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
check_pipe(struct perf_data_file * file)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
check_backup(struct perf_data_file * file)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
open_file_read(struct perf_data_file * file)49 static int open_file_read(struct perf_data_file *file)
50 {
51 struct stat st;
52 int fd;
53 char sbuf[STRERR_BUFSIZE];
54
55 fd = open(file->path, O_RDONLY);
56 if (fd < 0) {
57 int err = errno;
58
59 pr_err("failed to open %s: %s", file->path,
60 strerror_r(err, sbuf, sizeof(sbuf)));
61 if (err == ENOENT && !strcmp(file->path, "perf.data"))
62 pr_err(" (try 'perf record' first)");
63 pr_err("\n");
64 return -err;
65 }
66
67 if (fstat(fd, &st) < 0)
68 goto out_close;
69
70 if (!file->force && st.st_uid && (st.st_uid != geteuid())) {
71 pr_err("File %s not owned by current user or root (use -f to override)\n",
72 file->path);
73 goto out_close;
74 }
75
76 if (!st.st_size) {
77 pr_info("zero-sized file (%s), nothing to do!\n",
78 file->path);
79 goto out_close;
80 }
81
82 file->size = st.st_size;
83 return fd;
84
85 out_close:
86 close(fd);
87 return -1;
88 }
89
open_file_write(struct perf_data_file * file)90 static int open_file_write(struct perf_data_file *file)
91 {
92 int fd;
93 char sbuf[STRERR_BUFSIZE];
94
95 if (check_backup(file))
96 return -1;
97
98 fd = open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
99
100 if (fd < 0)
101 pr_err("failed to open %s : %s\n", file->path,
102 strerror_r(errno, sbuf, sizeof(sbuf)));
103
104 return fd;
105 }
106
open_file(struct perf_data_file * file)107 static int open_file(struct perf_data_file *file)
108 {
109 int fd;
110
111 fd = perf_data_file__is_read(file) ?
112 open_file_read(file) : open_file_write(file);
113
114 file->fd = fd;
115 return fd < 0 ? -1 : 0;
116 }
117
perf_data_file__open(struct perf_data_file * file)118 int perf_data_file__open(struct perf_data_file *file)
119 {
120 if (check_pipe(file))
121 return 0;
122
123 if (!file->path)
124 file->path = "perf.data";
125
126 return open_file(file);
127 }
128
perf_data_file__close(struct perf_data_file * file)129 void perf_data_file__close(struct perf_data_file *file)
130 {
131 close(file->fd);
132 }
133
perf_data_file__write(struct perf_data_file * file,void * buf,size_t size)134 ssize_t perf_data_file__write(struct perf_data_file *file,
135 void *buf, size_t size)
136 {
137 return writen(file->fd, buf, size);
138 }
139