perf sched: Include file offset in event skip messages

Add the perf.data file offset to the CPU out-of-bounds and
machine__resolve failure messages emitted when samples are skipped in
process_sched_switch_event(), process_sched_runtime_event(), and
timehist_sched_change_event().  Also switch event type from raw integer
to perf_event__name() string for readability.

Reviewed-by: Ian Rogers <irogers@google.com>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index 812a1b0d56d6e5f3f51379f3f4072de38b1ddd5e..9ec8e049e19b0038a7e756863c7bd0738b9419d6 100644 (file)
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1792,8 +1792,10 @@ static int process_sched_switch_event(const struct perf_tool *tool,
        u32 prev_pid = perf_sample__intval(sample, "prev_pid"),
            next_pid = perf_sample__intval(sample, "next_pid");
 
+       /* perf.data is untrusted input — CPU may be absent or corrupted */
        if (this_cpu < 0 || this_cpu >= MAX_CPUS) {
-               pr_warning("Out-of-bound sample CPU %d. Skipping sample\n", this_cpu);
+               pr_warning("WARNING: at offset %#" PRIx64 ": out-of-bound sample CPU %d, skipping sample\n",
+                          sample->file_offset, this_cpu);
                return 0;
        }
 
@@ -1819,8 +1821,10 @@ static int process_sched_runtime_event(const struct perf_tool *tool,
 {
        struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
 
+       /* perf.data is untrusted input — CPU may be absent or corrupted */
        if (sample->cpu >= MAX_CPUS) {
-               pr_warning("Out-of-bound sample CPU %u. Skipping sample\n", sample->cpu);
+               pr_warning("WARNING: at offset %#" PRIx64 ": out-of-bound sample CPU %u, skipping sample\n",
+                          sample->file_offset, sample->cpu);
                return 0;
        }
 
@@ -2786,15 +2790,18 @@ static int timehist_sched_change_event(const struct perf_tool *tool,
        int rc = 0;
        const char state = perf_sample__taskstate(sample, "prev_state");
 
+       /* perf.data is untrusted input — CPU may be absent or corrupted */
        if (sample->cpu >= MAX_CPUS) {
-               pr_warning("Out-of-bound sample CPU %d. Skipping sample\n", sample->cpu);
+               pr_warning("WARNING: at offset %#" PRIx64 ": out-of-bound sample CPU %d, skipping sample\n",
+                          sample->file_offset, sample->cpu);
                return 0;
        }
 
        addr_location__init(&al);
        if (machine__resolve(machine, &al, sample) < 0) {
-               pr_err("problem processing %d event. skipping it\n",
-                      event->header.type);
+               pr_err("problem processing %s (%u) event at offset %#" PRIx64 ", skipping it\n",
+                      perf_event__name(event->header.type), event->header.type,
+                      sample->file_offset);
                rc = -1;
                goto out;
        }