On Sat, Nov 15, 2014 at 06:42:34PM +0100, Nicolas Bedos wrote:
> In usr.bin/locate/locate/locate.c and util.c the variable dbv is defined
> as a pointer to char * and is used to access the path to every database
> provided to locate. E.g. when running
>
> locate -d /path/to/db1 -d /path/to/db2 -d /path/to/db3 *
>
> *dbv points to '/path/to/db1'
> *(dbv+1) points to '/path/to/db2'
> *(dbv+2) points to '/path/to/db3'
>
> However dbv is initialized with the following call
>
> dbv = malloc(sizeof(char **))
>
> which I believe should be
>
> dbv = malloc(sizeof(char *))
No. That's not how the code reads. dbv is an array of
"char *"-s, not a "char *". For each element in "path"
new "char *" of "slen + 1" is allocated, and "dbv" is
grown and the newly allocated string (char *) is stored.
Best,
--patrick
> The same goes for the variable newdbv. Please find the corresponding
> diff below. No binary change on amd64 since sizeof(char **) ==
> sizeof(char *).
>
> Nicolas Bedos
>
>
>
> Index: usr.bin/locate/locate/util.c
> ===================================================================
> RCS file: /cvs/src/usr.bin/locate/locate/util.c,v
> retrieving revision 1.11
> diff -u -p -u -r1.11 util.c
> --- usr.bin/locate/locate/util.c 8 Oct 2014 04:04:37 -0000 1.11
> +++ usr.bin/locate/locate/util.c 15 Nov 2014 14:08:15 -0000
> @@ -89,7 +89,7 @@ colon(dbv, path, dot)
> char **pv;
>
> if (dbv == NULL) {
> - if ((dbv = malloc(sizeof(char **))) == NULL)
> + if ((dbv = malloc(sizeof(char *))) == NULL)
> err(1, "malloc");
> *dbv = NULL;
> }
> @@ -123,7 +123,7 @@ colon(dbv, path, dot)
> }
> /* increase dbv with element p */
> if ((newdbv = reallocarray(dbv, vlen + 2,
> - sizeof(char **))) == NULL)
> + sizeof(char *))) == NULL)
> err(1, "realloc");
> dbv = newdbv;
> *(dbv + vlen) = p;
>
