We mark the end of kernel based on the first module,
but that could cover some bpf program maps. Reading
_etext symbol if it's present to get precise kernel
map end.

Link: http://lkml.kernel.org/n/tip-ynut991ttyyhvo1sbhlm4...@git.kernel.org
Signed-off-by: Jiri Olsa <jo...@kernel.org>
---
 tools/perf/util/machine.c | 27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index 3c520baa198c..ad0205fbb506 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -924,7 +924,8 @@ const char *ref_reloc_sym_names[] = {"_text", "_stext", 
NULL};
  * symbol_name if it's not that important.
  */
 static int machine__get_running_kernel_start(struct machine *machine,
-                                            const char **symbol_name, u64 
*start)
+                                            const char **symbol_name,
+                                            u64 *start, u64 *end)
 {
        char filename[PATH_MAX];
        int i, err = -1;
@@ -949,6 +950,11 @@ static int machine__get_running_kernel_start(struct 
machine *machine,
                *symbol_name = name;
 
        *start = addr;
+
+       err = kallsyms__get_function_start(filename, "_etext", &addr);
+       if (!err)
+               *end = addr;
+
        return 0;
 }
 
@@ -1440,7 +1446,7 @@ int machine__create_kernel_maps(struct machine *machine)
        struct dso *kernel = machine__get_kernel(machine);
        const char *name = NULL;
        struct map *map;
-       u64 addr = 0;
+       u64 start = 0, end = ~0ULL;
        int ret;
 
        if (kernel == NULL)
@@ -1459,9 +1465,9 @@ int machine__create_kernel_maps(struct machine *machine)
                                 "continuing anyway...\n", machine->pid);
        }
 
-       if (!machine__get_running_kernel_start(machine, &name, &addr)) {
+       if (!machine__get_running_kernel_start(machine, &name, &start, &end)) {
                if (name &&
-                   map__set_kallsyms_ref_reloc_sym(machine->vmlinux_map, name, 
addr)) {
+                   map__set_kallsyms_ref_reloc_sym(machine->vmlinux_map, name, 
start)) {
                        machine__destroy_kernel_maps(machine);
                        ret = -1;
                        goto out_put;
@@ -1471,16 +1477,19 @@ int machine__create_kernel_maps(struct machine *machine)
                 * we have a real start address now, so re-order the kmaps
                 * assume it's the last in the kmaps
                 */
-               machine__update_kernel_mmap(machine, addr, ~0ULL);
+               machine__update_kernel_mmap(machine, start, end);
        }
 
        if (machine__create_extra_kernel_maps(machine, kernel))
                pr_debug("Problems creating extra kernel maps, continuing 
anyway...\n");
 
-       /* update end address of the kernel map using adjacent module address */
-       map = map__next(machine__kernel_map(machine));
-       if (map)
-               machine__set_kernel_mmap(machine, addr, map->start);
+       if (end == ~0ULL) {
+               /* update end address of the kernel map using adjacent module 
address */
+               map = map__next(machine__kernel_map(machine));
+               if (map)
+                       machine__set_kernel_mmap(machine, start, map->start);
+       }
+
 out_put:
        dso__put(kernel);
        return ret;
-- 
2.17.2

Reply via email to