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From:   Jin Yao <yao.jin@linux.intel.com>
To:     acme@kernel.org, jolsa@kernel.org, peterz@infradead.org,
        mingo@redhat.com, alexander.shishkin@linux.intel.com
Cc:     Linux-kernel@vger.kernel.org, ak@linux.intel.com,
        kan.liang@intel.com, yao.jin@intel.com, drian.hunter@intel.com,
        Jin Yao <yao.jin@linux.intel.com>
Subject: [PATCH] perf script: Fix overrun issue for dynamically-allocated pmu type number
Date:   Thu, 26 Nov 2020 11:24:25 +0800
Message-Id: <20201126032425.19226-1-yao.jin@linux.intel.com>
Precedence: bulk

When unpacking the event which is from dynamic pmu, the array
output[OUTPUT_TYPE_MAX] may be overrun. For example, type number of
SKL uncore_imc is 10, but OUTPUT_TYPE_MAX is 7 now (OUTPUT_TYPE_MAX =
PERF_TYPE_MAX + 1).

/* In builtin-script.c */
process_event()
{
	unsigned int type = output_type(attr->type);

	if (output[type].fields == 0)
		return;
}

output[10] is overrun.

Create a type OUTPUT_TYPE_OTHER for dynamic pmu events, then
output_type(attr->type) will return OUTPUT_TYPE_OTHER here.

Note that if PERF_TYPE_MAX ever changed, then there would be a conflict
between old perf.data files that had a dynamicaliy allocated PMU number
that would then be the same as a fixed PERF_TYPE.

Example:

perf record --switch-events -C 0 -e "{cpu-clock,uncore_imc/data_reads/,uncore_imc/data_writes/}:SD" -a -- sleep 1
perf script

Before:
         swapper     0 [000] 1479253.987551:     277766               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1479253.987797:     246709               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1479253.988127:     329883               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1479253.988273:     146393               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1479253.988523:     249977               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1479253.988877:     354090               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1479253.989023:     145940               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1479253.989383:     359856               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1479253.989523:     140082               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])

After:
         swapper     0 [000] 1397040.402011:     272384               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1397040.402011:       5396  uncore_imc/data_reads/:
         swapper     0 [000] 1397040.402011:        967 uncore_imc/data_writes/:
         swapper     0 [000] 1397040.402259:     249153               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1397040.402259:       7231  uncore_imc/data_reads/:
         swapper     0 [000] 1397040.402259:       1297 uncore_imc/data_writes/:
         swapper     0 [000] 1397040.402508:     249108               cpu-clock:  ffffffff9d4ddb6f cpuidle_enter_state+0xdf ([kernel.kallsyms])
         swapper     0 [000] 1397040.402508:       5333  uncore_imc/data_reads/:
         swapper     0 [000] 1397040.402508:       1008 uncore_imc/data_writes/:

Fixes: 1405720d4f26 ("perf script: Add 'synth' event type for synthesized events")
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
 tools/perf/builtin-script.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 48588ccf902e..d68684fb9b53 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -183,6 +183,7 @@ struct output_option {
 
 enum {
 	OUTPUT_TYPE_SYNTH = PERF_TYPE_MAX,
+	OUTPUT_TYPE_OTHER,
 	OUTPUT_TYPE_MAX
 };
 
@@ -279,6 +280,18 @@ static struct {
 
 		.invalid_fields = PERF_OUTPUT_TRACE | PERF_OUTPUT_BPF_OUTPUT,
 	},
+
+	[OUTPUT_TYPE_OTHER] = {
+		.user_set = false,
+
+		.fields = PERF_OUTPUT_COMM | PERF_OUTPUT_TID |
+			      PERF_OUTPUT_CPU | PERF_OUTPUT_TIME |
+			      PERF_OUTPUT_EVNAME | PERF_OUTPUT_IP |
+			      PERF_OUTPUT_SYM | PERF_OUTPUT_SYMOFFSET |
+			      PERF_OUTPUT_DSO | PERF_OUTPUT_PERIOD,
+
+		.invalid_fields = PERF_OUTPUT_TRACE | PERF_OUTPUT_BPF_OUTPUT,
+	},
 };
 
 struct evsel_script {
@@ -339,8 +352,11 @@ static inline int output_type(unsigned int type)
 	case PERF_TYPE_SYNTH:
 		return OUTPUT_TYPE_SYNTH;
 	default:
-		return type;
+		if (type < PERF_TYPE_MAX)
+			return type;
 	}
+
+	return OUTPUT_TYPE_OTHER;
 }
 
 static inline unsigned int attr_type(unsigned int type)
-- 
2.17.1