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From:   James Clark <james.clark@arm.com>
To:     acme@kernel.org, linux-perf-users@vger.kernel.org
Cc:     denik@chromium.org, James Clark <james.clark@arm.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        linux-kernel@vger.kernel.org
Subject: [PATCH 1/3] perf tools: Refactor out kernel symbol argument sanity checking
Date:   Mon, 18 Oct 2021 14:48:41 +0100
Message-Id: <20211018134844.2627174-2-james.clark@arm.com>
In-Reply-To: <20211018134844.2627174-1-james.clark@arm.com>
References: <20211018134844.2627174-1-james.clark@arm.com>
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User supplied values for vmlinux and kallsyms are checked before
continuing. Refactor this into a function so that it can be used
elsewhere.

Signed-off-by: James Clark <james.clark@arm.com>
---
 tools/perf/builtin-report.c | 13 ++-----------
 tools/perf/util/symbol.c    | 22 ++++++++++++++++++++++
 tools/perf/util/symbol.h    |  2 ++
 3 files changed, 26 insertions(+), 11 deletions(-)

diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index a0316ce910db..8167ebfe776a 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -1378,18 +1378,9 @@ int cmd_report(int argc, const char **argv)
 	if (quiet)
 		perf_quiet_option();
 
-	if (symbol_conf.vmlinux_name &&
-	    access(symbol_conf.vmlinux_name, R_OK)) {
-		pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
-		ret = -EINVAL;
-		goto exit;
-	}
-	if (symbol_conf.kallsyms_name &&
-	    access(symbol_conf.kallsyms_name, R_OK)) {
-		pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
-		ret = -EINVAL;
+	ret = symbol__validate_sym_arguments();
+	if (ret)
 		goto exit;
-	}
 
 	if (report.inverted_callchain)
 		callchain_param.order = ORDER_CALLER;
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 0fc9a5410739..8fad1f0d41cb 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -2630,3 +2630,25 @@ struct mem_info *mem_info__new(void)
 		refcount_set(&mi->refcnt, 1);
 	return mi;
 }
+
+/*
+ * Checks that user supplied symbol kernel files are accessible because
+ * the default mechanism for accessing elf files fails silently. i.e. if
+ * debug syms for a build ID aren't found perf carries on normally. When
+ * they are user supplied we should assume that the user doesn't want to
+ * silently fail.
+ */
+int symbol__validate_sym_arguments(void)
+{
+	if (symbol_conf.vmlinux_name &&
+	    access(symbol_conf.vmlinux_name, R_OK)) {
+		pr_err("Invalid file: %s\n", symbol_conf.vmlinux_name);
+		return -EINVAL;
+	}
+	if (symbol_conf.kallsyms_name &&
+	    access(symbol_conf.kallsyms_name, R_OK)) {
+		pr_err("Invalid file: %s\n", symbol_conf.kallsyms_name);
+		return -EINVAL;
+	}
+	return 0;
+}
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 954d6a049ee2..166196686f2e 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -286,4 +286,6 @@ static inline void __mem_info__zput(struct mem_info **mi)
 
 #define mem_info__zput(mi) __mem_info__zput(&mi)
 
+int symbol__validate_sym_arguments(void);
+
 #endif /* __PERF_SYMBOL */
-- 
2.28.0