diff options
Diffstat (limited to 'tools/perf/util/data.c')
| -rw-r--r-- | tools/perf/util/data.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c new file mode 100644 index 000000000..d8cfc19dd --- /dev/null +++ b/tools/perf/util/data.c @@ -0,0 +1,189 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/compiler.h> +#include <linux/kernel.h> +#include <sys/types.h> +#include <sys/stat.h> +#include <errno.h> +#include <fcntl.h> +#include <unistd.h> +#include <string.h> + +#include "data.h" +#include "util.h" +#include "debug.h" + +static bool check_pipe(struct perf_data *data) +{ + struct stat st; + bool is_pipe = false; + int fd = perf_data__is_read(data) ? + STDIN_FILENO : STDOUT_FILENO; + + if (!data->file.path) { + if (!fstat(fd, &st) && S_ISFIFO(st.st_mode)) + is_pipe = true; + } else { + if (!strcmp(data->file.path, "-")) + is_pipe = true; + } + + if (is_pipe) + data->file.fd = fd; + + return data->is_pipe = is_pipe; +} + +static int check_backup(struct perf_data *data) +{ + struct stat st; + + if (!stat(data->file.path, &st) && st.st_size) { + /* TODO check errors properly */ + char oldname[PATH_MAX]; + snprintf(oldname, sizeof(oldname), "%s.old", + data->file.path); + unlink(oldname); + rename(data->file.path, oldname); + } + + return 0; +} + +static int open_file_read(struct perf_data *data) +{ + struct stat st; + int fd; + char sbuf[STRERR_BUFSIZE]; + + fd = open(data->file.path, O_RDONLY); + if (fd < 0) { + int err = errno; + + pr_err("failed to open %s: %s", data->file.path, + str_error_r(err, sbuf, sizeof(sbuf))); + if (err == ENOENT && !strcmp(data->file.path, "perf.data")) + pr_err(" (try 'perf record' first)"); + pr_err("\n"); + return -err; + } + + if (fstat(fd, &st) < 0) + goto out_close; + + if (!data->force && st.st_uid && (st.st_uid != geteuid())) { + pr_err("File %s not owned by current user or root (use -f to override)\n", + data->file.path); + goto out_close; + } + + if (!st.st_size) { + pr_info("zero-sized data (%s), nothing to do!\n", + data->file.path); + goto out_close; + } + + data->size = st.st_size; + return fd; + + out_close: + close(fd); + return -1; +} + +static int open_file_write(struct perf_data *data) +{ + int fd; + char sbuf[STRERR_BUFSIZE]; + + if (check_backup(data)) + return -1; + + fd = open(data->file.path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC, + S_IRUSR|S_IWUSR); + + if (fd < 0) + pr_err("failed to open %s : %s\n", data->file.path, + str_error_r(errno, sbuf, sizeof(sbuf))); + + return fd; +} + +static int open_file(struct perf_data *data) +{ + int fd; + + fd = perf_data__is_read(data) ? + open_file_read(data) : open_file_write(data); + + data->file.fd = fd; + return fd < 0 ? -1 : 0; +} + +int perf_data__open(struct perf_data *data) +{ + if (check_pipe(data)) + return 0; + + if (!data->file.path) + data->file.path = "perf.data"; + + return open_file(data); +} + +void perf_data__close(struct perf_data *data) +{ + close(data->file.fd); +} + +ssize_t perf_data_file__write(struct perf_data_file *file, + void *buf, size_t size) +{ + return writen(file->fd, buf, size); +} + +ssize_t perf_data__write(struct perf_data *data, + void *buf, size_t size) +{ + return perf_data_file__write(&data->file, buf, size); +} + +int perf_data__switch(struct perf_data *data, + const char *postfix, + size_t pos, bool at_exit) +{ + char *new_filepath; + int ret; + + if (check_pipe(data)) + return -EINVAL; + if (perf_data__is_read(data)) + return -EINVAL; + + if (asprintf(&new_filepath, "%s.%s", data->file.path, postfix) < 0) + return -ENOMEM; + + /* + * Only fire a warning, don't return error, continue fill + * original file. + */ + if (rename(data->file.path, new_filepath)) + pr_warning("Failed to rename %s to %s\n", data->file.path, new_filepath); + + if (!at_exit) { + close(data->file.fd); + ret = perf_data__open(data); + if (ret < 0) + goto out; + + if (lseek(data->file.fd, pos, SEEK_SET) == (off_t)-1) { + ret = -errno; + pr_debug("Failed to lseek to %zu: %s", + pos, strerror(errno)); + goto out; + } + } + ret = data->file.fd; +out: + free(new_filepath); + return ret; +} |