On Tue, 17 Dec 2024 11:38:00 -0800
Linus Torvalds [off-list ref] wrote:
On Tue, 17 Dec 2024 at 11:01, Steven Rostedt [off-list ref] wrote:
quoted
But instead, I'll replace the text/data_deltas with a kaslr offset (it will
only be exported if the trace contains data from a previous kernel so not
to export the current kaslr offset).
Right - never export the KASRL offset for the *current* kernel, but
the same interface that exports the "previous kernel trace data" can
certainly export the KASLR for that previous case.
But this will be future work and not something for this merge window, as
it's more of a feature. The only fix is to add that print_field() code, and
the patch series that removes trace_check_vprintf() (which fixes a
different bug).
quoted
Then, on our production systems, we'll save the meta data of the events we
enable (this can include module events as well as dynamic events) and after
a crash, we'll extract the data along with the saved data stored on disk,
and be able to recreate the entire trace.
Yes. And if you save the module names and load addresses, you can now
hopefully sort out things like %s (and %pS) from modules too.
Although maybe they don't happen that often?
Actually, they do appear a bit. As the kmalloc trace event records the call
sites that do allocation and many of them are in module code.
-- Steve