[PATCH 12/12] perf maps: Set maps pointer in the kmap area for kernel maps

From: Arnaldo Carvalho de Melo
Date: Tue Dec 17 2019 - 09:49:37 EST

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From: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>

When kernel maps are created with map__new2() we allocate an extra area
to store a pointer to the 'struct maps' for the kernel maps, and this
ends up being used in places like __map__is_kernel() to figure out if a
map is the main kernel one.

We were setting this up only in __machine__create_kernel_maps() and
machine__create_extra_kernel_map(), but not when splitting kallsyms,
kcore address ranges in new kernel maps such as
"[kernel.vmlinux].init.text", leading to assertion failures in
__map__is_kernel().

So make map__new2() receive the kernel 'struct maps' pointer so that all
kernel maps point back to it in its 'struct kmap' area.

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-z4qrek7y7s7sjnczremjdn1z@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
tools/perf/tests/maps.c | 8 ++++----
tools/perf/util/auxtrace.c | 2 +-
tools/perf/util/dso.c | 4 ++--
tools/perf/util/dso.h | 4 +++-
tools/perf/util/machine.c | 10 ++++------
tools/perf/util/map.c | 15 ++++++++++++++-
tools/perf/util/map.h | 2 +-
tools/perf/util/probe-event.c | 10 ++++++----
tools/perf/util/symbol-elf.c | 2 +-
tools/perf/util/symbol.c | 6 ++++--
10 files changed, 40 insertions(+), 23 deletions(-)

diff --git a/tools/perf/tests/maps.c b/tools/perf/tests/maps.c
index edcbc70ff9d6..7e32b4df8ff1 100644
--- a/tools/perf/tests/maps.c
+++ b/tools/perf/tests/maps.c
@@ -69,7 +69,7 @@ int test__maps__merge_in(struct test *t __maybe_unused, int subtest __maybe_unus
for (i = 0; i < ARRAY_SIZE(bpf_progs); i++) {
struct map *map;

- map = dso__new_map(bpf_progs[i].name);
+ map = dso__new_map(bpf_progs[i].name, &maps);
TEST_ASSERT_VAL("failed to create map", map);

map->start = bpf_progs[i].start;
@@ -78,13 +78,13 @@ int test__maps__merge_in(struct test *t __maybe_unused, int subtest __maybe_unus
map__put(map);
}

- map_kcore1 = dso__new_map("kcore1");
+ map_kcore1 = dso__new_map("kcore1", &maps);
TEST_ASSERT_VAL("failed to create map", map_kcore1);

- map_kcore2 = dso__new_map("kcore2");
+ map_kcore2 = dso__new_map("kcore2", &maps);
TEST_ASSERT_VAL("failed to create map", map_kcore2);

- map_kcore3 = dso__new_map("kcore3");
+ map_kcore3 = dso__new_map("kcore3", &maps);
TEST_ASSERT_VAL("failed to create map", map_kcore3);

/* kcore1 map overlaps over all bpf maps */
diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
index eb087e7df6f4..c5be6eeff069 100644
--- a/tools/perf/util/auxtrace.c
+++ b/tools/perf/util/auxtrace.c
@@ -2250,7 +2250,7 @@ static struct dso *load_dso(const char *name)
struct map *map;
struct dso *dso;

- map = dso__new_map(name);
+ map = dso__new_map(name, NULL);
if (!map)
return NULL;

diff --git a/tools/perf/util/dso.c b/tools/perf/util/dso.c
index 91f21239608b..dd5c2e71d8d7 100644
--- a/tools/perf/util/dso.c
+++ b/tools/perf/util/dso.c
@@ -1118,13 +1118,13 @@ ssize_t dso__data_write_cache_addr(struct dso *dso, struct map *map,
return dso__data_write_cache_offs(dso, machine, offset, data, size);
}

-struct map *dso__new_map(const char *name)
+struct map *dso__new_map(const char *name, struct maps *kmaps)
{
struct map *map = NULL;
struct dso *dso = dso__new(name);

if (dso)
- map = map__new2(0, dso);
+ map = map__new2(0, dso, kmaps);

return map;
}
diff --git a/tools/perf/util/dso.h b/tools/perf/util/dso.h
index 2db64b79617a..3b4f690c67e0 100644
--- a/tools/perf/util/dso.h
+++ b/tools/perf/util/dso.h
@@ -353,7 +353,9 @@ ssize_t dso__data_write_cache_addr(struct dso *dso, struct map *map,
struct machine *machine, u64 addr,
const u8 *data, ssize_t size);

-struct map *dso__new_map(const char *name);
+struct maps;
+
+struct map *dso__new_map(const char *name, struct maps *kmaps);
struct dso *machine__findnew_kernel(struct machine *machine, const char *name,
const char *short_name, int dso_type);

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index c8c5410315e8..7ee14963edc9 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -726,7 +726,7 @@ static int machine__process_ksymbol_register(struct machine *machine,
struct map *map = maps__find(&machine->kmaps, event->ksymbol.addr);

if (!map) {
- map = dso__new_map(event->ksymbol.name);
+ map = dso__new_map(event->ksymbol.name, &machine->kmaps);
if (!map)
return -ENOMEM;

@@ -784,7 +784,7 @@ static struct map *machine__addnew_module_map(struct machine *machine, u64 start
if (dso == NULL)
goto out;

- map = map__new2(start, dso);
+ map = map__new2(start, dso, &machine->kmaps);
if (map == NULL)
goto out;

@@ -963,7 +963,7 @@ int machine__create_extra_kernel_map(struct machine *machine,
struct kmap *kmap;
struct map *map;

- map = map__new2(xm->start, kernel);
+ map = map__new2(xm->start, kernel, &machine->kmaps);
if (!map)
return -1;

@@ -972,7 +972,6 @@ int machine__create_extra_kernel_map(struct machine *machine,

kmap = map__kmap(map);

- kmap->kmaps = &machine->kmaps;
strlcpy(kmap->name, xm->name, KMAP_NAME_LEN);

maps__insert(&machine->kmaps, map);
@@ -1088,7 +1087,7 @@ __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
/* In case of renewal the kernel map, destroy previous one */
machine__destroy_kernel_maps(machine);

- machine->vmlinux_map = map__new2(0, kernel);
+ machine->vmlinux_map = map__new2(0, kernel, &machine->kmaps);
if (machine->vmlinux_map == NULL)
return -1;

@@ -1098,7 +1097,6 @@ __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
if (!kmap)
return -1;

- kmap->kmaps = &machine->kmaps;
maps__insert(&machine->kmaps, map);

return 0;
diff --git a/tools/perf/util/map.c b/tools/perf/util/map.c
index fdd5bddb3075..a2cdfe62df94 100644
--- a/tools/perf/util/map.c
+++ b/tools/perf/util/map.c
@@ -223,7 +223,7 @@ struct map *map__new(struct machine *machine, u64 start, u64 len,
* they are loaded) and for vmlinux, where only after we load all the
* symbols we'll know where it starts and ends.
*/
-struct map *map__new2(u64 start, struct dso *dso)
+struct map *map__new2(u64 start, struct dso *dso, struct maps *kmaps)
{
struct map *map = calloc(1, (sizeof(*map) +
(dso->kernel ? sizeof(struct kmap) : 0)));
@@ -232,6 +232,19 @@ struct map *map__new2(u64 start, struct dso *dso)
* ->end will be filled after we load all the symbols
*/
map__init(map, start, 0, 0, dso);
+ if (dso->kernel) {
+ /*
+ * __map__is_kernel() Needs this for in-kernel map ranges
+ * such as:
+ * (gdb) print map->dso->name
+ * $8 = 0x1232d6c "[kernel.vmlinux].init.text"
+ * (gdb) print map->dso->kernel
+ * $9 = DSO_TYPE_KERNEL
+ * (gdb)
+ */
+ struct kmap *kmap = map__kmap(map);
+ kmap->kmaps = kmaps;
+ }
}

return map;
diff --git a/tools/perf/util/map.h b/tools/perf/util/map.h
index 067036e8970c..b4531876cd66 100644
--- a/tools/perf/util/map.h
+++ b/tools/perf/util/map.h
@@ -108,7 +108,7 @@ struct dso_id;
struct map *map__new(struct machine *machine, u64 start, u64 len,
u64 pgoff, struct dso_id *id, u32 prot, u32 flags,
char *filename, struct thread *thread);
-struct map *map__new2(u64 start, struct dso *dso);
+struct map *map__new2(u64 start, struct dso *dso, struct maps *kmaps);
void map__delete(struct map *map);
struct map *map__clone(struct map *map);

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index eea132f512b0..b123a800d260 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -146,7 +146,7 @@ static struct map *kernel_get_module_map(const char *module)

/* A file path -- this is an offline module */
if (module && strchr(module, '/'))
- return dso__new_map(module);
+ return dso__new_map(module, maps);

if (!module) {
pos = machine__kernel_map(host_machine);
@@ -170,7 +170,7 @@ struct map *get_target_map(const char *target, struct nsinfo *nsi, bool user)
if (user) {
struct map *map;

- map = dso__new_map(target);
+ map = dso__new_map(target, NULL);
if (map && map->dso)
map->dso->nsinfo = nsinfo__get(nsi);
return map;
@@ -651,12 +651,13 @@ static int
post_process_offline_probe_trace_events(struct probe_trace_event *tevs,
int ntevs, const char *pathname)
{
+ struct maps *maps = machine__kernel_maps(host_machine);
struct map *map;
unsigned long stext = 0;
int i, ret = 0;

/* Prepare a map for offline binary */
- map = dso__new_map(pathname);
+ map = dso__new_map(pathname, maps);
if (!map || get_text_start_address(pathname, &stext, NULL) < 0) {
pr_warning("Failed to get ELF symbols for %s\n", pathname);
return -EINVAL;
@@ -2111,7 +2112,8 @@ static int find_perf_probe_point_from_map(struct probe_trace_point *tp,
int ret = -ENOENT;

if (!is_kprobe) {
- map = dso__new_map(tp->module);
+ struct maps *maps = machine__kernel_maps(host_machine);
+ map = dso__new_map(tp->module, maps);
if (!map)
goto out;
sym = map__find_symbol(map, addr);
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 6658fbf196e6..cc896ba85a99 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -915,7 +915,7 @@ static int dso__process_kernel_symbol(struct dso *dso, struct map *map,
curr_dso->kernel = dso->kernel;
curr_dso->long_name = dso->long_name;
curr_dso->long_name_len = dso->long_name_len;
- curr_map = map__new2(start, curr_dso);
+ curr_map = map__new2(start, curr_dso, kmaps);
dso__put(curr_dso);
if (curr_map == NULL)
return -1;
diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c
index 3b379b1296f1..d166f0fb258c 100644
--- a/tools/perf/util/symbol.c
+++ b/tools/perf/util/symbol.c
@@ -856,7 +856,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta,

ndso->kernel = dso->kernel;

- curr_map = map__new2(pos->start, ndso);
+ curr_map = map__new2(pos->start, ndso, kmaps);
if (curr_map == NULL) {
dso__put(ndso);
return -1;
@@ -1144,6 +1144,7 @@ static int validate_kcore_addresses(const char *kallsyms_filename,

struct kcore_mapfn_data {
struct dso *dso;
+ struct maps *kmaps;
struct list_head maps;
};

@@ -1152,7 +1153,7 @@ static int kcore_mapfn(u64 start, u64 len, u64 pgoff, void *data)
struct kcore_mapfn_data *md = data;
struct map *map;

- map = map__new2(start, md->dso);
+ map = map__new2(start, md->dso, md->kmaps);
if (map == NULL)
return -ENOMEM;

@@ -1271,6 +1272,7 @@ static int dso__load_kcore(struct dso *dso, struct map *map,
return -EINVAL;

md.dso = dso;
+ md.kmaps = kmaps;
INIT_LIST_HEAD(&md.maps);

fd = open(kcore_filename, O_RDONLY);
--
2.21.0

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