[PATCH V5 2/3] tools/perf: Add "is_kmod" to struct dso to check if it is kernel module

Athira Rajeev atrajeev at linux.vnet.ibm.com
Thu Sep 28 17:52:12 AEST 2023

Update "struct dso" to include new member "is_kmod".
This new field will determine if the file is a kernel
module or not.

To resolve the address from a sample, perf looks at the
DSO maps. In case of address from a kernel module, there
were some address found to be not resolved. This was
observed while running perf test for "Object code reading".
Though the ip falls beteen the start address of the loaded
module (perf map->start ) and end address ( perf map->end),
it was unresolved.

This was happening because in some cases for kernel
modules, address from sample points to stub instructions.
To identify if the DSO is a kernel module, the new field
"is_kmod" is added to "struct dso".

Reported-by: Disha Goel <disgoel at linux.ibm.com>
Signed-off-by: Athira Rajeev <atrajeev at linux.vnet.ibm.com>
 This patch adds is_kmod field to dso to detect if
 the dso is a kernel module

 tools/perf/util/dso.c | 2 ++
 tools/perf/util/dso.h | 1 +
 2 files changed, 3 insertions(+)

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index bdfead36b83a..1f629b6fb7cf 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -477,6 +477,7 @@ void dso__set_module_info(struct dso *dso, struct kmod_path *m,
 		dso->comp = m->comp;
+	dso->is_kmod = 1;
 	dso__set_short_name(dso, strdup(m->name), true);
@@ -1338,6 +1339,7 @@ struct dso *dso__new_id(const char *name, struct dso_id *id)
 		dso->has_srcline = 1;
 		dso->a2l_fails = 1;
 		dso->kernel = DSO_SPACE__USER;
+		dso->is_kmod = 0;
 		dso->needs_swap = DSO_SWAP__UNSET;
 		dso->comp = COMP_ID__NONE;
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 70fe0fe69bef..3759de8c2267 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -162,6 +162,7 @@ struct dso {
 	char		 *symsrc_filename;
 	unsigned int	 a2l_fails;
 	enum dso_space_type	kernel;
+	bool			is_kmod;
 	enum dso_swap_type	needs_swap;
 	enum dso_binary_type	symtab_type;
 	enum dso_binary_type	binary_type;

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