer, and
this caused the system to crash.
Have the wrapper just print the trace event normally if the iterator
has no temporary buffer"
* tag 'trace-v5.12-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix checking event hash pointer logic when tp_printk is enabled
1fe5501ba1