1 #include <linux/compiler.h> 2 #include <linux/kernel.h> 3 #include <sys/types.h> 4 #include <sys/stat.h> 5 #include <errno.h> 6 #include <unistd.h> 7 #include <string.h> 8 9 #include "data.h" 10 #include "util.h" 11 #include "debug.h" 12 13 #ifndef O_CLOEXEC 14 #ifdef __sparc__ 15 #define O_CLOEXEC 0x400000 16 #elif defined(__alpha__) || defined(__hppa__) 17 #define O_CLOEXEC 010000000 18 #else 19 #define O_CLOEXEC 02000000 20 #endif 21 #endif 22 23 static bool check_pipe(struct perf_data_file *file) 24 { 25 struct stat st; 26 bool is_pipe = false; 27 int fd = perf_data_file__is_read(file) ? 28 STDIN_FILENO : STDOUT_FILENO; 29 30 if (!file->path) { 31 if (!fstat(fd, &st) && S_ISFIFO(st.st_mode)) 32 is_pipe = true; 33 } else { 34 if (!strcmp(file->path, "-")) 35 is_pipe = true; 36 } 37 38 if (is_pipe) 39 file->fd = fd; 40 41 return file->is_pipe = is_pipe; 42 } 43 44 static int check_backup(struct perf_data_file *file) 45 { 46 struct stat st; 47 48 if (!stat(file->path, &st) && st.st_size) { 49 /* TODO check errors properly */ 50 char oldname[PATH_MAX]; 51 snprintf(oldname, sizeof(oldname), "%s.old", 52 file->path); 53 unlink(oldname); 54 rename(file->path, oldname); 55 } 56 57 return 0; 58 } 59 60 static int open_file_read(struct perf_data_file *file) 61 { 62 struct stat st; 63 int fd; 64 char sbuf[STRERR_BUFSIZE]; 65 66 fd = open(file->path, O_RDONLY); 67 if (fd < 0) { 68 int err = errno; 69 70 pr_err("failed to open %s: %s", file->path, 71 str_error_r(err, sbuf, sizeof(sbuf))); 72 if (err == ENOENT && !strcmp(file->path, "perf.data")) 73 pr_err(" (try 'perf record' first)"); 74 pr_err("\n"); 75 return -err; 76 } 77 78 if (fstat(fd, &st) < 0) 79 goto out_close; 80 81 if (!file->force && st.st_uid && (st.st_uid != geteuid())) { 82 pr_err("File %s not owned by current user or root (use -f to override)\n", 83 file->path); 84 goto out_close; 85 } 86 87 if (!st.st_size) { 88 pr_info("zero-sized file (%s), nothing to do!\n", 89 file->path); 90 goto out_close; 91 } 92 93 file->size = st.st_size; 94 return fd; 95 96 out_close: 97 close(fd); 98 return -1; 99 } 100 101 static int open_file_write(struct perf_data_file *file) 102 { 103 int fd; 104 char sbuf[STRERR_BUFSIZE]; 105 106 if (check_backup(file)) 107 return -1; 108 109 fd = open(file->path, O_CREAT|O_RDWR|O_TRUNC|O_CLOEXEC, 110 S_IRUSR|S_IWUSR); 111 112 if (fd < 0) 113 pr_err("failed to open %s : %s\n", file->path, 114 str_error_r(errno, sbuf, sizeof(sbuf))); 115 116 return fd; 117 } 118 119 static int open_file(struct perf_data_file *file) 120 { 121 int fd; 122 123 fd = perf_data_file__is_read(file) ? 124 open_file_read(file) : open_file_write(file); 125 126 file->fd = fd; 127 return fd < 0 ? -1 : 0; 128 } 129 130 int perf_data_file__open(struct perf_data_file *file) 131 { 132 if (check_pipe(file)) 133 return 0; 134 135 if (!file->path) 136 file->path = "perf.data"; 137 138 return open_file(file); 139 } 140 141 void perf_data_file__close(struct perf_data_file *file) 142 { 143 close(file->fd); 144 } 145 146 ssize_t perf_data_file__write(struct perf_data_file *file, 147 void *buf, size_t size) 148 { 149 return writen(file->fd, buf, size); 150 } 151 152 int perf_data_file__switch(struct perf_data_file *file, 153 const char *postfix, 154 size_t pos, bool at_exit) 155 { 156 char *new_filepath; 157 int ret; 158 159 if (check_pipe(file)) 160 return -EINVAL; 161 if (perf_data_file__is_read(file)) 162 return -EINVAL; 163 164 if (asprintf(&new_filepath, "%s.%s", file->path, postfix) < 0) 165 return -ENOMEM; 166 167 /* 168 * Only fire a warning, don't return error, continue fill 169 * original file. 170 */ 171 if (rename(file->path, new_filepath)) 172 pr_warning("Failed to rename %s to %s\n", file->path, new_filepath); 173 174 if (!at_exit) { 175 close(file->fd); 176 ret = perf_data_file__open(file); 177 if (ret < 0) 178 goto out; 179 180 if (lseek(file->fd, pos, SEEK_SET) == (off_t)-1) { 181 ret = -errno; 182 pr_debug("Failed to lseek to %zu: %s", 183 pos, strerror(errno)); 184 goto out; 185 } 186 } 187 ret = file->fd; 188 out: 189 free(new_filepath); 190 return ret; 191 } 192