From 78c32f4cb12f9430e29402118635dcf972b7d325 Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Tue, 24 Oct 2023 15:23:07 -0700 Subject: [PATCH] libperf rc_check: Add RC_CHK_EQUAL Comparing pointers with reference count checking is tricky to avoid a SEGV. Add a convenience macro to simplify and use. Signed-off-by: Ian Rogers Cc: K Prateek Nayak Cc: Ravi Bangoria Cc: Sandipan Das Cc: Anshuman Khandual Cc: German Gomez Cc: James Clark Cc: Nick Terrell Cc: Sean Christopherson Cc: Changbin Du Cc: liuwenyu Cc: Yang Jihong Cc: Masami Hiramatsu Cc: Miguel Ojeda Cc: Song Liu Cc: Leo Yan Cc: Kajol Jain Cc: Andi Kleen Cc: Kan Liang Cc: Athira Rajeev Cc: Yanteng Si Cc: Liam Howlett Cc: Paolo Bonzini Link: https://lore.kernel.org/r/20231024222353.3024098-5-irogers@google.com Signed-off-by: Namhyung Kim --- tools/lib/perf/include/internal/rc_check.h | 7 +++++++ tools/perf/builtin-sched.c | 2 +- tools/perf/tests/hists_link.c | 4 ++-- tools/perf/tests/thread-maps-share.c | 9 ++++----- tools/perf/util/callchain.c | 2 +- tools/perf/util/hist.c | 2 +- tools/perf/util/machine.c | 4 ++-- tools/perf/util/sort.c | 2 +- tools/perf/util/symbol.c | 4 ++-- 9 files changed, 21 insertions(+), 15 deletions(-) diff --git a/tools/lib/perf/include/internal/rc_check.h b/tools/lib/perf/include/internal/rc_check.h index e88a6d8a0b0f..f80ddfc80129 100644 --- a/tools/lib/perf/include/internal/rc_check.h +++ b/tools/lib/perf/include/internal/rc_check.h @@ -54,6 +54,9 @@ /* A put operation removing the indirection layer. */ #define RC_CHK_PUT(object) {} +/* Pointer equality when the indirection may or may not be there. */ +#define RC_CHK_EQUAL(object1, object2) (object1 == object2) + #else /* Replaces "struct foo" so that the pointer may be interposed. */ @@ -101,6 +104,10 @@ } \ } while(0) +/* Pointer equality when the indirection may or may not be there. */ +#define RC_CHK_EQUAL(object1, object2) (object1 == object2 || \ + (object1 && object2 && object1->orig == object2->orig)) + #endif #endif /* __LIBPERF_INTERNAL_RC_CHECK_H */ diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c index 9ab300b6f131..dd6065afbbaf 100644 --- a/tools/perf/builtin-sched.c +++ b/tools/perf/builtin-sched.c @@ -1385,7 +1385,7 @@ static int pid_cmp(struct work_atoms *l, struct work_atoms *r) { pid_t l_tid, r_tid; - if (RC_CHK_ACCESS(l->thread) == RC_CHK_ACCESS(r->thread)) + if (RC_CHK_EQUAL(l->thread, r->thread)) return 0; l_tid = thread__tid(l->thread); r_tid = thread__tid(r->thread); diff --git a/tools/perf/tests/hists_link.c b/tools/perf/tests/hists_link.c index 2d19657ab5e0..5b6f1e883466 100644 --- a/tools/perf/tests/hists_link.c +++ b/tools/perf/tests/hists_link.c @@ -148,8 +148,8 @@ static int find_sample(struct sample *samples, size_t nr_samples, struct thread *t, struct map *m, struct symbol *s) { while (nr_samples--) { - if (RC_CHK_ACCESS(samples->thread) == RC_CHK_ACCESS(t) && - RC_CHK_ACCESS(samples->map) == RC_CHK_ACCESS(m) && + if (RC_CHK_EQUAL(samples->thread, t) && + RC_CHK_EQUAL(samples->map, m) && samples->sym == s) return 1; samples++; diff --git a/tools/perf/tests/thread-maps-share.c b/tools/perf/tests/thread-maps-share.c index faf980b26252..7fa6f7c568e2 100644 --- a/tools/perf/tests/thread-maps-share.c +++ b/tools/perf/tests/thread-maps-share.c @@ -46,9 +46,9 @@ static int test__thread_maps_share(struct test_suite *test __maybe_unused, int s TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(maps__refcnt(maps)), 4); /* test the maps pointer is shared */ - TEST_ASSERT_VAL("maps don't match", RC_CHK_ACCESS(maps) == RC_CHK_ACCESS(thread__maps(t1))); - TEST_ASSERT_VAL("maps don't match", RC_CHK_ACCESS(maps) == RC_CHK_ACCESS(thread__maps(t2))); - TEST_ASSERT_VAL("maps don't match", RC_CHK_ACCESS(maps) == RC_CHK_ACCESS(thread__maps(t3))); + TEST_ASSERT_VAL("maps don't match", RC_CHK_EQUAL(maps, thread__maps(t1))); + TEST_ASSERT_VAL("maps don't match", RC_CHK_EQUAL(maps, thread__maps(t2))); + TEST_ASSERT_VAL("maps don't match", RC_CHK_EQUAL(maps, thread__maps(t3))); /* * Verify the other leader was created by previous call. @@ -73,8 +73,7 @@ static int test__thread_maps_share(struct test_suite *test __maybe_unused, int s other_maps = thread__maps(other); TEST_ASSERT_EQUAL("wrong refcnt", refcount_read(maps__refcnt(other_maps)), 2); - TEST_ASSERT_VAL("maps don't match", RC_CHK_ACCESS(other_maps) == - RC_CHK_ACCESS(thread__maps(other_leader))); + TEST_ASSERT_VAL("maps don't match", RC_CHK_EQUAL(other_maps, thread__maps(other_leader))); /* release thread group */ thread__put(t3); diff --git a/tools/perf/util/callchain.c b/tools/perf/util/callchain.c index aee937d14fbb..18d545c0629e 100644 --- a/tools/perf/util/callchain.c +++ b/tools/perf/util/callchain.c @@ -1142,7 +1142,7 @@ int fill_callchain_info(struct addr_location *al, struct callchain_cursor_node * if (al->map == NULL) goto out; } - if (RC_CHK_ACCESS(al->maps) == RC_CHK_ACCESS(machine__kernel_maps(machine))) { + if (RC_CHK_EQUAL(al->maps, machine__kernel_maps(machine))) { if (machine__is_host(machine)) { al->cpumode = PERF_RECORD_MISC_KERNEL; al->level = 'k'; diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c index 3dc8a4968beb..cde0078e6c90 100644 --- a/tools/perf/util/hist.c +++ b/tools/perf/util/hist.c @@ -2142,7 +2142,7 @@ static bool hists__filter_entry_by_thread(struct hists *hists, struct hist_entry *he) { if (hists->thread_filter != NULL && - RC_CHK_ACCESS(he->thread) != RC_CHK_ACCESS(hists->thread_filter)) { + !RC_CHK_EQUAL(he->thread, hists->thread_filter)) { he->filtered |= (1 << HIST_FILTER__THREAD); return true; } diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c index e0e2c4a943e4..098600d983c5 100644 --- a/tools/perf/util/machine.c +++ b/tools/perf/util/machine.c @@ -969,7 +969,7 @@ static int machine__process_ksymbol_unregister(struct machine *machine, if (!map) return 0; - if (RC_CHK_ACCESS(map) != RC_CHK_ACCESS(machine->vmlinux_map)) + if (!RC_CHK_EQUAL(map, machine->vmlinux_map)) maps__remove(machine__kernel_maps(machine), map); else { struct dso *dso = map__dso(map); @@ -2058,7 +2058,7 @@ static void __machine__remove_thread(struct machine *machine, struct thread_rb_n if (!nd) nd = thread_rb_node__find(th, &threads->entries.rb_root); - if (threads->last_match && RC_CHK_ACCESS(threads->last_match) == RC_CHK_ACCESS(th)) + if (threads->last_match && RC_CHK_EQUAL(threads->last_match, th)) threads__set_last_match(threads, NULL); if (lock) diff --git a/tools/perf/util/sort.c b/tools/perf/util/sort.c index 6aa1c7f2b444..80e4f6132740 100644 --- a/tools/perf/util/sort.c +++ b/tools/perf/util/sort.c @@ -128,7 +128,7 @@ static int hist_entry__thread_filter(struct hist_entry *he, int type, const void if (type != HIST_FILTER__THREAD) return -1; - return th && RC_CHK_ACCESS(he->thread) != RC_CHK_ACCESS(th); + return th && !RC_CHK_EQUAL(he->thread, th); } struct sort_entry sort_thread = { diff --git a/tools/perf/util/symbol.c b/tools/perf/util/symbol.c index 96587fd7a5a2..822f4dcebfe6 100644 --- a/tools/perf/util/symbol.c +++ b/tools/perf/util/symbol.c @@ -877,7 +877,7 @@ static int maps__split_kallsyms(struct maps *kmaps, struct dso *dso, u64 delta, *module++ = '\0'; curr_map_dso = map__dso(curr_map); if (strcmp(curr_map_dso->short_name, module)) { - if (RC_CHK_ACCESS(curr_map) != RC_CHK_ACCESS(initial_map) && + if (!RC_CHK_EQUAL(curr_map, initial_map) && dso->kernel == DSO_SPACE__KERNEL_GUEST && machine__is_default_guest(machine)) { /* @@ -1469,7 +1469,7 @@ static int dso__load_kcore(struct dso *dso, struct map *map, list_del_init(&new_node->node); - if (RC_CHK_ACCESS(new_map) == RC_CHK_ACCESS(replacement_map)) { + if (RC_CHK_EQUAL(new_map, replacement_map)) { struct map *map_ref; map__set_start(map, map__start(new_map));