machine__get_kernel_start() gives out the kernel start address; some
architectures need to tweak the start address so that can reflect the
kernel start address correctly. This is not only for x86_64 arch, but
it is also required by other architectures, e.g. arm/arm64 needs to
tweak the kernel start address so can include the kernel memory regions
which are used before the '_stext' symbol.
This patch refactors machine__get_kernel_start() by adding a weak
arch__fix_kernel_text_start(), any architecture can implement it to
tweak its specific start address; this also allows the arch specific
code to be placed into 'arch' folder.
Signed-off-by: Leo Yan <leo.yan@xxxxxxxxxx>
---
tools/perf/arch/x86/util/machine.c | 10 ++++++++++
tools/perf/util/machine.c | 13 +++++++------
tools/perf/util/machine.h | 2 ++
3 files changed, 19 insertions(+), 6 deletions(-)
diff --git a/tools/perf/arch/x86/util/machine.c b/tools/perf/arch/x86/util/machine.c
index 1e9ec783b9a1..9f012131534a 100644
--- a/tools/perf/arch/x86/util/machine.c
+++ b/tools/perf/arch/x86/util/machine.c
@@ -101,4 +101,14 @@ int machine__create_extra_kernel_maps(struct machine *machine,
return ret;
}
+void arch__fix_kernel_text_start(u64 *start)
+{
+ /*
+ * 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.
+ */
+ *start = 1ULL << 63;
+}
+
#endif
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index f6ee7fbad3e4..603518835692 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -2671,6 +2671,10 @@ int machine__nr_cpus_avail(struct machine *machine)
return machine ? perf_env__nr_cpus_avail(machine->env) : 0;
}
+void __weak arch__fix_kernel_text_start(u64 *start __maybe_unused)
+{
+}
+
int machine__get_kernel_start(struct machine *machine)
{
struct map *map = machine__kernel_map(machine);
@@ -2687,14 +2691,11 @@ int machine__get_kernel_start(struct machine *machine)
machine->kernel_start = 1ULL << 63;
if (map) {
err = map__load(map);
- /*
- * 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"))
+ if (!err)
machine->kernel_start = map->start;
}
+
+ arch__fix_kernel_text_start(&machine->kernel_start);
return err;
}
diff --git a/tools/perf/util/machine.h b/tools/perf/util/machine.h
index ef803f08ae12..9cb459f4bfbc 100644
--- a/tools/perf/util/machine.h
+++ b/tools/perf/util/machine.h
@@ -278,6 +278,8 @@ void machine__get_kallsyms_filename(struct machine *machine, char *buf,
int machine__create_extra_kernel_maps(struct machine *machine,
struct dso *kernel);
+void arch__fix_kernel_text_start(u64 *start);
+
/* Kernel-space maps for symbols that are outside the main kernel map and module maps */
struct extra_kernel_map {
u64 start;
--
2.17.1
