[PATCH 1/5] perf tools: Add fallback functions for cases where cpumode is insufficient

[Adrian Hunter]

For branch stacks or branch samples, the sample cpumode might not be
correct because it applies only to the sample 'ip' and not necessary to
'addr' or branch stack addresses. Add fallback functions that can be used
to deal with those cases

Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # 4.19
---
 tools/perf/util/event.c   | 27 ++++++++++++++++++++++++++
 tools/perf/util/machine.c | 40 +++++++++++++++++++++++++++++++++++++++
 tools/perf/util/machine.h |  2 ++
 tools/perf/util/thread.h  |  4 ++++
 4 files changed, 73 insertions(+)

diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index bc646185f8d9..52b24b8ce29e 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -1576,6 +1576,24 @@ struct map *thread__find_map(struct thread *thread, u8 cpumode, u64 addr,
 	return al->map;
 }
 
+/*
+ * For branch stacks or branch samples, the sample cpumode might not be correct
+ * because it applies only to the sample 'ip' and not necessary to 'addr' or
+ * branch stack addresses. If possible, use a fallback to deal with those cases.
+ */
+struct map *thread__find_map_fallback(struct thread *thread, u8 cpumode,
+				      u64 addr, struct addr_location *al)
+{
+	struct map *map = thread__find_map(thread, cpumode, addr, al);
+	struct machine *machine = thread->mg->machine;
+	u8 addr_cpumode = machine__addr_cpumode(machine, cpumode, addr);
+
+	if (map || addr_cpumode == cpumode)
+		return map;
+
+	return thread__find_map(thread, addr_cpumode, addr, al);
+}
+
 struct symbol *thread__find_symbol(struct thread *thread, u8 cpumode,
 				   u64 addr, struct addr_location *al)
 {
@@ -1585,6 +1603,15 @@ struct symbol *thread__find_symbol(struct thread *thread, u8 cpumode,
 	return al->sym;
 }
 
+struct symbol *thread__find_symbol_fb(struct thread *thread, u8 cpumode,
+				      u64 addr, struct addr_location *al)
+{
+	al->sym = NULL;
+	if (thread__find_map_fallback(thread, cpumode, addr, al))
+		al->sym = map__find_symbol(al->map, al->addr);
+	return al->sym;
+}
+
 /*
  * Callers need to drop the reference to al->thread, obtained in
  * machine__findnew_thread()
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 111ae858cbcb..04edc0eac376 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2542,6 +2542,46 @@ int machine__get_kernel_start(struct machine *machine)
 	return err;
 }
 
+/*
+ * machine__single_ku_as - Machine has same address space for kernel and user.
+ * @machine: machine object
+ *
+ * Some architectures have a single address space for kernel and user addresses,
+ * which makes it possible to determine if an address is in kernel space or user
+ * space.
+ */
+static bool machine__single_ku_as(struct machine *machine)
+{
+	return strcmp(perf_env__arch(machine->env), "sparc");
+}
+
+u8 machine__addr_cpumode(struct machine *machine, u8 cpumode, u64 addr)
+{
+	u8 addr_cpumode = cpumode;
+	bool kernel_ip;
+
+	if (!machine__single_ku_as(machine))
+		goto out;
+
+	kernel_ip = machine__kernel_ip(machine, addr);
+	switch (cpumode) {
+	case PERF_RECORD_MISC_KERNEL:
+	case PERF_RECORD_MISC_USER:
+		addr_cpumode = kernel_ip ? PERF_RECORD_MISC_KERNEL :
+					   PERF_RECORD_MISC_USER;
+		break;
+	case PERF_RECORD_MISC_GUEST_KERNEL:
+	case PERF_RECORD_MISC_GUEST_USER:
+		addr_cpumode = kernel_ip ? PERF_RECORD_MISC_GUEST_KERNEL :
+					   PERF_RECORD_MISC_GUEST_USER;
+		break;
+	default:
+		break;
+	}
+out:
+	return addr_cpumode;
+}
+
 struct dso *machine__findnew_dso(struct machine *machine, const char *filename)
 {
 	return dsos__findnew(&machine->dsos, filename);
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index d856b85862e2..20d464135ed1 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -99,6 +99,8 @@ static inline bool machine__kernel_ip(struct machine *machine, u64 ip)
 	return ip >= kernel_start;
 }
 
+u8 machine__addr_cpumode(struct machine *machine, u8 cpumode, u64 addr);
+
 struct thread *machine__find_thread(struct machine *machine, pid_t pid,
 				    pid_t tid);
 struct comm *machine__thread_exec_comm(struct machine *machine,
diff --git a/tools/perf/util/thread.h b/tools/perf/util/thread.h
index 36c09a9904e6..e28f9dc1110a 100644
--- a/tools/perf/util/thread.h
+++ b/tools/perf/util/thread.h
@@ -96,9 +96,13 @@ struct thread *thread__main_thread(struct machine *machine, struct thread *threa
 
 struct map *thread__find_map(struct thread *thread, u8 cpumode, u64 addr,
 			     struct addr_location *al);
+struct map *thread__find_map_fallback(struct thread *thread, u8 cpumode,
+				      u64 addr, struct addr_location *al);
 
 struct symbol *thread__find_symbol(struct thread *thread, u8 cpumode,
 				   u64 addr, struct addr_location *al);
+struct symbol *thread__find_symbol_fb(struct thread *thread, u8 cpumode,
+				      u64 addr, struct addr_location *al);
 
 void thread__find_cpumode_addr_location(struct thread *thread, u64 addr,
 					struct addr_location *al);
-- 
2.17.1