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Subject[PATCH V1 06/19] perf tools: Fix kernel_start for PTI on x86
Date
On x86_64, PTI entry trampolines are less than the start of kernel text,
but still above 2^63. So leave kernel_start = 1ULL << 63 for x86_64.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
---
tools/perf/util/machine.c | 16 +++++++++++++++-
tools/perf/util/machine.h | 2 ++
2 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 72a351613d85..2f39a4d014de 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2296,6 +2296,15 @@ int machine__set_current_tid(struct machine *machine, int cpu, pid_t pid,
return 0;
}

+/*
+ * Compares the raw arch string. N.B. see instead perf_env__arch() if a
+ * normalized arch is needed.
+ */
+bool machine__is(struct machine *machine, const char *arch)
+{
+ return machine && machine->env && !strcmp(machine->env->arch, arch);
+}
+
int machine__get_kernel_start(struct machine *machine)
{
struct map *map = machine__kernel_map(machine);
@@ -2312,7 +2321,12 @@ int machine__get_kernel_start(struct machine *machine)
machine->kernel_start = 1ULL << 63;
if (map) {
err = map__load(map);
- if (!err)
+ /*
+ * On x86_64, PTI entry trampolines are less than the
+ * start of kernel text, but still above 2^63. So leave
+ * kernel_start = 1ULL << 63 for x86_64.
+ */
+ if (!err && !machine__is(machine, "x86_64"))
machine->kernel_start = map->start;
}
return err;
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index 388fb4741c54..b31d33b5aa2a 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -188,6 +188,8 @@ static inline bool machine__is_host(struct machine *machine)
return machine ? machine->pid == HOST_KERNEL_ID : false;
}

+bool machine__is(struct machine *machine, const char *arch);
+
struct thread *__machine__findnew_thread(struct machine *machine, pid_t pid, pid_t tid);
struct thread *machine__findnew_thread(struct machine *machine, pid_t pid, pid_t tid);

--
1.9.1
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