Extend the ASLR tool stripping helpers to drop register dump payloads
by masking out the relevant perf_event_attr fields (sample_regs_user,
sample_regs_intr) when the delegated tool is handling the data.

struct aslr_evsel_priv maintains the original perf_event_attr values
and is looked up via the evsel_orig_attrs hashmap so that sample sizes
can be properly parsed even when bits are stripped from the pipeline.
This is critical for bounded array copying within aslr_tool__process_sample,
which relies on orig_sample_type to determine exactly which fields were
captured by the kernel before any stripping occurred.

This allows us to keep samples that would otherwise be dropped because
they contain registers, while still obfuscating the registers.

Committer notes:

Moved now used variables from the previous patch:

        struct aslr_evsel_priv *priv = NULL;
        u64 orig_sample_type;
        u64 orig_regs_user;
        u64 orig_regs_intr;

Assisted-by: Antigravity:gemini-3.1-pro
Co-developed-by: Gabriel Marin <gmx@google.com>
Signed-off-by: Gabriel Marin <gmx@google.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

If perf.data files are taken from one machine to another they may
leak virtual addresses and so weaken ASLR on the machine they are
coming from. Add an aslr option for perf inject that remaps all
virtual addresses, or drops data/events, so that the virtual address
information isn't leaked.

This patch introduces the core ASLR remapping tool infrastructure and
implements remapping/tracking for metadata events (MMAP, MMAP2, COMM,
FORK, EXIT, KSYMBOL, TEXT_POKE). Sample events are delegated without
remapping for now.

Assisted-by: Antigravity:gemini-3.1-pro
Signed-off-by: Ian Rogers <irogers@google.com>
Co-developed-by: Gabriel Marin <gmx@google.com>
Signed-off-by: Gabriel Marin <gmx@google.com>
Tested-by: James Clark <james.clark@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>