perf session: Free the ref_reloc_sym memory at the right place

Which is at perf_session__destroy_kernel_maps, counterpart to the
perf_session__create_kernel_maps where the kmap structure is located, just
after the vmlinux_maps.

Make it also check if the kernel maps were actually created, which may not
be the case if, for instance, perf_session__new can't complete due to
permission problems in, for instance, a 'perf report' case, when a
segfault will take place, that is how this was noticed.

The problem was introduced in d65a458, thus post .35.

This also adds code to release guest machines as them are also created
in perf_session__create_kernel_maps, so should be deleted on this newly
introduced counterpart, perf_session__destroy_kernel_maps.

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
LKML-Reference: <new-submission>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 43 insertions, 0 deletions

diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 3b8c0050667..6f0dd90c36c 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -2107,6 +2107,36 @@ int __machine__create_kernel_maps(struct machine *self, struct dso *kernel)
         return 0;
 }
 
+void machine__destroy_kernel_maps(struct machine *self)
+{
+        enum map_type type;
+
+        for (type = 0; type < MAP__NR_TYPES; ++type) {
+                struct kmap *kmap;
+
+                if (self->vmlinux_maps[type] == NULL)
+                        continue;
+
+                kmap = map__kmap(self->vmlinux_maps[type]);
+                map_groups__remove(&self->kmaps, self->vmlinux_maps[type]);
+                if (kmap->ref_reloc_sym) {
+                        /*
+                         * ref_reloc_sym is shared among all maps, so free just
+                         * on one of them.
+                         */
+                        if (type == MAP__FUNCTION) {
+                                free((char *)kmap->ref_reloc_sym->name);
+                                kmap->ref_reloc_sym->name = NULL;
+                                free(kmap->ref_reloc_sym);
+                        }
+                        kmap->ref_reloc_sym = NULL;
+                }
+
+                map__delete(self->vmlinux_maps[type]);
+                self->vmlinux_maps[type] = NULL;
+        }
+}
+
 int machine__create_kernel_maps(struct machine *self)
 {
         struct dso *kernel = machine__create_kernel(self);
@@ -2351,6 +2381,19 @@ failure:
         return ret;
 }
 
+void machines__destroy_guest_kernel_maps(struct rb_root *self)
+{
+        struct rb_node *next = rb_first(self);
+
+        while (next) {
+                struct machine *pos = rb_entry(next, struct machine, rb_node);
+
+                next = rb_next(&pos->rb_node);
+                rb_erase(&pos->rb_node, self);
+                machine__delete(pos);
+        }
+}
+
 int machine__load_kallsyms(struct machine *self, const char *filename,
                            enum map_type type, symbol_filter_t filter)
 {