tools/perf/util/vdso.c

Source file repositories/reference/linux-study-clean/tools/perf/util/vdso.c

File Facts

System
Linux kernel
Corpus path
tools/perf/util/vdso.c
Extension
.c
Size
7568 bytes
Lines
370
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

struct vdso_file {
	bool found;
	bool error;
	char temp_file_name[sizeof(VDSO__TEMP_FILE_NAME)];
	const char *dso_name;
	const char *read_prog;
};

struct vdso_info {
	struct vdso_file vdso;
#if BITS_PER_LONG == 64
	struct vdso_file vdso32;
	struct vdso_file vdsox32;
#endif
};

static struct vdso_info *vdso_info__new(void)
{
	static const struct vdso_info vdso_info_init = {
		.vdso    = {
			.temp_file_name = VDSO__TEMP_FILE_NAME,
			.dso_name = DSO__NAME_VDSO,
		},
#if BITS_PER_LONG == 64
		.vdso32  = {
			.temp_file_name = VDSO__TEMP_FILE_NAME,
			.dso_name = DSO__NAME_VDSO32,
			.read_prog = "perf-read-vdso32",
		},
		.vdsox32  = {
			.temp_file_name = VDSO__TEMP_FILE_NAME,
			.dso_name = DSO__NAME_VDSOX32,
			.read_prog = "perf-read-vdsox32",
		},
#endif
	};

	return memdup(&vdso_info_init, sizeof(vdso_info_init));
}

static char *get_file(struct vdso_file *vdso_file)
{
	char *vdso = NULL;
	char *buf = NULL;
	void *start, *end;
	size_t size;
	int fd;

	if (vdso_file->found)
		return vdso_file->temp_file_name;

	if (vdso_file->error || find_map(&start, &end, VDSO__MAP_NAME))
		return NULL;

	size = end - start;

	buf = memdup(start, size);
	if (!buf)
		return NULL;

	fd = mkstemp(vdso_file->temp_file_name);
	if (fd < 0)
		goto out;

	if (size == (size_t) write(fd, buf, size))
		vdso = vdso_file->temp_file_name;

	close(fd);

 out:
	free(buf);

	vdso_file->found = (vdso != NULL);
	vdso_file->error = !vdso_file->found;
	return vdso;
}

void machine__exit_vdso(struct machine *machine)
{
	struct vdso_info *vdso_info = machine->vdso_info;

	if (!vdso_info)
		return;

	if (vdso_info->vdso.found)
		unlink(vdso_info->vdso.temp_file_name);
#if BITS_PER_LONG == 64
	if (vdso_info->vdso32.found)
		unlink(vdso_info->vdso32.temp_file_name);
	if (vdso_info->vdsox32.found)

Annotation

Implementation Notes