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 #include "debug.h" 11 12 static bool check_pipe(struct perf_data_file *file) 13 { 14 struct stat st; 15 bool is_pipe = false; 16 int fd = perf_data_file__is_read(file) ? 17 STDIN_FILENO : STDOUT_FILENO; 18 19 if (!file->path) { 20 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode)) 21 is_pipe = true; 22 } else { 23 if (!strcmp(file->path, "-")) 24 is_pipe = true; 25 } 26 27 if (is_pipe) 28 file->fd = fd; 29 30 return file->is_pipe = is_pipe; 31 } 32 33 static int check_backup(struct perf_data_file *file) 34 { 35 struct stat st; 36 37 if (!stat(file->path, &st) && st.st_size) { 38 /* TODO check errors properly */ 39 char oldname[PATH_MAX]; 40 snprintf(oldname, sizeof(oldname), "%s.old", 41 file->path); 42 unlink(oldname); 43 rename(file->path, oldname); 44 } 45 46 return 0; 47 } 48 49 static int open_file_read(struct perf_data_file *file) 50 { 51 struct stat st; 52 int fd; 53 54 fd = open(file->path, O_RDONLY); 55 if (fd < 0) { 56 int err = errno; 57 58 pr_err("failed to open %s: %s", file->path, strerror(err)); 59 if (err == ENOENT && !strcmp(file->path, "perf.data")) 60 pr_err(" (try 'perf record' first)"); 61 pr_err("\n"); 62 return -err; 63 } 64 65 if (fstat(fd, &st) < 0) 66 goto out_close; 67 68 if (!file->force && st.st_uid && (st.st_uid != geteuid())) { 69 pr_err("File %s not owned by current user or root (use -f to override)\n", 70 file->path); 71 goto out_close; 72 } 73 74 if (!st.st_size) { 75 pr_info("zero-sized file (%s), nothing to do!\n", 76 file->path); 77 goto out_close; 78 } 79 80 file->size = st.st_size; 81 return fd; 82 83 out_close: 84 close(fd); 85 return -1; 86 } 87 88 static int open_file_write(struct perf_data_file *file) 89 { 90 int fd; 91 92 if (check_backup(file)) 93 return -1; 94 95 fd = open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR); 96 97 if (fd < 0) 98 pr_err("failed to open %s : %s\n", file->path, strerror(errno)); 99 100 return fd; 101 } 102 103 static int open_file(struct perf_data_file *file) 104 { 105 int fd; 106 107 fd = perf_data_file__is_read(file) ? 108 open_file_read(file) : open_file_write(file); 109 110 file->fd = fd; 111 return fd < 0 ? -1 : 0; 112 } 113 114 int perf_data_file__open(struct perf_data_file *file) 115 { 116 if (check_pipe(file)) 117 return 0; 118 119 if (!file->path) 120 file->path = "perf.data"; 121 122 return open_file(file); 123 } 124 125 void perf_data_file__close(struct perf_data_file *file) 126 { 127 close(file->fd); 128 } 129 130 ssize_t perf_data_file__write(struct perf_data_file *file, 131 void *buf, size_t size) 132 { 133 return writen(file->fd, buf, size); 134 } 135