The perf top command needs to unshare its fs from the helper threads
in order to successfully setns(2) during its symbol lookup. It also
needs to impelement a force flag to ignore ownership of perf-<pid>.map
files.
Signed-off-by: Krister Johansen <k...@templeofstupid.com>
---
tools/perf/Documentation/perf-top.txt | 4 ++++
tools/perf/builtin-top.c | 15 +++++++++++++++
2 files changed, 19 insertions(+)
diff --git a/tools/perf/Documentation/perf-top.txt
b/tools/perf/Documentation/perf-top.txt
index e71d638..d864ea6 100644
--- a/tools/perf/Documentation/perf-top.txt
+++ b/tools/perf/Documentation/perf-top.txt
@@ -237,6 +237,10 @@ Default is to monitor all CPUS.
--hierarchy::
Enable hierarchy output.
+--force::
+ Don't do ownership validation.
+
+
INTERACTIVE PROMPTING KEYS
--------------------------
diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c
index 6052376..ef2aef4 100644
--- a/tools/perf/builtin-top.c
+++ b/tools/perf/builtin-top.c
@@ -586,6 +586,13 @@ static void *display_thread_tui(void *arg)
.refresh = top->delay_secs,
};
+ /* In order to read symbols from other namespaces perf to needs to call
+ * setns(2). This isn't permitted if the struct_fs has multiple users.
+ * unshare(2) the fs so that we may continue to setns into namespaces
+ * that we're observing.
+ */
+ (void) unshare(CLONE_FS);
+
perf_top__sort_new_samples(top);
/*
@@ -627,6 +634,13 @@ static void *display_thread(void *arg)
struct perf_top *top = arg;
int delay_msecs, c;
+ /* In order to read symbols from other namespaces perf to needs to call
+ * setns(2). This isn't permitted if the struct_fs has multiple users.
+ * unshare(2) the fs so that we may continue to setns into namespaces
+ * that we're observing.
+ */
+ (void) unshare(CLONE_FS);
+
display_setup_sig();
pthread__unblock_sigwinch();
repeat:
@@ -1205,6 +1219,7 @@ int cmd_top(int argc, const char **argv)
"Show raw trace event output (do not use print fmt or
plugins)"),
OPT_BOOLEAN(0, "hierarchy", &symbol_conf.report_hierarchy,
"Show entries in a hierarchy"),
+ OPT_BOOLEAN(0, "force", &symbol_conf.force, "don't complain, do it"),
OPT_END()
};
const char * const top_usage[] = {
--
2.7.4
