modpost: add read_text_file() and get_line() helpers

modpost uses grab_file() to open a file, but it is not suitable for
a text file because the mmap'ed file is not terminated by null byte.
Actually, I see some issues for the use of grab_file().

The new helper, read_text_file() loads the whole file content into a
malloc'ed buffer, and appends a null byte. Then, get_line() reads
each line.

To handle text files, I intend to replace as follows:

  grab_file()    -> read_text_file()
  get_new_line() -> get_line()

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
This commit is contained in:
Masahiro Yamada 2020-06-01 14:57:17 +09:00
parent 4ddea2f8e8
commit ac5100f543
2 changed files with 51 additions and 0 deletions

View File

@ -112,6 +112,55 @@ void *do_nofail(void *ptr, const char *expr)
return ptr;
}
char *read_text_file(const char *filename)
{
struct stat st;
size_t nbytes;
int fd;
char *buf;
fd = open(filename, O_RDONLY);
if (fd < 0) {
perror(filename);
exit(1);
}
if (fstat(fd, &st) < 0) {
perror(filename);
exit(1);
}
buf = NOFAIL(malloc(st.st_size + 1));
nbytes = st.st_size;
while (nbytes) {
ssize_t bytes_read;
bytes_read = read(fd, buf, nbytes);
if (bytes_read < 0) {
perror(filename);
exit(1);
}
nbytes -= bytes_read;
}
buf[st.st_size] = '\0';
close(fd);
return buf;
}
char *get_line(char **stringp)
{
/* do not return the unwanted extra line at EOF */
if (*stringp && **stringp == '\0')
return NULL;
return strsep(stringp, "\n");
}
/* A list of all modules we processed */
static struct module *modules;

View File

@ -191,6 +191,8 @@ void add_moddevtable(struct buffer *buf, struct module *mod);
void get_src_version(const char *modname, char sum[], unsigned sumlen);
/* from modpost.c */
char *read_text_file(const char *filename);
char *get_line(char **stringp);
void *grab_file(const char *filename, unsigned long *size);
char* get_next_line(unsigned long *pos, void *file, unsigned long size);
void release_file(void *file, unsigned long size);