Jiri Olsa | 6a4d98d | 2013-10-15 16:27:33 +0200 | [diff] [blame] | 1 | #include <linux/compiler.h> |
| 2 | #include <linux/kernel.h> |
| 3 | #include <sys/types.h> |
| 4 | #include <sys/stat.h> |
| 5 | #include <unistd.h> |
| 6 | #include <string.h> |
| 7 | |
| 8 | #include "data.h" |
| 9 | #include "util.h" |
| 10 | |
| 11 | static bool check_pipe(struct perf_data_file *file) |
| 12 | { |
| 13 | struct stat st; |
| 14 | bool is_pipe = false; |
| 15 | int fd = perf_data_file__is_read(file) ? |
| 16 | STDIN_FILENO : STDOUT_FILENO; |
| 17 | |
| 18 | if (!file->path) { |
| 19 | if (!fstat(fd, &st) && S_ISFIFO(st.st_mode)) |
| 20 | is_pipe = true; |
| 21 | } else { |
| 22 | if (!strcmp(file->path, "-")) |
| 23 | is_pipe = true; |
| 24 | } |
| 25 | |
| 26 | if (is_pipe) |
| 27 | file->fd = fd; |
| 28 | |
| 29 | return file->is_pipe = is_pipe; |
| 30 | } |
| 31 | |
| 32 | static int check_backup(struct perf_data_file *file) |
| 33 | { |
| 34 | struct stat st; |
| 35 | |
| 36 | if (!stat(file->path, &st) && st.st_size) { |
| 37 | /* TODO check errors properly */ |
| 38 | char oldname[PATH_MAX]; |
| 39 | snprintf(oldname, sizeof(oldname), "%s.old", |
| 40 | file->path); |
| 41 | unlink(oldname); |
| 42 | rename(file->path, oldname); |
| 43 | } |
| 44 | |
| 45 | return 0; |
| 46 | } |
| 47 | |
| 48 | static int open_file_read(struct perf_data_file *file) |
| 49 | { |
| 50 | struct stat st; |
| 51 | int fd; |
| 52 | |
| 53 | fd = open(file->path, O_RDONLY); |
| 54 | if (fd < 0) { |
| 55 | int err = errno; |
| 56 | |
| 57 | pr_err("failed to open %s: %s", file->path, strerror(err)); |
| 58 | if (err == ENOENT && !strcmp(file->path, "perf.data")) |
| 59 | pr_err(" (try 'perf record' first)"); |
| 60 | pr_err("\n"); |
| 61 | return -err; |
| 62 | } |
| 63 | |
| 64 | if (fstat(fd, &st) < 0) |
| 65 | goto out_close; |
| 66 | |
| 67 | if (!file->force && st.st_uid && (st.st_uid != geteuid())) { |
| 68 | pr_err("file %s not owned by current user or root\n", |
| 69 | file->path); |
| 70 | goto out_close; |
| 71 | } |
| 72 | |
| 73 | if (!st.st_size) { |
| 74 | pr_info("zero-sized file (%s), nothing to do!\n", |
| 75 | file->path); |
| 76 | goto out_close; |
| 77 | } |
| 78 | |
| 79 | file->size = st.st_size; |
| 80 | return fd; |
| 81 | |
| 82 | out_close: |
| 83 | close(fd); |
| 84 | return -1; |
| 85 | } |
| 86 | |
| 87 | static int open_file_write(struct perf_data_file *file) |
| 88 | { |
| 89 | if (check_backup(file)) |
| 90 | return -1; |
| 91 | |
| 92 | return open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR); |
| 93 | } |
| 94 | |
| 95 | static int open_file(struct perf_data_file *file) |
| 96 | { |
| 97 | int fd; |
| 98 | |
| 99 | fd = perf_data_file__is_read(file) ? |
| 100 | open_file_read(file) : open_file_write(file); |
| 101 | |
| 102 | file->fd = fd; |
| 103 | return fd < 0 ? -1 : 0; |
| 104 | } |
| 105 | |
| 106 | int perf_data_file__open(struct perf_data_file *file) |
| 107 | { |
| 108 | if (check_pipe(file)) |
| 109 | return 0; |
| 110 | |
| 111 | if (!file->path) |
| 112 | file->path = "perf.data"; |
| 113 | |
| 114 | return open_file(file); |
| 115 | } |
| 116 | |
| 117 | void perf_data_file__close(struct perf_data_file *file) |
| 118 | { |
| 119 | close(file->fd); |
| 120 | } |