On Wed, 19 Dec 2007 20:45:52 +0100 Remy Bohmer wrote:
> This patch adds a generic routine to the kernel, so that a map of
> settings can be entered on the kernel commandline.
>
> Signed-off-by: Remy Bohmer <linux@xxxxxxxxxx>
>
> ---
> ---
> include/linux/kernel.h | 1
> lib/cmdline.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 59 insertions(+)
>
> Index: linux-2.6.24-rc5-rt1/lib/cmdline.c
> ===================================================================
> --- linux-2.6.24-rc5-rt1.orig/lib/cmdline.c 2007-10-09 22:31:38.000000000 +0200
> +++ linux-2.6.24-rc5-rt1/lib/cmdline.c 2007-12-18 21:33:58.000000000 +0100
> @@ -114,6 +115,63 @@ char *get_options(const char *str, int n
> }
>
> /**
> + * get_map_option - Parse integer from an option map
The @param lines (below) need to go here, immediately following the
function short description (the line above). No intervening blank
lines.
> + *
> + * This function parses an integer from an option map like
> + * some_map=key1:99,key2:98,...,keyN:NN,NN
> + * Only the value of the first match is returned, or if no
> + * key option is given (key = NULL) the value of the first
> + * field without a ':' is returned.
> + *
> + * @str: option string
> + * @key: The key inside the map, can be NULL
> + * @pint: (output) integer value parsed from the map @str
> + *
> + * Return values:
> + * 0 - no int in string
> + * 1 - int found
> + */
> +int get_map_option(const char *str, const char *key, int *pint)
> +{
> + char buf[COMMAND_LINE_SIZE];
COMMAND_LINE_SIZE varies from 256 to 2048, depending on $ARCH.
That's a bit too much to declare on a function's local stack --
unless you are very certain of the call tree to this point and
that the total stack size is safe. Can you just kmalloc() this
buf?
> + char *p, *substr;
> + int found = 0;
> +
> + /* We must copy the string to the stack, because strsep()
> + changes it.*/
> + strncpy(buf, str, COMMAND_LINE_SIZE);
> + buf[COMMAND_LINE_SIZE-1] = '\0';
> +
> + p = buf;
> + substr = strsep(&p, ",");
> + while ((!found) && (substr != NULL)) {
> + if (strlen(substr) != 0) {
> + if (key == NULL) {
> + /* Check for the absence of any ':' */
> + if (strchr(substr, ':') == NULL) {
> + sscanf(substr, "%d", pint);
> + found = 1;
> + }
> + } else {
> + /* check if the first part of the key matches */
> + if (!strncmp(substr, key, strlen(key))) {
> + substr += strlen(key);
> + /* Now the next char must be a ':',
> + if not, search for the next match */
> + if (*substr == ':') {
> + substr++;
> + sscanf(substr, "%d", pint);
> + found = 1;
> + }
> + }
> + }
> + }
> + substr = strsep(&p, ",");
> + }
> + return found;
> +}
---
~Randy
-
To unsubscribe from this list: send the line "unsubscribe linux-rt-users" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
