int event__synthesize_kernel_mmap(event__handler_t process,
struct perf_session *session,
const char *symbol_name)
{
size_t size;
event_t ev = {
.header = {
.type = PERF_RECORD_MMAP,
.misc = 1, /* kernel uses 0 for user space maps, see kernel/perf_event.c __perf_event_mmap */
},
};
/*
* We should get this from /sys/kernel/sections/.text, but till that is
* available use this, and after it is use this as a fallback for older
* kernels.
*/
struct process_symbol_args args = { .name = symbol_name, };
if (kallsyms__parse("/proc/kallsyms", &args, find_symbol_cb) <= 0)
return -ENOENT;
size = snprintf(ev.mmap.filename, sizeof(ev.mmap.filename),
"[kernel.kallsyms.%s]", symbol_name) + 1;
size = ALIGN(size, sizeof(u64));
ev.mmap.header.size = (sizeof(ev.mmap) - (sizeof(ev.mmap.filename) - size));
ev.mmap.pgoff = args.start;
ev.mmap.start = session->vmlinux_maps[MAP__FUNCTION]->start;
ev.mmap.len = session->vmlinux_maps[MAP__FUNCTION]->end - ev.mmap.start ;
return process(&ev, session);
}
int event__synthesize_kernel_mmap(event__handler_t process,
struct perf_session *session,
struct machine *machine,
const char *symbol_name)
{
size_t size;
const char *filename, *mmap_name;
char path[PATH_MAX];
char name_buff[PATH_MAX];
struct map *map;
event_t ev = {
.header = {
.type = PERF_RECORD_MMAP,
},
};
/*
* We should get this from /sys/kernel/sections/.text, but till that is
* available use this, and after it is use this as a fallback for older
* kernels.
*/
struct process_symbol_args args = { .name = symbol_name, };
mmap_name = machine__mmap_name(machine, name_buff, sizeof(name_buff));
if (machine__is_host(machine)) {
/*
* kernel uses PERF_RECORD_MISC_USER for user space maps,
* see kernel/perf_event.c __perf_event_mmap
*/
ev.header.misc = PERF_RECORD_MISC_KERNEL;
filename = "/proc/kallsyms";
} else {
ev.header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
if (machine__is_default_guest(machine))
filename = (char *) symbol_conf.default_guest_kallsyms;
else {
sprintf(path, "%s/proc/kallsyms", machine->root_dir);
filename = path;
}
}
if (kallsyms__parse(filename, &args, find_symbol_cb) <= 0)
return -ENOENT;
map = machine->vmlinux_maps[MAP__FUNCTION];
size = snprintf(ev.mmap.filename, sizeof(ev.mmap.filename),
"%s%s", mmap_name, symbol_name) + 1;
size = ALIGN(size, sizeof(u64));
ev.mmap.header.size = (sizeof(ev.mmap) -
(sizeof(ev.mmap.filename) - size));
ev.mmap.pgoff = args.start;
ev.mmap.start = map->start;
ev.mmap.len = map->end - ev.mmap.start;
ev.mmap.pid = machine->pid;
return process(&ev, session);
}
u64 kallsyms__get_function_start(const char *kallsyms_filename,
const char *symbol_name)
{
struct process_symbol_args args = { .name = symbol_name, };
if (kallsyms__parse(kallsyms_filename, &args, find_symbol_cb) <= 0)
return 0;
return args.start;
}
int perf_event__synthesize_kernel_mmap(perf_event__handler_t process,
struct perf_session *session,
struct machine *machine,
const char *symbol_name)
{
size_t size;
const char *filename, *mmap_name;
char path[PATH_MAX];
char name_buff[PATH_MAX];
struct map *map;
int err;
/*
* We should get this from /sys/kernel/sections/.text, but till that is
* available use this, and after it is use this as a fallback for older
* kernels.
*/
struct process_symbol_args args = { .name = symbol_name, };
union perf_event *event = zalloc((sizeof(event->mmap) +
session->id_hdr_size));
if (event == NULL) {
pr_debug("Not enough memory synthesizing mmap event "
"for kernel modules\n");
return -1;
}
mmap_name = machine__mmap_name(machine, name_buff, sizeof(name_buff));
if (machine__is_host(machine)) {
/*
* kernel uses PERF_RECORD_MISC_USER for user space maps,
* see kernel/perf_event.c __perf_event_mmap
*/
event->header.misc = PERF_RECORD_MISC_KERNEL;
filename = "/proc/kallsyms";
} else {
event->header.misc = PERF_RECORD_MISC_GUEST_KERNEL;
if (machine__is_default_guest(machine))
filename = (char *) symbol_conf.default_guest_kallsyms;
else {
sprintf(path, "%s/proc/kallsyms", machine->root_dir);
filename = path;
}
}
if (kallsyms__parse(filename, &args, find_symbol_cb) <= 0)
return -ENOENT;
map = machine->vmlinux_maps[MAP__FUNCTION];
size = snprintf(event->mmap.filename, sizeof(event->mmap.filename),
"%s%s", mmap_name, symbol_name) + 1;
size = ALIGN(size, sizeof(u64));
event->mmap.header.type = PERF_RECORD_MMAP;
event->mmap.header.size = (sizeof(event->mmap) -
(sizeof(event->mmap.filename) - size) + session->id_hdr_size);
event->mmap.pgoff = args.start;
event->mmap.start = map->start;
event->mmap.len = map->end - event->mmap.start;
event->mmap.pid = machine->pid;
err = process(event, &synth_sample, session);
free(event);
return err;
}
