perf ui hists: Fix dso_filter reference leak and exit zoom cleanup

In hists_browser__zoom_map(), the active dso is assigned as a raw
pointer to hists->dso_filter without acquiring a reference using
dso__get(). This creates a potential use-after-free defect if the
underlying dso is released while the filter remains active.

Fix it by properly acquiring a reference via dso__get() when assigning
the filter, and releasing it with dso__put() when clearing it.
Additionally, since the browser stack relies on pstack__new() and deletes
it completely upon exiting, we must fully reset the persistent hists
structure by un-eliding columns and recalculating histogram filter
states for dso, thread, and symbols upon exit to guarantee immaculate,
uncorrupted state across browser tab switching.

Closes: https://lore.kernel.org/linux-perf-users/20260709170834.52F1A1F000E9@smtp.kernel.org/
Assisted-by: Antigravity:gemini-3.5-flash
Signed-off-by: Ian Rogers <irogers@google.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>

0 files changed, 0 insertions, 0 deletions