Re: Query regarding exec in mandocdb.c

Thank you for the replies Ingo and the diffs!

George Brown


On 26 August 2017 at 17:04, Ingo Schwarze <schwarze@usta.de> wrote:
> Hi George,
>
> George Brown wrote on Thu, Aug 24, 2017 at 02:01:05PM +0100:
>
>> In mandocdb.c it appears cmp(1) and rm(1) are executed in a child
>> process. It seems that if the logic from these programs were duplicated
>> the pledge in mandocdb.c could be further restricted and even not bother
>> with forking.
>
> Done as well, see the commit below.
>
> Thanks again for the suggestion,
> Ingo
>
>
> Log Message:
> -----------
> Do not fork and exec cmp(1); instead, simply fstat(2), mmap(2), and
> compare the files directly, allowing a much stricter pledge(2), at
> very little cost: merely 15 additional lines of very simple code.
> Suggested by George Brown <321 dot george at gmail dot com> on misc@.
>
> Modified Files:
> --------------
> mandoc:
> mandocdb.c
>
> Revision Data
> -------------
> Index: mandocdb.c
> ===================================================================
> RCS file: /home/cvs/mandoc/mandoc/mandocdb.c,v
> retrieving revision 1.254
> retrieving revision 1.255
> diff -Lmandocdb.c -Lmandocdb.c -u -p -r1.254 -r1.255
> --- mandocdb.c
> +++ mandocdb.c
> @@ -19,8 +19,8 @@
> #include "config.h"
>
> #include <sys/types.h>
> +#include <sys/mman.h>
> #include <sys/stat.h>
> -#include <sys/wait.h>
>
> #include <assert.h>
> #include <ctype.h>
> @@ -319,7 +319,7 @@ mandocdb(int argc, char *argv[])
> int ch, i;
>
> #if HAVE_PLEDGE
> - if (pledge("stdio rpath wpath cpath fattr flock proc exec", NULL) == -1) {
> + if (pledge("stdio rpath wpath cpath", NULL) == -1) {
> warn("pledge");
> return (int)MANDOCLEVEL_SYSERR;
> }
> @@ -440,15 +440,6 @@ mandocdb(int argc, char *argv[])
> * The existing database is usable. Process
> * all files specified on the command-line.
> */
> -#if HAVE_PLEDGE
> - if (!nodb) {
> - if (pledge("stdio rpath wpath cpath fattr flock", NULL) == -1) {
> - warn("pledge");
> - exitcode = (int)MANDOCLEVEL_SYSERR;
> - goto out;
> - }
> - }
> -