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um: fix races between line_open() and line_config()
Pull parse_chan_pair() call into setup_one_line(), under the mutex. We really don't want open() to succeed before parse_chan_pair() had been done (or after it has failed, BTW). We also want "remove con<n>" to free irqs, etc., same as "config con<n>=none". Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
parent
d8c215adbf
commit
31efcebb7d
2 changed files with 29 additions and 28 deletions
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@ -551,6 +551,9 @@ int parse_chan_pair(char *str, struct line *line, int device,
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INIT_LIST_HEAD(chans);
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}
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if (!str)
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return 0;
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out = strchr(str, ',');
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if (out != NULL) {
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in = str;
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@ -482,7 +482,7 @@ void close_lines(struct line *lines, int nlines)
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}
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static int setup_one_line(struct line *lines, int n, char *init,
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char **error_out)
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const struct chan_opts *opts, char **error_out)
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{
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struct line *line = &lines[n];
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int err = -EINVAL;
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@ -494,13 +494,28 @@ static int setup_one_line(struct line *lines, int n, char *init,
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goto out;
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}
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if (!strcmp(init, "none"))
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line->valid = 0;
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else {
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line->init_str = init;
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if (!strcmp(init, "none")) {
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if (line->valid) {
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line->valid = 0;
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kfree(line->init_str);
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parse_chan_pair(NULL, line, n, opts, error_out);
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err = 0;
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}
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} else {
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char *new = kstrdup(init, GFP_KERNEL);
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if (!new) {
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*error_out = "Failed to allocate memory";
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return -ENOMEM;
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}
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line->init_str = new;
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line->valid = 1;
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err = parse_chan_pair(new, line, n, opts, error_out);
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if (err) {
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line->init_str = NULL;
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line->valid = 0;
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kfree(new);
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}
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}
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err = 0;
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out:
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mutex_unlock(&line->count_lock);
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return err;
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@ -549,10 +564,8 @@ int line_setup(char **conf, unsigned int num, char **def,
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int line_config(struct line *lines, unsigned int num, char *str,
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const struct chan_opts *opts, char **error_out)
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{
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struct line *line;
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char *new;
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char *end;
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int n, err;
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int n;
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if (*str == '=') {
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*error_out = "Can't configure all devices from mconsole";
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@ -569,16 +582,7 @@ int line_config(struct line *lines, unsigned int num, char *str,
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return -EINVAL;
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}
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new = kstrdup(end, GFP_KERNEL);
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if (new == NULL) {
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*error_out = "Failed to allocate memory";
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return -ENOMEM;
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}
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err = setup_one_line(lines, n, new, error_out);
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if (err)
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return err;
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line = &lines[n];
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return parse_chan_pair(line->init_str, line, n, opts, error_out);
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return setup_one_line(lines, n, end, opts, error_out);
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}
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int line_get_config(char *name, struct line *lines, unsigned int num, char *str,
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@ -633,7 +637,7 @@ int line_remove(struct line *lines, unsigned int num, int n, char **error_out)
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*error_out = "Device number out of range";
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return -EINVAL;
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}
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return setup_one_line(lines, n, "none", error_out);
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return setup_one_line(lines, n, "none", NULL, error_out);
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}
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struct tty_driver *register_lines(struct line_driver *line_driver,
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@ -688,15 +692,9 @@ void lines_init(struct line *lines, int nlines, struct chan_opts *opts)
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if (line->init_str == NULL)
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continue;
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line->init_str = kstrdup(line->init_str, GFP_KERNEL);
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if (line->init_str == NULL)
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printk(KERN_ERR "lines_init - kstrdup returned NULL\n");
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if (parse_chan_pair(line->init_str, line, i, opts, &error)) {
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printk(KERN_ERR "parse_chan_pair failed for "
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if (setup_one_line(lines, i, line->init_str, opts, &error))
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printk(KERN_ERR "setup_one_line failed for "
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"device %d : %s\n", i, error);
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line->valid = 0;
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}
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}
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}
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